Merge branch 'dev' into partition-table-ota

tests/component_tests/esp32/test_esp32.py

@@ -8,10 +8,16 @@ from typing import Any
 
 import pytest
 
-from esphome.components.esp32 import VARIANTS
-from esphome.components.esp32.const import KEY_ESP32, KEY_SDKCONFIG_OPTIONS
+from esphome.components.esp32 import VARIANT_ESP32, VARIANTS
+from esphome.components.esp32.const import KEY_ESP32, KEY_SDKCONFIG_OPTIONS, KEY_VARIANT
+from esphome.components.esp32.gpio import validate_gpio_pin
 import esphome.config_validation as cv
-from esphome.const import CONF_ESPHOME, PlatformFramework
+from esphome.const import (
+    CONF_ESPHOME,
+    CONF_IGNORE_PIN_VALIDATION_ERROR,
+    CONF_NUMBER,
+    PlatformFramework,
+)
 from esphome.core import CORE
 from tests.component_tests.types import SetCoreConfigCallable
 
@@ -149,6 +155,73 @@ def test_execute_from_psram_p4_sdkconfig(
     assert "CONFIG_SPIRAM_RODATA" not in sdkconfig
 
 
+def test_ignore_pin_validation_error_on_clean_pin_warns(
+    set_core_config: SetCoreConfigCallable,
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """A pin that passes validation but sets `ignore_pin_validation_error: true`
+    should log a warning nudging the user to remove the flag, and not raise."""
+    set_core_config(
+        PlatformFramework.ESP32_IDF, platform_data={KEY_VARIANT: VARIANT_ESP32}
+    )
+
+    pin = {CONF_NUMBER: 4, CONF_IGNORE_PIN_VALIDATION_ERROR: True}
+    with caplog.at_level("WARNING"):
+        result = validate_gpio_pin(pin)
+
+    assert result[CONF_NUMBER] == 4
+    assert "GPIO4 has no validation errors to ignore" in caplog.text
+
+
+def test_ignore_pin_validation_error_on_dirty_pin_suppresses(
+    set_core_config: SetCoreConfigCallable,
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """A pin that fails validation with `ignore_pin_validation_error: true` should
+    log the suppression warning and not raise (existing behavior)."""
+    set_core_config(
+        PlatformFramework.ESP32_IDF, platform_data={KEY_VARIANT: VARIANT_ESP32}
+    )
+
+    # GPIO6 is a flash pin on ESP32 -> pin_validation raises cv.Invalid
+    pin = {CONF_NUMBER: 6, CONF_IGNORE_PIN_VALIDATION_ERROR: True}
+    with caplog.at_level("WARNING"):
+        result = validate_gpio_pin(pin)
+
+    assert result[CONF_NUMBER] == 6
+    assert "Ignoring validation error on pin 6" in caplog.text
+
+
+def test_dirty_pin_without_ignore_flag_raises(
+    set_core_config: SetCoreConfigCallable,
+) -> None:
+    """A pin that fails validation without the ignore flag should still raise."""
+    set_core_config(
+        PlatformFramework.ESP32_IDF, platform_data={KEY_VARIANT: VARIANT_ESP32}
+    )
+
+    pin = {CONF_NUMBER: 6, CONF_IGNORE_PIN_VALIDATION_ERROR: False}
+    with pytest.raises(cv.Invalid, match="flash interface"):
+        validate_gpio_pin(pin)
+
+
+def test_clean_pin_without_ignore_flag_does_not_warn(
+    set_core_config: SetCoreConfigCallable,
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """A clean pin without the ignore flag should pass silently."""
+    set_core_config(
+        PlatformFramework.ESP32_IDF, platform_data={KEY_VARIANT: VARIANT_ESP32}
+    )
+
+    pin = {CONF_NUMBER: 4, CONF_IGNORE_PIN_VALIDATION_ERROR: False}
+    with caplog.at_level("WARNING"):
+        result = validate_gpio_pin(pin)
+
+    assert result[CONF_NUMBER] == 4
+    assert "has no validation errors to ignore" not in caplog.text
+
+
 def test_execute_from_psram_disabled_sdkconfig(
     generate_main: Callable[[str | Path], str],
     component_config_path: Callable[[str], Path],

tests/component_tests/ili9xxx/config/ili9xxx_test.yaml

@@ -0,0 +1,20 @@
+esphome:
+  name: test
+
+esp32:
+  board: esp32dev
+  framework:
+    type: arduino
+
+spi:
+  clk_pin: GPIO18
+  mosi_pin: GPIO23
+
+display:
+  - platform: ili9xxx
+    id: tft_display
+    model: ST7789V
+    cs_pin: GPIO5
+    dc_pin: GPIO17
+    reset_pin: GPIO16
+    invert_colors: false

tests/component_tests/ili9xxx/test_ili9xxx.py

@@ -0,0 +1,31 @@
+"""Tests for the ili9xxx component."""
+
+from __future__ import annotations
+
+from collections.abc import Callable
+from pathlib import Path
+
+
+def test_ili9xxx_placement_new_uses_model_subclass(
+    generate_main: Callable[[str | Path], str],
+    component_config_path: Callable[[str], Path],
+) -> None:
+    """Regression test for ili9xxx picking the right constructor under placement new.
+
+    ili9xxx declares the ID as the base ``ILI9XXXDisplay`` but constructs a
+    model-specific subclass (e.g. ``ILI9XXXST7789V``) via ``MODELS[...].new()``.
+    Pvariable must emit placement new for the subclass — otherwise the base
+    default constructor runs and the panel is left with a null init sequence
+    and 0x0 dimensions, producing a silent blank screen.
+    """
+    main_cpp = generate_main(component_config_path("ili9xxx_test.yaml"))
+
+    # Storage is sized for the subclass so the full object fits.
+    assert "sizeof(ili9xxx::ILI9XXXST7789V)" in main_cpp
+    assert "alignas(ili9xxx::ILI9XXXST7789V)" in main_cpp
+    # Pointer is declared as the base type for polymorphism.
+    assert "static ili9xxx::ILI9XXXDisplay *const tft_display" in main_cpp
+    # Placement new runs the subclass constructor — this is the actual regression fix.
+    assert "new(tft_display) ili9xxx::ILI9XXXST7789V()" in main_cpp
+    # Base-class default constructor must NOT be used.
+    assert "new(tft_display) ili9xxx::ILI9XXXDisplay()" not in main_cpp

