Make failure_reason public now that two modules import it, cover interrupt() on a finished bar

Both prefetch warning loops format through _failure_reason so a
message-less exception cannot log blank. A bar-frame write failure in
the failure path cannot displace the download error, the failure list
is annotated BaseException (cancellations are entries too), the Ctrl-C
docstring notes an in-progress extraction runs to completion, and the
wave-prefetch docstring carries the superseded-sibling caveat.

esphome/__main__.py

@@ -857,7 +857,20 @@ def compile_program(args: ArgsProtocol, config: ConfigType) -> int:
         toolchain.create_factory_bin()
         toolchain.create_ota_bin()
         toolchain.create_elf_copy()
-        toolchain.get_idedata()
+        from esphome.build_helpers.idedata import IDEDATA_BEST_EFFORT_ERRORS
+
+        try:
+            if toolchain.get_idedata() is None:
+                _LOGGER.warning("No idedata was generated for this build")
+        except IDEDATA_BEST_EFFORT_ERRORS as err:
+            # The firmware already built; an idedata failure must not fail
+            # a successful build.
+            _LOGGER.warning(
+                "Could not generate idedata: %s (IDE, clang-tidy, and "
+                "memory-analysis data will be unavailable for this build)",
+                err,
+            )
+            _LOGGER.debug("Idedata failure detail", exc_info=True)
     else:
         from esphome.platformio import toolchain
 

esphome/build_helpers/__init__.py

@@ -0,0 +1 @@
+"""Build helpers shared by the native (non-PlatformIO) toolchains."""

esphome/build_helpers/idedata.py

@@ -1,10 +1,10 @@
-"""Derive idedata from an ESP-IDF native-toolchain ``compile_commands.json``.
+"""Derive idedata from a native (non-PlatformIO) build's ``compile_commands.json``.
 
-PlatformIO exposes a curated ``pio run -t idedata`` JSON; the native ESP-IDF
-toolchain has no such command, but its CMake build emits
-``build/compile_commands.json`` (CMAKE_EXPORT_COMPILE_COMMANDS). This module
-turns that file into the same fields consumers (IDE integration, clang-tidy)
-expect:
+PlatformIO exposes a curated ``pio run -t idedata`` JSON; the native
+toolchains have no such command, but each build produces a
+``compile_commands.json`` (CMAKE_EXPORT_COMPILE_COMMANDS for ESP-IDF, ninja's
+compdb tool otherwise). This module turns that file into the same fields
+consumers (IDE integration, clang-tidy) expect:
 
     {cc_path, cxx_path, cxx_flags, defines, includes: {build, toolchain}}
 """
@@ -18,6 +18,19 @@ from pathlib import Path
 import shlex
 import subprocess
 
+from esphome.core import EsphomeError
+from esphome.helpers import write_file
+
+# Everything idedata generation may raise after a successful link; idedata
+# is a bonus artifact, so consumers warn instead of failing the build
+IDEDATA_BEST_EFFORT_ERRORS = (
+    EsphomeError,
+    LookupError,
+    OSError,
+    RuntimeError,
+    ValueError,
+)
+
 _LOGGER = logging.getLogger(__name__)
 
 # C++ translation-unit suffixes used to identify ESPHome source files.
@@ -30,12 +43,8 @@ _ESPHOME_SRC_MARKER = "/src/esphome/"
 
 
 def _is_esphome_src(file: str) -> bool:
-    """Whether ``file`` is an ESPHome C++ translation unit.
-
-    ``compile_commands.json`` ``file`` paths use the OS-native separator, so on
-    Windows they contain backslashes; normalize to ``/`` before testing the
-    marker, otherwise no source matches and the build-include union is empty.
-    """
+    """Whether ``file`` is an ESPHome C++ translation unit; normalized to
+    ``/`` first since Windows compile DBs use backslashes."""
     return _ESPHOME_SRC_MARKER in file.replace("\\", "/") and file.endswith(
         _CXX_SUFFIXES
     )
@@ -106,11 +115,8 @@ def _expand_response_files(tokens: list[str], directory: Path) -> list[str]:
 
 
 def _pick_entry(entries: list[dict]) -> dict:
-    """Pick a representative ESPHome C++ translation unit.
-
-    All ESPHome sources share the same component flags/defines, so any one of
-    them yields the cxx_path / cxx_flags / defines we need.
-    """
+    """Pick a representative ESPHome C++ TU; all share the same component
+    flags/defines."""
     for entry in entries:
         if _is_esphome_src(entry["file"]):
             return entry
@@ -120,25 +126,46 @@ def _pick_entry(entries: list[dict]) -> dict:
     raise ValueError("no C++ translation unit found in compile_commands.json")
 
 
-def _parse_entry(entry: dict) -> tuple[str, list[str], list[str], list[str]]:
+# Compiler launchers that may prefix a compile command; a closed launcher
+# denylist beats enumerating compiler names, an open set.
+_LAUNCHER_STEMS = frozenset({"ccache", "sccache", "distcc", "icecc", "buildcache"})
+
+
+def _is_launcher(token: str) -> bool:
+    return Path(token).stem.lower() in _LAUNCHER_STEMS
+
+
+def parse_entry(
+    entry: dict, launcher: str | None = None
+) -> tuple[str, list[str], list[str], list[str]]:
     """Parse one compile_commands entry -> (cxx_path, defines, includes, cxx_flags)."""
     directory = Path(entry["directory"])
     tokens = _expand_response_files(_split_command(entry["command"]), directory)
 
     def _include(raw: str) -> str:
-        # Include paths in compile_commands are interpreted relative to the
-        # entry's ``directory`` (e.g. build-local ``-Iconfig``); resolve them
-        # so the cached idedata is usable regardless of the consumer's cwd.
-        # Emit forward slashes (``normpath`` yields ``\`` on Windows) so the
-        # paths match the absolute, already-forward-slash entries in the JSON.
+        # Resolve against the entry's ``directory`` so cached idedata works
+        # from any cwd; emit forward slashes to match the JSON's own entries
         raw = raw.strip()
         if raw and not Path(raw).is_absolute():
             raw = os.path.normpath(directory / raw)
         return raw.replace("\\", "/")
 
+    # A launcher-wrapped command ("ccache g++ ...") names the compiler second
+    if launcher is not None and tokens[:1] == [launcher]:
+        tokens = tokens[1:]
+    if not tokens:
+        # An empty command, or one that was only the launcher; fail by name
+        raise ValueError(f"empty compile command for {entry.get('file')}")
+    if _is_launcher(tokens[0]) and len(tokens) > 1 and not tokens[1].startswith("-"):
+        # Stale DB built with a launcher this run no longer configures; the
+        # real compiler is the next token
+        _LOGGER.warning("Stripping unconfigured launcher %s", tokens[0])
+        tokens = tokens[1:]
     # token0 is the compiler path; the rest of the command already uses forward
     # slashes on Windows, so normalize it too for a consistent idedata file.
     cxx_path = tokens[0].replace("\\", "/")
+    # Enforced here so no caller can record ccache as the compiler
+    reject_launcher_compiler(cxx_path)
     defines: list[str] = []
     includes: list[str] = []
     cxx_flags: list[str] = []
@@ -168,7 +195,7 @@ def _parse_entry(entry: dict) -> tuple[str, list[str], list[str], list[str]]:
     return cxx_path, defines, includes, cxx_flags
 
 
-def _get_toolchain_includes(cxx_path: str) -> list[str]:
+def get_toolchain_includes(cxx_path: str) -> list[str]:
     """Query the compiler for its builtin ``#include <...>`` search dirs."""
     result = subprocess.run(
         [cxx_path, "-E", "-x", "c++", "-", "-v"],
@@ -219,26 +246,128 @@ def _cc_path_from_cxx(cxx_path: str) -> str:
     return f"{stem}{suffix}"
 
 
-def idedata_from_build(compile_commands: Path) -> dict:
+def _cache_usable(cached: object) -> bool:
+    """Check a cached idedata dict against the guarantees of the write path.
+
+    Caches written by older versions predate the launcher rejection and the
+    include-union shape; serving one would bypass both. The dict check also
+    keeps "in" from substring-matching a bare JSON string.
+    """
+    if not isinstance(cached, dict) or "cc_path" not in cached:
+        return False
+    cxx_path = cached.get("cxx_path")
+    if not isinstance(cxx_path, str) or _is_launcher(cxx_path):
+        return False
+    includes = cached.get("includes")
+    return isinstance(includes, dict) and isinstance(includes.get("build"), list)
+
+
+def load_or_build_idedata(
+    compile_commands: Path,
+    elf_path: Path,
+    cache: Path,
+    launcher: str | None = None,
+) -> dict | None:
+    """Return idedata for a compile_commands.json build, cached on mtime.
+
+    Shared by the native ESP-IDF and ESP8266 Arduino toolchains. Returns None
+    when the compile DB doesn't exist yet (nothing was built). ``launcher``
+    is the compiler-launcher path (ccache) the build was generated with, if
+    any; commands in the compile DB are prefixed with it.
+    """
+    if not compile_commands.is_file():
+        _LOGGER.debug("No %s yet; skipping idedata generation", compile_commands)
+        return None
+
+    if cache.is_file() and cache.stat().st_mtime >= compile_commands.stat().st_mtime:
+        try:
+            cached = json.loads(cache.read_text(encoding="utf-8"))
+        except (ValueError, OSError) as err:
+            # A recurring cause (interrupted write, disk full) would otherwise
+            # look like unexplained slow builds
+            _LOGGER.warning("Discarding unreadable idedata cache %s: %s", cache, err)
+        else:
+            if _cache_usable(cached):
+                # Re-stamp so a relocated build dir cannot serve a stale ELF path
+                cached["prog_path"] = str(elf_path)
+                return cached
+            _LOGGER.debug("Regenerating idedata: cache %s fails validation", cache)
+
+    data = idedata_from_build(compile_commands, launcher)
+    data["prog_path"] = str(elf_path)
+    cache.parent.mkdir(parents=True, exist_ok=True)
+    # Atomic so a crash mid-write cannot leave a truncated cache
+    write_file(cache, json.dumps(data, indent=2) + "\n")
+    return data
+
+
+def reject_launcher_compiler(cxx_path: str) -> None:
+    """Reject a compile DB naming a launcher (ccache) as the compiler; it
+    must never be probed, cached, or consumed."""
+    if _is_launcher(cxx_path):
+        raise EsphomeError(
+            f"compile_commands.json names the launcher {cxx_path} as the "
+            "compiler; the compile database is unusable"
+        )
+
+
+def idedata_from_build(compile_commands: Path, launcher: str | None = None) -> dict:
     """Parse compile_commands.json into the idedata fields consumers expect.
 
-    A single ESP-IDF compile entry only carries its own component's REQUIRES
-    include set, but consumers (clang-tidy) analyze ESPHome headers that
-    transitively pull in other components. So take cxx_path / cxx_flags /
-    defines from a representative ESPHome TU, but union the include dirs across
-    all ESPHome TUs to get a project-wide superset (as PlatformIO's idedata
-    provides).
+    A single compile entry only carries the include set its own translation
+    unit was built with (per-component under ESP-IDF), but consumers
+    (clang-tidy) analyze ESPHome headers that transitively pull in other
+    components. So take cxx_path / cxx_flags / defines from a representative
+    ESPHome TU, but union the include dirs across all ESPHome TUs to get a
+    project-wide superset (as PlatformIO's idedata provides).
     """
     entries = json.loads(Path(compile_commands).read_text(encoding="utf-8"))
-    cxx_path, defines, _, cxx_flags = _parse_entry(_pick_entry(entries))
+    if not isinstance(entries, list) or not all(isinstance(e, dict) for e in entries):
+        # A TypeError here would escape IDEDATA_BEST_EFFORT_ERRORS
+        raise EsphomeError(f"{compile_commands} is not a compile-command list")
 
-    build_includes: dict[str, None] = {}
+    representative = _pick_entry(entries)
+    cxx_path, defines, rep_includes, cxx_flags = parse_entry(representative, launcher)
+
+    # Seed with the representative's includes so it is not parsed twice
+    has_esphome_tu = _is_esphome_src(representative["file"])
+    build_includes: dict[str, None] = dict.fromkeys(
+        rep_includes if has_esphome_tu else ()
+    )
+
+    def _shape(entry: dict) -> str:
+        # directory + command minus TU-specific paths: same shape means the
+        # same include set, so tokenize once per shape. Response-file
+        # commands never dedupe (the .rsp contents differ per object)
+        command = entry["command"]
+        directory = entry.get("directory", "")
+        if "@" in command:
+            return f"unique:{directory}|{entry.get('output') or command}"
+        stripped = command.replace(entry.get("file", ""), "").replace(
+            entry.get("output", ""), ""
+        )
+        return f"{directory}|{stripped}"
+
+    seen_shapes = {_shape(representative)}
     for entry in entries:
-        if not _is_esphome_src(entry["file"]):
+        if entry is representative or not _is_esphome_src(entry["file"]):
             continue
-        for inc in _parse_entry(entry)[2]:
+        has_esphome_tu = True
+        if (shape := _shape(entry)) in seen_shapes:
+            _LOGGER.debug("Include union: %s shares a command shape", entry["file"])
+            continue
+        seen_shapes.add(shape)
+        for inc in parse_entry(entry, launcher)[2]:
             build_includes.setdefault(inc, None)
 
+    if not has_esphome_tu:
+        # An arbitrary fallback TU breaks clang-tidy/IDE consumers, and a
+        # warning would be cached into permanence; call sites downgrade this
+        raise EsphomeError(
+            f"No ESPHome translation unit found in {compile_commands}; "
+            "refusing to cache unusable idedata"
+        )
+
     return {
         "cc_path": _cc_path_from_cxx(cxx_path),
         "cxx_path": cxx_path,
@@ -246,6 +375,6 @@ def idedata_from_build(compile_commands: Path) -> dict:
         "defines": defines,
         "includes": {
             "build": list(build_includes),
-            "toolchain": _get_toolchain_includes(cxx_path),
+            "toolchain": get_toolchain_includes(cxx_path),
         },
     }

esphome/build_helpers/size_summary.py

@@ -0,0 +1,24 @@
+"""The PlatformIO-format size bar shared by the native toolchains."""
+
+from __future__ import annotations
+
+
+def format_bar(used: int, total: int) -> str:
+    """Match PlatformIO's ``_format_availale_bytes`` (sic, pioupload.py) exactly."""
+    pct_raw = used / total if total else 0
+    blocks = 10
+    filled = min(int(round(blocks * pct_raw)), blocks)
+    progress = "=" * filled
+    return (
+        f"[{progress:<{blocks}}] {pct_raw: 6.1%} "
+        f"(used {used:d} bytes from {total:d} bytes)"
+    )
+
+
+def print_size_line(label: str, used: int, total: int) -> None:
+    """One PlatformIO-format summary line (``RAM``/``Flash``).
+
+    The label padding is part of the format: ``script/ci_memory_impact_extract.py``
+    matches these lines verbatim.
+    """
+    print(f"{label + ':':<7}{format_bar(used, total)}")

esphome/espidf/clang_tidy.py

@@ -23,6 +23,12 @@ from dataclasses import dataclass
 import os
 from pathlib import Path
 
+from esphome.build_helpers.idedata import (
+    get_toolchain_includes,
+    parse_entry,
+    reject_launcher_compiler,
+)
+
 TIDY_PROJECT_NAME = "esphome_tidy"
 
 # A do-nothing C++ app: just enough for IDF to configure a valid project. It's
@@ -415,13 +421,12 @@ def _idedata_from_tidy_project(compile_commands: Path) -> dict:
     """
     import json
 
-    from esphome.espidf.idedata import _get_toolchain_includes, _parse_entry
-
     entries = json.loads(Path(compile_commands).read_text(encoding="utf-8"))
     entry = next((e for e in entries if e["file"].endswith("tidy.cpp")), None)
     if entry is None:
         raise RuntimeError(f"tidy.cpp not found in {compile_commands}")
-    cxx_path, defines, includes, cxx_flags = _parse_entry(entry)
+    cxx_path, defines, includes, cxx_flags = parse_entry(entry)
+    reject_launcher_compiler(cxx_path)
 
     return {
         "cxx_path": cxx_path,
@@ -429,7 +434,7 @@ def _idedata_from_tidy_project(compile_commands: Path) -> dict:
         "defines": defines,
         "includes": {
             "build": includes,
-            "toolchain": _get_toolchain_includes(cxx_path),
+            "toolchain": get_toolchain_includes(cxx_path),
         },
     }
 

esphome/espidf/component.py

@@ -20,6 +20,7 @@ from esphome.platformio.library import (
     DEFAULT_BUILD_SRC_FILTER,
     ESPHOME_DATA_EXTRA_CMAKE_KEY,
     ESPHOME_DATA_KEY,
+    ESPHOME_DATA_LINK_FLAGS_KEY,
     SRC_FILE_EXTENSIONS,
     ConvertedLibrary as IDFComponent,
     LibraryBackend,
@@ -27,6 +28,7 @@ from esphome.platformio.library import (
     collect_filtered_files,
     convert_libraries,
     ensure_list,
+    lex_build_flags,
     split_list_by_condition,
 )
 
@@ -40,37 +42,6 @@ def _idf_framework() -> str:
     return "arduino" if CORE.using_arduino else "espidf"
 
 
-def _apply_extra_script(component: IDFComponent) -> None:
-    """Run a PIO ``extraScript`` and fold its captured env vars into
-    ``component.data["build"]["flags"]`` so the existing -L/-l/-D
-    extraction in ``generate_cmakelists_txt`` picks them up."""
-    extra_script = component.data.get("build", {}).get("extraScript")
-    if not extra_script:
-        return
-    # Resolve and confine to the library's source dir so a malicious
-    # library.json can't escape (e.g. ``"extraScript": "../../etc/passwd"``).
-    source_path = component.source_dir
-    library_root = source_path.resolve()
-    script_path = (source_path / extra_script).resolve()
-    if not script_path.is_relative_to(library_root) or not script_path.is_file():
-        return
-    from esphome.components.esp32 import get_esp32_variant
-    from esphome.espidf.extra_script import captured_as_build_flags, run_extra_script
-
-    idf_target = variant_to_idf_target(get_esp32_variant())
-    result = run_extra_script(
-        script_path, library_dir=source_path, idf_target=idf_target
-    )
-    extra_flags = captured_as_build_flags(result, library_dir=source_path)
-    if not extra_flags:
-        return
-    flags = component.data.setdefault("build", {}).setdefault("flags", [])
-    if isinstance(flags, str):
-        flags = [flags]
-    flags.extend(extra_flags)
-    component.data["build"]["flags"] = flags
-
-
 def generate_cmakelists_txt(component: IDFComponent) -> str:
     """
     Generate a CMakeLists.txt file for an ESP-IDF component.
@@ -85,10 +56,6 @@ def generate_cmakelists_txt(component: IDFComponent) -> str:
     Returns:
         str: The complete CMakeLists.txt content as a string
     """
-    # Late import: this module loads with the esp32 platform on every
-    # validate/compile, but shlex is only needed when generating component
-    # CMakeLists.
-    import shlex
 
     def escape_entry(p: PathType) -> str:
         # In CMakeLists.txt, backslashes need to be escaped
@@ -122,26 +89,12 @@ def generate_cmakelists_txt(component: IDFComponent) -> str:
     build_src_filter = ensure_list(
         component.data.get("build", {}).get("srcFilter", DEFAULT_BUILD_SRC_FILTER)
     )
-    build_flags = ensure_list(
-        component.data.get("build", {}).get("flags", DEFAULT_BUILD_FLAGS)
+    # PlatformIO shell-lexes each build.flags entry; bare -I/-L/-l/-D tokens
+    # re-glue to their argument so the prefix classifiers below route them.
+    build_flags = lex_build_flags(
+        component.data.get("build", {}).get("flags", DEFAULT_BUILD_FLAGS),
+        f"library {component.name}",
     )
-    # PlatformIO shell-lexes each build.flags entry, so one entry can carry a
-    # flag and its argument (e.g. "-include cp_custom_alloc.h"). Split the
-    # same way; emitting such an entry as a single quoted compile option
-    # hands the compiler one argv with an embedded space.
-    build_flags = [token for entry in build_flags for token in shlex.split(entry)]
-    # Re-glue bare -I/-L/-l tokens to their argument ("-I foo" -> "-Ifoo") so
-    # the prefix classifiers below still route them to INCLUDE_DIRS and the
-    # link handling.
-    tokens, build_flags = build_flags, []
-    i = 0
-    while i < len(tokens):
-        if tokens[i] in ("-I", "-L", "-l") and i + 1 < len(tokens):
-            build_flags.append(tokens[i] + tokens[i + 1])
-            i += 2
-        else:
-            build_flags.append(tokens[i])
-            i += 1
 
     # List all sources files
     build_src_files = collect_filtered_files(
@@ -253,6 +206,16 @@ def generate_cmakelists_txt(component: IDFComponent) -> str:
             content += f"  {str_build_flag}\n"
         content += ")\n"
 
+    # Extra-script LINKFLAGS: routed to the link line; in
+    # target_compile_options they would be silently ineffective
+    if link_flags := component.data.get(ESPHOME_DATA_KEY, {}).get(
+        ESPHOME_DATA_LINK_FLAGS_KEY, []
+    ):
+        content += "target_link_options(${COMPONENT_LIB} INTERFACE\n"
+        for link_flag in link_flags:
+            content += f"  {escape_entry(link_flag)}\n"
+        content += ")\n"
+
     # Add custom CMake scripts
     content += "\n".join(
         component.data.get(ESPHOME_DATA_KEY, {}).get(ESPHOME_DATA_EXTRA_CMAKE_KEY, [])
@@ -299,7 +262,14 @@ def generate_idf_component_yml(component: IDFComponent) -> str:
 
 def _emit_idf_component(component: IDFComponent) -> None:
     """Write the ESP-IDF build files for a resolved library into its cache dir."""
-    _apply_extra_script(component)
+    from esphome.components.esp32 import get_esp32_variant
+    from esphome.platformio.extra_script import apply_extra_script
+
+    apply_extra_script(
+        component,
+        board_mcu=lambda: variant_to_idf_target(get_esp32_variant()),
+        pio_platform="espressif32",
+    )
     write_file_if_changed(
         component.path / "CMakeLists.txt",
         generate_cmakelists_txt(component),

esphome/espidf/extra_script.py

@@ -1,161 +0,0 @@
-"""Run a PlatformIO ``extraScript`` against a captured SCons-env stand-in.
-
-PlatformIO libraries occasionally configure per-target link/build state
-via a Python ``extraScript`` declared in ``library.json``'s ``build``
-section instead of static fields. The script runs under SCons during
-PIO's build and mutates the active ``Environment`` (``env.Append``,
-``env.Replace``, …) — chiefly to set ``LIBPATH``/``LIBS`` per chip MCU.
-
-ESPHome's PIO→IDF converter doesn't run SCons, so these scripts were
-previously ignored and any library
-relying on them failed to link under ``toolchain: esp-idf``. This
-module provides a small shim that ``exec``s an extra-script with a
-fake ``env`` object, captures the common ``env.Append(...)`` calls,
-and returns the captured vars so the caller can fold them back into
-the library's generated CMakeLists.
-
-Caveats
--------
-* Only the ``env.Append`` API is captured. ``env.Replace``,
-  ``env.Prepend``, ``env.AddPreAction``, SCons file generators, and any
-  arbitrary I/O are silently no-ops. Scripts that depend on those will
-  produce incomplete output.
-* Running arbitrary Python from third-party libraries is a non-trivial
-  trust decision. The shim does no sandboxing — anything in the
-  script's process can run. Use only with libraries whose source you
-  trust.
-"""
-
-from __future__ import annotations
-
-from dataclasses import dataclass, field
-import logging
-import os
-from pathlib import Path
-
-_LOGGER = logging.getLogger(__name__)
-
-# Keys we know how to translate back into ESPHome's build-flag pipeline.
-# Other env.Append kwargs are recorded but ignored downstream.
-_CAPTURED_KEYS = frozenset({"LIBPATH", "LIBS", "CPPDEFINES", "LINKFLAGS", "CPPFLAGS"})
-
-
-@dataclass
-class ExtraScriptResult:
-    """Build-var deltas captured from a PIO extra-script ``env.Append`` call."""
-
-    libpath: list[str] = field(default_factory=list)
-    libs: list[str] = field(default_factory=list)
-    cppdefines: list[str | tuple[str, str]] = field(default_factory=list)
-    linkflags: list[str] = field(default_factory=list)
-    cppflags: list[str] = field(default_factory=list)
-
-
-class _FakeSConsEnv:
-    """Minimal stand-in for SCons ``Environment`` exposed to extra-scripts.
-
-    Implements just enough surface area to let scripts query ``BOARD_MCU``
-    / ``PIOENV`` and call ``env.Append(LIBPATH=…, LIBS=…, …)``. Every
-    other env method swallows silently so unrelated calls don't raise
-    ``AttributeError`` and abort the script.
-    """
-
-    def __init__(self, *, board_mcu: str, pio_env: str) -> None:
-        self._vars: dict[str, str] = {
-            "BOARD_MCU": board_mcu,
-            "PIOPLATFORM": "espressif32",
-            "PIOENV": pio_env,
-        }
-        self.result = ExtraScriptResult()
-
-    # ----- SCons env API the common scripts use -----
-
-    def get(self, key: str, default: str | None = None) -> str | None:
-        return self._vars.get(key, default)
-
-    def Append(self, **kwargs) -> None:  # noqa: N802 (SCons API name)
-        for key, value in kwargs.items():
-            if key not in _CAPTURED_KEYS:
-                continue
-            items = list(value) if isinstance(value, (list, tuple)) else [value]
-            bucket = getattr(self.result, key.lower())
-            bucket.extend(items)
-
-    # ----- Everything else is a no-op so unsupported scripts don't crash -----
-
-    def __getattr__(self, name: str):
-        def _noop(*args, **kwargs):
-            return None
-
-        return _noop
-
-
-def run_extra_script(
-    script_path: Path, *, library_dir: Path, idf_target: str
-) -> ExtraScriptResult:
-    """Execute ``script_path`` with a fake SCons env and return captured vars.
-
-    ``idf_target`` is the active ESP-IDF target name (e.g. ``esp32``,
-    ``esp32s3``); it's exposed to the script as PlatformIO's
-    ``BOARD_MCU`` so chip-conditional logic resolves the same way it
-    would under PIO. The script runs with ``library_dir`` as the
-    process CWD so relative-path lookups (``join``, ``realpath``,
-    ``open``) resolve against the library tree.
-
-    On any exception inside the script we log at debug level and return
-    an empty result — extra-scripts are best-effort, and an unsupported
-    script shouldn't block the build.
-    """
-    env = _FakeSConsEnv(board_mcu=idf_target, pio_env=f"esphome_{idf_target}")
-    code = compile(script_path.read_text(encoding="utf-8"), str(script_path), "exec")
-    old_cwd = Path.cwd()
-    try:
-        os.chdir(library_dir)
-        exec(  # noqa: S102 pylint: disable=exec-used
-            code,
-            {
-                "Import": lambda *_args: None,  # SCons-side import; harmless here
-                "env": env,
-                "__file__": str(script_path),
-                "__name__": "__pio_extra_script__",
-            },
-        )
-    except Exception as e:  # noqa: BLE001  # pylint: disable=broad-exception-caught
-        _LOGGER.warning("PIO extra-script %s raised %s; skipping", script_path, e)
-        return ExtraScriptResult()
-    finally:
-        os.chdir(old_cwd)
-    return env.result
-
-
-def captured_as_build_flags(
-    result: ExtraScriptResult, *, library_dir: Path
-) -> list[str]:
-    """Translate captured env vars into the ``-L`` / ``-l`` / ``-D`` /
-    raw-flag form ``_generate_cmakelists_txt`` already knows how to consume.
-
-    ``LIBPATH`` entries are made relative to ``library_dir`` so the
-    generated CMakeLists is portable; absolute paths outside the library
-    tree are kept as-is (CMake handles absolute paths in
-    ``target_link_directories`` fine).
-    """
-    flags: list[str] = []
-    library_root = library_dir.resolve()
-    for path in result.libpath:
-        # Anchor relative paths to library_dir (not the current CWD, which
-        # has been restored by the time we get here). Joining an absolute
-        # path against library_dir returns the absolute path unchanged.
-        resolved = (library_dir / path).resolve()
-        try:
-            flags.append(f"-L{resolved.relative_to(library_root)}")
-        except ValueError:
-            flags.append(f"-L{resolved}")
-    flags.extend(f"-l{lib}" for lib in result.libs)
-    for define in result.cppdefines:
-        if isinstance(define, tuple) and len(define) == 2:
-            flags.append(f"-D{define[0]}={define[1]}")
-        else:
-            flags.append(f"-D{define}")
-    flags.extend(result.linkflags)
-    flags.extend(result.cppflags)
-    return flags

esphome/espidf/framework.py

@@ -2,6 +2,7 @@
 
 from collections.abc import Callable
 from ctypes.util import find_library
+from functools import partial
 import json
 import logging
 import os
@@ -20,9 +21,11 @@ from esphome.framework_helpers import (
     create_venv,
     download_from_mirrors,
     download_with_resume,
+    failure_reason,
     get_python_env_executable_path,
     get_system_python_path,
     rmdir,
+    run_batch_downloads,
     run_command,
     run_command_ok,
     str_to_lst_of_str,
@@ -690,6 +693,18 @@ def _patch_tools_json_demote_unused_tools(framework_path: Path) -> None:
     )
 
 
+def _download_tool(
+    dist_path: Path, entry: dict, tracker: Callable[[int], None]
+) -> None:
+    download_with_resume(
+        entry["url"],
+        dist_path / entry["dest"],
+        sha256=entry["sha256"],
+        size=entry["size"],
+        progress=tracker,
+    )
+
+
 def _prefetch_idf_tool_archives(
     framework_path: Path,
     targets_str: str,
@@ -702,10 +717,10 @@ def _prefetch_idf_tool_archives(
     which makes large archives effectively impossible to fetch on unstable
     connections (#17703). This asks the framework's idf_tools (via
     ``get_tool_downloads.py``) which archives the coming install needs, then
-    downloads each into ``<IDF_TOOLS_PATH>/dist`` with
-    ``download_with_resume``. The installer then finds the verified archives
-    already in place ("file ... is already downloaded") and never touches the
-    network.
+    downloads them into ``<IDF_TOOLS_PATH>/dist`` with
+    ``download_with_resume``, a few at a time under one combined progress
+    bar. The installer then finds the verified archives already in place
+    ("file ... is already downloaded") and never touches the network.
 
