Merge branch 'esp8266-native-converter-hardening' into esp8266-native-library-converter

esphome/components/esp32_ble/__init__.py

@@ -22,6 +22,7 @@ from esphome.components.esp32 import (
     request_bluetooth,
 )
 from esphome.components.esp32.const import VARIANT_ESP32C2
+from esphome.config_helpers import filter_source_files_from_defines
 import esphome.config_validation as cv
 from esphome.const import (
     CONF_ENABLE_ON_BOOT,
@@ -637,3 +638,10 @@ async def ble_disable_to_code(
     args: TemplateArgsType,
 ) -> MockObj:
     return cg.new_Pvariable(action_id, template_arg)
+
+
+# ble_advertising.cpp is fully #ifdef'd on USE_ESP32_BLE_ADVERTISING, set
+# when advertising is enabled here or by esp32_ble_server / esp32_ble_beacon.
+FILTER_SOURCE_FILES = filter_source_files_from_defines(
+    {"ble_advertising.cpp": "USE_ESP32_BLE_ADVERTISING"}
+)

esphome/components/i2s_audio/speaker/__init__.py

@@ -1,6 +1,7 @@
 from esphome import pins
 import esphome.codegen as cg
 from esphome.components import audio, esp32, speaker
+from esphome.config_helpers import filter_source_files_from_defines
 import esphome.config_validation as cv
 from esphome.const import (
     CONF_BITS_PER_SAMPLE,
@@ -261,3 +262,13 @@ async def to_code(config: ConfigType) -> None:
     if config[CONF_TIMEOUT] != CONF_NEVER:
         cg.add(var.set_timeout(config[CONF_TIMEOUT]))
     cg.add(var.set_buffer_duration(config[CONF_BUFFER_DURATION]))
+
+
+# The SPDIF encoder and speaker are fully #ifdef'd on USE_I2S_AUDIO_SPDIF_MODE,
+# set only when spdif_mode is enabled.
+FILTER_SOURCE_FILES = filter_source_files_from_defines(
+    {
+        "spdif_encoder.cpp": "USE_I2S_AUDIO_SPDIF_MODE",
+        "i2s_audio_spdif.cpp": "USE_I2S_AUDIO_SPDIF_MODE",
+    }
+)

esphome/components/light/__init__.py

@@ -7,6 +7,7 @@ import esphome.automation as auto
 import esphome.codegen as cg
 from esphome.components import mqtt, power_supply, web_server
 from esphome.components.const import CONF_CHANNEL_COLORS, CONF_IS_WRGB
+from esphome.config_helpers import filter_source_files_from_defines
 import esphome.config_validation as cv
 from esphome.const import (
     CONF_BLUE,
@@ -557,3 +558,10 @@ async def new_light(config, *args):
 @coroutine_with_priority(CoroPriority.CORE)
 async def to_code(config):
     cg.add_global(light_ns.using)
+
+
+# light_json_schema.cpp is only used by mqtt and web_server, which both
+# auto load json; USE_JSON alone is too broad since other components load it.
+FILTER_SOURCE_FILES = filter_source_files_from_defines(
+    {"light_json_schema.cpp": ("USE_MQTT", "USE_WEBSERVER")}
+)

esphome/components/mqtt/__init__.py

@@ -8,7 +8,10 @@ from esphome.components.esp32 import (
     idf_version,
     include_builtin_idf_component,
 )
-from esphome.config_helpers import filter_source_files_from_platform
+from esphome.config_helpers import (
+    filter_source_files_from_defines,
+    filter_source_files_from_platform,
+)
 import esphome.config_validation as cv
 from esphome.const import (
     CONF_AVAILABILITY,
@@ -640,7 +643,7 @@ async def mqtt_disable_to_code(config, action_id, template_arg, args):
     return cg.new_Pvariable(action_id, template_arg, paren)
 