tests/component_tests/mipi_dsi/test_mipi_dsi_config.py

@@ -7,6 +7,11 @@ import pytest
 
 from esphome import config_validation as cv
 from esphome.components.esp32 import KEY_BOARD, VARIANT_ESP32P4
+
+# Importing xl9535 registers its pin schema with pins.PIN_SCHEMA_REGISTRY so that
+# models (e.g. SEEED-RETERMINAL-D1001) that reference xl9535-backed pins in their
+# defaults can be validated by the mipi_dsi CONFIG_SCHEMA in this test.
+import esphome.components.xl9535  # noqa: F401
 from esphome.const import (
     CONF_DIMENSIONS,
     CONF_HEIGHT,

tests/component_tests/mipi_spi/test_final_validate.py

@@ -0,0 +1,185 @@
+"""Tests for the _final_validate buffer size calculation in mipi_spi."""
+
+from __future__ import annotations
+
+from typing import Any
+
+import pytest
+
+from esphome.components.display import CONF_SHOW_TEST_CARD
+from esphome.components.esp32 import KEY_BOARD, KEY_VARIANT, VARIANT_ESP32
+from esphome.components.mipi_spi.display import CONFIG_SCHEMA, FINAL_VALIDATE_SCHEMA
+from esphome.const import CONF_BUFFER_SIZE, PlatformFramework
+from esphome.types import ConfigType
+from tests.component_tests.types import SetCoreConfigCallable
+
+
+def _validated(config: ConfigType) -> ConfigType:
+    """Run the component config schema followed by the final validation."""
+    config = CONFIG_SCHEMA(config)
+    FINAL_VALIDATE_SCHEMA(config)
+    return config
+
+
+def _custom_config(
+    width: int,
+    height: int,
+    color_depth: str | int | None = None,
+    **extra: Any,
+) -> ConfigType:
+    """Build a minimal valid custom-model config with the given dimensions."""
+    config: ConfigType = {
+        "model": "custom",
+        "dc_pin": 18,
+        "dimensions": {"width": width, "height": height},
+        "init_sequence": [[0xA0, 0x01]],
+    }
+    if color_depth is not None:
+        config["color_depth"] = color_depth
+    config.update(extra)
+    return config
+
+
+# The auto buffer-size selection inside _final_validate targets ~20 kB of
+# pixel buffer. For a buffer of ``depth_bytes * width * height``, it picks the
+# smallest integer ``x`` in range(2, 8) such that
+# ``min(20000, buffer // 4) / buffer >= 1 / x`` (falling back to ``x = 8``).
+# The test cases below cover the full range of possible outcomes (1/4 .. 1/8).
+@pytest.mark.parametrize(
+    ("width", "height", "color_depth", "expected"),
+    [
+        # 16-bit color depth -- buffer = 2 * width * height
+        # 128*160*2 = 40960 B -> fraction = 10240/40960 = 0.25 -> x = 4
+        pytest.param(128, 160, "16bit", 1.0 / 4, id="16bit_tiny"),
+        # 200*224*2 = 89600 B -> fraction = 20000/89600 ≈ 0.2232 -> x = 5
+        pytest.param(200, 224, "16bit", 1.0 / 5, id="16bit_small"),
+        # 240*224*2 = 107520 B -> fraction ≈ 0.1860 -> x = 6
+        pytest.param(240, 224, "16bit", 1.0 / 6, id="16bit_medium"),
+        # 200*320*2 = 128000 B -> fraction = 0.15625 -> x = 7
+        pytest.param(200, 320, "16bit", 1.0 / 7, id="16bit_large"),
+        # 240*320*2 = 153600 B -> fraction ≈ 0.1302 -> default x = 8
+        pytest.param(240, 320, "16bit", 1.0 / 8, id="16bit_xlarge"),
+        # 320*480*2 = 307200 B -> fraction ≈ 0.0651 -> default x = 8
+        pytest.param(320, 480, "16bit", 1.0 / 8, id="16bit_huge"),
+        # 8-bit color depth -- buffer = width * height
+        # 320*240 = 76800 B -> fraction = 19200/76800 = 0.25 -> x = 4
+        pytest.param(320, 240, "8bit", 1.0 / 4, id="8bit_tiny"),
+        # 400*224 = 89600 B -> fraction ≈ 0.2232 -> x = 5
+        pytest.param(400, 224, "8bit", 1.0 / 5, id="8bit_small"),
+        # 480*224 = 107520 B -> fraction ≈ 0.1860 -> x = 6
+        pytest.param(480, 224, "8bit", 1.0 / 6, id="8bit_medium"),
+        # 400*320 = 128000 B -> fraction = 0.15625 -> x = 7
+        pytest.param(400, 320, "8bit", 1.0 / 7, id="8bit_large"),
+        # 480*320 = 153600 B -> fraction ≈ 0.1302 -> default x = 8
+        pytest.param(480, 320, "8bit", 1.0 / 8, id="8bit_xlarge"),
+    ],
+)
+def test_buffer_size_auto_selected(
+    width: int,
+    height: int,
+    color_depth: str,
+    expected: float,
+    set_core_config: SetCoreConfigCallable,
+) -> None:
+    """Without PSRAM or an explicit buffer_size, a fraction is chosen from the display size.
+
+    Without any drawing method and without LVGL, final validation also auto-enables
+    ``show_test_card``, which in turn makes the component require a buffer and therefore