     Strictly best-effort: any failure here just logs and returns, leaving
     ``idf_tools.py install`` to download whatever is missing exactly as
@@ -727,30 +742,60 @@ def _prefetch_idf_tool_archives(
             )
             return
         dist_path = get_idf_tools_path() / "dist"
-        entries = [
-            entry
-            for entry in json.loads(stdout)
-            if not (dist_path / entry["dest"]).is_file()
-        ]
-        for index, entry in enumerate(entries, start=1):
-            _LOGGER.info(
-                "Downloading %s (%d/%d) ...", entry["name"], index, len(entries)
-            )
-            try:
-                download_with_resume(
-                    entry["url"],
-                    dist_path / entry["dest"],
-                    sha256=entry["sha256"],
-                    size=entry["size"],
+        entries = []
+        seen_dests: set[str] = set()
+        for entry in json.loads(stdout):
+            if (dist_path / entry["dest"]).is_file():
+                continue
+            # Never download unverified: an entry without sha256/size is
+            # left to the installer, which fails loudly on a bad archive.
+            # Checked before the dedupe so it cannot shadow a verifiable
+            # duplicate of the same dest.
+            if not (entry.get("sha256") and entry.get("size")):
+                _LOGGER.warning(
+                    "Tool %s has no sha256/size in the download list; "
+                    "leaving it to the installer",
+                    entry["name"],
                 )
-            except Exception as e:  # noqa: BLE001  # pylint: disable=broad-exception-caught
-                # Keep prefetching the remaining archives; the installer
-                # will retry this one itself (without resume).
-                _LOGGER.warning("Could not prefetch %s: %s", entry["name"], e)
+                continue
+            if entry["dest"] in seen_dests:
+                # Two workers on one .part file would interleave
+                # seek/truncate writes; mirror the library prefetch's dedupe
+                continue
+            seen_dests.add(entry["dest"])
+            entries.append(entry)
+        if not entries:
+            return
+        _LOGGER.info(
+            "Downloading %d ESP-IDF tool archive(s): %s",
+            len(entries),
+            ", ".join(entry["name"] for entry in entries),
+        )
+
+        # No sequential fallback here: skipping the prefetch would lose the
+        # resume workaround for #17703, and every entry has a size (above).
+        # A failed archive is retried by the installer itself (without
+        # resume); keep prefetching the rest.
+        failures = run_batch_downloads(
+            "Downloading ESP-IDF tools",
+            [
+                (
+                    entry["name"],
+                    entry["size"],
+                    partial(_download_tool, dist_path, entry),
+                )
+                for entry in entries
+            ],
+        )
+        for name, e in failures:
+            # failure_reason: a message-less exception must not log blank
+            _LOGGER.warning("Could not prefetch %s: %s", name, failure_reason(e))
+            _LOGGER.debug("Prefetch failure detail", exc_info=e)
     except Exception as e:  # noqa: BLE001  # pylint: disable=broad-exception-caught
         # The installer downloads anything missing itself; never let the
         # prefetch become a new way for the install to fail.
         _LOGGER.warning("ESP-IDF tool prefetch failed: %s", e)
+        _LOGGER.debug("Prefetch failure detail", exc_info=True)
 
 
 def _check_esphome_idf_framework_install(

esphome/espidf/size_summary.py

@@ -28,6 +28,8 @@ import json
 import logging
 from pathlib import Path
 
+from esphome.build_helpers.size_summary import print_size_line
+
 _LOGGER = logging.getLogger(__name__)
 _SIZE_SUFFIXES = {"K": 1024, "M": 1024 * 1024}
 
@@ -67,18 +69,6 @@ def _find_app_partition_size(partitions_csv: Path) -> int:
     raise ValueError(f"No app+factory or app+ota_0 partition in {partitions_csv}")
 
 
-def _format_bar(used: int, total: int) -> str:
-    """Match PlatformIO's ``_format_availale_bytes`` (pioupload.py) exactly."""
-    pct_raw = used / total if total else 0
-    blocks = 10
-    filled = min(int(round(blocks * pct_raw)), blocks)
-    progress = "=" * filled
-    return (
-        f"[{progress:<{blocks}}] {pct_raw: 6.1%} "
-        f"(used {used:d} bytes from {total:d} bytes)"
-    )
-
-
 def print_summary(size_json: Path, partitions_csv: Path | None) -> None:
     """Print PlatformIO-shaped RAM and Flash one-liners.
 
@@ -99,7 +89,7 @@ def print_summary(size_json: Path, partitions_csv: Path | None) -> None:
     ram_used = ram_region.get("used")
     ram_total = ram_region.get("size")
     if ram_total and ram_used is not None:
-        print(f"RAM:   {_format_bar(ram_used, ram_total)}")
+        print_size_line("RAM", ram_used, ram_total)
 
     image_size = data.get("image_size")
     if image_size is None or partitions_csv is None:
@@ -109,4 +99,4 @@ def print_summary(size_json: Path, partitions_csv: Path | None) -> None:
     except ValueError as e:
         _LOGGER.debug("Skipping Flash summary: %s", e)
         return
-    print(f"Flash: {_format_bar(image_size, app_size)}")
+    print_size_line("Flash", image_size, app_size)

esphome/espidf/toolchain.py

@@ -526,32 +526,15 @@ def get_idedata() -> dict | None:
     idedata fields IDE integrations and clang-tidy expect, cached alongside the
     PlatformIO idedata path. Returns None if the compile DB doesn't exist yet.
     """
-    from esphome.espidf.idedata import idedata_from_build
+    from esphome.build_helpers.idedata import load_or_build_idedata
 
-    compile_commands = CORE.relative_build_path("build", "compile_commands.json")
-    if not compile_commands.is_file():
-        _LOGGER.debug("No %s yet; skipping idedata generation", compile_commands)
-        return None
-
-    cache = CORE.relative_internal_path("idedata", f"{CORE.name}.json")
-    if cache.is_file() and cache.stat().st_mtime >= compile_commands.stat().st_mtime:
-        try:
-            cached = json.loads(cache.read_text(encoding="utf-8"))
-        except ValueError:
-            pass
-        else:
-            # Caches written before cc_path was emitted stay newer than
-            # compile_commands.json forever, so rebuild them on the field rather
-            # than on the timestamp. Check the type too: a corrupted cache can
-            # still be valid JSON, and "in" would match a substring of a string.
-            if isinstance(cached, dict) and "cc_path" in cached:
-                return cached
-
-    data = idedata_from_build(compile_commands)
-    data["prog_path"] = str(get_elf_path())
-    cache.parent.mkdir(parents=True, exist_ok=True)
-    cache.write_text(json.dumps(data, indent=2) + "\n", encoding="utf-8")
-    return data
+    # No launcher: CMake excludes CMAKE_<LANG>_COMPILER_LAUNCHER (ccache)
+    # from the exported compile database, unlike ninja's compdb dump.
+    return load_or_build_idedata(
+        CORE.relative_build_path("build", "compile_commands.json"),
+        get_elf_path(),
+        CORE.relative_internal_path("idedata", f"{CORE.name}.json"),
+    )
 
 
 def create_factory_bin() -> bool:

esphome/framework_helpers.py

@@ -1,7 +1,8 @@
 """Generic toolchain installation helpers shared across framework implementations."""
 
-from collections.abc import Iterable
-from contextlib import ExitStack
+from collections.abc import Callable, Iterable, Iterator
+from concurrent.futures import ThreadPoolExecutor
+from contextlib import ExitStack, contextmanager, suppress
 import hashlib
 import io
 import json
@@ -10,6 +11,7 @@ import os
 from pathlib import Path
 import subprocess
 import sys
+import threading
 import time
 from typing import IO, TYPE_CHECKING
 
@@ -24,6 +26,7 @@ PathType = str | os.PathLike
 
 _LOGGER = logging.getLogger(__name__)
 
+
 # Attempts per mirror URL before falling through to the next mirror; only
 # mid-stream drops retry (resuming when the server gave a validator),
 # connect errors move on to the next mirror immediately.
@@ -699,7 +702,11 @@ def _response_validator(resp: "requests.Response") -> str | None:
 
 
 def _stream_response_to_file(
-    resp: "requests.Response", f: IO[bytes], offset: int, size: int | None = None
+    resp: "requests.Response",
+    f: IO[bytes],
+    offset: int,
+    size: int | None = None,
+    progress: Callable[[int], None] | None = None,
 ) -> None:
     """Stream an open ``_open_ranged`` response body into ``f`` at ``offset``.
 
@@ -707,21 +714,182 @@ def _stream_response_to_file(
     (effective offset 0) discards the stale bytes. ``offset`` also seeds the
     progress bar so a resumed download shows overall progress. ``size`` is
     the known full file size; when None it is derived from the response's
-    content-length, and without either there is no progress bar.
+    content-length, and without either there is no bar. With ``progress``
+    set no bar is drawn here; the callback gets the absolute byte count.
     """
     f.seek(offset)
     f.truncate(offset)
     total_size = size or offset + _content_length(resp)
     downloaded = offset
-    progress = ProgressBar("Downloading") if total_size > 0 else None
+    own_bar: ProgressBar | None = None
+    if progress is None:
+        own_bar = ProgressBar("Downloading") if total_size > 0 else None
+        progress = (
+            (lambda done: own_bar.update(done / total_size))
+            if own_bar
+            else (lambda _: None)
+        )
+    progress(downloaded)
     for chunk in resp.iter_content(chunk_size=256 * 1024):
         if chunk:
             f.write(chunk)
             downloaded += len(chunk)
-        if progress is not None:
-            progress.update(downloaded / total_size)
-    if progress is not None:
-        progress.update(1)
+        progress(downloaded)
+    if own_bar is not None:
+        own_bar.update(1)
+
+
+# Concurrent downloads per batch; enough to hide latency without
+# hammering the host or the mirrors.
+BATCH_DOWNLOAD_WORKERS = 4
+
+
+def run_batch_downloads(
+    header: str,
+    jobs: list[tuple[str, int, Callable[[Callable[[int], None]], None]]],
+    max_workers: int = BATCH_DOWNLOAD_WORKERS,
+) -> list[tuple[str, BaseException]]:
+    """Run ``(name, size, fetch)`` download jobs concurrently under one bar.
+
+    Each ``fetch(tracker)`` reports absolute byte counts; the bar total is
+    the sum of the sizes. Failures are returned after the bar is done so
+    warnings never land on its row. Ctrl-C drops queued jobs and aborts
+    in-flight ones at their next progress tick or backoff boundary (a
+    parked socket read defers that by its timeout, and an in-progress
+    archive extraction runs to completion); resumable destinations
+    (``download_with_resume``) keep their fetched ``.part`` bytes.
+    ``jobs`` must be non-empty.
+    """
+    progress = _BatchDownloadProgress(header, sum(size for _, size, _ in jobs))
+    cancelled = threading.Event()
+
+    def _run(
+        name: str, fetch: Callable[[Callable[[int], None]], None]
+    ) -> tuple[str, BaseException] | None:
+        tracker = progress.tracker()
+
+        def checked(done: int) -> None:
+            if cancelled.is_set():
+                raise _BatchDownloadCancelled
+            tracker(done)
+
+        try:
+            fetch(checked)
+        except (_BatchDownloadCancelled, Exception) as err:  # noqa: BLE001  # pylint: disable=broad-exception-caught
+            # A cancelled job reports like a failure: an abandoned download
+            # must never read as completed if a caller sees the list after
+            # Ctrl-C
+            failure = (name, err)
+        else:
+            return None
+        # A bar-frame write failure must not displace the download error
+        with suppress(Exception):
+            tracker(0)
+        return failure
+
+    ex = ThreadPoolExecutor(max_workers=max_workers)
+    try:
+        with progress.logging_guard():
+            futures = [ex.submit(_run, name, fetch) for name, _, fetch in jobs]
+            return [failure for f in futures if (failure := f.result()) is not None]
+    except BaseException:
+        # Without this the non-daemon workers download to completion before
+        # the interpreter can exit, making Ctrl-C ineffective for minutes
+        cancelled.set()
+        raise
+    finally:
+        ex.shutdown(wait=True, cancel_futures=True)
+        progress.done()
+
+
+class _BatchDownloadCancelled(BaseException):
+    """Raised inside a download job to abandon it after Ctrl-C.
+
+    BaseException, like KeyboardInterrupt: a broad ``except Exception`` in
+    the download layers must not convert an abort into a retry.
+    """
+
+
+class _BatchDownloadProgress:
+    """One bar across several concurrent downloads, summing tracker bytes.
+
+    The lock also serialises stderr writes so workers never interleave
+    frames; a ``total`` of 0 draws nothing. Call ``done()`` at the end so a
+    bar short of 100% still ends its line.
+    """
+
+    def __init__(self, header: str, total: int) -> None:
+        self._bar = ProgressBar(header) if total > 0 else None
+        self._total = total
+        self._sum = 0
+        self._lock = threading.Lock()
+
+    def tracker(self) -> Callable[[int], None]:
+        if self._bar is None:
+            return lambda _: None
+        last = 0
+
+        def update(done: int) -> None:
+            nonlocal last
+            with self._lock:
+                self._sum += done - last
+                last = done
+                self._bar.update(min(self._sum / self._total, 1))
+
+        return update
+
+    def done(self) -> None:
+        if self._bar is not None:
+            self._bar.done()
+
+    @contextmanager
+    def logging_guard(self) -> Iterator[None]:
+        r"""End a partial bar row before any log record while active.
+
+        Worker warnings (mirror retries) share stderr with the bar's \r
+        frames; without this the record lands mid-row and the next frame
+        overwrites it. A handler-level filter runs just before emit, so
+        only a tiny window remains for a concurrent frame.
+        """
+        the_bar = self._bar
+        if the_bar is None:
+            yield
+            return
+        lock = self._lock
+
+        class _EndRow(logging.Filter):
+            def filter(self, record: logging.LogRecord) -> bool:
+                with lock:
+                    the_bar.interrupt()
+                return True
+
+        end_row = _EndRow()
+        handlers = logging.getLogger().handlers
+        for handler in handlers:
+            handler.addFilter(end_row)
+        try:
+            yield
+        finally:
+            for handler in handlers:
+                handler.removeFilter(end_row)
+
+
+def _part_path(dest: Path) -> Path:
+    """The in-progress sidecar ``download_with_resume`` streams into."""
+    return dest.with_name(dest.name + ".part")
+
+
+def _cancellable_sleep(
+    delay: float, progress: Callable[[int], None] | None, done: int
+) -> None:
+    """Backoff sleep that still observes a batch cancellation tick."""
+    if progress is None:
+        time.sleep(delay)
+        return
+    end = time.monotonic() + delay
+    while (remaining := end - time.monotonic()) > 0:
+        progress(done)  # raises when the batch was cancelled
+        time.sleep(min(0.5, remaining))
 
 
 def download_with_resume(
@@ -734,6 +902,7 @@ def download_with_resume(
     attempts: int = 5,
     timeout: int = 30,
     retry_connect_errors: bool = True,
+    progress: Callable[[int], None] | None = None,
 ) -> None:
     """Download ``url`` to ``dest``, resuming partial downloads.
 
@@ -756,6 +925,9 @@ def download_with_resume(
     of consuming attempts — for callers with their own fallback, like
     ``download_from_mirrors``.
 
+    ``progress`` replaces the built-in bar: it receives the absolute bytes of
+    ``dest`` obtained so far (see ``BatchDownloadProgress``).
+
     Raises EsphomeError when all attempts are exhausted.
     """
     # Imported lazily: requests is a heavy import (~85ms) and is only needed
@@ -767,7 +939,7 @@ def download_with_resume(
     ensure_happy_eyeballs()
 
     dest = Path(dest)
-    part = dest.with_name(dest.name + ".part")
+    part = _part_path(dest)
     meta = part.with_name(part.name + ".meta")
     dest.parent.mkdir(parents=True, exist_ok=True)
     last_error: Exception | None = None
@@ -779,6 +951,8 @@ def download_with_resume(
     if dest.is_file() and (sha256 is not None or size is not None):
         try:
             _verify_file(dest, sha256, size)
+            if progress is not None:
+                progress(size if size is not None else dest.stat().st_size)
             return
         except EsphomeError:
             dest.unlink()
@@ -824,7 +998,7 @@ def download_with_resume(
                             # Recorded so a later run can prove an If-Range
                             # resume of this part file safe.
                             _write_download_meta(meta, url, validator, expected_total)
-                        _stream_response_to_file(resp, f, offset, size)
+                        _stream_response_to_file(resp, f, offset, size, progress)
             # else: a previous run already wrote every byte (or more) but
             # was killed before the rename below. Skip the network entirely
             # — a Range request past EOF would draw HTTP 416 — and let
@@ -833,6 +1007,10 @@ def download_with_resume(
 
             expected_size = size if size is not None else expected_total
             _verify_file(part, sha256, expected_size or None)
+            if progress is not None:
+                # Also credits a part file an earlier run completed without
+                # streaming anything this time.
+                progress(expected_size or part.stat().st_size)
             if not expected_size and sha256 is None:
                 # No sha, no size, and the server sent no usable
                 # content-length: nothing can prove the download complete
@@ -880,11 +1058,11 @@ def download_with_resume(
 
     raise EsphomeError(
         f"Failed to download {url} after {attempts} attempts: "
-        f"{_failure_reason(last_error)}"
+        f"{failure_reason(last_error)}"
     ) from last_error
 
 
-def _failure_reason(e: Exception) -> str:
+def failure_reason(e: BaseException) -> str:
     """Format a download exception for the aggregated error message.
 
     ``requests`` appends " for url: <url>" to HTTP errors; the URL is already
@@ -900,7 +1078,7 @@ def _spent_attempts_error(e: Exception, attempts: int) -> Exception:
     the sweep classifies it as permanent."""
     from esphome.core import EsphomeError
 
-    err = EsphomeError(f"failed after {attempts} attempts: {_failure_reason(e)}")
+    err = EsphomeError(f"failed after {attempts} attempts: {failure_reason(e)}")
     err.__cause__ = e
     return err
 
@@ -911,6 +1089,7 @@ def _try_mirrors_once(
     f: IO[bytes] | None,
     timeout: int,
     failures: list[tuple[str, Exception]],
+    progress: Callable[[int], None] | None = None,
 ) -> str | None:
     """Single pass over the resolved mirror ``urls``, one try per URL.
 
@@ -939,6 +1118,7 @@ def _try_mirrors_once(
                     # next mirror immediately; only mid-stream drops
                     # retry-with-resume on the same URL.
                     retry_connect_errors=False,
+                    progress=progress,
                 )
                 return url
             except (requests.RequestException, OSError, EsphomeError) as e:
@@ -980,7 +1160,7 @@ def _try_mirrors_once(
                         if offset == 0:
                             validator = _response_validator(resp)
                             expected_total = _content_length(resp)
-                        _stream_response_to_file(resp, f, offset)
+                        _stream_response_to_file(resp, f, offset, progress=progress)
 
                 if expected_total and f.tell() != expected_total:
                     raise EsphomeError(
@@ -1029,6 +1209,7 @@ def download_from_mirrors(
     substitutions: dict[str, str],
     target: io.RawIOBase | IO[bytes] | PathType,
     timeout: int = 30,
+    progress: Callable[[int], None] | None = None,
 ) -> str:
     """
     Download file from multiple mirrors with substitution support.
@@ -1038,6 +1219,8 @@ def download_from_mirrors(
         substitutions: Dictionary of substitutions to apply to URLs
         target: Target file path or file-like object
         timeout: Download timeout in seconds
+        progress: Passed through to the download (see ``download_with_resume``);
+            replaces the built-in per-file bar
 
     Returns:
         The source URL.
@@ -1102,7 +1285,9 @@ def download_from_mirrors(
     for sweep in range(1, _MIRROR_SWEEP_ATTEMPTS + 1):
         sweep_failures: list[tuple[str, Exception]] = []
         if (
-            url := _try_mirrors_once(urls, path_target, f, timeout, sweep_failures)
+            url := _try_mirrors_once(
+                urls, path_target, f, timeout, sweep_failures, progress
+            )
         ) is not None:
             return url
         failures.extend(sweep_failures)
@@ -1119,12 +1304,19 @@ def download_from_mirrors(
             _LOGGER.warning(
                 "Download of %s failed (%s); retrying in %d seconds (attempt %d/%d)",
                 transient[0],
-                _failure_reason(transient[1]),
+                failure_reason(transient[1]),
                 delay,
                 sweep + 1,
                 _MIRROR_SWEEP_ATTEMPTS,
             )
-            time.sleep(delay)
+            # Tick with the bytes already on disk so a combined bar holds
+            # steady during the backoff instead of rewinding to zero
+            if f is not None:
+                done = f.tell()
+            else:
+                part = _part_path(path_target)
+                done = part.stat().st_size if part.is_file() else 0
+            _cancellable_sleep(delay, progress, done)
 
     # 4. Report every attempted URL if all mirrors failed. failures spans
     # all sweeps (deduplicated by URL and reason), so neither an early
@@ -1133,7 +1325,7 @@ def download_from_mirrors(
         seen: set[tuple[str, str]] = set()
         attempts = ""
         for url, e in failures:
-            reason = _failure_reason(e)
+            reason = failure_reason(e)
             if (url, reason) not in seen:
                 seen.add((url, reason))
                 attempts += f"\n  {url}\n    {reason}"

esphome/helpers.py

@@ -729,11 +729,22 @@ class ProgressBar:
         sys.stderr.flush()
 
     def done(self) -> None:
-        if not self.enabled:
+        # No frame drawn, or the 100% frame already ended its own line
+        if not self.enabled or self.last_progress is None or self.last_progress == 100:
             return
         sys.stderr.write("\n")
         sys.stderr.flush()
 
+    def interrupt(self) -> None:
+        """End a mid-row frame so the next write starts on its own row.
+
+        The next ``update()`` redraws the bar; a finished bar stays done.
+        """
+        if self.last_progress == 100:
+            return
+        self.done()
+        self.last_progress = None
+
 
 def docs_url(path: str) -> str:
     """Return the URL to the documentation for a given path."""

esphome/platformio/extra_script.py

@@ -0,0 +1,356 @@
+"""Run a PlatformIO library ``extraScript`` against a fake SCons env.
+
+The shim execs the script with a stand-in ``env``, captures ``env.Append``
+calls (everything else is a logged no-op), and folds the result into the
+library's build flags. No sandboxing: the script runs with full process
+access, so it carries the same trust as the library's own source.
+"""
+
+from __future__ import annotations
+
+from collections.abc import Callable
+from dataclasses import dataclass, field
+import logging
+import os
+from pathlib import Path
+import shlex
+from typing import TYPE_CHECKING, Any, NamedTuple
+
+from esphome.core import EsphomeError
+from esphome.platformio.library import ESPHOME_DATA_KEY, ESPHOME_DATA_LINK_FLAGS_KEY
+
+if TYPE_CHECKING:
+    from esphome.platformio.library import ConvertedLibrary
+
+_LOGGER = logging.getLogger(__name__)
+
+
+def apply_extra_script(
+    component: ConvertedLibrary,
+    board_mcu: Callable[[], str],
+    pio_platform: str,
+) -> None:
+    """Run a library's ``extraScript`` and fold its captured env vars into
+    ``build.flags``; ``board_mcu`` is a callable so it resolves lazily."""
+    extra_script = component.data.get("build", {}).get("extraScript")
+    if not extra_script:
+        return
+    if not isinstance(extra_script, str):
+        # A list/dict value would raise an opaque TypeError on the join below
+        raise EsphomeError(
+            f"extraScript of library {component.name} must be a string, "
+            f"got {type(extra_script).__name__}"
+        )
+    # Resolve and confine to the library's source dir so a malicious
+    # library.json can't escape (e.g. ``"extraScript": "../../etc/passwd"``).
+    source_path = component.source_dir
+    library_root = source_path.resolve()
+    script_path = (source_path / extra_script).resolve()
+    if not script_path.is_relative_to(library_root):
+        # More hostile than a missing script; must not be quieter than it
+        raise EsphomeError(
+            f"extraScript {extra_script} of library {component.name} escapes "
+            "the library directory"
+        )
+    if not script_path.is_file():
+        # A declared-but-absent script is a broken or half-downloaded
+        # package, not an unsupported script; PlatformIO fails on it too
+        raise EsphomeError(
+            f"extraScript {extra_script} of library {component.name} not found"
+        )
+    result = run_extra_script(
+        script_path,
+        library_dir=source_path,
+        board_mcu=board_mcu(),
+        pio_platform=pio_platform,
+    )
+    if link_flags := _str_entries(result.linkflags, "LINKFLAGS"):
+        # Kept apart from build.flags: the CMake emitters route those to
+        # target_compile_options, where a link flag is silently ineffective
+        esphome_data = component.data.setdefault(ESPHOME_DATA_KEY, {})
+        esphome_data.setdefault(ESPHOME_DATA_LINK_FLAGS_KEY, []).extend(link_flags)
+    extra_flags = captured_as_build_flags(result, library_dir=source_path)
+    if not extra_flags:
+        return
+    flags = component.data.setdefault("build", {}).setdefault("flags", [])
+    if isinstance(flags, str):
+        flags = [flags]
+    elif not isinstance(flags, list):
+        # A null/dict value coerced through a list wrapper would inject a
+        # non-string into the compiler command line; fail naming the library
+        raise EsphomeError(
+            f"Library {component.name} has a malformed build.flags "
+            f"({type(flags).__name__}); expected a string or list"
+        )
+    component.data["build"]["flags"] = [*flags, *extra_flags]
+
+
+# Keys we know how to translate back into ESPHome's build-flag pipeline.
+# Other env.Append kwargs are recorded but ignored downstream.
+_CAPTURED_KEYS = frozenset(
+    {"CPPPATH", "LIBPATH", "LIBS", "CPPDEFINES", "LINKFLAGS", "CPPFLAGS"}
+)
+
+
+@dataclass
+class ExtraScriptResult:
+    """Build-var deltas captured from a PIO extra-script ``env.Append`` call."""
+
+    cpppath: list[str] = field(default_factory=list)
+    libpath: list[str] = field(default_factory=list)
+    libs: list[str] = field(default_factory=list)
+    cppdefines: list[CppDefine] = field(default_factory=list)
+    linkflags: list[str] = field(default_factory=list)
+    cppflags: list[str] = field(default_factory=list)
+
+
+class CppDefine(NamedTuple):
+    """One normalized CPPDEFINES entry; a ``value`` of None is a bare -DNAME."""
+
+    name: str
+    value: str | None = None
+
+
+def _cppdefine(entry: Any) -> CppDefine | None:
+    """Normalize one CPPDEFINES element, or warn and drop an unsupported
+    shape; formatting those blind would hand the compiler garbage like
+    ``-D{'FOO': '1'}``."""
+    if isinstance(entry, str):
+        return CppDefine(entry)
+    if (
+        isinstance(entry, (tuple, list))
+        and len(entry) == 2
+        and isinstance(entry[0], (str, int))
+        and isinstance(entry[1], (str, int, type(None)))
+    ):
+        value = entry[1]
+        return CppDefine(str(entry[0]), None if value is None else str(value))
+    _LOGGER.warning("Ignoring unsupported CPPDEFINES entry %r", entry)
+    return None
+
+
+def _cppdefines_items(value: Any) -> list[CppDefine]:
+    """Normalize SCons ``processDefines`` spellings into ``CppDefine``s: a
+    bare 2-tuple is one ``name=value`` pair, a dict maps names to values, a
+    list is element-wise."""
+    if isinstance(value, tuple) and len(value) == 2:
+        elements: list[Any] = [value]
+    elif isinstance(value, dict):
+        elements = list(value.items())
+    else:
+        elements = list(value) if isinstance(value, (list, tuple)) else [value]
+    return [d for e in elements if (d := _cppdefine(e)) is not None]
+
+
+class _FakeSConsEnv:
+    """Minimal SCons ``Environment`` stand-in: ``get`` and ``Append`` work;
+    every other method is a swallowed no-op so scripts don't abort."""
+
+    def __init__(self, *, board_mcu: str, pio_env: str, pio_platform: str) -> None:
+        self._vars: dict[str, str] = {
+            "BOARD_MCU": board_mcu,
+            "PIOPLATFORM": pio_platform,
+            "PIOENV": pio_env,
+        }
+        self.result = ExtraScriptResult()
+        self._warned_methods: set[str] = set()
+        self._warned_keys: set[str] = set()
+        self._warned_gets: set[str] = set()
+
+    # ----- SCons env API the common scripts use -----
+
+    def get(self, key: str, default: str | None = None) -> str | None:
+        if key not in self._vars and key not in self._warned_gets:
+            # A script branching on an unmodelled var silently takes the
+            # default branch; make that diagnosable from a normal build log
+            self._warned_gets.add(key)
+            _LOGGER.warning(
+                "PIO extra-script env.get(%r) is not modelled; returning the default",
+                key,
+            )
+        return self._vars.get(key, default)
+
+    def __getitem__(self, key: str) -> str:
+        # Scripts also read env["BOARD_MCU"]; an unmodelled subscript
+        # degrades one branch instead of discarding the whole capture
+        if key not in self._vars and key not in self._warned_gets:
+            self._warned_gets.add(key)
+            _LOGGER.warning(
+                "PIO extra-script env[%r] is not modelled; returning ''", key
+            )
+        return self._vars.get(key, "")
+
+    def Append(self, **kwargs) -> None:  # noqa: N802 (SCons API name)
+        self._add(kwargs, prepend=False)
+
+    def Prepend(self, **kwargs) -> None:  # noqa: N802 (SCons API name)
+        self._add(kwargs, prepend=True)
+
+    def _add(self, kwargs: dict[str, Any], *, prepend: bool) -> None:
+        for key, value in kwargs.items():
+            if key not in _CAPTURED_KEYS:
+                # Warn once per key so a loop of Appends cannot spam
+                if key not in self._warned_keys:
+                    self._warned_keys.add(key)
+                    _LOGGER.warning(
+                        "PIO extra-script env.Append(%s=...) is not captured; ignoring",
+                        key,
+                    )
+                continue
+            if key == "CPPDEFINES":
+                items = _cppdefines_items(value)
+            else:
+                items = list(value) if isinstance(value, (list, tuple)) else [value]
+            bucket = getattr(self.result, key.lower())
+            if prepend:
+                # SCons order: new values ahead of what is already there
+                # (scripts prepend LIBS for static-link symbol resolution)
+                bucket[:0] = items
+            else:
+                bucket.extend(items)
+
+    # Dedup is not modelled; a repeated flag is harmless on the command line
+    AppendUnique = Append
+    PrependUnique = Prepend
+
+    # ----- Everything else is a no-op so unsupported scripts don't crash -----
+
+    def __getattr__(self, name: str):
+        if name.startswith("__") and name.endswith("__"):
+            # Protocol probes (copy, pickle, iteration) are not script calls
+            raise AttributeError(name)
+        if name not in self._warned_methods:
+            # Warn on access, not call: hasattr()/truthiness branches would
+            # otherwise silently take the wrong path; a script whose whole
+            # effect is env.Replace() stays diagnosable either way
+            self._warned_methods.add(name)
+            _LOGGER.warning("PIO extra-script env.%s is not supported; ignoring", name)
+
+        def _noop(*args, **kwargs):
+            return None
+
+        return _noop
+
+
+def run_extra_script(
+    script_path: Path,
+    *,
+    library_dir: Path,
+    board_mcu: str,
+    pio_platform: str,
+) -> ExtraScriptResult:
+    """Execute ``script_path`` with a fake SCons env, ``library_dir`` as CWD.
+
+    A crashed script warns and returns an empty result, never a partial
+    capture."""
+    env = _FakeSConsEnv(
+        board_mcu=board_mcu,
+        pio_env=f"esphome_{board_mcu}",
+        pio_platform=pio_platform,
+    )
+    try:
+        source = script_path.read_text(encoding="utf-8")
+    except OSError as err:
+        # An unreadable declared script is a broken package, exactly like a
+        # missing one; must not be quieter than that case
+        raise EsphomeError(f"extraScript {script_path} is unreadable: {err}") from err
+    except UnicodeDecodeError as e:
+        # A content problem, best-effort like a SyntaxError below
+        _LOGGER.warning(
+            "PIO extra-script %s (in %s) is not UTF-8 (%r); ignoring its output",
+            script_path,
+            library_dir.name,
+            e,
+        )
+        return ExtraScriptResult()
+    old_cwd = Path.cwd()
+    try:
+        # Inside the try: a SyntaxError in a vendored script is just as
+        # best-effort as a runtime failure
+        code = compile(source, str(script_path), "exec")
+        os.chdir(library_dir)
+        exec(  # noqa: S102 pylint: disable=exec-used
+            code,
+            {
+                "Import": lambda *_args: None,  # SCons-side import; harmless here
+                "env": env,
+                "__file__": str(script_path),
+                "__name__": "__pio_extra_script__",
+            },
+        )
+    except SystemExit as e:
+        if not e.code:
+            # sys.exit() / sys.exit(0) is a normal PlatformIO script ending;
+            # the capture is complete
+            return env.result
+        _LOGGER.warning(
+            "PIO extra-script %s (in %s) exited with status %r; ignoring its output",
+            script_path,
+            library_dir.name,
+            e.code,
+        )
+        return ExtraScriptResult()
+    except Exception as e:  # noqa: BLE001  # pylint: disable=broad-exception-caught
+        # Discard any partial capture: half-applied flags could build wrong
+        # firmware that links cleanly.
+        _LOGGER.warning(
+            "PIO extra-script %s (in %s) raised %r; ignoring its output",
+            script_path,
+            library_dir.name,
+            e,
+        )
+        return ExtraScriptResult()
+    finally:
+        os.chdir(old_cwd)
+    return env.result
+
+
+def _str_entries(bucket: list, kind: str) -> list[str]:
+    # Third-party scripts legally append SCons nodes, ints, or dicts;
+    # stringifying those into flags would hand the compiler garbage
+    good = [entry for entry in bucket if isinstance(entry, str)]
+    for entry in bucket:
+        if not isinstance(entry, str):
+            _LOGGER.warning("Ignoring unsupported %s entry %r", kind, entry)
+    return good
+
+
+def captured_as_build_flags(
+    result: ExtraScriptResult, *, library_dir: Path
+) -> list[str]:
+    """Translate captured env vars into -L/-l/-D/raw build flags; path
+    entries anchor to ``library_dir`` so the build files stay portable."""
+    flags: list[str] = []
+    library_root = library_dir.resolve()
+
+    def _anchored(path: str) -> str:
+        # Anchor relative paths to library_dir; the script's CWD has been
+        # restored by now
+        resolved = (library_dir / path).resolve()
+        try:
+            return str(resolved.relative_to(library_root))
+        except ValueError:
+            return str(resolved)
+
+    # shlex.quote so a spaced path survives lex_build_flags as one token
+    flags.extend(
+        f"-I{shlex.quote(_anchored(path))}"
+        for path in _str_entries(result.cpppath, "CPPPATH")
+    )
+    flags.extend(
+        f"-L{shlex.quote(_anchored(path))}"
+        for path in _str_entries(result.libpath, "LIBPATH")
+    )
+    flags.extend(f"-l{shlex.quote(lib)}" for lib in _str_entries(result.libs, "LIBS"))
+    for define in result.cppdefines:
+        if define.value is None:
+            # {"FOO": None} / ("FOO", None) is a bare -DFOO in SCons
+            flags.append(shlex.quote(f"-D{define.name}"))
+        else:
+            flags.append(shlex.quote(f"-D{define.name}={define.value}"))
+    # Each captured entry is one argv token in SCons; quote so the
+    # lex_build_flags round-trip cannot split a spaced value into two.
+    # LINKFLAGS are deliberately absent: they travel via
+    # ESPHOME_DATA_LINK_FLAGS_KEY straight to the link line.
+    flags.extend(shlex.quote(f) for f in _str_entries(result.cppflags, "CPPFLAGS"))
+    return flags