 
-FILTER_SOURCE_FILES = filter_source_files_from_platform(
+_platform_filter = filter_source_files_from_platform(
     {
         "mqtt_backend_esp32.cpp": {
             PlatformFramework.ESP32_ARDUINO,
@@ -648,3 +651,34 @@ FILTER_SOURCE_FILES = filter_source_files_from_platform(
         },
     }
 )
+
+# Each entity file is fully #ifdef'd on the USE_<ENTITY> define the core
+# emits for entity platforms present in the config.
+_define_filter = filter_source_files_from_defines(
+    {
+        "mqtt_alarm_control_panel.cpp": "USE_ALARM_CONTROL_PANEL",
+        "mqtt_binary_sensor.cpp": "USE_BINARY_SENSOR",
+        "mqtt_button.cpp": "USE_BUTTON",
+        "mqtt_climate.cpp": "USE_CLIMATE",
+        "mqtt_cover.cpp": "USE_COVER",
+        "mqtt_date.cpp": "USE_DATETIME_DATE",
+        "mqtt_datetime.cpp": "USE_DATETIME_DATETIME",
+        "mqtt_event.cpp": "USE_EVENT",
+        "mqtt_fan.cpp": "USE_FAN",
+        "mqtt_light.cpp": "USE_LIGHT",
+        "mqtt_lock.cpp": "USE_LOCK",
+        "mqtt_number.cpp": "USE_NUMBER",
+        "mqtt_select.cpp": "USE_SELECT",
+        "mqtt_sensor.cpp": "USE_SENSOR",
+        "mqtt_switch.cpp": "USE_SWITCH",
+        "mqtt_text.cpp": "USE_TEXT",
+        "mqtt_text_sensor.cpp": "USE_TEXT_SENSOR",
+        "mqtt_time.cpp": "USE_DATETIME_TIME",
+        "mqtt_update.cpp": "USE_UPDATE",
+        "mqtt_valve.cpp": "USE_VALVE",
+    }
+)
+
+
+def FILTER_SOURCE_FILES() -> list[str]:
+    return _platform_filter() + _define_filter()

esphome/components/uart/__init__.py

@@ -5,7 +5,10 @@ import re
 from esphome import automation, pins
 import esphome.codegen as cg
 from esphome.components.const import CONF_DATA_BITS, CONF_PARITY, CONF_STOP_BITS
-from esphome.config_helpers import filter_source_files_from_platform
+from esphome.config_helpers import (
+    filter_source_files_from_defines,
+    filter_source_files_from_platform,
+)
 import esphome.config_validation as cv
 from esphome.const import (
     CONF_AFTER,
@@ -521,7 +524,7 @@ async def final_step():
         cg.add_define("USE_UART_WAKE_LOOP_ON_RX")
 
 
-FILTER_SOURCE_FILES = filter_source_files_from_platform(
+_platform_filter = filter_source_files_from_platform(
     {
         "uart_component_esp_idf.cpp": {
             PlatformFramework.ESP32_IDF,
@@ -537,3 +540,13 @@ FILTER_SOURCE_FILES = filter_source_files_from_platform(
         },
     }
 )
+
+# uart_debugger.cpp is fully #ifdef'd on USE_UART_DEBUGGER, set only when a
+# debug block is configured.
+_define_filter = filter_source_files_from_defines(
+    {"uart_debugger.cpp": "USE_UART_DEBUGGER"}
+)
+
+
+def FILTER_SOURCE_FILES() -> list[str]:
+    return _platform_filter() + _define_filter()

esphome/core/helpers.cpp

@@ -233,6 +233,26 @@ bool str_contains_ignore_case_fallback(const char *haystack, const char *needle)
   return false;
 }
 
+#ifdef USE_ESP8266
+// _P mirror of str_contains_ignore_case_fallback above; host tests cover only the fallback,
+// so keep the two bodies in sync.
+bool str_contains_ignore_case_p(const char *haystack, PGM_P needle) {
+  if (haystack == nullptr || needle == nullptr) {
+    return false;
+  }
+  const size_t needle_len = strlen_P(needle);
+  if (needle_len == 0) {
+    return true;
+  }
+  for (const char *p = haystack; *p != '\0'; p++) {
+    if (strncasecmp_P(p, needle, needle_len) == 0) {
+      return true;
+    }
+  }
+  return false;
+}
+#endif  // USE_ESP8266
+
 // str_truncate, str_until, str_lower_case, str_upper_case, str_snake_case moved to alloc_helpers.cpp
 char *str_sanitize_to(char *buffer, size_t buffer_size, const char *str) {
   if (buffer_size == 0) {

esphome/core/helpers.h

@@ -984,6 +984,15 @@ inline bool str_endswith_ignore_case(const std::string &str, const char *suffix)
 /// Fallback implementation for case insensitive substring comparison.
 bool str_contains_ignore_case_fallback(const char *haystack, const char *needle);
 