+    triggers the buffer-size selection path.
+    """
+    set_core_config(
+        PlatformFramework.ESP32_IDF,
+        platform_data={KEY_BOARD: "esp32dev", KEY_VARIANT: VARIANT_ESP32},
+    )
+
+    config = _validated(_custom_config(width, height, color_depth))
+
+    # Sanity check: final validation should have enabled the test card for us,
+    # which is what causes the buffer-size calculation to actually run.
+    assert config.get(CONF_SHOW_TEST_CARD) is True
+    assert config[CONF_BUFFER_SIZE] == pytest.approx(expected)
+
+
+@pytest.mark.parametrize(
+    "buffer_size",
+    [0.125, 0.25, 0.5, 1.0],
+    ids=["one_eighth", "one_quarter", "half", "full"],
+)
+def test_explicit_buffer_size_is_preserved(
+    buffer_size: float,
+    set_core_config: SetCoreConfigCallable,
+) -> None:
+    """An explicitly configured buffer_size is never overridden by final validation."""
+    set_core_config(
+        PlatformFramework.ESP32_IDF,
+        platform_data={KEY_BOARD: "esp32dev", KEY_VARIANT: VARIANT_ESP32},
+    )
+
+    config = _validated(
+        _custom_config(240, 320, "16bit", buffer_size=buffer_size),
+    )
+
+    assert config[CONF_BUFFER_SIZE] == pytest.approx(buffer_size)
+
+
+def test_buffer_size_not_set_when_psram_enabled(
+    set_core_config: SetCoreConfigCallable,
+    set_component_config,
+) -> None:
+    """When PSRAM is enabled the auto buffer-size selection is skipped."""
+    set_core_config(
+        PlatformFramework.ESP32_IDF,
+        platform_data={KEY_BOARD: "esp32dev", KEY_VARIANT: VARIANT_ESP32},
+    )
+    # Presence of the psram domain in the full config is what _final_validate checks.
+    set_component_config("psram", True)
+
+    config = _validated(_custom_config(240, 320, "16bit"))
+
+    assert CONF_BUFFER_SIZE not in config
+
+
+def test_buffer_size_not_set_when_buffer_not_required(
+    set_core_config: SetCoreConfigCallable,
+    set_component_config,
+) -> None:
+    """With LVGL present and no drawing methods, no buffer fraction is chosen.
+
+    LVGL suppresses the automatic show_test_card injection, which means
+    ``requires_buffer`` is False and the early-return branch fires.
+    """
+    set_core_config(
+        PlatformFramework.ESP32_IDF,
+        platform_data={KEY_BOARD: "esp32dev", KEY_VARIANT: VARIANT_ESP32},
+    )
+    set_component_config("lvgl", [])
+
+    config = _validated(_custom_config(240, 320, "16bit"))
+
+    assert CONF_BUFFER_SIZE not in config
+    # And no test card should have been auto-enabled either.
+    assert not config.get(CONF_SHOW_TEST_CARD)
+
+
+def test_buffer_size_selected_when_lvgl_with_test_card(
+    set_core_config: SetCoreConfigCallable,
+    set_component_config,
+) -> None:
+    """LVGL present + an explicit drawing method still triggers buffer sizing.
+
+    When LVGL is enabled, ``show_test_card`` is not injected automatically,
+    but users can still request it explicitly -- in that case ``requires_buffer``
+    is True and the buffer-size heuristic still runs.
+    """
+    set_core_config(
+        PlatformFramework.ESP32_IDF,
+        platform_data={KEY_BOARD: "esp32dev", KEY_VARIANT: VARIANT_ESP32},
+    )
+    set_component_config("lvgl", [])
+
+    # 128x160 @ 16bit -> expected 1/4 (see test_buffer_size_auto_selected).
+    config = _validated(
+        _custom_config(128, 160, "16bit", show_test_card=True),
+    )
+
+    assert config[CONF_BUFFER_SIZE] == pytest.approx(1.0 / 4)

tests/component_tests/packages/test_packages.py

@@ -2,18 +2,20 @@
 
 import logging
 from pathlib import Path
+import re
 from unittest.mock import MagicMock, patch
 
 import pytest
 
 from esphome.components.packages import (
     CONFIG_SCHEMA,
+    _substitute_package_definition,
     _walk_packages,
     do_packages_pass,
     is_package_definition,
     merge_packages,
 )
-from esphome.components.substitutions import do_substitution_pass
+from esphome.components.substitutions import ContextVars, do_substitution_pass
 import esphome.config as config_module
 from esphome.config import resolve_extend_remove
 from esphome.config_helpers import Extend, Remove
@@ -44,7 +46,7 @@ from esphome.const import (
 )
 from esphome.core import CORE
 from esphome.util import OrderedDict
-from esphome.yaml_util import IncludeFile, add_context
+from esphome.yaml_util import IncludeFile, add_context, load_yaml
 