esphome/platformio/library.py

@@ -13,8 +13,9 @@ regardless of which toolchain consumes the result.
 """
 
 from collections import deque
-from collections.abc import Callable
+from collections.abc import Callable, Iterable
 from dataclasses import dataclass, field
+from functools import partial
 import glob
 import hashlib
 import itertools
@@ -30,7 +31,13 @@ from urllib.request import url2pathname
 
 from esphome import git
 from esphome.core import CORE, EsphomeError, Library
-from esphome.framework_helpers import archive_extract_all, download_from_mirrors, rmdir
+from esphome.framework_helpers import (
+    archive_extract_all,
+    download_from_mirrors,
+    failure_reason,
+    rmdir,
+    run_batch_downloads,
+)
 
 _LOGGER = logging.getLogger(__name__)
 
@@ -47,25 +54,38 @@ DEFAULT_BUILD_SRC_FILTER = (
 DEFAULT_BUILD_SRC_DIRS = "src"
 DEFAULT_BUILD_INCLUDE_DIR = "include"
 DEFAULT_BUILD_FLAGS = []
-SRC_FILE_EXTENSIONS = [
-    ".c",
-    ".cpp",
-    ".cc",
-    ".cxx",
-    ".c++",
-    ".S",
-    ".spp",
-    ".SPP",
-    ".sx",
-    ".s",
-    ".asm",
-    ".ASM",
-]
+# Suffix -> compiler kind (PlatformIO's CSUFFIXES/CXXSUFFIXES/ASSUFFIXES);
+# "asm" merges SCons's AS and ASPP sets. Per CXXSUFFIXES .C/.C++ are C++
+# here, even where SCons demotes .C on case-insensitive filesystems.
+SOURCE_KIND_FOR_SUFFIX: dict[str, str] = {
+    ".c": "c",
+    ".cpp": "cxx",
+    ".cc": "cxx",
+    ".cxx": "cxx",
+    ".c++": "cxx",
+    ".C": "cxx",
+    ".C++": "cxx",
+    ".S": "asm",
+    ".spp": "asm",
+    ".SPP": "asm",
+    ".sx": "asm",
+    ".s": "asm",
+    ".asm": "asm",
+    ".ASM": "asm",
+}
+SRC_FILE_EXTENSIONS = list(SOURCE_KIND_FOR_SUFFIX)
 
 DOMAIN = "pio_components"
 
+# Marks a cache dir whose archive finished extracting; a missing marker
+# means a torn extraction that must be redone
+_EXTRACTED_MARKER = ".esphome_extracted"
+
 ESPHOME_DATA_KEY = "ESPHOME"
 ESPHOME_DATA_EXTRA_CMAKE_KEY = "EXTRA_CMAKE"
+# Captured extra-script LINKFLAGS; kept apart from build.flags so they reach
+# the link line (target_link_options), not target_compile_options
+ESPHOME_DATA_LINK_FLAGS_KEY = "LINK_FLAGS"
 
 
 class Source:
@@ -84,12 +104,13 @@ class Source:
 
 
 class URLSource(Source):
-    def __init__(self, url: str):
+    def __init__(self, url: str, size: int | None = None):
         self.url = url
+        # Archive size as reported by the registry, when known; sizes the
+        # combined prefetch bar without any extra network probe
+        self.size = size
 
-    def download(
-        self, dir_suffix: str, force: bool = False, salt: str = "", namespace: str = ""
-    ) -> Path:
+    def _cache_dir(self, dir_suffix: str, salt: str, namespace: str) -> Path:
         # Namespace the cache per backend (e.g. pio_components/idf, .../zephyr) so
         # the build files each backend writes into the library dir can't collide.
         base_dir = Path(CORE.data_dir) / DOMAIN
@@ -99,22 +120,40 @@ class URLSource(Source):
         h.update(self.url.encode())
         if salt:
             h.update(salt.encode())
-        path = base_dir / h.hexdigest()[:8] / dir_suffix
+        return base_dir / h.hexdigest()[:8] / dir_suffix
+
+    def is_cached(self, dir_suffix: str, salt: str = "", namespace: str = "") -> bool:
+        """Whether a completed extraction already exists for this source."""
+        return (
+            self._cache_dir(dir_suffix, salt, namespace) / _EXTRACTED_MARKER
+        ).is_file()
+
+    def download(
+        self,
+        dir_suffix: str,
+        force: bool = False,
+        salt: str = "",
+        namespace: str = "",
+        progress: Callable[[int], None] | None = None,
+    ) -> Path:
+        path = self._cache_dir(dir_suffix, salt, namespace)
         # Marker file written last to signal a complete extraction. Using a
         # marker (instead of just `path.is_dir()`) means an interrupted
         # extraction is correctly detected and re-run on the next invocation,
         # and lets us extract directly into ``path`` — avoiding a
         # post-extraction rename that races with antivirus on Windows.
-        extracted_marker = path / ".esphome_extracted"
+        extracted_marker = path / _EXTRACTED_MARKER
         if not extracted_marker.is_file() or force:
             rmdir(path, msg=f"Clean up library directory {path}")
 
             # Download in temporary file
             with tempfile.NamedTemporaryFile() as tmp:
-                _LOGGER.info("Downloading %s ...", self.url)
+                if progress is None:
+                    # A batch caller draws one combined bar and logs the list
+                    _LOGGER.info("Downloading %s ...", self.url)
                 _LOGGER.debug("Location: %s", path)
 
-                download_from_mirrors([self.url], {}, tmp.file)
+                download_from_mirrors([self.url], {}, tmp.file, progress=progress)
 
                 _LOGGER.debug("Extracting archive to %s ...", path)
                 archive_extract_all(tmp.file, path)
@@ -203,6 +242,11 @@ class InvalidLibrary(Exception):
     pass
 
 
+class IncompatiblePlatform(InvalidLibrary):
+    """The routine cross-platform skip, typed so callers need not match
+    message text."""
+
+
 class ConvertedLibrary:
     """A resolved PlatformIO library plus its parsed manifest and on-disk path.
 
@@ -427,17 +471,22 @@ def check_library_data(data: dict, platform: str | None, framework: str):
     if isinstance(platforms, str):
         platforms = [a.strip() for a in platforms.split(",")]
     platforms = ensure_list(platforms)
+    if not all(isinstance(pf, str) for pf in platforms):
+        # A real (non-platform) manifest problem; callers warn, not skip
+        raise InvalidLibrary(f"Malformed platforms value: {platforms!r}")
 
     # Check if library supports the target platform
     valid_platforms = platform is None or "*" in platforms or platform in platforms
 
     if not valid_platforms:
-        raise InvalidLibrary(f"Unsupported library platforms: {platforms}")
+        raise IncompatiblePlatform(f"Unsupported library platforms: {platforms}")
 
     frameworks = data.get("frameworks", "*")
     if isinstance(frameworks, str):
         frameworks = [a.strip() for a in frameworks.split(",")]
     frameworks = ensure_list(frameworks)
+    if not all(isinstance(fw, str) for fw in frameworks):
+        raise InvalidLibrary(f"Malformed frameworks value: {frameworks!r}")
 
     # Check if library declares the active framework. PIO library manifests
     # often list only "arduino" even when the library actually compiles fine
@@ -455,7 +504,7 @@ def check_library_data(data: dict, platform: str | None, framework: str):
         )
 
 
-def _parse_library_json(library_json_path: PathType):
+def parse_library_json(library_json_path: PathType):
     """
     Load and parse a JSON file describing a library.
 
@@ -469,7 +518,7 @@ def _parse_library_json(library_json_path: PathType):
         return json.load(fp)
 
 
-def _parse_library_properties(library_properties_path: PathType):
+def parse_library_properties(library_properties_path: PathType):
     """
     Parse a key-value platformio .properties style file into a dictionary.
 
@@ -518,9 +567,10 @@ def _make_registry_client() -> Any:
 
 def _resolve_registry_version(
     owner: str | None, pkgname: str, requirements: set[str]
-) -> tuple[str, str, str, str]:
+) -> tuple[str, str, str, str, int | None]:
     """Resolve a registry package to the single highest version satisfying ALL
-    the given requirements; return ``(owner, name, version, download_url)``.
+    the given requirements; return ``(owner, name, version, download_url,
+    size)`` (``size`` is None when the registry omits it).
 
     Intersecting every requirement (rather than resolving each consumer in
     isolation) makes the result independent of processing order and guarantees
@@ -550,22 +600,130 @@ def _resolve_registry_version(
     pkgfile = registry.pick_compatible_pkg_file(best["files"])
     if not pkgfile:
         raise RuntimeError(f"No package file for {owner}/{name}@{best['name']}")
-    return owner, name, best["name"], pkgfile["download_url"]
+    return owner, name, best["name"], pkgfile["download_url"], pkgfile.get("size")
 
 
-def _normalize_dependencies(dependencies: Any) -> list[dict]:
+def split_flag_entry(entry: Any, owner: str) -> list[str]:
+    """``shlex.split`` with a clean error naming the offending flags entry."""
+    # Late import: shlex is only needed when actually lexing flags
+    import shlex
+
+    try:
+        return shlex.split(entry)
+    except (ValueError, AttributeError, TypeError) as err:
+        # AttributeError/TypeError: a dict or number from a third-party
+        # manifest; name the entry instead of an opaque shlex traceback
+        raise EsphomeError(f"Malformed build flag {entry!r} in {owner}: {err}") from err
+
+
+def lex_build_flags(entries: str | list[str], owner: str) -> list[str]:
+    """Shell-lex ``build.flags`` entries the way PlatformIO's ParseFlags
+    does; bare -I/-L/-l/-D tokens re-glue to their argument."""
+    # Lex per entry as ParseFlags does: a dangling -I must warn, not absorb
+    # the next entry's first token
+    return [
+        token
+        for entry in ensure_list(entries)
+        for token in join_flag_args(split_flag_entry(entry, owner), owner)
+    ]
+
+
+# Flags whose argument may follow as a separate token; ParseFlags glues them
+BARE_ARG_FLAGS = frozenset({"-I", "-L", "-l", "-D"})
+
+
+def join_flag_args(tokens: Iterable[str], owner: str) -> list[str]:
+    """Join a bare ``-I``/``-L``/``-l``/``-D`` with its following token, as
+    PlatformIO's ParseFlags does. A trailing or empty argument is warned and
+    dropped: the bare flag would make gcc eat the next flag."""
+    out: list[str] = []
+    it = iter(tokens)
+    for tok in it:
+        if tok in BARE_ARG_FLAGS:
+            arg = next(it, None)
+            if arg is None:
+                _LOGGER.warning("Ignoring trailing '%s' in %s build flags", tok, owner)
+                break
+            if not arg:
+                _LOGGER.warning(
+                    "Ignoring '%s' with empty argument in %s build flags", tok, owner
+                )
+                continue
+            tok += arg
+        out.append(tok)
+    return out
+
+
+def warn_properties_depends(name: str, data: object) -> None:
+    """Warn for ``depends=``-only manifests; the walk reads only the JSON
+    ``dependencies`` key, so they would otherwise drop silently."""
+    if isinstance(data, dict) and not data.get("dependencies") and data.get("depends"):
+        # INFO: common and unactionable for transitive libraries; a WARNING
+        # on every build would train users to ignore the stream
+        _LOGGER.info(
+            "Library %s declares dependencies via library.properties "
+            "depends=, which are not resolved automatically; add them with "
+            "add_library() if needed",
+            name,
+        )
+
+
+def dependency_is_usable(
+    dep: dict, platform: str | None, framework: str, requester: str
+) -> bool:
+    """Compatibility filter for a manifest dependency: platform mismatches
+    skip at debug, any other ``InvalidLibrary`` warns naming the requester."""
+    try:
+        check_library_data(dep, platform, framework)
+    except IncompatiblePlatform as e:
+        _LOGGER.debug("Skip dependency %s of %s: %s", dep.get("name"), requester, e)
+        return False
+    except InvalidLibrary as e:
+        _LOGGER.warning(
+            "Skipping dependency %s of %s: %s", dep.get("name"), requester, e
+        )
+        return False
+    return True
+
+
+def _valid_dependency_entry(entry: dict, manifest_name: str) -> bool:
+    """Whether a normalized entry carries a usable name (non-empty string)
+    and version (string, if present); invalid entries warn naming the
+    manifest."""
+    name = entry.get("name")
+    if (
+        isinstance(name, str)
+        and name
+        and ("version" not in entry or isinstance(entry["version"], str))
+    ):
+        return True
+    _LOGGER.warning(
+        "Ignoring unrecognized dependency entry %r of %s", entry, manifest_name
+    )
+    return False
+
+
+def normalize_dependencies(
+    dependencies: Any, manifest_name: str = "manifest"
+) -> list[dict]:
     """Normalize a library manifest's ``dependencies`` to a list of dicts.
 
-    PIO's library.json accepts both the list-of-dicts form and the shorthand
-    dict form (``{"owner/Name": "version_spec"}``); normalize the latter so
-    callers see a uniform list.
+    PIO's library.json accepts the list-of-dicts form, the shorthand dict
+    form (``{"owner/Name": "version_spec"}``), bare name strings inside the
+    list, and a plain (possibly comma-separated) string; normalize them all
+    so callers see a uniform list. ``manifest_name`` names the manifest in the
+    warning for entries that cannot be normalized.
     """
     if not dependencies:
         return []
+    if isinstance(dependencies, str):
+        # A plain string is one or more comma-separated names; iterating it
+        # as a list would shred it into one-character "libraries"
+        return [{"name": n.strip()} for n in dependencies.split(",") if n.strip()]
     if isinstance(dependencies, dict):
         normalized = []
         for raw_name, spec in dependencies.items():
-            if "/" in raw_name:
+            if isinstance(raw_name, str) and "/" in raw_name:
                 owner, pkgname = raw_name.split("/", 1)
             else:
                 owner, pkgname = None, raw_name
@@ -574,9 +732,31 @@ def _normalize_dependencies(dependencies: Any) -> list[dict]:
                 entry.update(spec)
             else:
                 entry["version"] = spec
-            normalized.append(entry)
+            if _valid_dependency_entry(entry, manifest_name):
+                normalized.append(entry)
         return normalized
-    return [d for d in dependencies if isinstance(d, dict)]
+    if not isinstance(dependencies, (list, tuple)):
+        _LOGGER.warning(
+            "Ignoring unrecognized dependencies %r of %s",
+            dependencies,
+            manifest_name,
+        )
+        return []
+    normalized = []
+    for entry in dependencies:
+        if isinstance(entry, dict):
+            if _valid_dependency_entry(entry, manifest_name):
+                normalized.append(entry)
+        elif isinstance(entry, str) and entry:
+            # PIO also accepts a bare list of names ("dependencies": ["Wire"])
+            normalized.append({"name": entry})
+        else:
+            _LOGGER.warning(
+                "Ignoring unrecognized dependency entry %r of %s",
+                entry,
+                manifest_name,
+            )
+    return normalized
 
 
 @dataclass
@@ -688,6 +868,102 @@ def _node_key(
     return name, "registry", (owner, pkgname)
 
 
+def lib_ignore_set() -> set[str]:
+    """The ``lib_ignore`` names from ``esphome->platformio_options``,
+    normalized to lowercase short names (the part after the ``/``)."""
+    return {
+        name.split("/")[-1].lower()
+        for name in CORE.platformio_options.get("lib_ignore", [])
+    }
+
+
+def is_lib_ignored(name: str | None, lib_ignore: set[str]) -> bool:
+    """Whether ``name`` matches the normalized ``lib_ignore`` set."""
+    return (
+        bool(lib_ignore)
+        and name is not None
+        and (name.split("/")[-1].lower() in lib_ignore)
+    )
+
+
+def _fetch_source(
+    component: ConvertedLibrary,
+    salt: str,
+    namespace: str,
+    tracker: Callable[[int], None],
+) -> None:
+    # Straight to URLSource: only it takes progress, and mutating the
+    # shared component from a worker is the authoritative loop's job
+    component.source.download(
+        component.get_sanitized_name(), salt=salt, namespace=namespace, progress=tracker
+    )
+
+
+def _prefetch_wave(
+    wave: list[tuple[str, ConvertedLibrary]], salt: str, namespace: str
+) -> None:
+    """Best-effort parallel download of a wave's registry archives.
+
+    The walk's own ``download()`` stays authoritative; duplicate URLs
+    prefetch once so two threads never share a cache directory. Archives
+    whose size the registry did not report are left to the sequential
+    loop, whose per-file bars don't interleave. A node a sibling in the
+    same wave supersedes has its archive fetched in vain (knowing better
+    would need the manifests being downloaded).
+    """
+    try:
+        components: list[ConvertedLibrary] = []
+        seen: set[str] = set()
+        for _key, component in wave:
+            source = component.source
+            if not isinstance(source, URLSource) or not source.size:
+                continue
+            if source.url in seen:
+                continue
+            seen.add(source.url)
+            try:
+                cached = source.is_cached(
+                    component.get_sanitized_name(), salt=salt, namespace=namespace
+                )
+            except Exception as err:  # noqa: BLE001  # pylint: disable=broad-exception-caught
+                # Best-effort: a failing probe prefetches (and re-downloads)
+                _LOGGER.debug("Cache probe for %s failed: %s", component.name, err)
+                cached = False
+            if cached:
+                # A warm build must stay silent
+                continue
+            components.append(component)
+        if not components:
+            return
+        # Single-item waves (a dependency chain discovers one archive per
+        # wave) go through the same runner: one download method, one bar
+        _LOGGER.info(
+            "Downloading %d library archive(s): %s",
+            len(components),
+            ", ".join(c.name for c in components),
+        )
+        failures = run_batch_downloads(
+            "Downloading libraries",
+            [
+                (c.name, c.source.size, partial(_fetch_source, c, salt, namespace))
+                for c in components
+            ],
+        )
+        for name, err in failures:
+            # The sequential call below retries and raises the real error
+            _LOGGER.warning(
+                "Prefetch of %s failed (retrying sequentially): %s",
+                name,
+                failure_reason(err),
+            )
+            _LOGGER.debug("Prefetch failure detail", exc_info=err)
+    except Exception as err:  # noqa: BLE001  # pylint: disable=broad-exception-caught
+        # Same policy as the ESP-IDF twin: the prefetch must never become a
+        # new way for the build to fail
+        _LOGGER.warning("Library prefetch failed: %s", err)
+        _LOGGER.debug("Prefetch failure detail", exc_info=True)
+
+
 def convert_libraries(
     libraries: list[Library], backend: LibraryBackend
 ) -> list[ConvertedLibrary]:
@@ -713,10 +989,7 @@ def convert_libraries(
     """
     nodes: dict[str, _LibNode] = {}
 
-    lib_ignore = {
-        name.split("/")[-1].lower()
-        for name in CORE.platformio_options.get("lib_ignore", [])
-    }
+    lib_ignore = lib_ignore_set()
 
     # The generated build files inside the shared cache bake in the dependency
     # wiring, which lib_ignore changes; salt the cache path so configs with
@@ -728,11 +1001,6 @@ def convert_libraries(
         else ""
     )
 
-    def is_ignored(name: str | None) -> bool:
-        if not lib_ignore or name is None:
-            return False
-        return name.split("/")[-1].lower() in lib_ignore
-
     def add_spec(name: str | None, version: str | None, repository: str | None) -> str:
         key, kind, locator = _node_key(name, version, repository)
         node = nodes.get(key) or _LibNode(key=key, is_git=kind == "git")
@@ -781,7 +1049,7 @@ def convert_libraries(
     top_level = [
         add_spec(library.name, library.version, library.repository)
         for library in libraries
-        if not is_ignored(library.name)
+        if not is_lib_ignored(library.name, lib_ignore)
     ]
 
     # Collect + resolve to a fixpoint: a node is (re)resolved whenever its
@@ -792,105 +1060,130 @@ def convert_libraries(
     top_level_keys = set(top_level)
     worklist = deque(dict.fromkeys(top_level))
     while worklist:
-        key = worklist.popleft()
-        node = nodes[key]
+        # Drain the frontier sequentially (spec resolution mutates shared
+        # state), then prefetch the wave in parallel
+        wave: list[tuple[str, ConvertedLibrary]] = []
+        while worklist:
+            key = worklist.popleft()
+            node = nodes[key]
 
-        # A node is queued once per referring edge; skip the (uncached) registry
-        # lookup + download + dependency walk unless its requirement set grew
-        # since the last resolve. Requirements only ever grow, so this still
-        # converges the fixpoint and terminates dependency cycles.
-        requirements = frozenset(node.requirements)
-        if resolved_requirements.get(key) == requirements:
-            continue
-        resolved_requirements[key] = requirements
+            # Re-resolve only when the requirement set grew; requirements
+            # only ever grow, so the fixpoint converges and cycles terminate
+            requirements = frozenset(node.requirements)
+            if resolved_requirements.get(key) == requirements:
+                continue
+            resolved_requirements[key] = requirements
 
-        if node.is_git:
-            component = ConvertedLibrary(key, "*", GitSource(node.url, node.ref))
-        elif node.is_local:
-            component = ConvertedLibrary(key, "*", LocalSource(node.local_path))
-        else:
-            owner, name, version, url = _resolve_registry_version(
-                node.owner, node.pkgname, node.requirements
-            )
-            component = ConvertedLibrary(
-                _owner_pkgname_to_name(owner, name), version, URLSource(url)
-            )
-        component.download(salt=salt, namespace=backend.cache_key)
+            if node.is_git:
+                component = ConvertedLibrary(key, "*", GitSource(node.url, node.ref))
+            elif node.is_local:
+                component = ConvertedLibrary(key, "*", LocalSource(node.local_path))
+            else:
+                owner, name, version, url, size = _resolve_registry_version(
+                    node.owner, node.pkgname, node.requirements
+                )
+                component = ConvertedLibrary(
+                    _owner_pkgname_to_name(owner, name), version, URLSource(url, size)
+                )
+            wave.append((key, component))
+        _prefetch_wave(wave, salt, backend.cache_key)
+        for key, component in wave:
+            node = nodes[key]
+            if frozenset(node.requirements) != resolved_requirements[key]:
+                # Requirements grew mid-wave: skip parsing a manifest the
+                # next wave will re-resolve and replace
+                worklist.append(key)
+                continue
+            component.download(salt=salt, namespace=backend.cache_key)
 