+#ifdef USE_ESP8266
+/// ESP8266 internal implementation reading the needle from flash — prefer the
+/// `str_contains_ignore_case` macro which wraps needle literals with PSTR() automatically.
+bool str_contains_ignore_case_p(const char *haystack, PGM_P needle);
+/// Case-insensitive check if needle string is contained in haystack (no heap allocation).
+/// On ESP8266 the needle is wrapped with PSTR() so it stays in flash, which requires it to be
+/// a string literal; a runtime needle needs str_contains_ignore_case_p behind #ifdef USE_ESP8266.
+#define str_contains_ignore_case(haystack, needle) str_contains_ignore_case_p(haystack, PSTR(needle))
+#else
 /// Case-insensitive check if needle string is contained in haystack (no heap allocation).
 inline bool str_contains_ignore_case(const char *haystack, const char *needle) {
   if (!needle || !haystack) {
@@ -991,7 +1000,7 @@ inline bool str_contains_ignore_case(const char *haystack, const char *needle) {
   }
 
 // strcasestr is a GNU extension: newlib only declares it when _GNU_SOURCE is set.
-// ESP32/ESP8266/host builds get it from their framework or from g++ on Linux;
+// ESP32/host builds get it from their framework or from g++ on Linux;
 // LibreTiny, RP2 and Zephyr do not, so they use the hand-rolled fallback.
 #if defined(USE_LIBRETINY) || defined(USE_RP2) || defined(USE_ZEPHYR)
   return str_contains_ignore_case_fallback(haystack, needle);
@@ -999,6 +1008,7 @@ inline bool str_contains_ignore_case(const char *haystack, const char *needle) {
   return strcasestr(haystack, needle) != nullptr;
 #endif  // defined(USE_LIBRETINY) || defined(USE_RP2) || defined(USE_ZEPHYR)
 }
+#endif  // USE_ESP8266
 
 // str_truncate moved to alloc_helpers.h - remove this include before 2026.11.0
 

esphome/helpers.py

@@ -31,6 +31,13 @@ SockAddr = IPv4SockAddr | IPv6SockAddr
 
 _LOGGER = logging.getLogger(__name__)
 
+# cv.boolean's closed spelling tables, shared with the env-knob parsing below
+TRUTHY_BOOL_STRINGS = frozenset({"true", "yes", "on", "enable"})
+FALSY_BOOL_STRINGS = frozenset({"false", "no", "off", "disable"})
+# cv.boolean's spelling tables plus the 1/0 env convention
+TRUTHY_ENV_STRINGS = TRUTHY_BOOL_STRINGS | {"1"}
+FALSY_ENV_STRINGS = FALSY_BOOL_STRINGS | {"0"}
+
 IS_MACOS = platform.system() == "Darwin"
 IS_WINDOWS = platform.system() == "Windows"
 IS_LINUX = platform.system() == "Linux"
@@ -395,12 +402,14 @@ def sort_ip_addresses(address_list: list[str]) -> list[str]:
 
 
 def get_bool_env(var, default=False):
+    """Read a boolean env var: the ``cv.boolean`` spellings plus ``1``/``0``;
+    anything else falls through to ``bool(value)``."""
     value = os.getenv(var, default)
     if isinstance(value, str):
         value = value.lower()
-        if value in ["1", "true"]:
+        if value in TRUTHY_ENV_STRINGS:
             return True
-        if value in ["0", "false"]:
+        if value in FALSY_ENV_STRINGS:
             return False
     return bool(value)
 

esphome/writer.py

@@ -337,12 +337,29 @@ def copy_src_tree():
     else:
         try:
             existing = json.loads(build_info_json_path.read_text(encoding="utf-8"))
-            if (
+            if not isinstance(existing, dict) or (
                 existing.get("config_hash") != config_hash
                 or existing.get("esphome_version") != __version__
             ):
+                # Non-object JSON is stale like every other damage case
                 sources_changed = True
-        except (json.JSONDecodeError, KeyError, OSError):
+        except FileNotFoundError:
+            # An absent build_info.json is stale, not damaged; rebuild quietly
+            sources_changed = True
+        except (ValueError, OSError) as err:
+            # ValueError covers both JSONDecodeError and UnicodeDecodeError;
+            # unlink so the regenerating write never re-reads the bad copy.
+            # "Unreadable" not "damaged": EACCES/EISDIR land here too
+            _LOGGER.warning("Regenerating unreadable build_info.json: %s", err)
+            try:
+                # missing_ok: a concurrent clean may have removed it already
+                build_info_json_path.unlink(missing_ok=True)
+            except OSError as unlink_err:
+                # The later write re-reads the file, so a kept unreadable copy
+                # fails again with a misattributed error; name the real cause
+                _LOGGER.warning(
+                    "Could not remove unreadable build_info.json: %s", unlink_err
+                )
             sources_changed = True
 