 # Test strings
 TEST_DEVICE_NAME = "test_device_name"
@@ -1399,3 +1401,85 @@ def test_raw_config_contains_merged_esphome_from_package(tmp_path) -> None:
         "CORE.raw_config should contain esphome section after package merge"
     )
     assert CORE.raw_config[CONF_ESPHOME][CONF_NAME] == TEST_DEVICE_NAME
+
+
+# ---------------------------------------------------------------------------
+# _substitute_package_definition
+# ---------------------------------------------------------------------------
+
+
+def test_substitute_package_definition_local_dict_returned_unchanged() -> None:
+    """A plain local config dict is not substituted and is returned as-is."""
+    pkg = {CONF_WIFI: {CONF_SSID: "test"}}
+    result = _substitute_package_definition(pkg, ContextVars())
+    assert result is pkg
+
+
+def test_substitute_package_definition_string_resolved_with_context() -> None:
+    """A string package definition has its variables substituted."""
+    ctx = ContextVars({"variant": "esp32"})
+    result = _substitute_package_definition("device-${variant}.yaml", ctx)
+    assert result == "device-esp32.yaml"
+
+
+def test_substitute_package_definition_undefined_in_string() -> None:
+    """An undefined variable in a package URL string raises cv.Invalid."""
+    with pytest.raises(cv.Invalid, match="Undefined variable in package definition"):
+        _substitute_package_definition(
+            "github://org/repo/${undefined_var}/pkg.yaml", ContextVars()
+        )
+
+
+def test_substitute_package_definition_undefined_in_remote_dict_field() -> None:
+    """An undefined variable inside a remote-dict field names the offending field."""
+    with pytest.raises(cv.Invalid) as exc_info:
+        _substitute_package_definition(
+            {CONF_URL: "github://${typo}/repo"}, ContextVars()
+        )
+    err = str(exc_info.value)
+    assert "'typo' is undefined" in err
+    assert CONF_URL in err
+
+
+def test_substitute_package_definition_undefined_in_remote_dict_non_first_field() -> (
+    None
+):
+    """The field path joins correctly for non-first dict fields (e.g. ``ref``)."""
+    with pytest.raises(cv.Invalid) as exc_info:
+        _substitute_package_definition(
+            {
+                CONF_URL: "github://org/repo",
+                CONF_REF: "branch-${branch_typo}",
+            },
+            ContextVars(),
+        )
+    err = str(exc_info.value)
+    assert "'branch_typo' is undefined" in err
+    assert CONF_REF in err
+
+
+def test_substitute_package_definition_includes_source_location(tmp_path: Path) -> None:
+    """A package loaded from YAML surfaces file/line/col in the cv.Invalid message.
+
+    Line/column are rendered 1-based (matching config.line_info() and editor
+    line numbering) and point at the offending scalar, not the enclosing dict.
+    """
+    yaml_file = tmp_path / "main.yaml"
+    yaml_file.write_text(
+        "packages:\n  broken: github://org/repo/${undefined_var}/pkg.yaml\n"
+    )
+    config = load_yaml(yaml_file)
+    package_config = config[CONF_PACKAGES]["broken"]
+
+    with pytest.raises(cv.Invalid) as exc_info:
+        _substitute_package_definition(package_config, ContextVars())
+
+    err = str(exc_info.value)
+    assert "main.yaml" in err
+    # The offending value lives on line 2 (1-based). Column depends on the YAML
+    # loader, so we only pin line and check that a 1-based column is present.
+    match = re.search(r"main\.yaml (\d+):(\d+)", err)
+    assert match, err
+    line, col = int(match.group(1)), int(match.group(2))
+    assert line == 2, f"expected 1-based line 2, got {line} (err={err!r})"
+    assert col >= 1, f"expected 1-based column ≥ 1, got {col} (err={err!r})"

tests/component_tests/template/config/template_text_restore.yaml

@@ -0,0 +1,14 @@
+esphome:
+  name: test
+
+host:
+
+text:
+  - platform: template
+    name: "Test Text Restore"
+    id: test_text_restore
+    optimistic: true
+    max_length: 10
+    mode: text
+    initial_value: "hello"
+    restore_value: true

tests/component_tests/template/test_template_text.py

@@ -0,0 +1,44 @@
+"""Tests for the template text component."""
+
+from __future__ import annotations
+
+from collections.abc import Callable
+from pathlib import Path
+
+
+def test_template_text_saver_uses_placement_new_with_templated_subclass(
+    generate_main: Callable[[str | Path], str],
+    component_config_path: Callable[[str], Path],
+) -> None:
+    """Regression test for template text restore saver using placement new.
+
+    When ``restore_value: true``, the saver is its own Pvariable with
+    placement new: storage is sized for ``TextSaver<MAX_LENGTH>``, the
+    declared pointer stays at ``TemplateTextSaverBase *`` for polymorphism,
+    and the templated subclass constructor runs. A regression would either
+    reintroduce the heap ``new TextSaver<...>()`` expression or size the
+    storage for the base class and silently skip the subclass ctor.
+    """
+    main_cpp = generate_main(component_config_path("template_text_restore.yaml"))
+
+    # Storage is sized and aligned for the templated subclass.
+    assert "sizeof(template_::TextSaver<10>)" in main_cpp
+    assert "alignas(template_::TextSaver<10>)" in main_cpp
+    # Pointer declared as base type for polymorphism.
+    assert (
+        "static template_::TemplateTextSaverBase *const test_text_restore_value_saver"
+        in main_cpp
+    )
+    # Placement new runs the templated subclass constructor.
+    assert "new(test_text_restore_value_saver) template_::TextSaver<10>()" in main_cpp
+    # Base-class default ctor must NOT be used.
+    assert (
+        "new(test_text_restore_value_saver) template_::TemplateTextSaverBase()"
+        not in main_cpp
+    )
+    # No heap `new TextSaver<...>()` left over — the pre-fix pattern.
+    assert "new template_::TextSaver<" not in main_cpp
+    # Saver is wired into the text component.
+    assert (
+        "test_text_restore->set_value_saver(test_text_restore_value_saver)" in main_cpp
+    )