-        source_dir = component.source_dir
-        library_json_path = source_dir / "library.json"
-        library_properties_path = source_dir / "library.properties"
-        has_json = library_json_path.is_file()
-        has_properties = library_properties_path.is_file()
-        if not has_json and not has_properties and not node.is_local:
-            # The shared cache can hold a broken copy (e.g. a clone or an
-            # extraction interrupted by a killed process). Force one
-            # re-download so a bad cache entry self-heals instead of failing
-            # every build until the user runs a full clean. A local source is
-            # read in place, so there is nothing to re-download.
-            _LOGGER.warning(
-                "Library %s at %s is missing library.json and library.properties; "
-                "re-downloading",
-                key,
-                source_dir,
-            )
-            component.download(force=True, salt=salt, namespace=backend.cache_key)
+            source_dir = component.source_dir
+            library_json_path = source_dir / "library.json"
+            library_properties_path = source_dir / "library.properties"
             has_json = library_json_path.is_file()
             has_properties = library_properties_path.is_file()
-        if has_json:
-            component.data = _parse_library_json(library_json_path)
-        elif has_properties:
-            component.data = _parse_library_properties(library_properties_path)
-        else:
-            # For a local library a missing manifest is user input, so raise
-            # EsphomeError (clean CLI message) like the missing-directory case;
-            # for registry/git a missing manifest means a corrupt cache, which
-            # is not user error, so keep RuntimeError.
-            error_cls = EsphomeError if node.is_local else RuntimeError
-            raise error_cls(
-                f"Invalid PIO library {key}: missing library.json and "
-                f"library.properties in {source_dir}"
-            )
+            if not has_json and not has_properties and not node.is_local:
+                # An interrupted clone/extraction self-heals with one forced
+                # re-download; a local source has nothing to re-download
+                _LOGGER.warning(
+                    "Library %s at %s is missing library.json and library.properties; "
+                    "re-downloading",
+                    key,
+                    source_dir,
+                )
+                component.download(force=True, salt=salt, namespace=backend.cache_key)
+                has_json = library_json_path.is_file()
+                has_properties = library_properties_path.is_file()
+            if has_json:
+                component.data = parse_library_json(library_json_path)
+            elif has_properties:
+                component.data = parse_library_properties(library_properties_path)
+            else:
+                # Local sources are user input (EsphomeError); a registry/git
+                # miss means a corrupt cache (RuntimeError)
+                error_cls = EsphomeError if node.is_local else RuntimeError
+                raise error_cls(
+                    f"Invalid PIO library {key}: missing library.json and "
+                    f"library.properties in {source_dir}"
+                )
 
-        try:
-            check_library_data(component.data, backend.platform, backend.framework)
-        except InvalidLibrary as e:
-            # Skip an incompatible transitive dependency, but fail fast if a
-            # top-level library the build explicitly requested is incompatible.
-            if key in top_level_keys:
-                raise RuntimeError(
-                    f"Requested library {key} is not compatible with "
-                    f"{backend.framework}: {e}"
-                ) from e
-            _LOGGER.debug("Skip incompatible dependency %s: %s", key, str(e))
-            continue
-        components[key] = component
+            if not isinstance(component.data, dict) or not isinstance(
+                component.data.get("build", {}), dict
+            ):
+                # A bare json.load imposes no shape; every backend dereferences
+                # data/build, so validate once here and name the library
+                raise EsphomeError(f"Library {key} has a malformed manifest")
+            warn_properties_depends(component.name, component.data)
 
-        # Requirements changed (we got past the short-circuit above), so
-        # (re)walk this component's dependencies.
-        node.edges = set()
-        for dependency in _normalize_dependencies(component.data.get("dependencies")):
-            if "name" not in dependency or "version" not in dependency:
-                continue
             try:
-                check_library_data(dependency, backend.platform, backend.framework)
+                check_library_data(component.data, backend.platform, backend.framework)
             except InvalidLibrary as e:
-                _LOGGER.debug("Skip dependency %s: %s", dependency.get("name"), str(e))
+                # An explicitly requested library fails fast; the routine
+                # cross-platform skip stays at debug, other causes warn
+                if key in top_level_keys:
+                    raise RuntimeError(
+                        f"Requested library {key} is not compatible with "
+                        f"{backend.framework}: {e}"
+                    ) from e
+                if isinstance(e, IncompatiblePlatform):
+                    _LOGGER.debug("Skip incompatible dependency %s: %s", key, str(e))
+                else:
+                    _LOGGER.warning("Skipping dependency %s: %s", key, str(e))
                 continue
-            dep_name = _owner_pkgname_to_name(
-                dependency.get("owner"), dependency.get("name")
-            )
-            if is_ignored(dep_name):
-                _LOGGER.debug("Skip ignored dependency %s", dep_name)
-                continue
-            # The version field may actually be a URL (git/archive dependency).
-            dep_version = dependency["version"]
-            dep_url = _url_or_none(dep_version)
-            if dep_url is not None:
-                dep_version = None
-            dep_key = add_spec(dep_name, dep_version, dep_url)
-            node.edges.add(dep_key)
-            worklist.append(dep_key)
+            components[key] = component
+
+            # Requirements changed (we got past the short-circuit above), so
+            # (re)walk this component's dependencies.
+            node.edges = set()
+            for dependency in normalize_dependencies(
+                component.data.get("dependencies"), component.name
+            ):
+                if "version" not in dependency:
+                    # Cannot resolve from the registry; common for bundled
+                    # names (Wire, SPI) -- unactionable noise above debug
+                    _LOGGER.debug(
+                        "Skip version-less dependency %r of %s",
+                        dependency.get("name"),
+                        component.name,
+                    )
+                    continue
+                if not dependency_is_usable(
+                    dependency, backend.platform, backend.framework, component.name
+                ):
+                    continue
+                dep_name = _owner_pkgname_to_name(
+                    dependency.get("owner"), dependency.get("name")
+                )
+                if is_lib_ignored(dep_name, lib_ignore):
+                    _LOGGER.debug("Skip ignored dependency %s", dep_name)
+                    continue
+                # The version field may actually be a URL (git/archive dependency).
+                dep_version = dependency["version"]
+                dep_url = _url_or_none(dep_version)
+                if dep_url is not None:
+                    dep_version = None
+                dep_key = add_spec(dep_name, dep_version, dep_url)
+                node.edges.add(dep_key)
+                worklist.append(dep_key)
 
     # A git or local source wins over the same component requested from the
     # registry. That's intentional, but warn so the dropped registry spec isn't

esphome/platformio/toolchain.py

@@ -254,6 +254,9 @@ def _ccache_runs(ccache: str) -> bool:
             stdout=subprocess.DEVNULL,
             stderr=subprocess.DEVNULL,
             timeout=15,
+            # Repo-wide convention (posix_spawn fast path); see the
+            # close_fds=False call sites across esphome/ and script/helpers.py
+            close_fds=False,
         )
     except (OSError, subprocess.SubprocessError):
         _LOGGER.warning(

script/determine-jobs.py

@@ -525,13 +525,21 @@ def _esp32_platformio_path_or_file_trigger(files: list[str]) -> bool:
     return False
 
 
-# ESP-IDF infra: changes under esphome/espidf/ or to the IDF build generator
-# affect every esp32 IDF build (now the default toolchain) but aren't
+# Native-build infra: changes under esphome/espidf/, the shared
+# esphome/build_helpers/ package, or the modules the native ESP-IDF build
+# imports affect every esp32 IDF build (now the default toolchain) but aren't
 # components, so the component matrix wouldn't otherwise force any esp32
 # compile. When they change we fold the `esp32` component into the matrix so
 # the default native-IDF build path is still compiled on an infra-only PR.
-ESP_IDF_INFRA_TRIGGER_PATH_PREFIXES = ("esphome/espidf/",)
-ESP_IDF_INFRA_TRIGGER_FILES = frozenset({"esphome/build_gen/espidf.py"})
+ESP_IDF_INFRA_TRIGGER_PATH_PREFIXES = ("esphome/espidf/", "esphome/build_helpers/")
+ESP_IDF_INFRA_TRIGGER_FILES = frozenset(
+    {
+        "esphome/build_gen/espidf.py",
+        "esphome/framework_helpers.py",
+        "esphome/platformio/library.py",
+        "esphome/platformio/extra_script.py",
+    }
+)
 
 
 def _esp_idf_infra_changed(files: list[str]) -> bool:

tests/script/test_determine_jobs.py

@@ -1120,7 +1120,14 @@ def test_should_run_esp32_platformio_with_branch() -> None:
         (["esphome/espidf/runner.py"], True),
         (["esphome/espidf/framework.py"], True),
         (["esphome/build_gen/espidf.py"], True),
-        # PlatformIO build gen and esp32 component are NOT IDF-infra triggers
+        # Shared native-build modules the IDF build imports -> trigger
+        (["esphome/build_helpers/idedata.py"], True),
+        (["esphome/platformio/library.py"], True),
+        (["esphome/framework_helpers.py"], True),
+        (["esphome/platformio/extra_script.py"], True),
+        # PlatformIO build gen, its toolchain, and the esp32 component are
+        # NOT IDF-infra triggers
+        (["esphome/platformio/toolchain.py"], False),
         (["esphome/build_gen/platformio.py"], False),
         (["esphome/components/esp32/__init__.py"], False),
         (["README.md"], False),
@@ -1132,6 +1139,16 @@ def test_esp_idf_infra_changed(changed_files: list[str], expected: bool) -> None
     assert determine_jobs._esp_idf_infra_changed(changed_files) is expected
 
 
+def test_esp_idf_infra_trigger_paths_exist() -> None:
+    """A renamed or moved trigger module must fail here, not silently stop
+    forcing the esp32 IDF compile."""
+    repo_root = Path(__file__).resolve().parents[2]
+    for file in determine_jobs.ESP_IDF_INFRA_TRIGGER_FILES:
+        assert (repo_root / file).is_file(), f"trigger file {file} moved or renamed"
+    for prefix in determine_jobs.ESP_IDF_INFRA_TRIGGER_PATH_PREFIXES:
+        assert (repo_root / prefix).is_dir(), f"trigger dir {prefix} moved or renamed"
+
+
 @pytest.mark.parametrize(
     ("changed_files", "expected_result"),
     [

tests/unit_tests/analyze_memory/test_build_artifacts.py

@@ -9,7 +9,7 @@ from esphome.analyze_memory.toolchain import (
     find_idedata_path,
     idedata_candidates,
 )
-from esphome.espidf.idedata import _cc_path_from_cxx
+from esphome.build_helpers.idedata import _cc_path_from_cxx
 from esphome.platformio.toolchain import IDEData
 
 

tests/unit_tests/build_helpers/test_idedata.py

@@ -0,0 +1,678 @@
+"""Tests for esphome.build_helpers.idedata (compile_commands.json -> idedata)."""
+
+# pylint: disable=protected-access
+
+import json
+import logging
+import os
+from pathlib import Path
+from unittest.mock import MagicMock, patch
+
+import pytest
+
+from esphome.build_helpers import idedata
+from esphome.core import EsphomeError
+
+# An absolute, forward-slash (shlex-safe) path prefix valid on the host OS, so
+# tests exercise the same is-absolute / normalize behavior as a real compile DB
+# (a drive-qualified path on Windows, a leading slash elsewhere).
+ABS = "C:/" if os.name == "nt" else "/"
+
+
+def _entry(directory: str, file: str, command: str) -> dict:
+    return {"directory": directory, "file": file, "command": command}
+
+
+def test_parse_entry_extracts_fields() -> None:
+    """cxx_path, defines, includes and remaining flags are split apart."""
+    entry = _entry(
+        f"{ABS}build",
+        f"{ABS}build/src/esphome/core/application.cpp",
+        f"/tools/xtensa-esp32-elf-g++ -DUSE_ESP32 -DESPHOME_LOG_LEVEL=5 "
+        f"-I{ABS}inc/a -isystem {ABS}sys/b -std=gnu++20 -c app.cpp -o app.cpp.o",
+    )
+
+    cxx_path, defines, includes, cxx_flags = idedata.parse_entry(entry)
+
+    assert cxx_path == "/tools/xtensa-esp32-elf-g++"
+    assert "USE_ESP32" in defines
+    assert "ESPHOME_LOG_LEVEL=5" in defines
+    assert f"{ABS}inc/a" in includes
+    assert f"{ABS}sys/b" in includes
+    assert "-std=gnu++20" in cxx_flags
+    # input/output files and their flags are not treated as flags
+    assert "-c" not in cxx_flags
+    assert "-o" not in cxx_flags
+    assert "app.cpp" not in cxx_flags
+    assert "app.cpp.o" not in cxx_flags
+
+
+def test_parse_entry_space_separated_args() -> None:
+    """``-D X`` / ``-I path`` (separate arg) and ``-isystem<path>`` (joined)."""
+    entry = _entry(
+        f"{ABS}build",
+        f"{ABS}build/src/esphome/x.cpp",
+        f"g++ -D FOO=1 -I {ABS}inc/sep -isystem{ABS}sys/joined -c x.cpp",
+    )
+
+    _, defines, includes, _ = idedata.parse_entry(entry)
+
+    assert "FOO=1" in defines
+    assert f"{ABS}inc/sep" in includes
+    assert f"{ABS}sys/joined" in includes
+
+
+def test_parse_entry_resolves_relative_includes() -> None:
+    """Relative includes are resolved against the entry's ``directory``."""
+    directory = f"{ABS}build/proj"
+    entry = _entry(
+        directory,
+        f"{directory}/src/esphome/x.cpp",
+        "g++ -Iconfig -I../shared -isystem rel/sys -c x.cpp",
+    )
+
+    _, _, includes, _ = idedata.parse_entry(entry)
+
+    def resolved(rel: str) -> str:
+        # parse_entry emits forward slashes for consistency (normpath would
+        # yield backslashes on Windows).
+        return os.path.normpath(Path(directory) / rel).replace("\\", "/")
+
+    assert resolved("config") in includes
+    assert resolved("../shared") in includes  # ../ normalized away
+    assert resolved("rel/sys") in includes
+    # nothing is left relative
+    assert all(Path(inc).is_absolute() for inc in includes)
+
+
+def test_parse_entry_skips_dependency_flags() -> None:
+    """Dependency-generation flags (and their args) are dropped."""
+    entry = _entry(
+        "/build",
+        "/build/src/esphome/x.cpp",
+        "g++ -MD -MT x.cpp.o -MF x.cpp.o.d -c x.cpp -o x.cpp.o",
+    )
+
+    _, _, _, cxx_flags = idedata.parse_entry(entry)
+
+    for tok in ("-MD", "-MT", "x.cpp.o", "-MF", "x.cpp.o.d", "-c", "-o", "x.cpp"):
+        assert tok not in cxx_flags
+
+
+def test_expand_response_files(tmp_path: Path) -> None:
+    """``@file`` arguments are inlined relative to the directory."""
+    rsp = tmp_path / "flags.rsp"
+    rsp.write_text("-DFROM_RSP -I/rsp/inc")
+
+    tokens = idedata._expand_response_files(
+        ["g++", f"@{rsp.name}", "-c", "x.cpp"], tmp_path
+    )
+
+    assert "-DFROM_RSP" in tokens
+    assert "-I/rsp/inc" in tokens
+    assert not any(t.startswith("@") for t in tokens)
+
+
+def test_expand_response_files_keeps_literal_when_missing(tmp_path: Path) -> None:
+    """An unreadable ``@file`` token is kept verbatim rather than dropped."""
+    tokens = idedata._expand_response_files(["g++", "@nope.rsp"], tmp_path)
+    assert "@nope.rsp" in tokens
+
+
+def test_pick_entry_prefers_esphome_tu() -> None:
+    """A ``/src/esphome/`` C++ TU is picked over other compile entries."""
+    entries = [
+        _entry("/b", "/b/managed_components/foo/foo.c", "gcc -c foo.c"),
+        _entry("/b", "/b/src/esphome/core/app.cpp", "g++ -c app.cpp"),
+    ]
+    assert idedata._pick_entry(entries)["file"].endswith("app.cpp")
+
+
+def test_pick_entry_falls_back_to_any_cxx_tu() -> None:
+    """With no ``/src/esphome/`` TU present, the first C++ entry is the fallback."""
+    entries = [
+        _entry("/b", "/b/managed_components/foo/foo.c", "gcc -c foo.c"),
+        _entry("/b", "/b/components/x/x.cpp", "g++ -c x.cpp"),
+    ]
+    assert idedata._pick_entry(entries)["file"].endswith("x.cpp")
+
+
+def test_is_esphome_src_handles_backslash_paths() -> None:
+    r"""The src marker must match Windows ``\src\esphome\`` paths too.
+
+    compile_commands ``file`` entries use the OS-native separator; if the
+    marker only matched forward slashes no source would match on Windows and
+    the build-include union would be silently empty.
+    """
+    assert idedata._is_esphome_src(r"C:\b\src\esphome\core\app.cpp")
+    assert idedata._is_esphome_src("/b/src/esphome/core/app.cpp")
+    # non-esphome and non-C++ still rejected regardless of separator
+    assert not idedata._is_esphome_src(r"C:\b\managed_components\x\x.cpp")
+    assert not idedata._is_esphome_src(r"C:\b\src\esphome\core\app.h")
+
+
+@pytest.mark.parametrize(
+    ("command", "launcher"),
+    [
+        ("", None),
+        # A command that is only the launcher strips to nothing
+        ("/usr/bin/ccache", "/usr/bin/ccache"),
+    ],
+)
+def test_parse_entry_empty_command_raises(command: str, launcher: str | None) -> None:
+    """A blank (or launcher-only) command fails with a named ValueError,
+    not an IndexError."""
+    entry = {"directory": "/b", "file": "/b/src/x.cpp", "command": command}
+    with pytest.raises(ValueError, match="empty compile command"):
+        idedata.parse_entry(entry, launcher)
+
+
+def test_idedata_from_build_empty_includes_raises(tmp_path: Path) -> None:
+    """A compile DB with no ESPHome TU is never usable idedata and must
+    not be cached (call sites downgrade the raise to a build warning)."""
+    compile_commands = tmp_path / "compile_commands.json"
+    compile_commands.write_text(
+        json.dumps(
+            [
+                _entry(
+                    f"{ABS}build",
+                    f"{ABS}build/other/lib.cpp",
+                    "/tools/g++ -c other/lib.cpp -o lib.o",
+                )
+            ]
+        )
+    )
+    with (
+        patch.object(idedata, "get_toolchain_includes", return_value=[]),
+        pytest.raises(EsphomeError, match="No ESPHome translation unit found"),
+    ):
+        idedata.idedata_from_build(compile_commands)
+
+
+def test_idedata_from_build_rsp_commands_never_dedupe(tmp_path: Path) -> None:
+    """Per-object response files strip to one shape while holding different
+    include sets; @-commands must tokenize per TU."""
+    entries = []
+    for name in ("a", "b"):
+        rsp = tmp_path / f"{name}.cpp.o.rsp"
+        rsp.write_text(f"-I{ABS}inc/{name}")
+        file = f"{ABS}build/src/esphome/core/{name}.cpp"
+        entries.append(
+            {
+                "directory": str(tmp_path),
+                "file": file,
+                "command": f"/tools/g++ @{rsp.name} -c {file} -o {name}.o",
+                "output": f"{name}.o",
+            }
+        )
+    compile_commands = tmp_path / "compile_commands.json"
+    compile_commands.write_text(json.dumps(entries))
+    with patch.object(idedata, "get_toolchain_includes", return_value=[]):
+        data = idedata.idedata_from_build(compile_commands)
+    joined = " ".join(data["includes"]["build"])
+    assert "inc/a" in joined and "inc/b" in joined
+
+
+def test_idedata_from_build_dedupes_identical_command_shapes(
+    tmp_path: Path,
+) -> None:
+    """Translation units sharing one ninja rule (same command modulo
+    file/output) carry
+    identical includes, so only one per shape is tokenized; a differing
+    shape still contributes its includes."""
+
+    def _tu(name: str, inc: str) -> dict:
+        # ninja's compdb embeds the file and output strings verbatim
+        file = f"{ABS}build/src/esphome/core/{name}.cpp"
+        return _entry(
+            f"{ABS}build", file, f"/tools/g++ -I{ABS}inc/{inc} -c {file} -o {name}.o"
+        ) | {"output": f"{name}.o"}
+
+    entries = [_tu(name, "shared") for name in ("application", "component", "helpers")]
+    entries.append(_tu("extra", "extra"))
+    compile_commands = tmp_path / "compile_commands.json"
+    compile_commands.write_text(json.dumps(entries))
+    with (
+        patch.object(idedata, "get_toolchain_includes", return_value=[]),
+        patch.object(idedata, "parse_entry", wraps=idedata.parse_entry) as spy,
+    ):
+        data = idedata.idedata_from_build(compile_commands)
+    includes = set(data["includes"]["build"])
+    assert f"{ABS}inc/shared".replace("\\", "/") in {
+        i.replace("\\", "/") for i in includes
+    }
+    assert any("inc/extra" in i for i in includes)
+    # Representative + one distinct shape; the two same-shape duplicates
+    # are never tokenized
+    assert spy.call_count == 2
+
+
+def test_idedata_from_build(tmp_path: Path) -> None:
+    """Full transform: representative entry + include union + toolchain dirs."""
+    compile_commands = tmp_path / "compile_commands.json"
+    entries = [
+        _entry(
+            f"{ABS}b",
+            f"{ABS}b/src/esphome/core/app.cpp",
+            f"g++ -DUSE_ESP32 -I{ABS}inc/core -std=gnu++20 -c app.cpp -o app.cpp.o",
+        ),
+        _entry(
+            f"{ABS}b",
+            f"{ABS}b/src/esphome/sensor/s.cpp",
+            f"g++ -DUSE_ESP32 -I{ABS}inc/sensor -c s.cpp -o s.cpp.o",
+        ),
+        # non-esphome TU: its includes must not leak into the union
+        _entry(
+            f"{ABS}b",
+            f"{ABS}b/managed_components/x/x.c",
+            f"gcc -I{ABS}inc/managed -c x.c",
+        ),
+    ]
+    compile_commands.write_text(json.dumps(entries))
+
+    fake_proc = MagicMock(
+        returncode=0,
+        stderr=(
+            "ignored\n"
+            "#include <...> search starts here:\n"
+            " /tc/inc/c++\n"
+            " /tc/inc\n"
+            "End of search list.\n"
+            "more ignored\n"
+        ),
+    )
+    with patch.object(idedata.subprocess, "run", return_value=fake_proc):
+        data = idedata.idedata_from_build(compile_commands)
+
+    assert data["cxx_path"] == "g++"
+    assert "USE_ESP32" in data["defines"]
+    assert "-std=gnu++20" in data["cxx_flags"]
+    # include dirs unioned across all esphome TUs
+    assert f"{ABS}inc/core" in data["includes"]["build"]
+    assert f"{ABS}inc/sensor" in data["includes"]["build"]
+    # the non-esphome TU is excluded from the union
+    assert f"{ABS}inc/managed" not in data["includes"]["build"]
+    # toolchain search dirs parsed from the compiler's -v output
+    assert data["includes"]["toolchain"] == ["/tc/inc/c++", "/tc/inc"]
+
+
+def test_get_toolchain_includes_raises_on_probe_failure() -> None:
+    """A failed compiler probe is a hard error, not a silent empty list."""
+    fake_proc = MagicMock(returncode=1, stderr="xtensa-esp32-elf-g++: not found")
+    with (
+        patch.object(idedata.subprocess, "run", return_value=fake_proc),
+        pytest.raises(RuntimeError, match="builtin include dirs"),
+    ):
+        idedata.get_toolchain_includes("/bad/compiler")
+
+
+def test_get_toolchain_includes_raises_when_no_dirs_found() -> None:
+    """Markers present but no dirs (anomalous output) also raises."""
+    fake_proc = MagicMock(
+        returncode=0,
+        stderr="#include <...> search starts here:\nEnd of search list.\n",
+    )
+    with (
+        patch.object(idedata.subprocess, "run", return_value=fake_proc),
+        pytest.raises(RuntimeError, match="builtin include dirs"),
+    ):
+        idedata.get_toolchain_includes("/some/compiler")
+
+
+# ESP-IDF's compile_commands.json on Windows mixes literal backslash path
+# separators in the compiler path with shell ``\"`` quote-escaping in defines,
+# which only the real Windows argv parser handles. These exercise that path.
+@pytest.mark.skipif(os.name != "nt", reason="Windows argv tokenization")
+def test_split_command_preserves_paths_and_unescapes_quotes() -> None:
+    r"""Backslash paths survive while ``\"`` define-quoting is unescaped."""
+    command = r"C:\esp\bin\riscv32-esp-elf-g++.exe -DVER=\"1.2.3\" -IC:/inc/a -c x.cpp"
+
+    tokens = idedata._split_command(command)
+
+    assert tokens[0] == r"C:\esp\bin\riscv32-esp-elf-g++.exe"
+    assert '-DVER="1.2.3"' in tokens
+    assert "-IC:/inc/a" in tokens
+
+
+@pytest.mark.skipif(os.name != "nt", reason="Windows argv tokenization")
+def test_split_command_empty_returns_empty() -> None:
+    """An empty or blank command tokenizes to ``[]`` (e.g. an empty response file).
+
+    Guards against ``CommandLineToArgvW("")`` returning the current process name
+    instead of an empty list.
+    """
+    assert idedata._split_command("") == []
+    assert idedata._split_command("   ") == []
+
+
+@pytest.mark.skipif(os.name != "nt", reason="Windows argv tokenization")
+def test_parse_entry_normalizes_windows_cxx_path() -> None:
+    """A backslash compiler path is emitted forward-slashed; define unescaped."""
+    entry = _entry(
+        r"C:\b",
+        r"C:\b\src\esphome\x.cpp",
+        r"C:\esp\bin\g++.exe -DVER=\"1.2.3\" -IC:/inc/a -c x.cpp",
+    )
+
+    cxx_path, defines, includes, _ = idedata.parse_entry(entry)
+
+    assert cxx_path == "C:/esp/bin/g++.exe"
+    assert "\\" not in cxx_path
+    assert 'VER="1.2.3"' in defines
+    assert "C:/inc/a" in includes
+
+
+def test_parse_entry_strips_launcher_prefix() -> None:
+    """A launcher-wrapped compile names the compiler second; the exact
+    configured launcher is stripped, not anything ccache-shaped."""
+    entry = _entry(
+        f"{ABS}build",
+        f"{ABS}build/src/esphome/core/application.cpp",
+        "/opt/homebrew/bin/ccache /tools/xtensa-lx106-elf-g++ -DUSE_ESP8266 "
+        "-c app.cpp -o app.cpp.o",
+    )
+    cxx_path, defines, _, _ = idedata.parse_entry(
+        entry, launcher="/opt/homebrew/bin/ccache"
+    )
+    assert cxx_path == "/tools/xtensa-lx106-elf-g++"
+    assert defines == ["USE_ESP8266"]
+
+
+def test_parse_entry_recovers_from_unconfigured_launcher(
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """A stale compile DB built with a launcher this run no longer configures
+    still yields the real compiler (the next token), not the launcher."""
+    entry = _entry(
+        f"{ABS}build",
+        f"{ABS}build/src/esphome/core/application.cpp",
+        "/opt/homebrew/bin/ccache /tools/xtensa-lx106-elf-g++ -c a.cpp -o a.o",
+    )
+    caplog.set_level(logging.DEBUG)
+    cxx_path, _, _, _ = idedata.parse_entry(entry)
+    assert cxx_path == "/tools/xtensa-lx106-elf-g++"
+    assert "Stripping unconfigured launcher" in caplog.text
+
+
+def test_parse_entry_rejects_launcher_without_program() -> None:
+    """A launcher followed only by flags is rejected in the parser itself,
+    so no caller can record ccache as the compiler."""
+    entry = _entry(
+        f"{ABS}build",
+        f"{ABS}build/src/esphome/core/application.cpp",
+        "/opt/homebrew/bin/ccache -c a.cpp -o a.o",
+    )
+    with pytest.raises(EsphomeError, match="compile database is unusable"):
+        idedata.parse_entry(entry)
+
+
+def _write_compile_commands(tmp_path: Path) -> Path:
+    compile_commands = tmp_path / "compile_commands.json"
+    compile_commands.write_text(
+        json.dumps(
+            [
+                _entry(
+                    f"{ABS}build",
+                    f"{ABS}build/src/esphome/core/application.cpp",
+                    "/tools/g++ -DUSE_ESP8266 -c app.cpp -o app.cpp.o",
+                )
+            ]
+        )
+    )
+    return compile_commands
+
+
+def test_load_or_build_idedata_missing_compile_db(tmp_path: Path) -> None:
+    assert (
+        idedata.load_or_build_idedata(
+            tmp_path / "compile_commands.json", tmp_path / "f.elf", tmp_path / "c.json"
+        )
+        is None
+    )
+
+
+def test_load_or_build_idedata_builds_and_caches(tmp_path: Path) -> None:
+    compile_commands = _write_compile_commands(tmp_path)
+    cache = tmp_path / "cache" / "test.json"
+    with patch.object(
+        idedata, "get_toolchain_includes", return_value=["/toolchain/include"]
+    ):
+        data = idedata.load_or_build_idedata(
+            compile_commands, tmp_path / "firmware.elf", cache
+        )
+    assert data["cc_path"] == "/tools/gcc"
+    assert data["prog_path"] == str(tmp_path / "firmware.elf")
+    assert json.loads(cache.read_text()) == data
+
+    # A fresh cache is served without re-parsing the compile DB
+    os.utime(cache, (compile_commands.stat().st_mtime + 10,) * 2)
+    with patch.object(idedata, "idedata_from_build") as mock_build:
+        assert (
+            idedata.load_or_build_idedata(
+                compile_commands, tmp_path / "firmware.elf", cache
+            )
+            == data
+        )
+    mock_build.assert_not_called()
+
+
+def test_load_or_build_idedata_rebuilds_bad_cache(tmp_path: Path) -> None:
+    compile_commands = _write_compile_commands(tmp_path)
+    cache = tmp_path / "cache.json"
+    for bad in ("not json", json.dumps({"no_cc_path": True})):
+        cache.write_text(bad)
+        os.utime(cache, (compile_commands.stat().st_mtime + 10,) * 2)
+        with patch.object(idedata, "get_toolchain_includes", return_value=[]):
+            data = idedata.load_or_build_idedata(
+                compile_commands, tmp_path / "f.elf", cache
+            )
+        assert "cc_path" in data
+
+
+def test_load_or_build_idedata_rebuilds_when_compile_db_newer(tmp_path: Path) -> None:
+    """A compile DB newer than the cache forces regeneration."""
+    compile_commands = _write_compile_commands(tmp_path)
+    cache = tmp_path / "cache.json"
+    cache.write_text(json.dumps({"cc_path": "stale"}))
+    os.utime(compile_commands, (cache.stat().st_mtime + 10,) * 2)
+    with patch.object(idedata, "get_toolchain_includes", return_value=[]):
+        data = idedata.load_or_build_idedata(
+            compile_commands, tmp_path / "f.elf", cache
+        )
+    assert data["cc_path"] != "stale"
+
+
+def test_load_or_build_idedata_rebuilds_non_dict_cache(tmp_path: Path) -> None:
+    """Valid JSON that is not an object is regenerated, never handed out.
+
+    A bare string would otherwise pass the cc_path check by substring.
+    """
+    compile_commands = _write_compile_commands(tmp_path)
+    cache = tmp_path / "cache.json"
+    for bad in ('"cc_path is a string"', "[]", "42"):
+        cache.write_text(bad)
+        os.utime(cache, (compile_commands.stat().st_mtime + 10,) * 2)
+        with patch.object(idedata, "get_toolchain_includes", return_value=[]):
+            data = idedata.load_or_build_idedata(
+                compile_commands, tmp_path / "f.elf", cache
+            )
+        assert isinstance(data, dict)
+        assert "cc_path" in data
+
+
+def test_is_launcher_matches_only_known_launchers() -> None:
+    """Compilers of any shape pass; only the closed launcher set matches."""
+    for token in ("/t/g++-13", "gcc-8.4.0", "clang++-17", "armcc", "icx", "cc"):
+        assert not idedata._is_launcher(token)
+    for token in ("/opt/homebrew/bin/ccache", "CCACHE.EXE", "distcc", "sccache"):
+        assert idedata._is_launcher(token)
+
+
+def test_load_or_build_idedata_corrupted_cache_is_logged(
+    tmp_path: Path, caplog: pytest.LogCaptureFixture
+) -> None:
+    """A truncated cache is diagnosable, not a silent slow-build cause."""
+    compile_commands = _write_compile_commands(tmp_path)
+    cache = tmp_path / "c.json"
+    cache.write_text('{"cc_path": trunc')
+    os.utime(cache, (compile_commands.stat().st_mtime + 5,) * 2)
+    with patch.object(idedata, "get_toolchain_includes", return_value=[]):
+        data = idedata.load_or_build_idedata(
+            compile_commands, tmp_path / "f.elf", cache
+        )
+    assert data["cxx_path"] == "/tools/g++"
+    assert "Discarding unreadable idedata cache" in caplog.text
+
+
+def test_load_or_build_idedata_discards_unreadable_cache_file(
+    tmp_path: Path, caplog: pytest.LogCaptureFixture
+) -> None:
+    """An OSError on the cache read (permissions, I/O) regenerates like a
+    parse failure instead of aborting the consumer."""
+    compile_commands = _write_compile_commands(tmp_path)
+    cache = tmp_path / "c.json"
+    cache.write_text("{}")
+    os.utime(cache, (compile_commands.stat().st_mtime + 5,) * 2)
+    real_read_text = Path.read_text
+
+    def fail_cache_read(self: Path, *args: object, **kwargs: object) -> str:
+        # chmod(0) cannot revoke read access on Windows, so fault the read
+        # itself for a platform-independent OSError
+        if self == cache:
+            raise OSError("permission denied")
+        return real_read_text(self, *args, **kwargs)
+
+    with (
+        patch.object(idedata, "get_toolchain_includes", return_value=[]),
+        patch.object(Path, "read_text", fail_cache_read),
+    ):
+        data = idedata.load_or_build_idedata(
+            compile_commands, tmp_path / "f.elf", cache
+        )
+    assert data["cxx_path"] == "/tools/g++"
+    assert "Discarding unreadable idedata cache" in caplog.text
+
+
+def test_load_or_build_idedata_never_caches_a_launcher(tmp_path: Path) -> None:
+    """A compile DB naming a launcher as the compiler is rejected, never cached."""
+    compile_commands = tmp_path / "compile_commands.json"
+    compile_commands.write_text(
+        json.dumps(
+            [
+                _entry(
+                    f"{ABS}build",
+                    f"{ABS}build/src/esphome/core/application.cpp",
+                    "/opt/homebrew/bin/ccache -c app.cpp -o app.cpp.o",
+                )
+            ]
+        )
+    )
+    cache = tmp_path / "c.json"
+    # No probe patch needed: the launcher is rejected before the probe runs
+    with pytest.raises(EsphomeError, match="compile database is unusable"):
+        idedata.load_or_build_idedata(compile_commands, tmp_path / "f.elf", cache)
+    assert not cache.exists()
+
+
+@pytest.mark.parametrize(
+    "cached",
+    (
+        {"cc_path": "/x/gcc", "cxx_path": "/opt/homebrew/bin/ccache"},
+        {"cc_path": "/x/gcc", "cxx_path": "/tools/g++"},
+        {"cc_path": "/x/gcc", "cxx_path": "/tools/g++", "includes": {}},
+    ),
+    ids=("launcher-cxx", "no-includes", "no-build-list"),
+)
+def test_load_or_build_idedata_regenerates_invalid_cache(
+    tmp_path: Path, cached: dict
+) -> None:
+    """A cache written by an older version fails validation and regenerates."""
+    compile_commands = _write_compile_commands(tmp_path)
+    cache = tmp_path / "c.json"
+    cache.write_text(json.dumps(cached))
+    os.utime(cache, (compile_commands.stat().st_mtime + 5,) * 2)
+    with patch.object(idedata, "get_toolchain_includes", return_value=[]):
+        data = idedata.load_or_build_idedata(
+            compile_commands, tmp_path / "f.elf", cache
+        )
+    assert data["cxx_path"] == "/tools/g++"
+    assert "includes" in data
+
+
+def test_load_or_build_idedata_cache_hit_restamps_prog_path(tmp_path: Path) -> None:
+    """A served cache carries the current ELF path, not the one it was written with."""
+    compile_commands = _write_compile_commands(tmp_path)
+    cache = tmp_path / "c.json"
+    cache.write_text(
+        json.dumps(
+            {
+                "cc_path": "/tools/gcc",
+                "cxx_path": "/tools/g++",
+                "includes": {"build": [], "toolchain": []},
+                "prog_path": "/old/location/firmware.elf",
+            }
+        )
+    )
+    os.utime(cache, (compile_commands.stat().st_mtime + 5,) * 2)
+    data = idedata.load_or_build_idedata(
+        compile_commands, tmp_path / "firmware.elf", cache
+    )
+    assert data["prog_path"] == str(tmp_path / "firmware.elf")
+
+
+def test_idedata_from_build_non_list_compile_db_raises(tmp_path: Path) -> None:
+    """Valid JSON that is not a list raises by name, inside the best-effort tuple."""
+    compile_commands = tmp_path / "compile_commands.json"
+    for bad in ("{}", "null", '"text"', '["a", "b"]', "[1, 2]"):
+        compile_commands.write_text(bad)
+        with pytest.raises(EsphomeError, match="not a compile-command list"):
+            idedata.idedata_from_build(compile_commands)
+
+
+def test_idedata_from_build_same_file_rsp_commands_never_dedupe(
+    tmp_path: Path,
+) -> None:
+    """Two objects built from one source with different .rsp files keep both
+    include sets; the rsp sentinel keys on the output, not the source."""
+    file = f"{ABS}build/src/esphome/core/shared.cpp"
+    entries = []
+    for name in ("a", "b"):
+        rsp = tmp_path / f"{name}.o.rsp"
+        rsp.write_text(f"-I{ABS}inc/{name}")
+        entries.append(
+            {
+                "directory": str(tmp_path),
+                "file": file,
+                "command": f"/tools/g++ @{rsp.name} -c {file} -o {name}.o",
+                "output": f"{name}.o",
+            }
+        )
+    compile_commands = tmp_path / "compile_commands.json"
+    compile_commands.write_text(json.dumps(entries))
+    with patch.object(idedata, "get_toolchain_includes", return_value=[]):
+        data = idedata.idedata_from_build(compile_commands)
+    joined = " ".join(data["includes"]["build"])
+    assert "inc/a" in joined and "inc/b" in joined
+
+
+def test_load_or_build_idedata_cache_hit_skips_rebuild(tmp_path: Path) -> None:
+    """A valid cache newer than the compile DB is served without re-parsing."""
+    compile_commands = _write_compile_commands(tmp_path)
+    cache = tmp_path / "c.json"
+    cache.write_text(
+        json.dumps(
+            {
+                "cc_path": "/tools/gcc",
+                "cxx_path": "/tools/g++",
+                "includes": {"build": ["/inc"], "toolchain": []},
+                "cached": True,
+            }
+        )
+    )
+    os.utime(cache, (compile_commands.stat().st_mtime + 5,) * 2)
+    with patch.object(idedata, "idedata_from_build") as mock_build:
+        data = idedata.load_or_build_idedata(
+            compile_commands, tmp_path / "f.elf", cache
+        )
+    mock_build.assert_not_called()
+    assert data["cached"] is True