     # Write build_info header and JSON metadata

tests/components/core/helpers_test.cpp

@@ -121,7 +121,7 @@ TEST(StringContainsIgnoreCaseTest, MiscNotMatching) {
 
 TEST(StringContainsIgnoreCaseTest, FallbackMatchesLibc) {
   const char *haystack = "Hello World";
-  for (const char *needle : {"", "Hello", "hELLO", "Hell", "world", "Heaven", "Hello!", "d"}) {
+  for (const char *needle : {"", "Hello", "hELLO", "HELLO", "Hell", "world", "World", "Heaven", "Hello!", "d"}) {
     EXPECT_EQ(str_contains_ignore_case_fallback(haystack, needle), str_contains_ignore_case(haystack, needle))
         << "needle: " << needle;
   }

tests/unit_tests/test_helpers.py

@@ -171,6 +171,13 @@ def test_is_ip_address__valid(value):
         ("FOO", "fAlSe", True, False),
         ("FOO", "Yes", False, True),
         ("FOO", "123", False, True),
+        # cv.boolean's spellings; falsy rows use default=True on purpose
+        ("FOO", "on", False, True),
+        ("FOO", "enable", False, True),
+        ("FOO", "no", True, False),
+        ("FOO", "off", True, False),
+        ("FOO", "OFF", True, False),
+        ("FOO", "Disable", True, False),
     ),
 )
 def test_get_bool_env(monkeypatch, var, value, default, expected):

tests/unit_tests/test_writer.py

@@ -2041,6 +2041,38 @@ def test_copy_src_tree_writes_build_info_files(
     assert build_info_json["esphome_version"] == "2025.1.0-dev"
 
 
+def _setup_build_info_mocks(
+    mock_core: MagicMock,
+    mock_iter_components: MagicMock,
+    mock_walk_files: MagicMock,
+    tmp_path: Path,
+) -> Path:
+    """Point CORE at tmp_path and return the build_info.json path."""
+    src_path = tmp_path / "src"
+    (src_path / "esphome" / "core").mkdir(parents=True)
+    build_path = tmp_path / "build"
+    build_path.mkdir()
+    mock_core.relative_src_path.side_effect = src_path.joinpath
+    mock_core.relative_build_path.side_effect = build_path.joinpath
+    mock_core.defines = []
+    mock_core.config_hash = 0xDEADBEEF
+    mock_core.comment = ""
+    mock_core.target_platform = "test_platform"
+    mock_core.config = {}
+    mock_iter_components.return_value = []
+    mock_walk_files.return_value = []
+    return build_path / "build_info.json"
+
+
+def _run_copy_src_tree(version: str = "2025.1.0-dev") -> None:
+    with (
+        patch("esphome.writer.__version__", version),
+        patch("esphome.writer.importlib.import_module") as mock_import,
+    ):
+        mock_import.side_effect = AttributeError
+        copy_src_tree()
+
+
 @patch("esphome.writer.CORE")
 @patch("esphome.writer.iter_components")
 @patch("esphome.writer.walk_files")
@@ -2050,59 +2082,17 @@ def test_copy_src_tree_detects_config_hash_change(
     mock_core: MagicMock,
     tmp_path: Path,
 ) -> None:
-    """Test copy_src_tree detects when config_hash changes."""
-    # Setup directory structure
-    src_path = tmp_path / "src"
-    src_path.mkdir()
-    esphome_core_path = src_path / "esphome" / "core"
-    esphome_core_path.mkdir(parents=True)
-    build_path = tmp_path / "build"
-    build_path.mkdir()
-
-    # Create existing build_info.json with different config_hash
-    build_info_json_path = build_path / "build_info.json"
-    build_info_json_path.write_text(
-        json.dumps(
-            {
-                "config_hash": 0x12345678,  # Different from current
-                "build_time": 1700000000,
-                "build_time_str": "2023-11-14 22:13:20 +0000",
-                "esphome_version": "2025.1.0-dev",
-            }
-        )
+    """A changed config_hash regenerates build_info after a steady-state run."""
+    build_info_json_path = _setup_build_info_mocks(
+        mock_core, mock_iter_components, mock_walk_files, tmp_path
     )
+    _run_copy_src_tree()
+    assert json.loads(build_info_json_path.read_text())["config_hash"] == 0xDEADBEEF
 