tests/components/core/helpers_test.cpp

@@ -0,0 +1,58 @@
+#include <gtest/gtest.h>
+#include <cmath>
+#include "esphome/core/helpers.h"
+
+namespace esphome {
+
+TEST(HelpersTest, Ilog10PowersOfTen) {
+  EXPECT_EQ(ilog10(1.0f), 0);
+  EXPECT_EQ(ilog10(10.0f), 1);
+  EXPECT_EQ(ilog10(100.0f), 2);
+  EXPECT_EQ(ilog10(1000.0f), 3);
+  EXPECT_EQ(ilog10(10000.0f), 4);
+  EXPECT_EQ(ilog10(100000.0f), 5);
+  EXPECT_EQ(ilog10(0.1f), -1);
+  EXPECT_EQ(ilog10(0.001f), -3);
+}
+
+TEST(HelpersTest, Ilog10General) {
+  EXPECT_EQ(ilog10(5.0f), 0);
+  EXPECT_EQ(ilog10(9.99f), 0);
+  EXPECT_EQ(ilog10(50.0f), 1);
+  EXPECT_EQ(ilog10(99.0f), 1);
+  EXPECT_EQ(ilog10(999.0f), 2);
+  EXPECT_EQ(ilog10(0.5f), -1);
+  EXPECT_EQ(ilog10(0.0072f), -3);
+  EXPECT_EQ(ilog10(120000.0f), 5);
+  EXPECT_EQ(ilog10(123456.789f), 5);
+}
+
+TEST(HelpersTest, Ilog10Negative) {
+  EXPECT_EQ(ilog10(-1.0f), 0);
+  EXPECT_EQ(ilog10(-10.0f), 1);
+  EXPECT_EQ(ilog10(-0.1f), -1);
+  EXPECT_EQ(ilog10(-123.456f), 2);
+}
+
+// Verify that ilog10 + pow10_int produces the same rounding result as log10/pow.
+// ilog10 may differ from floor(log10f()) for values not exactly representable in float
+// (e.g. 0.01f is 0.00999...), but the full round-trip must match.
+TEST(HelpersTest, Ilog10RoundTripMatchesLog10) {
+  float values[] = {0.0072f, 0.05f,   0.1f,     0.5f,     1.0f,      3.14f,     9.99f, 10.0f, 42.0f,     100.0f,
+                    1234.5f, 9999.0f, 10000.0f, 99999.0f, 120000.0f, 999999.0f, -1.0f, -0.1f, -123.456f, -10000.0f};
+  for (uint8_t digits = 1; digits <= 6; digits++) {
+    for (float v : values) {
+      // New implementation using ilog10 + pow10_int
+      float factor_new = pow10_int(digits - 1 - ilog10(v));
+      float result_new = roundf(v * factor_new) / factor_new;
+
+      // Reference using log10/pow
+      double factor_ref = pow(10.0, digits - std::ceil(std::log10(std::fabs(v))));
+      float result_ref = static_cast<float>(round(v * factor_ref) / factor_ref);
+
+      EXPECT_FLOAT_EQ(result_new, result_ref) << "mismatch for value=" << v << " digits=" << (int) digits;
+    }
+  }
+}
+
+}  // namespace esphome

tests/components/epaper_spi/test.esp32-s3-idf.yaml

@@ -145,3 +145,19 @@ display:
       it.filled_rectangle(0, 0, it.get_width(), it.get_height(), Color::WHITE);
       it.circle(it.get_width() / 2, it.get_height() / 2, 30, Color::BLACK);
       it.circle(it.get_width() / 2, it.get_height() / 2, 20, Color(255, 0, 0));
+
+  - platform: epaper_spi
+    spi_id: spi_bus
+    model: goodisplay-gdey042t81-4.2
+    cs_pin:
+      allow_other_uses: true
+      number: GPIO5
+    dc_pin:
+      allow_other_uses: true
+      number: GPIO17
+    reset_pin:
+      allow_other_uses: true
+      number: GPIO16
+    busy_pin:
+      allow_other_uses: true
+      number: GPIO4

tests/components/esp32_ble/common_use_psram.yaml

@@ -0,0 +1,4 @@
+esp32_ble:
+  use_psram: true
+
+psram:

tests/components/esp32_ble/test.esp32-ard.yaml

@@ -1 +1,2 @@
 <<: !include common.yaml
+<<: !include common_use_psram.yaml

tests/components/esp32_ble/test.esp32-idf.yaml

@@ -1,4 +1,5 @@
 <<: !include common.yaml
+<<: !include common_use_psram.yaml
 
 esp32_ble:
   io_capability: keyboard_only

tests/components/esp32_ble/test.esp32-p4-idf.yaml

@@ -2,6 +2,7 @@ packages:
   ble: !include ../../test_build_components/common/ble/esp32-p4-idf.yaml
 
 <<: !include common.yaml
+<<: !include common_use_psram.yaml
 
 esp32_ble:
   io_capability: keyboard_only

tests/components/ethernet/test.esp32-c3-idf.yaml

@@ -0,0 +1,19 @@
+ethernet:
+  type: W5500
+  clk_pin: 6
+  mosi_pin: 7
+  miso_pin: 2
+  cs_pin: 10
+  interrupt_pin: 3
+  reset_pin: 4
+  clock_speed: 10Mhz
+  manual_ip:
+    static_ip: 192.168.178.56
+    gateway: 192.168.178.1
+    subnet: 255.255.255.0
+  domain: .local
+  mac_address: "02:AA:BB:CC:DD:01"
+  on_connect:
+    - logger.log: "Ethernet connected!"
+  on_disconnect:
+    - logger.log: "Ethernet disconnected!"