tests/unit_tests/build_helpers/test_size_summary.py

@@ -0,0 +1,22 @@
+"""Tests for the shared PlatformIO-format size bar."""
+
+from __future__ import annotations
+
+import pytest
+
+from esphome.build_helpers.size_summary import format_bar, print_size_line
+
+
+def test_format_bar_zero_total() -> None:
+    """A zero total must not divide by zero."""
+    assert format_bar(0, 0) == "[          ]   0.0% (used 0 bytes from 0 bytes)"
+
+
+def test_print_size_line_label_padding(capsys: pytest.CaptureFixture[str]) -> None:
+    """The label column is exactly what ci_memory_impact_extract.py greps."""
+    print_size_line("RAM", 47932, 180736)
+    print_size_line("Flash", 888511, 1835008)
+    out = capsys.readouterr().out.splitlines()
+    assert out[0].startswith("RAM:   [")
+    assert out[1].startswith("Flash: [")
+    assert "26.5% (used 47932 bytes from 180736 bytes)" in out[0]

tests/unit_tests/test_core.py

@@ -6,9 +6,9 @@ from unittest.mock import patch
 
 from hypothesis import given
 import pytest
-from strategies import mac_addr_strings
 
 from esphome import const, core
+from tests.unit_tests.strategies import mac_addr_strings
 
 
 class TestHexInt:

tests/unit_tests/test_espidf_clang_tidy.py

@@ -1,10 +1,13 @@
 """Tests for esphome.espidf.clang_tidy tidy-project generation."""
 
+import json
 import os
 from pathlib import Path
+from unittest.mock import patch
 
 import pytest
 
+from esphome.espidf import clang_tidy
 from esphome.espidf.clang_tidy import _Settings, _setup_core, _write_tidy_project
 
 REPO_ROOT = Path(__file__).resolve().parents[2]
@@ -64,3 +67,35 @@ def test_setup_core_sets_arduino_env(
     _setup_core(tmp_path / "proj", _settings(target_framework=target_framework))
 
     assert os.environ["ESPHOME_ARDUINO_COMPONENT"] == expected
+
+
+def test_idedata_from_tidy_project(tmp_path) -> None:
+    """The tidy TU's compile entry is assembled into consumer-shaped idedata."""
+    compile_commands = tmp_path / "compile_commands.json"
+    compile_commands.write_text(
+        json.dumps(
+            [
+                {
+                    "directory": str(tmp_path),
+                    "file": str(tmp_path / "main" / "tidy.cpp"),
+                    "command": "/tc/xtensa-esp32-elf-g++ -DUSE_ESP32 "
+                    f"-I{tmp_path}/inc -c main/tidy.cpp -o tidy.o",
+                }
+            ]
+        )
+    )
+    with patch(
+        "esphome.espidf.clang_tidy.get_toolchain_includes", return_value=["/tc/inc"]
+    ):
+        data = clang_tidy._idedata_from_tidy_project(compile_commands)
+    assert data["cxx_path"] == "/tc/xtensa-esp32-elf-g++"
+    assert data["defines"] == ["USE_ESP32"]
+    assert data["includes"]["toolchain"] == ["/tc/inc"]
+    assert any(inc.endswith("/inc") for inc in data["includes"]["build"])
+
+
+def test_idedata_from_tidy_project_missing_tu_raises(tmp_path) -> None:
+    compile_commands = tmp_path / "compile_commands.json"
+    compile_commands.write_text(json.dumps([]))
+    with pytest.raises(RuntimeError, match="tidy.cpp not found"):
+        clang_tidy._idedata_from_tidy_project(compile_commands)

tests/unit_tests/test_espidf_component.py

@@ -1,12 +1,12 @@
 import glob
 import hashlib
 import json
-import os
 from pathlib import Path
 from unittest.mock import MagicMock
 
 import pytest
 
+from esphome.components import esp32 as esp32_module
 from esphome.const import (
     KEY_CORE,
     KEY_TARGET_FRAMEWORK,
@@ -16,21 +16,24 @@ from esphome.const import (
 )
 from esphome.core import CORE, Library
 from esphome.espidf.component import (
+    _emit_idf_component,
     generate_cmakelists_txt,
     generate_idf_component_yml,
     generate_idf_components,
 )
 import esphome.platformio.library
 from esphome.platformio.library import (
+    ESPHOME_DATA_KEY,
+    ESPHOME_DATA_LINK_FLAGS_KEY,
     ConvertedLibrary as IDFComponent,
     GitSource,
     URLSource,
     _node_key,
-    _normalize_dependencies,
-    _parse_library_json,
-    _parse_library_properties,
     _resolve_registry_version,
     collect_filtered_files,
+    normalize_dependencies,
+    parse_library_json,
+    parse_library_properties,
     split_list_by_condition,
 )
 
@@ -291,6 +294,25 @@ def test_generate_cmakelists_txt_multi_token_flag(tmp_component):
     assert '  "-include"\n  "cp_custom_alloc.h"\n' in content
 
 
+def test_generate_cmakelists_txt_extra_script_link_flags(tmp_component):
+    """Captured extra-script LINKFLAGS come out as target_link_options, not
+    compile options where they would be silently ineffective."""
+    src_dir = tmp_component.path / "src"
+    src_dir.mkdir()
+    (src_dir / "main.c").write_text("int main() {}")
+
+    tmp_component.data = {
+        ESPHOME_DATA_KEY: {ESPHOME_DATA_LINK_FLAGS_KEY: ["-Wl,--gc-sections"]}
+    }
+
+    content = generate_cmakelists_txt(tmp_component)
+    assert (
+        'target_link_options(${COMPONENT_LIB} INTERFACE\n  "-Wl,--gc-sections"\n)'
+        in content
+    )
+    assert "target_compile_options" not in content
+
+
 def test_generate_cmakelists_txt_space_separated_classified_flags(tmp_component):
     # Space-separated -I/-L/-l entries routed to INCLUDE_DIRS and the link
     # handling before the shlex split was added; splitting must not leak
@@ -369,133 +391,11 @@ def test_generate_idf_component_yml_missing_path_raises(tmp_component):
         generate_idf_component_yml(tmp_component)
 
 
-def test_extra_script_captures_libpath_libs_and_defines(tmp_path):
-    from esphome.espidf.extra_script import captured_as_build_flags, run_extra_script
-
-    (tmp_path / "src" / "esp32").mkdir(parents=True)
-    script = tmp_path / "extra_script.py"
-    script.write_text(
-        "Import('env')\n"
-        "mcu = env.get('BOARD_MCU')\n"
-        "env.Append(\n"
-        "    LIBPATH=[join('src', mcu)],\n"
-        "    LIBS=['algobsec'],\n"
-        "    CPPDEFINES=['FOO', ('BAR', '1')],\n"
-        "    LINKFLAGS=['-Wl,--gc-sections'],\n"
-        ")\n"
-    )
-    # The script uses bare ``join`` (PIO's extra-scripts run inside SCons
-    # where this is in scope). Inject it via the script header so the
-    # shim's exec namespace can resolve it.
-    script.write_text("from os.path import join\n" + script.read_text())
-
-    result = run_extra_script(script, library_dir=tmp_path, idf_target="esp32")
-
-    assert result.libpath == [str(Path("src") / "esp32")]
-    assert result.libs == ["algobsec"]
-    assert ("BAR", "1") in result.cppdefines
-    assert "FOO" in result.cppdefines
-    assert result.linkflags == ["-Wl,--gc-sections"]
-
-    flags = captured_as_build_flags(result, library_dir=tmp_path)
-    sep = os.sep
-    assert f"-Lsrc{sep}esp32" in flags
-    assert "-lalgobsec" in flags
-    assert "-DFOO" in flags
-    assert "-DBAR=1" in flags
-    assert "-Wl,--gc-sections" in flags
-
-
-def test_extra_script_libpath_relative_resolves_against_library_dir(
-    tmp_path, monkeypatch
-):
-    """Relative LIBPATH entries must resolve against ``library_dir``, not the
-    caller's CWD (the shim restores CWD before ``captured_as_build_flags``
-    runs)."""
-    from esphome.espidf.extra_script import ExtraScriptResult, captured_as_build_flags
-
-    (tmp_path / "lib" / "esp32").mkdir(parents=True)
-    elsewhere = tmp_path.parent / "not_the_library_dir"
-    elsewhere.mkdir(exist_ok=True)
-    monkeypatch.chdir(elsewhere)
-
-    result = ExtraScriptResult(libpath=["lib/esp32"])
-    flags = captured_as_build_flags(result, library_dir=tmp_path)
-
-    sep = os.sep
-    assert flags == [f"-Llib{sep}esp32"]
-
-
-def test_extra_script_libpath_absolute_outside_library_dir(tmp_path):
-    from esphome.espidf.extra_script import ExtraScriptResult, captured_as_build_flags
-
-    outside = tmp_path.parent / "system_lib"
-    outside.mkdir(exist_ok=True)
-    result = ExtraScriptResult(libpath=[str(outside)])
-
-    flags = captured_as_build_flags(result, library_dir=tmp_path)
-    assert flags == [f"-L{outside.resolve()}"]
-
-
-def test_extra_script_failure_returns_empty_result(tmp_path, caplog):
-    from esphome.espidf.extra_script import run_extra_script
-
-    script = tmp_path / "broken.py"
-    script.write_text("raise RuntimeError('boom')\n")
-
-    with caplog.at_level("WARNING"):
-        result = run_extra_script(script, library_dir=tmp_path, idf_target="esp32")
-
-    assert result.libpath == []
-    assert result.libs == []
-    assert "broken.py" in caplog.text
-
-
-def test_apply_extra_script_path_traversal_is_rejected(tmp_path):
-    from esphome.espidf.component import _apply_extra_script
-
-    library_dir = tmp_path / "lib"
-    library_dir.mkdir()
-    outside = tmp_path / "evil.py"
-    outside.write_text("env.Append(LIBS=['pwned'])\n")
-
-    c = IDFComponent("owner/name", "1.0", source=URLSource("http://dummy"))
-    c.path = library_dir
-    c.data = {"build": {"extraScript": "../evil.py"}}
-
-    _apply_extra_script(c)
-
-    # Nothing was folded into flags: the traversal was rejected before
-    # the script could run.
-    assert "flags" not in c.data["build"]
-
-
-def test_apply_extra_script_merges_into_existing_flags(tmp_path, monkeypatch):
-    from esphome.components import esp32 as esp32_module
-
-    monkeypatch.setattr(esp32_module, "get_esp32_variant", lambda: "ESP32")
-
-    from esphome.espidf.component import _apply_extra_script
-
-    (tmp_path / "src").mkdir()
-    script = tmp_path / "extra.py"
-    script.write_text("env.Append(LIBS=['algobsec'])\n")
-
-    c = IDFComponent("owner/name", "1.0", source=URLSource("http://dummy"))
-    c.path = tmp_path
-    c.data = {"build": {"extraScript": "extra.py", "flags": ["-DEXISTING"]}}
-
-    _apply_extra_script(c)
-
-    assert "-DEXISTING" in c.data["build"]["flags"]
-    assert "-lalgobsec" in c.data["build"]["flags"]
-
-
 def test_parse_library_json(tmp_path):
     f = tmp_path / "library.json"
     f.write_text(json.dumps({"name": "test"}))
 
-    result = _parse_library_json(f)
+    result = parse_library_json(f)
     assert result["name"] == "test"
 
 
@@ -510,7 +410,7 @@ empty=
 """
     )
 
-    result = _parse_library_properties(f)
+    result = parse_library_properties(f)
 
     assert result["name"] == "Test"
     assert result["version"] == "1.0"
@@ -680,22 +580,22 @@ def test_node_key_registry_bare_name():
 
 
 def test_normalize_dependencies_none():
-    assert _normalize_dependencies(None) == []
+    assert normalize_dependencies(None) == []
 
 
 def test_normalize_dependencies_list_form():
     deps = [{"name": "foo", "version": "1.0"}]
-    assert _normalize_dependencies(deps) == [{"name": "foo", "version": "1.0"}]
+    assert normalize_dependencies(deps) == [{"name": "foo", "version": "1.0"}]
 
 
 def test_normalize_dependencies_dict_form():
-    out = _normalize_dependencies({"nanopb/Nanopb": "^0.4.91", "BareName": "1.2.3"})
+    out = normalize_dependencies({"nanopb/Nanopb": "^0.4.91", "BareName": "1.2.3"})
     assert {"name": "Nanopb", "owner": "nanopb", "version": "^0.4.91"} in out
     assert {"name": "BareName", "owner": None, "version": "1.2.3"} in out
 
 
 def test_normalize_dependencies_dict_form_nested_spec():
-    out = _normalize_dependencies(
+    out = normalize_dependencies(
         {"nanopb/Nanopb": {"version": "^0.4.91", "platforms": "espidf"}}
     )
     assert out == [
@@ -735,7 +635,7 @@ def _patch_registry(monkeypatch, versions):
 
 def test_resolve_registry_version_intersects_constraints(monkeypatch):
     _patch_registry(monkeypatch, ["1.10018.1", "1.10021.0", "1.10021.1"])
-    owner, name, version, url = _resolve_registry_version(
+    owner, name, version, url, _size = _resolve_registry_version(
         "esphome", "libsodium", {"==1.10021.0", "^1.10018.1"}
     )
     assert (owner, name, version) == ("esphome", "libsodium", "1.10021.0")
@@ -744,7 +644,9 @@ def test_resolve_registry_version_intersects_constraints(monkeypatch):
 
 def test_resolve_registry_version_picks_highest_satisfying(monkeypatch):
     _patch_registry(monkeypatch, ["1.0.0", "1.5.0", "2.0.0"])
-    _owner, _name, version, _url = _resolve_registry_version("o", "p", {"^1.0.0"})
+    _owner, _name, version, _url, _size = _resolve_registry_version(
+        "o", "p", {"^1.0.0"}
+    )
     assert version == "1.5.0"
 
 
@@ -794,7 +696,7 @@ def test_generate_idf_components_dedupes_shared_dependency(
         resolve_calls.append(pkgname)
         captured[f"{owner}/{pkgname}"] = set(requirements)
         version = "1.10021.0" if pkgname == "C" else "1.0.0"
-        return owner, pkgname, version, f"http://x/{pkgname}.tar.gz"
+        return owner, pkgname, version, f"http://x/{pkgname}.tar.gz", None
 
     monkeypatch.setattr(
         esphome.platformio.library, "_resolve_registry_version", fake_resolve
@@ -853,7 +755,7 @@ def test_generate_idf_components_lib_ignore_filters_top_level_and_dependencies(
 
     def fake_resolve(owner, pkgname, requirements):
         resolve_calls.append(pkgname)
-        return owner, pkgname, "1.0.0", f"http://x/{pkgname}.tar.gz"
+        return owner, pkgname, "1.0.0", f"http://x/{pkgname}.tar.gz", None
 
     monkeypatch.setattr(
         esphome.platformio.library, "_resolve_registry_version", fake_resolve
@@ -909,6 +811,7 @@ def test_generate_idf_components_handles_dependency_cycle(
             pkgname,
             "1.0.0",
             f"http://x/{pkgname}.tar.gz",
+            None,
         ),
     )
 
@@ -966,6 +869,7 @@ def test_generate_idf_components_git_overrides_registry_warns(
             pkgname,
             "1.0.0",
             f"http://x/{pkgname}.tar.gz",
+            None,
         ),
     )
 
@@ -1002,6 +906,7 @@ def test_generate_idf_components_missing_manifest_raises(
             pkgname,
             "1.0.0",
             f"http://x/{pkgname}.tar.gz",
+            None,
         ),
     )
 
@@ -1046,6 +951,7 @@ def test_generate_idf_components_warns_on_noncanonical_duplicate(
             pkgname,
             "1.0.0",
             f"http://x/{pkgname}.tar.gz",
+            None,
         ),
     )
 
@@ -1079,6 +985,7 @@ def test_generate_idf_components_incompatible_top_level_raises(
             pkgname,
             "1.0.0",
             f"http://x/{pkgname}.tar.gz",
+            None,
         ),
     )
 
@@ -1115,6 +1022,7 @@ def test_generate_idf_components_incompatible_dependency_skipped(
             pkgname,
             "1.0.0",
             f"http://x/{pkgname}.tar.gz",
+            None,
         ),
     )
 
@@ -1190,3 +1098,33 @@ def test_idf_component_download_passes_salt() -> None:
         "owner/name", force=True, salt="abcd1234", namespace="idf"
     )
     assert c.path == Path("/converted/owner/name")
+
+
+def test_emit_idf_component_wires_esp32_target(tmp_path, monkeypatch):
+    """Emitting a component resolves the esp32 variant into the shared
+    extraScript helper."""
+
+    monkeypatch.setattr(esp32_module, "get_esp32_variant", lambda: "ESP32")
+    (tmp_path / "src").mkdir()
+    script = tmp_path / "extra.py"
+    script.write_text("env.Append(LIBS=[env.get('BOARD_MCU')])\n")
+    c = IDFComponent("owner/name", "1.0", source=URLSource("http://dummy"))
+    c.path = tmp_path
+    c.data = {"build": {"extraScript": "extra.py"}}
+    _emit_idf_component(c)
+    assert c.data["build"]["flags"] == ["-lesp32"]
+
+
+def test_build_flags_dangling_flag_does_not_cross_entries(
+    tmp_path, caplog: pytest.LogCaptureFixture
+) -> None:
+    """Each entry is lexed independently, as ParseFlags does: a dangling -I ending one
+    entry warns instead of absorbing the next entry's first token."""
+    (tmp_path / "src").mkdir()
+    c = IDFComponent("owner/name", "1.0", source=URLSource("http://dummy"))
+    c.path = tmp_path
+    c.data = {"build": {"flags": ["-Wall -I", "-DFOO=1"]}}
+    content = generate_cmakelists_txt(c)
+    assert "FOO=1" in content
+    assert "-I-DFOO" not in content
+    assert "Ignoring trailing '-I'" in caplog.text

tests/unit_tests/test_espidf_framework.py

@@ -2,6 +2,7 @@
 
 # pylint: disable=protected-access
 
+from concurrent.futures import ThreadPoolExecutor
 from contextlib import contextmanager
 import importlib.util
 import io
@@ -14,7 +15,7 @@ import subprocess
 import sys
 import tarfile
 from types import SimpleNamespace
-from unittest.mock import patch
+from unittest.mock import MagicMock, patch
 
 import pytest
 
@@ -887,6 +888,78 @@ _PREFETCH_JSON = json.dumps(
 )
 