-    # Create existing build_info_data.h
-    build_info_h_path = esphome_core_path / "build_info_data.h"
-    build_info_h_path.write_text("// old build_info_data.h")
-
-    # Setup mocks
-    mock_core.relative_src_path.side_effect = src_path.joinpath
-    mock_core.relative_build_path.side_effect = build_path.joinpath
-    mock_core.defines = []
-    mock_core.config_hash = 0xDEADBEEF  # Different from existing
-    mock_core.comment = ""
-    mock_core.target_platform = "test_platform"
-    mock_core.config = {}
-    mock_iter_components.return_value = []
-    mock_walk_files.return_value = []
-
-    with (
-        patch("esphome.writer.__version__", "2025.1.0-dev"),
-        patch("esphome.writer.importlib.import_module") as mock_import,
-    ):
-        mock_import.side_effect = AttributeError
-        copy_src_tree()
-
-    # Verify build_info files were updated due to config_hash change
-    assert build_info_h_path.exists()
-    build_info_cpp_path = esphome_core_path / "build_info_data.cpp"
-    assert build_info_cpp_path.exists()
-    new_content = build_info_cpp_path.read_text()
-    assert "0xdeadbeef" in new_content.lower()
-
-    new_json = json.loads(build_info_json_path.read_text())
-    assert new_json["config_hash"] == 0xDEADBEEF
+    # Second run only regenerates if the hash comparison detects the change
+    mock_core.config_hash = 0xC0FFEE
+    _run_copy_src_tree()
+    assert json.loads(build_info_json_path.read_text())["config_hash"] == 0xC0FFEE
 
 
 @patch("esphome.writer.CORE")
@@ -2114,104 +2104,93 @@ def test_copy_src_tree_detects_version_change(
     mock_core: MagicMock,
     tmp_path: Path,
 ) -> None:
-    """Test copy_src_tree detects when esphome_version changes."""
-    # Setup directory structure
-    src_path = tmp_path / "src"
-    src_path.mkdir()
-    esphome_core_path = src_path / "esphome" / "core"
-    esphome_core_path.mkdir(parents=True)
-    build_path = tmp_path / "build"
-    build_path.mkdir()
-
-    # Create existing build_info.json with different version
-    build_info_json_path = build_path / "build_info.json"
-    build_info_json_path.write_text(
-        json.dumps(
-            {
-                "config_hash": 0xDEADBEEF,
-                "build_time": 1700000000,
-                "build_time_str": "2023-11-14 22:13:20 +0000",
-                "esphome_version": "2024.12.0",  # Old version
-            }
-        )
+    """A changed esphome_version regenerates build_info after a steady-state run."""
+    build_info_json_path = _setup_build_info_mocks(
+        mock_core, mock_iter_components, mock_walk_files, tmp_path
     )
-
-    # Create existing build_info_data.h
-    build_info_h_path = esphome_core_path / "build_info_data.h"
-    build_info_h_path.write_text("// old build_info_data.h")
-
-    # Setup mocks
-    mock_core.relative_src_path.side_effect = src_path.joinpath
-    mock_core.relative_build_path.side_effect = build_path.joinpath
-    mock_core.defines = []
-    mock_core.config_hash = 0xDEADBEEF
-    mock_core.comment = ""
-    mock_core.target_platform = "test_platform"
-    mock_core.config = {}
-    mock_iter_components.return_value = []
-    mock_walk_files.return_value = []
-
-    with (
-        patch("esphome.writer.__version__", "2025.1.0-dev"),  # New version
-        patch("esphome.writer.importlib.import_module") as mock_import,
-    ):
-        mock_import.side_effect = AttributeError
-        copy_src_tree()
-
-    # Verify build_info files were updated due to version change
-    assert build_info_h_path.exists()
+    # Pin version.h so only the build_info comparison can see the bump
+    with patch("esphome.writer.generate_version_h", return_value="// version.h\n"):
+        _run_copy_src_tree(version="2024.12.0")
+        _run_copy_src_tree(version="2025.1.0-dev")
     new_json = json.loads(build_info_json_path.read_text())
     assert new_json["esphome_version"] == "2025.1.0-dev"
 