tests/components/http_request/http_request.yaml

@@ -45,6 +45,11 @@ esphome:
                   args:
                     - response->status_code
                     - body.c_str()
+              - delay: 1s
+              - logger.log:
+                  format: "After delay, body still: %s"
+                  args:
+                    - body.c_str()
 
 http_request:
   useragent: esphome/tagreader

tests/components/modbus/modbus_helpers_test.cpp

@@ -0,0 +1,22 @@
+#include <gtest/gtest.h>
+
+#include "esphome/components/modbus/modbus_helpers.h"
+
+namespace esphome::modbus::helpers {
+
+TEST(ModbusHelpersTest, PayloadToNumberRejectsOffsetAtEndOfBuffer) {
+  const std::vector<uint8_t> data{0x12, 0x34};
+  EXPECT_EQ(payload_to_number(data, SensorValueType::U_WORD, 2, 0xFFFFFFFF), 0);
+}
+
+TEST(ModbusHelpersTest, PayloadToNumberRejectsTruncatedMultiRegisterValue) {
+  const std::vector<uint8_t> data{0x12, 0x34, 0x56};
+  EXPECT_EQ(payload_to_number(data, SensorValueType::U_DWORD, 0, 0xFFFFFFFF), 0);
+}
+
+TEST(ModbusHelpersTest, PayloadToNumberDecodesValidWord) {
+  const std::vector<uint8_t> data{0x12, 0x34};
+  EXPECT_EQ(payload_to_number(data, SensorValueType::U_WORD, 0, 0xFFFFFFFF), 0x1234);
+}
+
+}  // namespace esphome::modbus::helpers

tests/components/rtttl/common.yaml

@@ -3,6 +3,22 @@ esphome:
     then:
       - rtttl.play: 'siren:d=8,o=5,b=100:d,e,d,e,d,e,d,e'
       - rtttl.stop
+      # Test all note features: all notes, denominators (1,2,4,8,16,32), sharp (#), octaves (4-7), dotted (.), note gap (c5,c5), pause (p)
+      - rtttl.play: 'special:d=4,o=5,b=120:1c4,2d#5,4e6.,8f#7,16g4,32a5,8a#5,4b6,8h5,c5,c5,8p,2c4'
+      # Different orders of control parameters
+      - rtttl.play: 'test_odb:o=5,d=8,b=100:c'
+      - rtttl.play: 'test_bod:b=100,o=5,d=8:c'
+      - rtttl.play: 'test_bdo:b=100,d=8,o=5:c'
+      - rtttl.play: 'test_obd:o=5,b=100,d=8:c'
+      - rtttl.play: 'test_dbo:d=8,b=100,o=5:c'
+      # Missing parameters (use defaults)
+      - rtttl.play: 'test_no_d:o=5,b=100:c'
+      - rtttl.play: 'test_no_o:d=8,b=100:c'
+      - rtttl.play: 'test_no_b:d=8,o=5:c'
+      - rtttl.play: 'test_only_d:d=8:c'
+      - rtttl.play: 'test_only_o:o=5:c'
+      - rtttl.play: 'test_only_b:b=100:c'
+      - rtttl.play: 'test_empty::c'
 
 output:
   - platform: ${output_platform}

tests/components/template/common-base.yaml

@@ -171,6 +171,7 @@ sensor:
               quantile: .9
           - round: 1
       - round_to_multiple_of: 0.25
+      - round_to_significant_digits: 3
       - skip_initial: 3
       - sliding_window_moving_average:
           window_size: 15

tests/integration/fixtures/external_components/wake_test_component/__init__.py

@@ -0,0 +1,19 @@
+import esphome.codegen as cg
+import esphome.config_validation as cv
+from esphome.const import CONF_ID
+
+CODEOWNERS = ["@esphome/tests"]
+
+wake_test_component_ns = cg.esphome_ns.namespace("wake_test_component")
+WakeTestComponent = wake_test_component_ns.class_("WakeTestComponent", cg.Component)
+
+CONFIG_SCHEMA = cv.Schema(
+    {
+        cv.GenerateID(): cv.declare_id(WakeTestComponent),
+    }
+).extend(cv.COMPONENT_SCHEMA)
+
+
+async def to_code(config):
+    var = cg.new_Pvariable(config[CONF_ID])
+    await cg.register_component(var, config)

tests/integration/fixtures/external_components/wake_test_component/wake_test_component.cpp

@@ -0,0 +1,19 @@
+#include "wake_test_component.h"
+#include "esphome/core/application.h"
+#include "esphome/core/log.h"
+#include <chrono>
+#include <thread>
+
+namespace esphome::wake_test_component {
+
+static const char *const TAG = "wake_test_component";
+
+void WakeTestComponent::start_async_wake() {
+  ESP_LOGI(TAG, "Spawning async wake thread (50ms delay)");
+  std::thread([] {
+    std::this_thread::sleep_for(std::chrono::milliseconds(50));
+    App.wake_loop_threadsafe();
+  }).detach();
+}
+
+}  // namespace esphome::wake_test_component

tests/integration/fixtures/external_components/wake_test_component/wake_test_component.h