 
+def test_prefetch_leaves_unverifiable_entries_to_the_installer(
+    tmp_path: Path, caplog: pytest.LogCaptureFixture
+) -> None:
+    """An entry missing sha256 or size must not download unverified; the
+    installer handles it and fails loudly on a bad archive."""
+    entries = json.loads(_PREFETCH_JSON)
+    del entries[0]["sha256"]
+    del entries[1]["size"]
+    entries.append(
+        {
+            "name": "gcc@14.2.0",
+            "url": "https://example.com/gcc.tar.gz",
+            "size": 67,
+            "sha256": "ef" * 32,
+            "dest": "gcc.tar.gz",
+        }
+    )
+    with (
+        patch(
+            "esphome.espidf.framework.run_command",
+            return_value=(True, json.dumps(entries), ""),
+        ),
+        patch("esphome.espidf.framework.download_with_resume") as download,
+        patch("esphome.espidf.framework.get_system_python_path", return_value="python"),
+        patch("esphome.framework_helpers._BatchDownloadProgress") as progress_cls,
+    ):
+        _prefetch_idf_tool_archives(tmp_path, "esp32", ["required"], None)
+    assert [call[0][0] for call in download.call_args_list] == [
+        "https://example.com/gcc.tar.gz"
+    ]
+    assert download.call_args[1]["sha256"] == "ef" * 32
+    progress_cls.assert_called_once_with("Downloading ESP-IDF tools", 67)
+    assert "cmake@3.30.2 has no sha256/size" in caplog.text
+    assert "ninja@1.12.1 has no sha256/size" in caplog.text
+
+
+def test_prefetch_all_entries_unverifiable_is_a_noop(tmp_path: Path) -> None:
+    entries = json.loads(_PREFETCH_JSON)
+    for entry in entries:
+        del entry["sha256"]
+    with (
+        patch(
+            "esphome.espidf.framework.run_command",
+            return_value=(True, json.dumps(entries), ""),
+        ),
+        patch("esphome.espidf.framework.download_with_resume") as download,
+        patch("esphome.espidf.framework.get_system_python_path", return_value="python"),
+    ):
+        _prefetch_idf_tool_archives(tmp_path, "esp32", ["required"], None)
+    download.assert_not_called()
+
+
+def test_prefetch_dedupes_entries_by_dest(tmp_path: Path) -> None:
+    """Two entries resolving to one dest would interleave writes into the
+    same .part file; only the first downloads."""
+    entries = json.loads(_PREFETCH_JSON)
+    dup = dict(entries[0]) | {"name": "cmake-alias@3.30.2"}
+    entries.append(dup)
+    with (
+        patch(
+            "esphome.espidf.framework.run_command",
+            return_value=(True, json.dumps(entries), ""),
+        ),
+        patch("esphome.espidf.framework.download_with_resume") as download,
+        patch("esphome.espidf.framework.get_system_python_path", return_value="python"),
+        patch("esphome.framework_helpers._BatchDownloadProgress"),
+    ):
+        _prefetch_idf_tool_archives(tmp_path, "esp32", ["required"], None)
+    dests = [call[0][1].name for call in download.call_args_list]
+    assert dests.count("cmake-3.30.2.tar.gz") == 1
+
+
 def test_prefetch_downloads_each_archive_with_resume(tmp_path: Path) -> None:
     with (
         patch(
@@ -895,16 +968,58 @@ def test_prefetch_downloads_each_archive_with_resume(tmp_path: Path) -> None:
         ),
         patch("esphome.espidf.framework.download_with_resume") as download,
         patch("esphome.espidf.framework.get_system_python_path", return_value="python"),
+        patch("esphome.framework_helpers._BatchDownloadProgress") as progress_cls,
     ):
+        # Materialize the lazy mock before threads race its first creation
+        tracker = progress_cls.return_value.tracker.return_value
         _prefetch_idf_tool_archives(tmp_path, "esp32", ["required"], None)
 
     dist = get_idf_tools_path() / "dist"
-    assert download.call_count == 2
-    assert download.call_args_list[0][0] == (
-        "https://example.com/cmake.tar.gz",
-        dist / "cmake-3.30.2.tar.gz",
-    )
-    assert download.call_args_list[0][1] == {"sha256": "ab" * 32, "size": 123}
+    # Archives download concurrently, so the call order is not fixed.
+    calls = {call[0]: call[1] for call in download.call_args_list}
+    assert set(calls) == {
+        ("https://example.com/cmake.tar.gz", dist / "cmake-3.30.2.tar.gz"),
+        ("https://example.com/ninja.zip", dist / "ninja.zip"),
+    }
+    kwargs = calls[("https://example.com/cmake.tar.gz", dist / "cmake-3.30.2.tar.gz")]
+    assert kwargs["sha256"] == "ab" * 32
+    assert kwargs["size"] == 123
+    # every archive reports into the one combined progress bar via the
+    # cancellation-checked wrapper; verify it delegates to the tracker
+    progress_cls.assert_called_once_with("Downloading ESP-IDF tools", 123 + 45)
+    before = tracker.call_count
+    for kw in calls.values():
+        kw["progress"](7)
+    assert tracker.call_count == before + len(calls)
+
+
+def test_prefetch_downloads_archives_concurrently(tmp_path: Path) -> None:
+    """More than one archive fans out over a bounded thread pool."""
+    entries = [
+        {
+            "name": f"tool{i}@1",
+            "url": f"https://example.com/tool{i}.tar.gz",
+            "size": 10,
+            "sha256": "ab" * 32,
+            "dest": f"tool{i}.tar.gz",
+        }
+        for i in range(6)
+    ]
+    with (
+        patch(
+            "esphome.espidf.framework.run_command",
+            return_value=(True, json.dumps(entries), ""),
+        ),
+        patch("esphome.espidf.framework.download_with_resume") as download,
+        patch("esphome.espidf.framework.get_system_python_path", return_value="python"),
+        patch(
+            "esphome.framework_helpers.ThreadPoolExecutor", wraps=ThreadPoolExecutor
+        ) as pool,
+    ):
+        _prefetch_idf_tool_archives(tmp_path, "esp32", ["required"], None)
+
+    pool.assert_called_once_with(max_workers=4)
+    assert download.call_count == 6
 
 
 def test_prefetch_skips_already_downloaded_archives(tmp_path: Path) -> None:
@@ -964,6 +1079,11 @@ def test_prefetch_one_failed_archive_does_not_stop_the_rest(
 ) -> None:
     """A single archive failing its download must not abort the prefetch of
     the remaining archives."""
+
+    def _fail_cmake_download(url: str, *args, **kwargs) -> None:
+        if "cmake" in url:
+            raise OSError("network down")
+
     with (
         patch(
             "esphome.espidf.framework.run_command",
@@ -971,7 +1091,7 @@ def test_prefetch_one_failed_archive_does_not_stop_the_rest(
         ),
         patch(
             "esphome.espidf.framework.download_with_resume",
-            side_effect=[OSError("network down"), None],
+            side_effect=_fail_cmake_download,
         ) as download,
         patch("esphome.espidf.framework.get_system_python_path", return_value="python"),
     ):
@@ -981,6 +1101,27 @@ def test_prefetch_one_failed_archive_does_not_stop_the_rest(
     assert "Could not prefetch cmake@3.30.2" in caplog.text
 
 
+def test_prefetch_finishes_progress_bar_and_cancels_queue(tmp_path: Path) -> None:
+    """The batch bar is closed out after the pool, and the pool is shut down
+    with cancel_futures so Ctrl-C does not drain every queued archive."""
+    with (
+        patch(
+            "esphome.espidf.framework.run_command",
+            return_value=(True, _PREFETCH_JSON, ""),
+        ),
+        patch("esphome.espidf.framework.download_with_resume"),
+        patch("esphome.espidf.framework.get_system_python_path", return_value="python"),
+        patch("esphome.framework_helpers._BatchDownloadProgress") as progress_cls,
+        patch("esphome.framework_helpers.ThreadPoolExecutor") as pool_cls,
+    ):
+        pool = MagicMock(wraps=ThreadPoolExecutor(max_workers=2))
+        pool_cls.return_value = pool
+        _prefetch_idf_tool_archives(tmp_path, "esp32", ["required"], None)
+
+    pool.shutdown.assert_called_once_with(wait=True, cancel_futures=True)
+    progress_cls.return_value.done.assert_called_once_with()
+
+
 def test_prefetch_passes_targets_and_tools_to_script(tmp_path: Path) -> None:
     with (
         patch(

tests/unit_tests/test_espidf_idedata.py

@@ -1,264 +0,0 @@
-"""Tests for esphome.espidf.idedata (compile_commands.json -> idedata)."""
-
-# pylint: disable=protected-access
-
-import json
-import os
-from pathlib import Path
-from unittest.mock import MagicMock, patch
-
-import pytest
-
-from esphome.espidf import idedata
-
-# An absolute, forward-slash (shlex-safe) path prefix valid on the host OS, so
-# tests exercise the same is-absolute / normalize behavior as a real compile DB
-# (a drive-qualified path on Windows, a leading slash elsewhere).
-ABS = "C:/" if os.name == "nt" else "/"
-
-
-def _entry(directory: str, file: str, command: str) -> dict:
-    return {"directory": directory, "file": file, "command": command}
-
-
-def test_parse_entry_extracts_fields() -> None:
-    """cxx_path, defines, includes and remaining flags are split apart."""
-    entry = _entry(
-        f"{ABS}build",
-        f"{ABS}build/src/esphome/core/application.cpp",
-        f"/tools/xtensa-esp32-elf-g++ -DUSE_ESP32 -DESPHOME_LOG_LEVEL=5 "
-        f"-I{ABS}inc/a -isystem {ABS}sys/b -std=gnu++20 -c app.cpp -o app.cpp.o",
-    )
-
-    cxx_path, defines, includes, cxx_flags = idedata._parse_entry(entry)
-
-    assert cxx_path == "/tools/xtensa-esp32-elf-g++"
-    assert "USE_ESP32" in defines
-    assert "ESPHOME_LOG_LEVEL=5" in defines
-    assert f"{ABS}inc/a" in includes
-    assert f"{ABS}sys/b" in includes
-    assert "-std=gnu++20" in cxx_flags
-    # input/output files and their flags are not treated as flags
-    assert "-c" not in cxx_flags
-    assert "-o" not in cxx_flags
-    assert "app.cpp" not in cxx_flags
-    assert "app.cpp.o" not in cxx_flags
-
-
-def test_parse_entry_space_separated_args() -> None:
-    """``-D X`` / ``-I path`` (separate arg) and ``-isystem<path>`` (joined)."""
-    entry = _entry(
-        f"{ABS}build",
-        f"{ABS}build/src/esphome/x.cpp",
-        f"g++ -D FOO=1 -I {ABS}inc/sep -isystem{ABS}sys/joined -c x.cpp",
-    )
-
-    _, defines, includes, _ = idedata._parse_entry(entry)
-
-    assert "FOO=1" in defines
-    assert f"{ABS}inc/sep" in includes
-    assert f"{ABS}sys/joined" in includes
-
-
-def test_parse_entry_resolves_relative_includes() -> None:
-    """Relative includes are resolved against the entry's ``directory``."""
-    directory = f"{ABS}build/proj"
-    entry = _entry(
-        directory,
-        f"{directory}/src/esphome/x.cpp",
-        "g++ -Iconfig -I../shared -isystem rel/sys -c x.cpp",
-    )
-
-    _, _, includes, _ = idedata._parse_entry(entry)
-
-    def resolved(rel: str) -> str:
-        # _parse_entry emits forward slashes for consistency (normpath would
-        # yield backslashes on Windows).
-        return os.path.normpath(Path(directory) / rel).replace("\\", "/")
-
-    assert resolved("config") in includes
-    assert resolved("../shared") in includes  # ../ normalized away
-    assert resolved("rel/sys") in includes
-    # nothing is left relative
-    assert all(Path(inc).is_absolute() for inc in includes)
-
-
-def test_parse_entry_skips_dependency_flags() -> None:
-    """Dependency-generation flags (and their args) are dropped."""
-    entry = _entry(
-        "/build",
-        "/build/src/esphome/x.cpp",
-        "g++ -MD -MT x.cpp.o -MF x.cpp.o.d -c x.cpp -o x.cpp.o",
-    )
-
-    _, _, _, cxx_flags = idedata._parse_entry(entry)
-
-    for tok in ("-MD", "-MT", "x.cpp.o", "-MF", "x.cpp.o.d", "-c", "-o", "x.cpp"):
-        assert tok not in cxx_flags
-
-
-def test_expand_response_files(tmp_path: Path) -> None:
-    """``@file`` arguments are inlined relative to the directory."""
-    rsp = tmp_path / "flags.rsp"
-    rsp.write_text("-DFROM_RSP -I/rsp/inc")
-
-    tokens = idedata._expand_response_files(
-        ["g++", f"@{rsp.name}", "-c", "x.cpp"], tmp_path
-    )
-
-    assert "-DFROM_RSP" in tokens
-    assert "-I/rsp/inc" in tokens
-    assert not any(t.startswith("@") for t in tokens)
-
-
-def test_expand_response_files_keeps_literal_when_missing(tmp_path: Path) -> None:
-    """An unreadable ``@file`` token is kept verbatim rather than dropped."""
-    tokens = idedata._expand_response_files(["g++", "@nope.rsp"], tmp_path)
-    assert "@nope.rsp" in tokens
-
-
-def test_pick_entry_prefers_esphome_tu() -> None:
-    """A ``/src/esphome/`` C++ TU is picked over other compile entries."""
-    entries = [
-        _entry("/b", "/b/managed_components/foo/foo.c", "gcc -c foo.c"),
-        _entry("/b", "/b/src/esphome/core/app.cpp", "g++ -c app.cpp"),
-    ]
-    assert idedata._pick_entry(entries)["file"].endswith("app.cpp")
-
-
-def test_pick_entry_falls_back_to_any_cxx_tu() -> None:
-    """With no ``/src/esphome/`` TU present, the first C++ entry is the fallback."""
-    entries = [
-        _entry("/b", "/b/managed_components/foo/foo.c", "gcc -c foo.c"),
-        _entry("/b", "/b/components/x/x.cpp", "g++ -c x.cpp"),
-    ]
-    assert idedata._pick_entry(entries)["file"].endswith("x.cpp")
-
-
-def test_is_esphome_src_handles_backslash_paths() -> None:
-    r"""The src marker must match Windows ``\src\esphome\`` paths too.
-
-    compile_commands ``file`` entries use the OS-native separator; if the
-    marker only matched forward slashes no source would match on Windows and
-    the build-include union would be silently empty.
-    """
-    assert idedata._is_esphome_src(r"C:\b\src\esphome\core\app.cpp")
-    assert idedata._is_esphome_src("/b/src/esphome/core/app.cpp")
-    # non-esphome and non-C++ still rejected regardless of separator
-    assert not idedata._is_esphome_src(r"C:\b\managed_components\x\x.cpp")
-    assert not idedata._is_esphome_src(r"C:\b\src\esphome\core\app.h")
-
-
-def test_idedata_from_build(tmp_path: Path) -> None:
-    """Full transform: representative entry + include union + toolchain dirs."""
-    compile_commands = tmp_path / "compile_commands.json"
-    entries = [
-        _entry(
-            f"{ABS}b",
-            f"{ABS}b/src/esphome/core/app.cpp",
-            f"g++ -DUSE_ESP32 -I{ABS}inc/core -std=gnu++20 -c app.cpp -o app.cpp.o",
-        ),
-        _entry(
-            f"{ABS}b",
-            f"{ABS}b/src/esphome/sensor/s.cpp",
-            f"g++ -DUSE_ESP32 -I{ABS}inc/sensor -c s.cpp -o s.cpp.o",
-        ),
-        # non-esphome TU: its includes must not leak into the union
-        _entry(
-            f"{ABS}b",
-            f"{ABS}b/managed_components/x/x.c",
-            f"gcc -I{ABS}inc/managed -c x.c",
-        ),
-    ]
-    compile_commands.write_text(json.dumps(entries))
-
-    fake_proc = MagicMock(
-        returncode=0,
-        stderr=(
-            "ignored\n"
-            "#include <...> search starts here:\n"
-            " /tc/inc/c++\n"
-            " /tc/inc\n"
-            "End of search list.\n"
-            "more ignored\n"
-        ),
-    )
-    with patch.object(idedata.subprocess, "run", return_value=fake_proc):
-        data = idedata.idedata_from_build(compile_commands)
-
-    assert data["cxx_path"] == "g++"
-    assert "USE_ESP32" in data["defines"]
-    assert "-std=gnu++20" in data["cxx_flags"]
-    # include dirs unioned across all esphome TUs
-    assert f"{ABS}inc/core" in data["includes"]["build"]
-    assert f"{ABS}inc/sensor" in data["includes"]["build"]
-    # the non-esphome TU is excluded from the union
-    assert f"{ABS}inc/managed" not in data["includes"]["build"]
-    # toolchain search dirs parsed from the compiler's -v output
-    assert data["includes"]["toolchain"] == ["/tc/inc/c++", "/tc/inc"]
-
-
-def test_get_toolchain_includes_raises_on_probe_failure() -> None:
-    """A failed compiler probe is a hard error, not a silent empty list."""
-    fake_proc = MagicMock(returncode=1, stderr="xtensa-esp32-elf-g++: not found")
-    with (
-        patch.object(idedata.subprocess, "run", return_value=fake_proc),
-        pytest.raises(RuntimeError, match="builtin include dirs"),
-    ):
-        idedata._get_toolchain_includes("/bad/compiler")
-
-
-def test_get_toolchain_includes_raises_when_no_dirs_found() -> None:
-    """Markers present but no dirs (anomalous output) also raises."""
-    fake_proc = MagicMock(
-        returncode=0,
-        stderr="#include <...> search starts here:\nEnd of search list.\n",
-    )
-    with (
-        patch.object(idedata.subprocess, "run", return_value=fake_proc),
-        pytest.raises(RuntimeError, match="builtin include dirs"),
-    ):
-        idedata._get_toolchain_includes("/some/compiler")
-
-
-# ESP-IDF's compile_commands.json on Windows mixes literal backslash path
-# separators in the compiler path with shell ``\"`` quote-escaping in defines,
-# which only the real Windows argv parser handles. These exercise that path.
-@pytest.mark.skipif(os.name != "nt", reason="Windows argv tokenization")
-def test_split_command_preserves_paths_and_unescapes_quotes() -> None:
-    r"""Backslash paths survive while ``\"`` define-quoting is unescaped."""
-    command = r"C:\esp\bin\riscv32-esp-elf-g++.exe -DVER=\"1.2.3\" -IC:/inc/a -c x.cpp"
-
-    tokens = idedata._split_command(command)
-
-    assert tokens[0] == r"C:\esp\bin\riscv32-esp-elf-g++.exe"
-    assert '-DVER="1.2.3"' in tokens
-    assert "-IC:/inc/a" in tokens
-
-
-@pytest.mark.skipif(os.name != "nt", reason="Windows argv tokenization")
-def test_split_command_empty_returns_empty() -> None:
-    """An empty or blank command tokenizes to ``[]`` (e.g. an empty response file).
-
-    Guards against ``CommandLineToArgvW("")`` returning the current process name
-    instead of an empty list.
-    """
-    assert idedata._split_command("") == []
-    assert idedata._split_command("   ") == []
-
-
-@pytest.mark.skipif(os.name != "nt", reason="Windows argv tokenization")
-def test_parse_entry_normalizes_windows_cxx_path() -> None:
-    """A backslash compiler path is emitted forward-slashed; define unescaped."""
-    entry = _entry(
-        r"C:\b",
-        r"C:\b\src\esphome\x.cpp",
-        r"C:\esp\bin\g++.exe -DVER=\"1.2.3\" -IC:/inc/a -c x.cpp",
-    )
-
-    cxx_path, defines, includes, _ = idedata._parse_entry(entry)
-
-    assert cxx_path == "C:/esp/bin/g++.exe"
-    assert "\\" not in cxx_path
-    assert 'VER="1.2.3"' in defines
-    assert "C:/inc/a" in includes

tests/unit_tests/test_espidf_toolchain.py

@@ -140,7 +140,7 @@ def test_get_idedata_generates_and_caches(setup_core: Path) -> None:
     compile_commands.write_text("[]")
 
     with patch(
-        "esphome.espidf.idedata.idedata_from_build",
+        "esphome.build_helpers.idedata.idedata_from_build",
         return_value={"cxx_path": "g++"},
     ) as mock_transform:
         result = toolchain.get_idedata()
@@ -151,114 +151,6 @@ def test_get_idedata_generates_and_caches(setup_core: Path) -> None:
     assert json.loads(cache.read_text()) == {"cxx_path": "g++", "prog_path": prog_path}
 
 
-def test_get_idedata_uses_cache_when_valid(setup_core: Path) -> None:
-    """A cache at least as new as the compile DB is reused without regenerating."""
-    compile_commands, cache = _setup_build(setup_core)
-    compile_commands.parent.mkdir(parents=True, exist_ok=True)
-    compile_commands.write_text("[]")
-    cache.parent.mkdir(parents=True, exist_ok=True)
-    cache.write_text('{"cc_path": "cached-gcc", "cxx_path": "cached"}')
-    cc_mtime = compile_commands.stat().st_mtime
-    os.utime(cache, (cc_mtime + 1, cc_mtime + 1))
-
-    with patch("esphome.espidf.idedata.idedata_from_build") as mock_transform:
-        result = toolchain.get_idedata()
-
-    mock_transform.assert_not_called()
-    assert result == {"cc_path": "cached-gcc", "cxx_path": "cached"}
-
-
-def test_get_idedata_regenerates_cache_without_cc_path(setup_core: Path) -> None:
-    """A cache predating cc_path is rebuilt even though it is newer.
-
-    Such a cache stays newer than the compile DB forever, so consumers that
-    derive the binutils paths from cc_path would keep failing on it.
-    """
-    compile_commands, cache = _setup_build(setup_core)
-    compile_commands.parent.mkdir(parents=True, exist_ok=True)
-    compile_commands.write_text("[]")
-    cache.parent.mkdir(parents=True, exist_ok=True)
-    cache.write_text('{"cxx_path": "cached"}')
-    cc_mtime = compile_commands.stat().st_mtime
-    os.utime(cache, (cc_mtime + 1, cc_mtime + 1))
-
-    with patch(
-        "esphome.espidf.idedata.idedata_from_build",
-        return_value={"cc_path": "gcc", "cxx_path": "g++"},
-    ) as mock_transform:
-        result = toolchain.get_idedata()
-
-    mock_transform.assert_called_once()
-    assert result["cc_path"] == "gcc"
-
-
-def test_get_idedata_regenerates_when_compile_commands_newer(setup_core: Path) -> None:
-    """A compile DB newer than the cache forces regeneration."""
-    compile_commands, cache = _setup_build(setup_core)
-    cache.parent.mkdir(parents=True, exist_ok=True)
-    cache.write_text('{"cxx_path": "stale"}')
-    compile_commands.parent.mkdir(parents=True, exist_ok=True)
-    compile_commands.write_text("[]")
-    cache_mtime = cache.stat().st_mtime
-    os.utime(compile_commands, (cache_mtime + 1, cache_mtime + 1))
-
-    with patch(
-        "esphome.espidf.idedata.idedata_from_build",
-        return_value={"cxx_path": "fresh"},
-    ) as mock_transform:
-        result = toolchain.get_idedata()
-
-    mock_transform.assert_called_once()
-    assert result == {"cxx_path": "fresh", "prog_path": str(toolchain.get_elf_path())}
-
-
-@pytest.mark.parametrize("cached", ['"cc_path is a string"', "[]", "42"])
-def test_get_idedata_regenerates_on_non_dict_cache(
-    setup_core: Path, cached: str
-) -> None:
-    """A newer cache holding valid JSON that is not an object is regenerated.
-
-    A bare string would otherwise pass the cc_path check by substring and be
-    handed to consumers expecting a dict.
-    """
-    compile_commands, cache = _setup_build(setup_core)
-    compile_commands.parent.mkdir(parents=True, exist_ok=True)
-    compile_commands.write_text("[]")
-    cache.parent.mkdir(parents=True, exist_ok=True)
-    cache.write_text(cached)
-    cc_mtime = compile_commands.stat().st_mtime
-    os.utime(cache, (cc_mtime + 1, cc_mtime + 1))
-
-    with patch(
-        "esphome.espidf.idedata.idedata_from_build",
-        return_value={"cc_path": "gcc", "cxx_path": "g++"},
-    ) as mock_transform:
-        result = toolchain.get_idedata()
-
-    mock_transform.assert_called_once()
-    assert isinstance(result, dict)
-
-
-def test_get_idedata_regenerates_on_corrupted_cache(setup_core: Path) -> None:
-    """An unparseable (but newer) cache falls back to regeneration."""
-    compile_commands, cache = _setup_build(setup_core)
-    compile_commands.parent.mkdir(parents=True, exist_ok=True)
-    compile_commands.write_text("[]")
-    cache.parent.mkdir(parents=True, exist_ok=True)
-    cache.write_text("{not json")
-    cc_mtime = compile_commands.stat().st_mtime
-    os.utime(cache, (cc_mtime + 1, cc_mtime + 1))
-
-    with patch(
-        "esphome.espidf.idedata.idedata_from_build",
-        return_value={"cxx_path": "regen"},
-    ) as mock_transform:
-        result = toolchain.get_idedata()
-
-    mock_transform.assert_called_once()
-    assert result == {"cxx_path": "regen", "prog_path": str(toolchain.get_elf_path())}
-
-
 def test_get_idedata_prog_path_points_at_firmware_elf(setup_core: Path) -> None:
     """The idedata exposes prog_path (the ELF) so consumers like build-action
     can locate firmware.factory.bin / firmware.ota.bin as its siblings."""
@@ -267,7 +159,7 @@ def test_get_idedata_prog_path_points_at_firmware_elf(setup_core: Path) -> None:
     compile_commands.write_text("[]")
 
     with patch(
-        "esphome.espidf.idedata.idedata_from_build",
+        "esphome.build_helpers.idedata.idedata_from_build",
         return_value={"cxx_path": "g++"},
     ):
         result = toolchain.get_idedata()

tests/unit_tests/test_espota2.py

@@ -998,10 +998,10 @@ def test_progress_bar(capsys: CaptureFixture[str]) -> None:
     assert "100%" in captured.err
     assert "Done" in captured.err
 
-    # Test done method
+    # done() after the 100% frame adds nothing; that frame ended its line
     progress.done()
     captured = capsys.readouterr()
-    assert captured.err == "\n"
+    assert captured.err == ""
 
     # Test same progress doesn't update
     progress.update(0.5)
@@ -1010,6 +1010,10 @@ def test_progress_bar(capsys: CaptureFixture[str]) -> None:
     # Should only see one update (second call shouldn't write)
     assert captured.err.count("50%") == 1
 
+    # done() after a mid-way frame ends the line
+    progress.done()
+    assert capsys.readouterr().err == "\n"
+
 
 # Tests for SHA256 authentication
 @pytest.mark.usefixtures("mock_time")

tests/unit_tests/test_framework_helpers.py

@@ -12,6 +12,8 @@ from pathlib import Path
 import subprocess
 import sys
 import tarfile
+import threading
+import time
 from unittest.mock import MagicMock, Mock, call, patch
 import zipfile
 
@@ -22,6 +24,7 @@ from esphome import framework_helpers
 from esphome.core import EsphomeError
 from esphome.framework_helpers import (
     _7z_extract_all,
+    _BatchDownloadProgress,
     _detect_archive_root,
     _rename_with_retry,
     _tar_extract_all,
@@ -36,6 +39,7 @@ from esphome.framework_helpers import (
     get_python_env_executable_path,
     get_system_python_path,
     rmdir,
+    run_batch_downloads,
     run_command,
     run_command_ok,
     str_to_lst_of_str,
@@ -1111,6 +1115,220 @@ class TestDownloadWithResume:
         assert mock_get.call_args[1]["headers"] == {}
         assert dest.read_bytes() == b"data"
 
+    def test_progress_callback_reports_absolute_bytes(self, tmp_path: Path) -> None:
+        """With a callback no bar is drawn; the callback sees the running
+        byte count of this file, then its final verified size."""
+        dest = tmp_path / "tool.tar.gz"
+        resp = _mock_response(b"")
+        resp.headers = {"content-length": "7"}
+        resp.iter_content.return_value = [b"1234", b"567"]
+        seen: list[int] = []
+        with (
+            patch("requests.get", return_value=resp),
+            patch("esphome.framework_helpers.ProgressBar") as bar_cls,
+        ):
+            download_with_resume(
+                "https://example.com/t", dest, size=7, progress=seen.append
+            )
+        assert seen == [0, 4, 7, 7]
+        bar_cls.assert_not_called()
+
+    def test_progress_callback_seeds_with_resume_offset(self, tmp_path: Path) -> None:
+        dest = tmp_path / "tool.tar.gz"
+        (tmp_path / "tool.tar.gz.part").write_bytes(b"12345")
+        good = hashlib.sha256(b"12345678").hexdigest()
+        seen: list[int] = []
+        with patch("requests.get", return_value=_resumed_response(b"678")):
+            download_with_resume(
+                "https://example.com/t", dest, sha256=good, size=8, progress=seen.append
+            )
+        assert seen[0] == 5
+        assert seen[-1] == 8
+
+    def test_progress_callback_credits_already_complete_download(
+        self, tmp_path: Path
+    ) -> None:
+        """A verified dest from an earlier run still counts toward the batch."""
+        dest = tmp_path / "tool.tar.gz"
+        dest.write_bytes(b"12345678")
+        seen: list[int] = []
+        with patch("requests.get") as mock_get:
+            download_with_resume(
+                "https://example.com/t", dest, size=8, progress=seen.append
+            )
+        mock_get.assert_not_called()
+        assert seen == [8]
+
+
+def test_run_batch_downloads_ctrl_c_aborts_in_flight_jobs() -> None:
+    """Ctrl-C cancels in-flight downloads at their next tick instead of
+    letting non-daemon workers download to completion."""
+    started = threading.Event()
+    ticks: list[int] = []
+
+    def interrupter(tracker) -> None:
+        started.wait(5)
+        raise KeyboardInterrupt
+
+    def slow_download(tracker) -> None:
+        started.set()
+        for i in range(500):
+            tracker(i)
+            ticks.append(i)
+            time.sleep(0.01)
+
+    t0 = time.monotonic()
+    with pytest.raises(KeyboardInterrupt):
+        run_batch_downloads(
+            "Downloading",
+            [("boom", 0, interrupter), ("slow", 0, slow_download)],
+            max_workers=2,
+        )
+    # Uncancelled, slow_download alone takes ~5s
+    assert time.monotonic() - t0 < 3
+    assert len(ticks) < 500
+
+
+def test_cancellation_escapes_broad_except_in_fetch() -> None:
+    """A fetch that wraps its work in except Exception cannot swallow the
+    Ctrl-C sentinel (it is a BaseException)."""
+    from esphome.framework_helpers import _BatchDownloadCancelled
+
+    started = threading.Event()
+    swallowed = []
+
+    def interrupter(tracker) -> None:
+        started.wait(5)
+        raise KeyboardInterrupt
+
+    def greedy_fetch(tracker) -> None:
+        started.set()
+        try:
+            for i in range(500):
+                tracker(i)
+                time.sleep(0.01)
+        except Exception as err:  # noqa: BLE001  # pylint: disable=broad-exception-caught
+            swallowed.append(err)
+
+    t0 = time.monotonic()
+    with pytest.raises(KeyboardInterrupt):
+        run_batch_downloads(
+            "Downloading",
+            [("boom", 0, interrupter), ("greedy", 0, greedy_fetch)],
+            max_workers=2,
+        )
+    assert time.monotonic() - t0 < 3
+    assert not swallowed
+    assert issubclass(_BatchDownloadCancelled, BaseException)
+    assert not issubclass(_BatchDownloadCancelled, Exception)
+
+
+def test_logging_guard_ends_the_bar_row_before_a_record() -> None:
+    r"""A worker warning gets its own line instead of the bar's \r row."""
+    stream = io.StringIO()
+    stream.isatty = lambda: True  # type: ignore[method-assign]
+    with patch("esphome.helpers.sys.stderr", stream):
+        progress = _BatchDownloadProgress("Downloading", 10)
+        progress.tracker()(5)
+        with progress.logging_guard():
+            logging.getLogger("esphome.test").warning("mirror retry")
+        # The partial 50% frame ended its line before the record was emitted
+        assert stream.getvalue().endswith("50% \n")
+        # And the next tick redraws the frame on a fresh row
+        progress.tracker()(2)
+        assert stream.getvalue().endswith("70% ")
+
+
+def test_logging_guard_without_a_bar_is_a_no_op() -> None:
+    """An unknown total draws no bar; the guard passes records through."""
+    from esphome.framework_helpers import _BatchDownloadProgress
+
+    progress = _BatchDownloadProgress("Downloading", 0)
+    with progress.logging_guard():
+        logging.getLogger("esphome.test").warning("plain record")
+
+
+def test_cancellable_sleep_sleeps_between_ticks() -> None:
+    """An uncancelled backoff actually waits out its delay in slices."""
+    from esphome.framework_helpers import _cancellable_sleep
+
+    ticks: list[int] = []
+    t0 = time.monotonic()
+    _cancellable_sleep(0.05, ticks.append, 3)
+    assert time.monotonic() - t0 >= 0.05
+    assert ticks and all(t == 3 for t in ticks)
+
+
+def test_cancellable_sleep_aborts_at_the_tick() -> None:
+    """A backoff sleep observes the cancellation raise promptly."""
+    from esphome.framework_helpers import _BatchDownloadCancelled, _cancellable_sleep
+
+    def cancelled_tick(done: int) -> None:
+        raise _BatchDownloadCancelled
+
+    t0 = time.monotonic()
+    with pytest.raises(_BatchDownloadCancelled):
+        _cancellable_sleep(30, cancelled_tick, 0)
+    assert time.monotonic() - t0 < 1
+
+
+class Test_BatchDownloadProgress:
+    def test_sums_trackers_into_one_bar(self) -> None:
+        with patch("esphome.framework_helpers.ProgressBar") as bar_cls:
+            progress = _BatchDownloadProgress("Downloading", 100)
+            a = progress.tracker()
+            b = progress.tracker()
+            a(10)
+            b(20)
+            a(30)
+            a(0)  # a restart from zero takes that file's bytes back out
+        bar_cls.assert_called_once_with("Downloading")
+        updates = [c[0][0] for c in bar_cls.return_value.update.call_args_list]
+        assert updates == [0.1, 0.3, 0.5, 0.2]
+
+    def test_clamps_at_one(self) -> None:
+        """Sizes are advisory; an over-delivering server never pushes past 100%."""
+        with patch("esphome.framework_helpers.ProgressBar") as bar_cls:
+            progress = _BatchDownloadProgress("Downloading", 10)
+            progress.tracker()(25)
+        assert bar_cls.return_value.update.call_args[0][0] == 1
+
+    def test_unknown_total_draws_nothing(self) -> None:
+        with patch("esphome.framework_helpers.ProgressBar") as bar_cls:
+            progress = _BatchDownloadProgress("Downloading", 0)
+            progress.tracker()(5)
+            progress.done()
+        bar_cls.assert_not_called()
+
+    def test_done_ends_an_unfinished_bar(self) -> None:
+        """A batch that stops short of 100% (a failed archive) still ends its
+        line so the next log message starts on a fresh row."""
+        stream = io.StringIO()
+        stream.isatty = lambda: True  # type: ignore[method-assign]
+        with patch("esphome.helpers.sys.stderr", stream):
+            progress = _BatchDownloadProgress("Downloading", 10)
+            progress.tracker()(5)
+            progress.done()
+        assert stream.getvalue().endswith("50% \n")
+
+    def test_done_before_any_frame_writes_nothing(self) -> None:
+        """A batch aborted before any tracker fired must not emit a stray
+        newline for a bar that was never drawn."""
+        stream = io.StringIO()
+        stream.isatty = lambda: True  # type: ignore[method-assign]
+        with patch("esphome.helpers.sys.stderr", stream):
+            _BatchDownloadProgress("Downloading", 10).done()
+        assert stream.getvalue() == ""
+
+    def test_done_after_full_bar_adds_nothing(self) -> None:
+        stream = io.StringIO()
+        stream.isatty = lambda: True  # type: ignore[method-assign]
+        with patch("esphome.helpers.sys.stderr", stream):
+            progress = _BatchDownloadProgress("Downloading", 10)
+            progress.tracker()(10)
+            progress.done()
+        assert stream.getvalue().endswith("100% Done...\r\n")
+
 
 class TestDownloadFromMirrors:
     def test_success_returns_url_and_writes_content(self, tmp_path: Path) -> None:
@@ -1123,6 +1341,22 @@ class TestDownloadFromMirrors:
         assert url == "https://example.com/f"
         assert target.read_bytes() == b"filedata"
 