 
+@pytest.mark.parametrize(
+    "damage",
+    (b"invalid json {{{", b"[]", b'\xff{"config_hash": 1}'),
+    ids=("invalid-json", "non-object", "non-utf8"),
+)
+@patch("esphome.writer.CORE")
+@patch("esphome.writer.iter_components")
+@patch("esphome.writer.walk_files")
+def test_copy_src_tree_regenerates_damaged_build_info(
+    mock_walk_files: MagicMock,
+    mock_iter_components: MagicMock,
+    mock_core: MagicMock,
+    tmp_path: Path,
+    damage: bytes,
+) -> None:
+    """A damaged build_info.json reads as stale and is regenerated, not left in place."""
+    build_info_json_path = _setup_build_info_mocks(
+        mock_core, mock_iter_components, mock_walk_files, tmp_path
+    )
+    _run_copy_src_tree()
+    build_info_json_path.write_bytes(damage)
+    # Second run only rewrites the file if the damage branch fires
+    _run_copy_src_tree()
+    new_json = json.loads(build_info_json_path.read_text())
+    assert new_json["config_hash"] == 0xDEADBEEF
+
+
 @patch("esphome.writer.CORE")
 @patch("esphome.writer.iter_components")
 @patch("esphome.writer.walk_files")
-def test_copy_src_tree_handles_invalid_build_info_json(
+def test_copy_src_tree_missing_build_info_rebuilds_quietly(
     mock_walk_files: MagicMock,
     mock_iter_components: MagicMock,
     mock_core: MagicMock,
     tmp_path: Path,
+    caplog: pytest.LogCaptureFixture,
 ) -> None:
-    """Test copy_src_tree handles invalid build_info.json gracefully."""
-    # Setup directory structure
-    src_path = tmp_path / "src"
-    src_path.mkdir()
-    esphome_core_path = src_path / "esphome" / "core"
-    esphome_core_path.mkdir(parents=True)
-    build_path = tmp_path / "build"
-    build_path.mkdir()
+    """An absent build_info.json regenerates without claiming damage."""
+    build_info_json_path = _setup_build_info_mocks(
+        mock_core, mock_iter_components, mock_walk_files, tmp_path
+    )
+    _run_copy_src_tree()
+    build_info_json_path.unlink()
+    _run_copy_src_tree()
+    assert json.loads(build_info_json_path.read_text())["config_hash"] == 0xDEADBEEF
+    assert "unreadable" not in caplog.text
 
-    # Create invalid build_info.json
-    build_info_json_path = build_path / "build_info.json"
+
+@patch("esphome.writer.CORE")
+@patch("esphome.writer.iter_components")
+@patch("esphome.writer.walk_files")
+def test_copy_src_tree_unremovable_damaged_build_info_is_logged(
+    mock_walk_files: MagicMock,
+    mock_iter_components: MagicMock,
+    mock_core: MagicMock,
+    tmp_path: Path,
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """A failed unlink of the damaged file names the real cause."""
+    build_info_json_path = _setup_build_info_mocks(
+        mock_core, mock_iter_components, mock_walk_files, tmp_path
+    )
+    _run_copy_src_tree()
     build_info_json_path.write_text("invalid json {{{")
+    real_unlink = Path.unlink
 
-    # Create existing build_info_data.h
-    build_info_h_path = esphome_core_path / "build_info_data.h"
-    build_info_h_path.write_text("// old build_info_data.h")
+    def fail_on_build_info(self: Path, missing_ok: bool = False) -> None:
+        if self.name == "build_info.json":
+            raise OSError("simulated EACCES")
+        real_unlink(self, missing_ok=missing_ok)
 
-    # Setup mocks
-    mock_core.relative_src_path.side_effect = src_path.joinpath
-    mock_core.relative_build_path.side_effect = build_path.joinpath
-    mock_core.defines = []
-    mock_core.config_hash = 0xDEADBEEF
-    mock_core.comment = ""
-    mock_core.target_platform = "test_platform"
-    mock_core.config = {}
-    mock_iter_components.return_value = []
-    mock_walk_files.return_value = []
-
-    with (
-        patch("esphome.writer.__version__", "2025.1.0-dev"),
-        patch("esphome.writer.importlib.import_module") as mock_import,
-    ):
-        mock_import.side_effect = AttributeError
-        copy_src_tree()
-
-    # Verify build_info files were created despite invalid JSON
-    assert build_info_h_path.exists()
-    new_json = json.loads(build_info_json_path.read_text())
-    assert new_json["config_hash"] == 0xDEADBEEF
+    with patch.object(Path, "unlink", fail_on_build_info):
+        _run_copy_src_tree()
+    assert "Could not remove unreadable build_info.json" in caplog.text
+    assert json.loads(build_info_json_path.read_text())["config_hash"] == 0xDEADBEEF
 
 
 @patch("esphome.writer.CORE")