@@ -0,0 +1,27 @@
+#pragma once
+
+#include "esphome/core/component.h"
+#include <atomic>
+
+namespace esphome::wake_test_component {
+
+class WakeTestComponent : public Component {
+ public:
+  void setup() override {}
+  void loop() override { this->loop_count_.fetch_add(1, std::memory_order_relaxed); }
+
+  int get_loop_count() const { return this->loop_count_.load(std::memory_order_relaxed); }
+
+  // Spawn a detached thread that sleeps briefly then calls
+  // App.wake_loop_threadsafe(). Used by the integration test to verify a
+  // cross-thread wake forces a component-phase iteration even when
+  // loop_interval_ has been raised high enough to gate it off otherwise.
+  void start_async_wake();
+
+  float get_setup_priority() const override { return setup_priority::DATA; }
+
+ protected:
+  std::atomic<int> loop_count_{0};
+};
+
+}  // namespace esphome::wake_test_component

tests/integration/fixtures/loop_interval_decoupling.yaml

@@ -0,0 +1,60 @@
+esphome:
+  name: loop-interval-decouple
+  on_boot:
+    priority: -100
+    then:
+      - lambda: |-
+          // Raise loop_interval_ to 500ms. With the decoupling fix the
+          // component phase should run ~twice per second while the 50ms
+          // scheduler interval below still fires at its requested cadence.
+          App.set_loop_interval(500);
+      # Start measurement after 1s so boot transients settle.
+      - delay: 1000ms
+      - lambda: |-
+          id(loop_at_start) = id(loop_counter)->get_loop_count();
+          id(sched_at_start) = id(sched_count);
+          ESP_LOGI("test", "MEASUREMENT_STARTED loop=%d sched=%d",
+                   id(loop_at_start), id(sched_at_start));
+      # Observe for 2s.
+      - delay: 2000ms
+      - lambda: |-
+          int loop_delta = id(loop_counter)->get_loop_count() - id(loop_at_start);
+          int sched_delta = id(sched_count) - id(sched_at_start);
+          ESP_LOGI("test", "MEASUREMENT_DONE loop_delta=%d sched_delta=%d",
+                   loop_delta, sched_delta);
+
+host:
+api:
+logger:
+  level: INFO
+  logs:
+    loop_test_component: WARN   # Silence per-loop log spam
+
+external_components:
+  - source:
+      type: local
+      path: EXTERNAL_COMPONENT_PATH
+
+globals:
+  - id: sched_count
+    type: int
+    initial_value: "0"
+  - id: loop_at_start
+    type: int
+    initial_value: "0"
+  - id: sched_at_start
+    type: int
+    initial_value: "0"
+
+loop_test_component:
+  components:
+    - id: loop_counter
+      name: loop_counter
+
+interval:
+  # Fast scheduler interval — with the decoupling fix this should fire at
+  # its requested 50ms cadence regardless of loop_interval_.
+  - interval: 50ms
+    then:
+      - lambda: |-
+          id(sched_count) += 1;

tests/integration/fixtures/loop_interval_default_not_pulled_forward.yaml

@@ -0,0 +1,51 @@
+esphome:
+  name: loop-default-not-pulled
+  on_boot:
+    priority: -100
+    then:
+      # Leave loop_interval_ at its default (16 ms → ~62 Hz). Do NOT call
+      # set_loop_interval here. The fast scheduler interval below used to
+      # pull the component phase forward to ~128 Hz via the old
+      # std::max(next_schedule, delay_time / 2) floor.
+      # Start measurement after 1s so boot transients settle.
+      - delay: 1000ms
+      - lambda: |-
+          id(loop_at_start) = id(loop_counter)->get_loop_count();
+          ESP_LOGI("test", "MEASUREMENT_STARTED loop=%d", id(loop_at_start));
+      # Observe for 2s.
+      - delay: 2000ms
+      - lambda: |-
+          int loop_delta = id(loop_counter)->get_loop_count() - id(loop_at_start);
+          ESP_LOGI("test", "MEASUREMENT_DONE loop_delta=%d", loop_delta);
+
+host:
+api:
+logger:
+  level: INFO
+  logs:
+    loop_test_component: WARN   # Silence per-loop log spam
+
+external_components:
+  - source:
+      type: local
+      path: EXTERNAL_COMPONENT_PATH
+
+globals:
+  - id: loop_at_start
+    type: int
+    initial_value: "0"
+
+loop_test_component:
+  components:
+    - id: loop_counter
+      name: loop_counter
+
+interval:
+  # Fast scheduler interval (well under loop_interval_/2 = 8ms). In the
+  # pre-decoupling code this would have pulled the component phase forward
+  # to ~128 Hz. After the decoupling fix the component phase stays at
+  # ~62 Hz regardless.
+  - interval: 5ms
+    then:
+      - lambda: |-
+          // No-op; the presence of a due scheduler item is what matters.

tests/integration/fixtures/scheduler_interval_zero_coerced.yaml

@@ -0,0 +1,27 @@
+esphome:
+  name: sched-interval-zero
+
+host:
+api:
+logger:
+  level: DEBUG
+
+globals:
+  - id: fire_count
+    type: int
+    initial_value: "0"
+
+interval:
+  # Deliberately configure 0ms — this path goes through the C++
+  # Scheduler::set_timer_common_ coercion (not the Python cv.update_interval
+  # path, since interval: doesn't call cv.update_interval — it's an intervals
+  # component schema, not a PollingComponent's update_interval).
+  # Expected: scheduler coerces to 1ms at registration, emits ESP_LOGE,
+  # fires at ~1kHz instead of spinning.
+  - interval: 0ms
+    then:
+      - lambda: |-
+          id(fire_count) += 1;
+          if (id(fire_count) == 50) {
+            ESP_LOGI("test", "ZERO_INTERVAL_50_FIRES_REACHED");
+          }