+    def test_file_object_target_reports_progress(self) -> None:
+        """The library prefetch's production path: a file-object target
+        streams through the mirror fallback and ticks the tracker."""
+        buf = io.BytesIO()
+        ticks: list[int] = []
+        with patch(
+            "requests.get",
+            return_value=_mock_response(b"filedata"),
+        ):
+            url = download_from_mirrors(
+                ["https://example.com/f"], {}, buf, progress=ticks.append
+            )
+        assert url == "https://example.com/f"
+        assert buf.getvalue() == b"filedata"
+        assert ticks and ticks[-1] == len(b"filedata")
+
     def test_substitutions_applied_to_url(self, tmp_path: Path) -> None:
         with patch(
             "requests.get",
@@ -1468,6 +1702,27 @@ class TestDownloadFromMirrors:
         assert mock_get.call_count == 2
         mock_sleep.assert_called_once_with(2)
 
+    def test_backoff_tick_reports_partial_bytes(self, tmp_path: Path) -> None:
+        """The backoff tick carries the bytes already in the part file, so a
+        combined bar holds steady instead of rewinding to zero."""
+        dest = tmp_path / "out.bin"
+        (tmp_path / "out.bin.part").write_bytes(b"12345")
+        ticks: list[int] = []
+        with (
+            patch(
+                "requests.get",
+                side_effect=[
+                    req.ConnectionError("down"),
+                    _mock_response(b"data"),
+                ],
+            ),
+            patch("esphome.framework_helpers._cancellable_sleep") as mock_sleep,
+        ):
+            download_from_mirrors(
+                ["https://mirror1.com/f"], {}, dest, progress=ticks.append
+            )
+        assert mock_sleep.call_args == call(2, ticks.append, 5)
+
     def test_permanent_failure_does_not_retry_sweep(self, tmp_path: Path) -> None:
         """An HTTP 404 will not heal on its own; fail after a single pass."""
         with (

tests/unit_tests/test_helpers.py

@@ -1117,6 +1117,20 @@ def test_progressbar_enabled_on_pipe_with_dashboard(monkeypatch) -> None:
     assert bar.enabled is True
 
 
+def test_progressbar_interrupt_keeps_finished_bar_done(monkeypatch) -> None:
+    """interrupt() on a bar whose 100% frame already ended its own line
+    must not reset it, or the next tick would redraw a second Done row."""
+    stream = MagicMock(spec=io.TextIOWrapper)
+    stream.isatty.return_value = True
+    monkeypatch.setattr(CORE, "dashboard", False)
+
+    bar = ProgressBar("Uploading", stream=stream)
+    bar.update(1)
+    assert bar.last_progress == 100
+    bar.interrupt()
+    assert bar.last_progress == 100
+
+
 @pytest.mark.parametrize(
     ("seconds", "expected"),
     [

tests/unit_tests/test_main.py

@@ -17,6 +17,7 @@ from unittest.mock import AsyncMock, MagicMock, Mock, patch
 
 import pytest
 from pytest import CaptureFixture
+import serial
 from zeroconf import ServiceStateChange
 
 from esphome import __main__ as main, yaml_util
@@ -26,6 +27,7 @@ from esphome.__main__ import (
     _make_crystal_freq_callback,
     _redact_with_legacy_fallback,
     _resolve_network_devices,
+    _should_subscribe_states,
     _split_network_devices,
     _unresolved_default_error,
     _validate_bootloader_binary,
@@ -69,19 +71,21 @@ from esphome.__main__ import (
 )
 from esphome.address_cache import AddressCache
 from esphome.bundle import BUNDLE_EXTENSION, BundleFile, BundleResult
-from esphome.components import esp32, esp8266
+from esphome.components import esp32, esp8266, mqtt
 from esphome.components.esp32 import (
     KEY_ESP32,
     KEY_VARIANT,
     VARIANT_ESP32,
     get_esp32_variant,
 )
+from esphome.config import Config
 from esphome.const import (
     CONF_API,
     CONF_AUTH,
     CONF_BAUD_RATE,
     CONF_BROKER,
     CONF_DISABLED,
+    CONF_DISCOVER_IP,
     CONF_ESPHOME,
     CONF_LEVEL,
     CONF_LOG,
@@ -103,6 +107,7 @@ from esphome.const import (
     CONF_WEB_SERVER,
     CONF_WIFI,
     KEY_CORE,
+    KEY_TARGET_FRAMEWORK,
     KEY_TARGET_PLATFORM,
     PLATFORM_BK72XX,
     PLATFORM_ESP32,
@@ -567,8 +572,6 @@ def test_command_config__no_defaults_dumps_user_snapshot(
 ) -> None:
     """``--no-defaults`` dumps ``config.user_config`` instead of the
     validated config, so schema defaults don't leak into the output."""
-    from esphome.config import Config
-
     setup_core(tmp_path=tmp_path, config={"esphome": {"name": "test"}})
     args = MockArgs()
     args.show_secrets = True
@@ -621,8 +624,6 @@ def test_command_config__no_defaults_skips_strip_default_ids(
 ) -> None:
     """When ``--no-defaults`` is set, ``strip_default_ids`` isn't run --
     the user snapshot is already free of schema-injected IDs."""
-    from esphome.config import Config
-
     setup_core(tmp_path=tmp_path, config={"esphome": {"name": "test"}})
     args = MockArgs()
     args.show_secrets = True
@@ -3440,9 +3441,6 @@ def test_get_port_type() -> None:
 
 def test_mqtt_reexports_discover_ip() -> None:
     """The old import path must keep working for external code."""
-    from esphome.components import mqtt
-    from esphome.const import CONF_DISCOVER_IP
-
     assert mqtt.CONF_DISCOVER_IP is CONF_DISCOVER_IP
 
 
@@ -5909,8 +5907,6 @@ class MockSerial:
             chunk = self.chunks[self.chunk_index]
             if chunk is MOCK_SERIAL_END:
                 # Sentinel means we're done - simulate port closed
-                import serial
-
                 raise serial.SerialException("Port closed")
             # Respect the requested size and keep any remaining bytes
             if size <= 0:
@@ -5924,8 +5920,6 @@ class MockSerial:
                 # Entire chunk consumed; advance to the next one
                 self.chunk_index += 1
             return data  # type: ignore[return-value]
-        import serial
-
         raise serial.SerialException("Port closed")
 
 
@@ -6784,8 +6778,6 @@ def test_parse_args_argcomplete_only_runs_when_completing() -> None:
 
 def test_should_subscribe_states_default() -> None:
     """Test that states are shown by default when nothing is set."""
-    from esphome.__main__ import _should_subscribe_states
-
     args = parse_args(["esphome", "logs", "device.yaml"])
     with patch.dict(os.environ, {}, clear=False):
         os.environ.pop("ESPHOME_LOG_STATES", None)
@@ -6794,8 +6786,6 @@ def test_should_subscribe_states_default() -> None:
 
 def test_should_subscribe_states_env_suppresses() -> None:
     """Test that ESPHOME_LOG_STATES=false suppresses states by default."""
-    from esphome.__main__ import _should_subscribe_states
-
     args = parse_args(["esphome", "logs", "device.yaml"])
     with patch.dict(os.environ, {"ESPHOME_LOG_STATES": "false"}):
         assert _should_subscribe_states(args) is False
@@ -6803,8 +6793,6 @@ def test_should_subscribe_states_env_suppresses() -> None:
 
 def test_should_subscribe_states_env_enables() -> None:
     """Test that ESPHOME_LOG_STATES=true enables states by default."""
-    from esphome.__main__ import _should_subscribe_states
-
     args = parse_args(["esphome", "logs", "device.yaml"])
     with patch.dict(os.environ, {"ESPHOME_LOG_STATES": "true"}):
         assert _should_subscribe_states(args) is True
@@ -6812,8 +6800,6 @@ def test_should_subscribe_states_env_enables() -> None:
 
 def test_should_subscribe_states_flag_overrides_env() -> None:
     """Test that --states overrides ESPHOME_LOG_STATES=false."""
-    from esphome.__main__ import _should_subscribe_states
-
     args = parse_args(["esphome", "logs", "--states", "device.yaml"])
     with patch.dict(os.environ, {"ESPHOME_LOG_STATES": "false"}):
         assert _should_subscribe_states(args) is True
@@ -6821,8 +6807,6 @@ def test_should_subscribe_states_flag_overrides_env() -> None:
 
 def test_should_subscribe_states_no_flag_overrides_env() -> None:
     """Test that --no-states overrides ESPHOME_LOG_STATES=true."""
-    from esphome.__main__ import _should_subscribe_states
-
     args = parse_args(["esphome", "logs", "--no-states", "device.yaml"])
     with patch.dict(os.environ, {"ESPHOME_LOG_STATES": "true"}):
         assert _should_subscribe_states(args) is False
@@ -7135,6 +7119,82 @@ def test_warn_source_tree_mismatch_falls_back_when_stat_fails(
     assert not caplog.text
 
 
+@pytest.mark.parametrize(
+    "error",
+    [
+        FileNotFoundError("no such compiler"),
+        RuntimeError("Could not query builtin include dirs"),
+        ValueError("no C++ translation unit found"),
+        KeyError("command"),
+        None,  # replaced with EsphomeError inside
+    ],
+)
+def test_compile_program_espidf_idedata_failure_does_not_fail_build(
+    error: Exception,
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """A post-compile idedata error is a warning: the firmware already built."""
+    if error is None:
+        error = EsphomeError("compile database is unusable")
+    CORE.toolchain = Toolchain.ESP_IDF
+    CORE.data[KEY_CORE] = {
+        KEY_TARGET_PLATFORM: "esp32",
+        KEY_TARGET_FRAMEWORK: "esp-idf",
+    }
+    with (
+        patch("esphome.espidf.toolchain.run_compile", return_value=0),
+        patch("esphome.espidf.toolchain.create_factory_bin"),
+        patch("esphome.espidf.toolchain.create_ota_bin"),
+        patch("esphome.espidf.toolchain.create_elf_copy"),
+        patch("esphome.espidf.toolchain.get_idedata", side_effect=error),
+        patch("esphome.__main__._check_and_emit_build_info"),
+    ):
+        assert compile_program(MagicMock(), {}) == 0
+    assert "Could not generate idedata" in caplog.text
+
+
+def test_compile_program_espidf_idedata_success_is_silent(
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """The healthy path: idedata generated, nothing to warn about."""
+    CORE.toolchain = Toolchain.ESP_IDF
+    CORE.data[KEY_CORE] = {
+        KEY_TARGET_PLATFORM: "esp32",
+        KEY_TARGET_FRAMEWORK: "esp-idf",
+    }
+    with (
+        patch("esphome.espidf.toolchain.run_compile", return_value=0),
+        patch("esphome.espidf.toolchain.create_factory_bin"),
+        patch("esphome.espidf.toolchain.create_ota_bin"),
+        patch("esphome.espidf.toolchain.create_elf_copy"),
+        patch("esphome.espidf.toolchain.get_idedata", return_value={"cc_path": "x"}),
+        patch("esphome.__main__._check_and_emit_build_info"),
+    ):
+        assert compile_program(MagicMock(), {}) == 0
+    assert "idedata" not in caplog.text
+
+
+def test_compile_program_espidf_idedata_none_warns(
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """A silent None from the post-compile idedata refresh is made visible."""
+    CORE.toolchain = Toolchain.ESP_IDF
+    CORE.data[KEY_CORE] = {
+        KEY_TARGET_PLATFORM: "esp32",
+        KEY_TARGET_FRAMEWORK: "esp-idf",
+    }
+    with (
+        patch("esphome.espidf.toolchain.run_compile", return_value=0),
+        patch("esphome.espidf.toolchain.create_factory_bin"),
+        patch("esphome.espidf.toolchain.create_ota_bin"),
+        patch("esphome.espidf.toolchain.create_elf_copy"),
+        patch("esphome.espidf.toolchain.get_idedata", return_value=None),
+        patch("esphome.__main__._check_and_emit_build_info"),
+    ):
+        assert compile_program(MagicMock(), {}) == 0
+    assert "No idedata was generated" in caplog.text
+
+
 @pytest.mark.asyncio
 async def test_wrap_to_code_comment_is_insertion_order_independent() -> None:
     """The config comment dumps with sorted keys: voluptuous fills schema

tests/unit_tests/test_platformio_extra_script.py

@@ -0,0 +1,542 @@
+"""Tests for the shared extraScript machinery (platformio.extra_script)."""
+
+from __future__ import annotations
+
+import logging
+import os
+from pathlib import Path
+from unittest.mock import patch
+
+import pytest
+
+from esphome.core import EsphomeError
+from esphome.platformio.extra_script import (
+    CppDefine,
+    ExtraScriptResult,
+    _FakeSConsEnv,
+    apply_extra_script,
+    captured_as_build_flags,
+    run_extra_script,
+)
+from esphome.platformio.library import (
+    ESPHOME_DATA_KEY,
+    ESPHOME_DATA_LINK_FLAGS_KEY,
+    ConvertedLibrary as IDFComponent,
+    URLSource,
+    lex_build_flags,
+)
+
+
+def test_extra_script_captures_libpath_libs_and_defines(tmp_path):
+
+    (tmp_path / "src" / "esp32").mkdir(parents=True)
+    script = tmp_path / "extra_script.py"
+    script.write_text(
+        "Import('env')\n"
+        "mcu = env.get('BOARD_MCU')\n"
+        "env.Append(\n"
+        "    LIBPATH=[join('src', mcu)],\n"
+        "    LIBS=['algobsec'],\n"
+        "    CPPDEFINES=['FOO', ('BAR', '1')],\n"
+        "    LINKFLAGS=['-Wl,--gc-sections'],\n"
+        ")\n"
+    )
+    # The script uses bare ``join`` (PIO's extra-scripts run inside SCons
+    # where this is in scope). Inject it via the script header so the
+    # shim's exec namespace can resolve it.
+    script.write_text("from os.path import join\n" + script.read_text())
+
+    result = run_extra_script(
+        script, library_dir=tmp_path, board_mcu="esp32", pio_platform="espressif32"
+    )
+
+    assert result.libpath == [str(Path("src") / "esp32")]
+    assert result.libs == ["algobsec"]
+    assert CppDefine("BAR", "1") in result.cppdefines
+    assert CppDefine("FOO") in result.cppdefines
+    assert result.linkflags == ["-Wl,--gc-sections"]
+
+    # Lex like the consumer does: quoting makes raw strings platform-varying
+    tokens = lex_build_flags(
+        captured_as_build_flags(result, library_dir=tmp_path), "test"
+    )
+    sep = os.sep
+    assert f"-Lsrc{sep}esp32" in tokens
+    assert "-lalgobsec" in tokens
+    assert "-DFOO" in tokens
+    assert "-DBAR=1" in tokens
+    # LINKFLAGS travel via the link-flags channel, never the compile flags
+    assert "-Wl,--gc-sections" not in tokens
+
+
+def test_extra_script_libpath_relative_resolves_against_library_dir(
+    tmp_path, monkeypatch
+):
+    """Relative LIBPATH entries must resolve against ``library_dir``, not the
+    caller's CWD (the shim restores CWD before ``captured_as_build_flags``
+    runs)."""
+
+    (tmp_path / "lib" / "esp32").mkdir(parents=True)
+    elsewhere = tmp_path.parent / "not_the_library_dir"
+    elsewhere.mkdir(exist_ok=True)
+    monkeypatch.chdir(elsewhere)
+
+    result = ExtraScriptResult(libpath=["lib/esp32"])
+    flags = captured_as_build_flags(result, library_dir=tmp_path)
+
+    sep = os.sep
+    assert lex_build_flags(flags, "test") == [f"-Llib{sep}esp32"]
+
+
+def test_extra_script_libpath_absolute_outside_library_dir(tmp_path):
+
+    outside = tmp_path.parent / "system_lib"
+    outside.mkdir(exist_ok=True)
+    result = ExtraScriptResult(libpath=[str(outside)])
+
+    flags = captured_as_build_flags(result, library_dir=tmp_path)
+    assert lex_build_flags(flags, "test") == [f"-L{outside.resolve()}"]
+
+
+def test_extra_script_failure_returns_empty_result(tmp_path, caplog):
+
+    script = tmp_path / "broken.py"
+    script.write_text("raise RuntimeError('boom')\n")
+
+    with caplog.at_level("WARNING"):
+        result = run_extra_script(
+            script, library_dir=tmp_path, board_mcu="esp32", pio_platform="espressif32"
+        )
+
+    assert result.libpath == []
+    assert result.libs == []
+    assert "broken.py" in caplog.text
+
+
+def test_apply_extra_script_path_traversal_is_rejected(tmp_path):
+
+    library_dir = tmp_path / "lib"
+    library_dir.mkdir()
+    outside = tmp_path / "evil.py"
+    outside.write_text("env.Append(LIBS=['pwned'])\n")
+
+    c = IDFComponent("owner/name", "1.0", source=URLSource("http://dummy"))
+    c.path = library_dir
+    c.data = {"build": {"extraScript": "../evil.py"}}
+
+    with pytest.raises(EsphomeError, match="escapes the library directory"):
+        apply_extra_script(c, board_mcu=lambda: "esp32", pio_platform="espressif32")
+    # Nothing was folded into flags: the traversal was rejected before
+    # the script could run.
+    assert "flags" not in c.data["build"]
+
+
+def test_apply_extra_script_merges_into_existing_flags(tmp_path):
+
+    (tmp_path / "src").mkdir()
+    script = tmp_path / "extra.py"
+    script.write_text("env.Append(LIBS=['algobsec'])\n")
+
+    c = IDFComponent("owner/name", "1.0", source=URLSource("http://dummy"))
+    c.path = tmp_path
+    c.data = {"build": {"extraScript": "extra.py", "flags": ["-DEXISTING"]}}
+
+    apply_extra_script(c, board_mcu=lambda: "esp32", pio_platform="espressif32")
+
+    assert "-DEXISTING" in c.data["build"]["flags"]
+    assert "-lalgobsec" in c.data["build"]["flags"]
+
+
+def test_apply_extra_script_malformed_flags_raises(tmp_path) -> None:
+    """A null/dict build.flags fails naming the library instead of injecting
+    a non-string into the compiler command line."""
+
+    (tmp_path / "src").mkdir()
+    script = tmp_path / "extra.py"
+    script.write_text("env.Append(LIBS=['algobsec'])\n")
+
+    c = IDFComponent("owner/name", "1.0", source=URLSource("http://dummy"))
+    c.path = tmp_path
+    c.data = {"build": {"extraScript": "extra.py", "flags": None}}
+
+    with pytest.raises(EsphomeError, match="malformed build.flags"):
+        apply_extra_script(c, board_mcu=lambda: "esp32", pio_platform="espressif32")
+
+
+def test_apply_extra_script_callable_target_and_str_flags(tmp_path) -> None:
+    """The shared helper resolves the board_mcu callable lazily and normalizes
+    a string ``build.flags`` value into a list before extending it."""
+
+    (tmp_path / "src").mkdir()
+    script = tmp_path / "extra.py"
+    script.write_text("env.Append(LIBS=[env.get('BOARD_MCU')])\n")
+
+    c = IDFComponent("owner/name", "1.0", source=URLSource("http://dummy"))
+    c.path = tmp_path
+    c.data = {"build": {"extraScript": "extra.py", "flags": "-DBASE=1"}}
+
+    apply_extra_script(c, board_mcu=lambda: "esp8266", pio_platform="espressif8266")
+
+    assert c.data["build"]["flags"] == ["-DBASE=1", "-lesp8266"]
+
+
+def test_captured_nonstring_buckets_warn_and_skip(tmp_path, caplog) -> None:
+    """Non-string LIBS/LINKFLAGS/CPPFLAGS/LIBPATH entries (legal SCons
+    nodes) are skipped by name instead of stringified into garbage flags."""
+    (tmp_path / "src").mkdir()
+    script = tmp_path / "extra.py"
+    script.write_text(
+        "env.Append(LIBS=['m', 42], LINKFLAGS=['-Wl,-x', {'no': 1}], "
+        "CPPFLAGS=['-Os', 3.5], LIBPATH=['libs', 7])\n"
+    )
+    (tmp_path / "libs").mkdir()
+
+    c = IDFComponent("owner/name", "1.0", source=URLSource("http://dummy"))
+    c.path = tmp_path
+    c.data = {"build": {"extraScript": "extra.py"}}
+
+    apply_extra_script(c, board_mcu=lambda: "esp8266", pio_platform="espressif8266")
+
+    flags = c.data["build"]["flags"]
+    assert "-lm" in flags and "-Os" in flags
+    assert c.data[ESPHOME_DATA_KEY][ESPHOME_DATA_LINK_FLAGS_KEY] == ["-Wl,-x"]
+    assert not any("42" in f or "no" in f or "3.5" in f for f in flags)
+    assert "Ignoring unsupported LIBS entry 42" in caplog.text
+    assert "Ignoring unsupported LINKFLAGS entry {'no': 1}" in caplog.text
+    assert "Ignoring unsupported LIBPATH entry 7" in caplog.text
+
+
+def test_captured_dict_cppdefines_warn_and_skip(tmp_path, caplog) -> None:
+    """A dict CPPDEFINES entry (legal SCons) must warn and skip; formatting
+    it blind would hand the compiler -D{'FOO': '1'} garbage."""
+    (tmp_path / "src").mkdir()
+    script = tmp_path / "extra.py"
+    script.write_text(
+        "env.Append(CPPDEFINES=[{'FOO': '1'}, ('BAR', 2), ['BAZ', 3], 'PLAIN'])\n"
+    )
+
+    c = IDFComponent("owner/name", "1.0", source=URLSource("http://dummy"))
+    c.path = tmp_path
+    c.data = {"build": {"extraScript": "extra.py"}}
+
+    apply_extra_script(c, board_mcu=lambda: "esp8266", pio_platform="espressif8266")
+
+    assert c.data["build"]["flags"] == ["-DBAR=2", "-DBAZ=3", "-DPLAIN"]
+    assert "Ignoring unsupported CPPDEFINES entry" in caplog.text
+
+
+def test_apply_extra_script_subscript_env_read(tmp_path) -> None:
+    """Scripts also read env["BOARD_MCU"]; the subscript form must work or
+    the broad handler discards every flag the script captured."""
+    (tmp_path / "src").mkdir()
+    script = tmp_path / "extra.py"
+    script.write_text("env.Append(LIBS=[env['BOARD_MCU']])\n")
+
+    c = IDFComponent("owner/name", "1.0", source=URLSource("http://dummy"))
+    c.path = tmp_path
+    c.data = {"build": {"extraScript": "extra.py"}}
+
+    apply_extra_script(c, board_mcu=lambda: "esp8266", pio_platform="espressif8266")
+
+    assert c.data["build"]["flags"] == ["-lesp8266"]
+
+
+def test_apply_extra_script_no_script_and_no_flags(tmp_path) -> None:
+
+    # No extraScript declared: nothing happens, the target is never resolved
+    c = IDFComponent("owner/name", "1.0", source=URLSource("http://dummy"))
+    c.path = tmp_path
+    c.data = {"build": {}}
+    apply_extra_script(
+        c,
+        board_mcu=lambda: pytest.fail("target resolved without a script"),
+        pio_platform="espressif8266",
+    )
+
+    # A script that captures nothing leaves the flags untouched
+    script = tmp_path / "noop.py"
+    script.write_text("pass\n")
+    c.data = {"build": {"extraScript": "noop.py"}}
+    apply_extra_script(c, board_mcu=lambda: "esp8266", pio_platform="espressif8266")
+    assert "flags" not in c.data["build"]
+
+
+def test_apply_extra_script_ignores_uncaptured_env_calls(tmp_path, caplog) -> None:
+    """Un-captured env vars and unsupported env methods are skipped but
+    diagnosable from the build log."""
+
+    caplog.set_level(logging.DEBUG)
+    script = tmp_path / "extra.py"
+    script.write_text(
+        "env.Replace(CC='clang')\nenv.Append(UNCAPTURED=['x'], LIBS='single')\n"
+    )
+    c = IDFComponent("owner/name", "1.0", source=URLSource("http://dummy"))
+    c.path = tmp_path
+    c.data = {"build": {"extraScript": "extra.py"}}
+    apply_extra_script(c, board_mcu=lambda: "esp8266", pio_platform="espressif8266")
+    assert c.data["build"]["flags"] == ["-lsingle"]
+    assert "env.Append(UNCAPTURED=...) is not captured" in caplog.text
+    assert "env.Replace is not supported" in caplog.text
+
+
+def test_apply_extra_script_swallows_script_errors(tmp_path, caplog) -> None:
+    """A raising extra-script is best-effort: logged and skipped."""
+
+    script = tmp_path / "extra.py"
+    script.write_text("raise RuntimeError('boom')\n")
+    c = IDFComponent("owner/name", "1.0", source=URLSource("http://dummy"))
+    c.path = tmp_path
+    c.data = {"build": {"extraScript": "extra.py"}}
+    apply_extra_script(c, board_mcu=lambda: "esp8266", pio_platform="espressif8266")
+    assert "flags" not in c.data["build"]
+    assert "ignoring its output" in caplog.text
+
+
+def test_apply_extra_script_pio_platform(tmp_path) -> None:
+    """The backend's platform token is exposed to the script as PIOPLATFORM."""
+
+    script = tmp_path / "extra.py"
+    script.write_text("env.Append(LIBS=[env.get('PIOPLATFORM')])\n")
+    c = IDFComponent("owner/name", "1.0", source=URLSource("http://dummy"))
+    c.path = tmp_path
+    c.data = {"build": {"extraScript": "extra.py"}}
+    apply_extra_script(c, board_mcu=lambda: "esp8266", pio_platform="espressif8266")
+    assert c.data["build"]["flags"] == ["-lespressif8266"]
+
+
+def test_apply_extra_script_missing_script_raises(tmp_path) -> None:
+    """A declared but absent extraScript is a broken package and fails by
+    name, as it would under PlatformIO."""
+
+    c = IDFComponent("owner/name", "1.0", source=URLSource("http://dummy"))
+    c.path = tmp_path
+    c.data = {"build": {"extraScript": "nope.py"}}
+    with pytest.raises(EsphomeError, match="nope.py of library owner/name not found"):
+        apply_extra_script(c, board_mcu=lambda: "esp8266", pio_platform="espressif8266")
+
+
+@pytest.mark.parametrize("bad", (["a.py"], {"esp32": "a.py"}), ids=("list", "dict"))
+def test_apply_extra_script_non_string_raises(tmp_path, bad) -> None:
+    """A non-string extraScript fails naming the library, not with a TypeError."""
+
+    c = IDFComponent("owner/name", "1.0", source=URLSource("http://dummy"))
+    c.path = tmp_path
+    c.data = {"build": {"extraScript": bad}}
+    with pytest.raises(EsphomeError, match="of library owner/name must be a string"):
+        apply_extra_script(c, board_mcu=lambda: "esp8266", pio_platform="espressif8266")
+
+
+def test_extra_script_cpppath_captured_as_include_flags(tmp_path, monkeypatch):
+    """CPPPATH entries translate to -I flags anchored like LIBPATH."""
+
+    (tmp_path / "include").mkdir()
+    outside = tmp_path.parent / "system_inc"
+    outside.mkdir(exist_ok=True)
+    elsewhere = tmp_path.parent / "not_the_library_dir"
+    elsewhere.mkdir(exist_ok=True)
+    monkeypatch.chdir(elsewhere)
+
+    result = ExtraScriptResult(cpppath=["include", str(outside), 7])
+    flags = captured_as_build_flags(result, library_dir=tmp_path)
+
+    assert lex_build_flags(flags, "test") == ["-Iinclude", f"-I{outside.resolve()}"]
+
+
+def test_extra_script_spaced_paths_survive_relexing(tmp_path):
+    """-I/-L paths with spaces round-trip through lex_build_flags as one token."""
+    (tmp_path / "my libs").mkdir()
+    result = ExtraScriptResult(cpppath=["my libs"], libpath=["my libs"])
+    flags = captured_as_build_flags(result, library_dir=tmp_path)
+    assert lex_build_flags(flags, "test") == ["-Imy libs", "-Lmy libs"]
+
+
+def test_run_extra_script_failure_discards_partial_capture(tmp_path, caplog) -> None:
+    """A crashed script yields an empty result: half-applied flags could
+    build wrong-output firmware that links cleanly."""
+
+    script = tmp_path / "extra.py"
+    script.write_text("env.Append(LIBS=['algobsec'])\nraise RuntimeError('boom')\n")
+    result = run_extra_script(
+        script, library_dir=tmp_path, board_mcu="esp32", pio_platform="espressif32"
+    )
+    assert result.libs == []
+    assert "ignoring its output" in caplog.text
+
+
+def test_run_extra_script_syntax_error_is_best_effort(tmp_path, caplog) -> None:
+    """A vendored script that does not even compile warns and skips instead
+    of aborting the build."""
+
+    script = tmp_path / "extra.py"
+    script.write_text("def broken(:\n")
+    result = run_extra_script(
+        script, library_dir=tmp_path, board_mcu="esp32", pio_platform="espressif32"
+    )
+    assert result.libs == []
+    assert "ignoring its output" in caplog.text
+
+
+def test_unsupported_env_method_warns_once(caplog) -> None:
+    """Repeated calls to the same unsupported method warn only once."""
+
+    env = _FakeSConsEnv(
+        board_mcu="esp8266", pio_env="esphome_esp8266", pio_platform="espressif8266"
+    )
+    env.Replace(CC="clang")
+    env.Replace(CC="gcc")
+    assert caplog.text.count("env.Replace is not supported") == 1
+
+
+def test_run_extra_script_sys_exit_is_best_effort(tmp_path, caplog) -> None:
+    """A nonzero sys.exit() in a vendored script must not kill the esphome
+    run, and its output is discarded."""
+
+    script = tmp_path / "extra.py"
+    script.write_text("import sys\nenv.Append(LIBS=['x'])\nsys.exit(3)\n")
+    result = run_extra_script(
+        script, library_dir=tmp_path, board_mcu="esp32", pio_platform="espressif32"
+    )
+    assert result.libs == []
+    assert "exited with status 3" in caplog.text
+
+
+def test_run_extra_script_sys_exit_zero_is_success(tmp_path, caplog) -> None:
+    """sys.exit(0) is a normal PlatformIO script ending: the capture is kept."""
+
+    script = tmp_path / "extra.py"
+    script.write_text("import sys\nenv.Append(LIBS=['algobsec'])\nsys.exit(0)\n")
+    result = run_extra_script(
+        script, library_dir=tmp_path, board_mcu="esp32", pio_platform="espressif32"
+    )
+    assert result.libs == ["algobsec"]
+    assert "ignoring its output" not in caplog.text
+
+
+def test_run_extra_script_unreadable_raises(tmp_path) -> None:
+    """An unreadable declared script is a broken package, like a missing one."""
+
+    script = tmp_path / "extra.py"
+    script.write_text("")
+    with (
+        patch("pathlib.Path.read_text", side_effect=OSError("denied")),
+        pytest.raises(EsphomeError, match="is unreadable"),
+    ):
+        run_extra_script(
+            script, library_dir=tmp_path, board_mcu="esp32", pio_platform="espressif32"
+        )
+
+
+def test_run_extra_script_bad_encoding_is_best_effort(tmp_path, caplog) -> None:
+    """Undecodable content warns and skips, like a SyntaxError."""
+
+    script = tmp_path / "extra.py"
+    script.write_bytes(b"\xff\xfe\x00bad")
+    result = run_extra_script(
+        script, library_dir=tmp_path, board_mcu="esp32", pio_platform="espressif32"
+    )
+    assert result.libs == []
+    assert "is not UTF-8" in caplog.text
+
+
+@pytest.mark.parametrize("method", ("Prepend", "AppendUnique", "PrependUnique"))
+def test_append_variants_capture_like_append(method: str) -> None:
+    """Prepend/AppendUnique/PrependUnique write the captured keys too."""
+    env = _FakeSConsEnv(
+        board_mcu="esp8266", pio_env="esphome_esp8266", pio_platform="espressif8266"
+    )
+    getattr(env, method)(LIBS=["algobsec"], LIBPATH=["lib"])
+    assert env.result.libs == ["algobsec"]
+    assert env.result.libpath == ["lib"]
+
+
+@pytest.mark.parametrize("method", ("Prepend", "PrependUnique"))
+def test_prepend_inserts_ahead_of_existing(method: str) -> None:
+    """Prepend keeps SCons order: new values land ahead of what is already
+    captured (scripts prepend LIBS for static-link symbol resolution)."""
+    env = _FakeSConsEnv(
+        board_mcu="esp8266", pio_env="esphome_esp8266", pio_platform="espressif8266"
+    )
+    env.Append(LIBS=["m"])
+    getattr(env, method)(LIBS=["algobsec", "bsec"])
+    assert env.result.libs == ["algobsec", "bsec", "m"]
+
+
+def test_env_get_unknown_key_warns_once(caplog) -> None:
+    """A script branching on an unmodelled env var is diagnosable."""
+    env = _FakeSConsEnv(
+        board_mcu="esp8266", pio_env="esphome_esp8266", pio_platform="espressif8266"
+    )
+    assert env.get("BOARD") is None
+    assert env.get("BOARD", "d1") == "d1"
+    assert env.get("BOARD_MCU") == "esp8266"
+    assert caplog.text.count("env.get('BOARD') is not modelled") == 1
+    assert "BOARD_MCU" not in caplog.text
+
+
+def test_spaced_cppflag_survives_relexing(tmp_path) -> None:
+    """A captured argv token with a space stays one token after lexing."""
+    result = ExtraScriptResult(
+        cppflags=["-include my hdr.h"],
+        cppdefines=[CppDefine("MSG", '"hello world"'), CppDefine("PLAIN")],
+    )
+    flags = captured_as_build_flags(result, library_dir=tmp_path)
+    assert lex_build_flags(flags, "test") == [
+        '-DMSG="hello world"',
+        "-DPLAIN",
+        "-include my hdr.h",
+    ]
+
+
+def test_env_attribute_access_warns_without_call(caplog) -> None:
+    """hasattr()/truthiness on an unsupported method is diagnosable; dunder
+    protocol probes stay silent."""
+    env = _FakeSConsEnv(
+        board_mcu="esp8266", pio_env="esphome_esp8266", pio_platform="espressif8266"
+    )
+    assert env.GetProjectOption
+    assert caplog.text.count("env.GetProjectOption is not supported") == 1
+    assert not hasattr(env, "__deepcopy__")
+    assert "__deepcopy__" not in caplog.text
+
+
+def test_env_unmodelled_subscript_degrades_one_branch(caplog) -> None:
+    """env[...] on an unmodelled var returns '' instead of KeyError
+    discarding the whole capture."""
+    env = _FakeSConsEnv(
+        board_mcu="esp8266", pio_env="esphome_esp8266", pio_platform="espressif8266"
+    )
+    assert env["PIOFRAMEWORK"] == ""
+    assert env["PIOFRAMEWORK"] == ""
+    assert caplog.text.count("env['PIOFRAMEWORK'] is not modelled") == 1
+    assert env["BOARD_MCU"] == "esp8266"
+    env.Append(LIBS=["still_captured"])
+    assert env.result.libs == ["still_captured"]
+
+
+def test_cppdefines_scons_spellings(tmp_path) -> None:
+    """A bare 2-tuple is one name=value pair, a dict maps names to values,
+    and a None value is a bare define (SCons processDefines)."""
+    env = _FakeSConsEnv(
+        board_mcu="esp8266", pio_env="esphome_esp8266", pio_platform="espressif8266"
+    )
+    env.Append(CPPDEFINES=("FOO", "1"))
+    env.Append(CPPDEFINES={"BAR": "2", "BAZ": None})
+    env.Append(CPPDEFINES=["PLAIN"])
+    flags = captured_as_build_flags(env.result, library_dir=tmp_path)
+    assert lex_build_flags(flags, "test") == [
+        "-DFOO=1",
+        "-DBAR=2",
+        "-DBAZ",
+        "-DPLAIN",
+    ]
+
+
+def test_uncaptured_append_key_warns_once(caplog) -> None:
+    """A loop of Appends to the same uncaptured key warns once."""
+
+    env = _FakeSConsEnv(
+        board_mcu="esp8266", pio_env="esphome_esp8266", pio_platform="espressif8266"
+    )
+    env.Append(RANLIBFLAGS=["a"])
+    env.Append(RANLIBFLAGS=["b"])
+    assert caplog.text.count("env.Append(RANLIBFLAGS=...) is not captured") == 1

tests/unit_tests/test_platformio_library.py

@@ -13,6 +13,7 @@ import pytest
 from esphome.core import EsphomeError, Library
 import esphome.platformio.library as lib
 from esphome.platformio.library import (
+    SOURCE_KIND_FOR_SUFFIX,
     ConvertedLibrary,
     GitSource,
     InvalidLibrary,
@@ -23,6 +24,8 @@ from esphome.platformio.library import (
     _resolve_registry_version,
     check_library_data,
     convert_libraries,
+    join_flag_args,
+    split_flag_entry,
 )
 
 
@@ -150,11 +153,15 @@ def test_localsource_download_returns_empty_build_dir(setup_core: Path) -> None:
     assert plain != out
 
 
-def test_urlsource_download_extracts_then_reuses_marker(setup_core, monkeypatch):
+def test_urlsource_download_extracts_then_reuses_marker(
+    setup_core, monkeypatch, caplog
+):
     monkeypatch.setattr(lib, "rmdir", lambda path, msg="": None)
     dl_calls: list[list[str]] = []
     monkeypatch.setattr(
-        lib, "download_from_mirrors", lambda urls, headers, f: dl_calls.append(urls)
+        lib,
+        "download_from_mirrors",
+        lambda urls, headers, f, progress=None: dl_calls.append(urls),
     )
 
     def fake_extract(fileobj, path):
@@ -173,6 +180,12 @@ def test_urlsource_download_extracts_then_reuses_marker(setup_core, monkeypatch)
     assert out2 == out
     assert len(dl_calls) == 1
 
+    # A batch caller passes a tracker and owns the messaging; no per-file INFO
+    caplog.set_level("INFO")
+    src.download("mylib-batch", progress=lambda done: None)
+    assert len(dl_calls) == 2
+    assert "Downloading" not in caplog.text
+
 
 def test_resolve_registry_version_raises_without_pkg_file(monkeypatch):
     registry = lib._make_registry_client()
@@ -206,6 +219,7 @@ def _patch_registry_resolve(monkeypatch: pytest.MonkeyPatch) -> None:
             pkgname,
             "1.0.0",
             f"http://x/{pkgname}.tar.gz",
+            None,
         ),
     )
 
@@ -225,6 +239,38 @@ def _patch_download_with_manifests(monkeypatch, tmp_path, manifests, *, properti
     _patch_registry_resolve(monkeypatch)
 
 
+def test_wave_requirement_growth_defers_the_superseded_download(tmp_path, monkeypatch):
+    """A's manifest constrains B while B sits in the same wave: B's
+    drain-time resolution is superseded, so its download defers to the
+    next wave instead of fetching a version that is immediately replaced."""
+    download_names: list[str] = []
+    manifests = {
+        "esphome/A": {
+            "name": "A",
+            "build": {},
+            "dependencies": {"esphome/B": ">=1.0"},
+        },
+        "esphome/B": {"name": "B", "build": {}},
+    }
+
+    def fake_download(self, force=False, salt="", namespace="", progress=None):
+        download_names.append(self.name)
+        self.path = tmp_path / self.get_require_name()
+        self.path.mkdir(parents=True, exist_ok=True)
+        (self.path / "library.json").write_text(json.dumps(manifests[self.name]))
+
+    monkeypatch.setattr(ConvertedLibrary, "download", fake_download)
+    # Hermetic: the stubbed registry reports no size, so no batch prefetch
+    _patch_registry_resolve(monkeypatch)
+    top = convert_libraries(
+        [Library("esphome/A", "1.0.0", None), Library("esphome/B", None, None)],
+        _backend(),
+    )
+    assert sorted(c.name for c in top) == ["esphome/A", "esphome/B"]
+    # B downloads exactly once, after its requirement set stabilized
+    assert download_names.count("esphome/B") == 1
+
+
 def test_convert_libraries_parses_library_properties(tmp_path, monkeypatch):
     # A manifest provided as library.properties (Arduino style) instead of
     # library.json must still be parsed and converted.
@@ -292,7 +338,10 @@ def _patch_download_without_manifest(
     calls: list[bool] = []
 
     def fake_download(
-        self: ConvertedLibrary, force: bool = False, salt: str = "", namespace: str = ""
+        self: ConvertedLibrary,
+        force: bool = False,
+        salt: str = "",
+        namespace: str = "",
     ) -> None:
         calls.append(force)
         self.path = tmp_path / self.get_require_name()
@@ -531,3 +580,313 @@ def test_convert_libraries_skips_incompatible_dependency(tmp_path, monkeypatch):
     top = convert_libraries([Library("esphome/A", "1.0.0", None)], _backend())
 
     assert top[0].dependencies == []
+
+
+def test_split_flag_entry_unbalanced_quote_is_clean() -> None:
+    """A malformed flags entry raises EsphomeError, not a raw ValueError."""
+
+    assert split_flag_entry('-DX="a b"', "library x") == ["-DX=a b"]
+    with pytest.raises(EsphomeError, match=r"Malformed build flag.*library x"):
+        split_flag_entry('-DX="unclosed', "library x")
+
+
+def test_join_flag_args_reglues_spaced_define() -> None:
+    """A spaced -D re-glues to its argument, as ParseFlags does."""
+
+    assert join_flag_args(["-D", "FOO=1", "-Os"], "x") == ["-DFOO=1", "-Os"]
+
+
+def test_join_flag_args_trailing_bare_flag_warns(
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+
+    assert join_flag_args(["-Os", "-l"], "library x") == ["-Os"]
+    assert "Ignoring trailing '-l'" in caplog.text
+
+
+def test_lex_build_flags_dangling_flag_does_not_cross_entries(
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """Each entry is lexed independently, as ParseFlags does: a dangling -I
+    ending one entry warns instead of absorbing the next entry's first token."""
+    from esphome.platformio.library import lex_build_flags
+
+    assert lex_build_flags(["-Wall -I", "-DFOO=1"], "lib x") == ["-Wall", "-DFOO=1"]
+    assert "Ignoring trailing '-I'" in caplog.text
+
+
+def test_prefetch_wave_downloads_registry_archives_in_parallel(
+    setup_core, monkeypatch: pytest.MonkeyPatch, caplog: pytest.LogCaptureFixture
+) -> None:
+    """Registry archives in one wave download concurrently, deduped by URL;
+    git/local sources and failures are left to the sequential call."""
+    calls: list[str] = []
+
+    def fake_download(
+        self, dir_suffix, force=False, salt="", namespace="", progress=None
+    ):
+        calls.append(self.url)
+        if progress is not None:
+            progress(0)
+        if "boom" in self.url:
+            raise RuntimeError("boom")
+
+    monkeypatch.setattr(URLSource, "download", fake_download)
+    wave = [
+        ("a", ConvertedLibrary("a", "1.0", URLSource("https://x/a.tar.gz", 1))),
+        ("b", ConvertedLibrary("b", "1.0", URLSource("https://x/b.tar.gz", 1))),
+        # Duplicate URL must prefetch once (two threads must never extract
+        # into the same cache directory)
+        ("b2", ConvertedLibrary("b2", "1.0", URLSource("https://x/b.tar.gz", 1))),
+        ("c", ConvertedLibrary("c", "1.0", URLSource("https://x/boom.tar.gz", 1))),
+        ("g", ConvertedLibrary("g", "*", lib.GitSource("https://x/g.git", None))),
+    ]
+    lib._prefetch_wave(wave, "", "idf")
+    assert sorted(calls) == [
+        "https://x/a.tar.gz",
+        "https://x/b.tar.gz",
+        "https://x/boom.tar.gz",
+    ]
+    # The failure surfaces at default verbosity, after the bar
+    assert "Prefetch of c failed (retrying sequentially)" in caplog.text
+
+
+def test_prefetch_wave_unknown_size_left_to_sequential(
+    setup_core, monkeypatch: pytest.MonkeyPatch
+) -> None:
+    """Archives without a registry-reported size skip the batch (their
+    sequential per-file bars don't interleave); the known subset still
+    prefetches."""
+    calls: list[str] = []
+    monkeypatch.setattr(
+        URLSource,
+        "download",
+        lambda self, dir_suffix, force=False, salt="", namespace="", progress=None: (
+            calls.append(self.url)
+        ),
+    )
+    wave = [
+        ("a", ConvertedLibrary("a", "1.0", URLSource("https://x/a.tar.gz", 1))),
+        ("b", ConvertedLibrary("b", "1.0", URLSource("https://x/b.tar.gz", 1))),
+        ("u", ConvertedLibrary("u", "1.0", URLSource("https://x/u.tar.gz"))),
+    ]
+    lib._prefetch_wave(wave, "", "idf")
+    assert sorted(calls) == ["https://x/a.tar.gz", "https://x/b.tar.gz"]
+
+
+def test_join_flag_args_empty_argument_warns_and_drops(
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """An empty glued argument is dropped: a bare -D would eat the next flag."""
+    assert lib.lex_build_flags('-D "" -DFOO', "build_flags") == ["-DFOO"]
+    assert "Ignoring '-D' with empty argument in build_flags" in caplog.text
+
+
+def test_prefetch_wave_cache_probe_failure_still_prefetches(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    """The cache probe is best-effort; a failing probe prefetches anyway."""
+    calls: list[str] = []
+    monkeypatch.setattr(
+        URLSource,
+        "download",
+        lambda self, dir_suffix, **kw: calls.append(self.url),
+    )
+    monkeypatch.setattr(
+        URLSource,
+        "is_cached",
+        lambda self, *a, **kw: (_ for _ in ()).throw(RuntimeError("no core")),
+    )
+    wave = [
+        ("a", ConvertedLibrary("a", "1.0", URLSource("https://x/a.tar.gz", 1))),
+        ("b", ConvertedLibrary("b", "1.0", URLSource("https://x/b.tar.gz", 1))),
+    ]
+    lib._prefetch_wave(wave, "", "idf")
+    assert sorted(calls) == ["https://x/a.tar.gz", "https://x/b.tar.gz"]
+
+
+def test_prefetch_wave_internal_error_never_fails_the_build(
+    monkeypatch: pytest.MonkeyPatch, caplog: pytest.LogCaptureFixture
+) -> None:
+    """The blanket guard keeps a prefetch bug from failing the walk."""
+    monkeypatch.setattr(
+        lib,
+        "run_batch_downloads",
+        lambda *a, **kw: (_ for _ in ()).throw(RuntimeError("bug")),
+    )
+    wave = [
+        ("a", ConvertedLibrary("a", "1.0", URLSource("https://x/a.tar.gz", 1))),
+        ("b", ConvertedLibrary("b", "1.0", URLSource("https://x/b.tar.gz", 1))),
+    ]
+    lib._prefetch_wave(wave, "", "idf")
+    assert "Library prefetch failed: bug" in caplog.text
+
+
+def test_prefetch_wave_warm_cache_is_silent(
+    setup_core, monkeypatch: pytest.MonkeyPatch, caplog: pytest.LogCaptureFixture
+) -> None:
+    """Already-extracted archives download nothing; a warm build must not
+    print a Downloading line or draw a bar."""
+    monkeypatch.setattr(
+        URLSource,
+        "download",
+        lambda self, dir_suffix, **kw: (_ for _ in ()).throw(
+            AssertionError("downloaded")
+        ),
+    )
+    wave = []
+    for name in ("a", "b", "c"):
+        comp = ConvertedLibrary(name, "1.0", URLSource(f"https://x/{name}.tar.gz", 1))
+        marker_dir = comp.source._cache_dir(comp.get_sanitized_name(), "", "idf")
+        marker_dir.mkdir(parents=True)
+        (marker_dir / ".esphome_extracted").touch()
+        wave.append((name, comp))
+    lib._prefetch_wave(wave, "", "idf")
+    assert "Downloading" not in caplog.text
+
+
+def test_prefetch_wave_single_archive_uses_the_batch(
+    monkeypatch: pytest.MonkeyPatch, caplog: pytest.LogCaptureFixture
+) -> None:
+    """A dependency chain discovers one archive per wave; it downloads
+    through the same runner so there is one download method and one bar."""
+    caplog.set_level("INFO")
+    calls: list[str] = []
+    monkeypatch.setattr(
+        URLSource,
+        "download",
+        lambda self, dir_suffix, force=False, salt="", namespace="", progress=None: (
+            calls.append(self.url)
+        ),
+    )
+    lib._prefetch_wave(
+        [("a", ConvertedLibrary("a", "1.0", URLSource("https://x/a.tar.gz", 1)))],
+        "",
+        "idf",
+    )
+    assert calls == ["https://x/a.tar.gz"]
+    assert "Downloading 1 library archive(s): a" in caplog.text
+
+
+def test_normalize_dependencies_forms(caplog) -> None:
+    """Every PIO-legal spelling normalizes; unrecognizable entries warn."""
+    from esphome.platformio.library import normalize_dependencies
+
+    assert normalize_dependencies(
+        ["Wire", {"name": "SPI"}, 5, "", {"version": "1.0"}], "libx"
+    ) == [
+        {"name": "Wire"},
+        {"name": "SPI"},
+    ]
+    # The int, the empty string, and the nameless dict all warn
+    assert caplog.text.count("unrecognized dependency entry") == 3
+    # A plain string is names, never iterated into characters
+    assert normalize_dependencies("Wire, SPI") == [
+        {"name": "Wire"},
+        {"name": "SPI"},
+    ]
+    assert normalize_dependencies("Wire") == [{"name": "Wire"}]
+    # A non-iterable value fails by manifest name, never a bare TypeError
+    assert normalize_dependencies(5, "libx") == []
+    assert "Ignoring unrecognized dependencies 5 of libx" in caplog.text
+    # The dict-shorthand form validates names like the list form: an empty
+    # key and a spec overriding name with a non-string both warn and drop
+    assert normalize_dependencies(
+        {"": "1.0", "Wire": {"name": 123, "version": "1.0"}, "SPI": "*"}, "libx"
+    ) == [{"name": "SPI", "owner": None, "version": "*"}]
+    assert caplog.text.count("unrecognized dependency entry") == 5
+    # A container or numeric version would raise from set.add() or fail
+    # opaquely in the registry; both spellings warn and drop
+    assert normalize_dependencies({"Foo": ["1.0", "2.0"]}, "libx") == []
+    assert normalize_dependencies([{"name": "Foo", "version": 1}], "libx") == []
+    assert caplog.text.count("unrecognized dependency entry") == 7
+
+
+@pytest.mark.parametrize(
+    "manifest", [["not", "a", "manifest"], {"name": "A", "build": "src"}]
+)
+def test_convert_libraries_malformed_manifest_raises(
+    tmp_path, monkeypatch, manifest
+) -> None:
+    """A manifest without the expected dict shape fails by library name
+    before any backend dereferences data/build."""
+    _patch_download_with_manifests(monkeypatch, tmp_path, {"esphome/A": manifest})
+    with pytest.raises(EsphomeError, match="has a malformed manifest"):
+        convert_libraries([Library("esphome/A", None, None)], _backend())
+
+
+def test_walk_warns_for_properties_only_depends(
+    tmp_path, monkeypatch, caplog: pytest.LogCaptureFixture
+) -> None:
+    """A manifest declaring dependencies only as library.properties depends=
+    warns in the shared walk, so every backend reports the drop."""
+    _patch_download_with_manifests(
+        monkeypatch,
+        tmp_path,
+        {"esphome/A": "name=A\nversion=1.0\ndepends=Wire, SPI\n"},
+        properties=("esphome/A",),
+    )
+    caplog.set_level("INFO")
+    convert_libraries([Library("esphome/A", "1.0.0", None)], _backend())
+    assert "declares dependencies via library.properties" in caplog.text
+
+
+def test_walk_warns_for_nonplatform_invalid_library(
+    tmp_path, monkeypatch, caplog: pytest.LogCaptureFixture
+) -> None:
+    """A dependency dropped for any cause other than the routine platform
+    filter is visible in every backend."""
+    _patch_download_with_manifests(
+        monkeypatch,
+        tmp_path,
+        {
+            "esphome/A": {
+                "name": "A",
+                "dependencies": [{"name": "B", "version": "1.0", "platforms": [123]}],
+            }
+        },
+    )
+    convert_libraries([Library("esphome/A", None, None)], _backend())
+    assert "Skipping dependency B of esphome/A: Malformed platforms" in caplog.text
+
+
+def test_convert_libraries_warns_for_nonplatform_invalid_dependency_component(
+    tmp_path, monkeypatch, caplog: pytest.LogCaptureFixture
+) -> None:
+    """A dependency component dropped for any cause other than the platform
+    filter warns; only the routine cross-platform skip stays at debug."""
+    _patch_download_with_manifests(
+        monkeypatch,
+        tmp_path,
+        {
+            "esphome/A": {
+                "name": "A",
+                "dependencies": [{"name": "C", "owner": "esphome", "version": "1.0"}],
+            },
+            "esphome/C": {"name": "C", "frameworks": [None]},
+        },
+    )
+    convert_libraries([Library("esphome/A", "1.0.0", None)], _backend())
+    assert "Malformed frameworks" in caplog.text
+    assert "Skipping dependency" in caplog.text
+
+
+def test_split_flag_entry_non_string_is_clean() -> None:
+    """A dict or number from a third-party manifest fails naming the entry,
+    not with an opaque shlex traceback."""
+
+    with pytest.raises(EsphomeError, match="Malformed build flag"):
+        split_flag_entry({"esp32": ["-DX"]}, "lib x")
+    with pytest.raises(EsphomeError, match="Malformed build flag 5"):
+        split_flag_entry(5, "lib x")
+
+
+def test_source_kind_map_shape() -> None:
+    """The kind values the native compile rules key on, and the deliberate
+    AS/ASPP merge (.s and .S both map to asm)."""
+
+    assert set(SOURCE_KIND_FOR_SUFFIX.values()) == {"c", "cxx", "asm"}
+    assert SOURCE_KIND_FOR_SUFFIX[".s"] == "asm"
+    assert SOURCE_KIND_FOR_SUFFIX[".S"] == "asm"
+    assert SOURCE_KIND_FOR_SUFFIX[".c"] == "c"
+    assert SOURCE_KIND_FOR_SUFFIX[".cpp"] == "cxx"

tests/unit_tests/test_platformio_toolchain.py

@@ -1977,3 +1977,10 @@ def test_run_platformio_cli_invokes_heal(
     with patch.object(toolchain, "heal_platformio_python_env") as mock_heal:
         toolchain.run_platformio_cli("test")
     mock_heal.assert_called_once()
+
+
+def test_ccache_probe_spawns_with_close_fds_false() -> None:
+    """The probe follows the repo-wide posix_spawn convention."""
+    with patch("subprocess.run") as mock_run:
+        assert toolchain._ccache_runs("/usr/bin/ccache") is True
+    assert mock_run.call_args.kwargs["close_fds"] is False

tests/unit_tests/test_size_summary.py

@@ -126,3 +126,20 @@ def test_print_summary_handles_no_memory_types(
     size_json = _write_size_json(tmp_path, {"image_size": 0})
     print_summary(size_json, partitions_csv=None)
     assert capsys.readouterr().out == ""
+
+
+def test_print_summary_flash_line(
+    tmp_path: Path, capsys: pytest.CaptureFixture[str]
+) -> None:
+    """A partition table with an app row yields the Flash line in the exact
+    padded shape script/ci_memory_impact_extract.py greps."""
+    size_json = _write_size_json(tmp_path, _esp32_size_data())
+    partitions = tmp_path / "partitions.csv"
+    partitions.write_text(
+        "# name, type, subtype, offset, size, flags\n"
+        "app0, app, ota_0, 0x10000, 0x1C0000,\n"
+    )
+    print_summary(size_json, partitions)
+    out = capsys.readouterr().out
+    assert "Flash: " in out
+    assert "(used 827455 bytes from 1835008 bytes)" in out