tests/integration/fixtures/wake_loop_forces_phase_b.yaml

@@ -0,0 +1,52 @@
+esphome:
+  name: wake-loop-phase-b
+  on_boot:
+    priority: -100
+    then:
+      - lambda: |-
+          // Raise loop_interval_ to 2000ms. Without the wake-request flag,
+          // a wake_loop_threadsafe() call would only run Phase A (scheduler)
+          // and leave the component phase gated for ~2s.
+          App.set_loop_interval(2000);
+      # Let boot transients settle.
+      - delay: 1000ms
+      - lambda: |-
+          // Snapshot the loop counter, then ask the component to spawn a
+          // background thread that calls App.wake_loop_threadsafe() after
+          // ~50ms. With the fix, that wake forces Phase B on the next tick
+          // and the counter increments well within the 500ms observation
+          // window below.
+          id(count_at_start) = id(wake_counter)->get_loop_count();
+          id(start_time) = millis();
+          id(wake_counter)->start_async_wake();
+          ESP_LOGI("test", "WAKE_STARTED count=%d", id(count_at_start));
+      # Observation window must be much shorter than loop_interval_ (2000ms)
+      # so a "false pass" isn't possible by simply waiting out the gate.
+      - delay: 500ms
+      - lambda: |-
+          int count_now = id(wake_counter)->get_loop_count();
+          int delta = count_now - id(count_at_start);
+          uint32_t elapsed = millis() - id(start_time);
+          ESP_LOGI("test", "WAKE_RESULT delta=%d elapsed=%u", delta, elapsed);
+
+host:
+api:
+logger:
+  level: INFO
+
+external_components:
+  - source:
+      type: local
+      path: EXTERNAL_COMPONENT_PATH
+    components: [wake_test_component]
+
+globals:
+  - id: count_at_start
+    type: int
+    initial_value: "0"
+  - id: start_time
+    type: uint32_t
+    initial_value: "0"
+
+wake_test_component:
+  id: wake_counter

tests/integration/test_loop_interval_decoupling.py

@@ -0,0 +1,75 @@
+"""Test that loop_interval_ no longer clamps scheduler cadence.
+
+Regression test for the decoupling of Application::loop() component-phase
+cadence from scheduler wake timing.
+
+Setup:
+- App.set_loop_interval(500) — raised for power-savings style cadence
+- Scheduler interval at 50ms — should fire at 50ms regardless of loop_interval_
+- Component loop (LoopTestComponent) — should run at 500ms cadence
+
+Before the decoupling fix the old `std::max(next_schedule, delay_time / 2)`
+floor clamped the sleep to ~250ms, so the 50ms scheduler only fired ~8 times
+per 2s (vs the ~40 expected). After the fix the scheduler fires close to its
+requested cadence while the component phase stays gated at loop_interval_.
+"""
+
+from __future__ import annotations
+
+import asyncio
+import re
+
+import pytest
+
+from .types import APIClientConnectedFactory, RunCompiledFunction
+
+
+@pytest.mark.asyncio
+async def test_loop_interval_decoupling(
+    yaml_config: str,
+    run_compiled: RunCompiledFunction,
+    api_client_connected: APIClientConnectedFactory,
+) -> None:
+    """Raised loop_interval_ must not clamp scheduler item cadence."""
+    loop = asyncio.get_running_loop()
+    measurement_done: asyncio.Future[tuple[int, int]] = loop.create_future()
+
+    def on_log_line(line: str) -> None:
+        match = re.search(r"MEASUREMENT_DONE loop_delta=(\d+) sched_delta=(\d+)", line)
+        if match and not measurement_done.done():
+            measurement_done.set_result((int(match.group(1)), int(match.group(2))))
+
+    async with (
+        run_compiled(yaml_config, line_callback=on_log_line),
+        api_client_connected() as client,
+    ):
+        device_info = await client.device_info()
+        assert device_info is not None
+        assert device_info.name == "loop-interval-decouple"
+
+        try:
+            loop_delta, sched_delta = await asyncio.wait_for(
+                measurement_done, timeout=10.0
+            )
+        except TimeoutError:
+            pytest.fail("MEASUREMENT_DONE marker never appeared")
+
+        # Observation window = 2s, loop_interval_ = 500ms.
+        # Component phase should fire ~4 times in 2s. The upper bound must be
+        # less than 8: the pre-decoupling behavior clamped to ~250ms cadence
+        # giving ~8 loops/2s, so allowing 8 would let the old behavior pass.
+        # Lower bound 3 (not 2) keeps the test honest: a >30% slowdown from
+        # the ~4 nominal is not normal CI jitter and should fail.
+        assert 3 <= loop_delta <= 6, (
+            f"Component loop should fire ~4 times in 2s at loop_interval=500ms, "
+            f"got {loop_delta}"
+        )
+
+        # Scheduler interval = 50ms → ~40 fires in 2s. Before the decoupling
+        # fix this clamped to ~8 fires. Assert >= 20 to catch the old clamped
+        # behavior with comfortable jitter headroom for slow CI hosts.
+        assert sched_delta >= 20, (
+            f"50ms scheduler interval should fire ~40 times in 2s but only "
+            f"fired {sched_delta}. This indicates loop_interval_ is still "
+            f"clamping scheduler cadence."
+        )

tests/integration/test_loop_interval_default_not_pulled_forward.py

@@ -0,0 +1,67 @@
+"""Test that a fast scheduler item does not pull the component phase forward.
+
+Regression test for the original ~128 Hz → ~62 Hz bug fixed by decoupling
+Application::loop() component-phase cadence from scheduler wake timing.
+
+Setup:
+- loop_interval_ left at its default (16 ms → ~62 Hz component phase).
+- Scheduler interval at 5 ms (well under the old loop_interval_/2 = 8 ms floor).
+
+Before the decoupling fix the ``std::max(next_schedule, delay_time / 2)`` floor
+clamped the sleep to ~8 ms whenever any scheduler item was due sooner than
+loop_interval_/2. That pulled the component phase forward to ~128 Hz — twice
+what the documented ~62 Hz default promised. After the fix the component
+phase stays at ~62 Hz regardless of scheduler activity.
+"""
+
+from __future__ import annotations
+
+import asyncio
+import re
+
+import pytest
+
+from .types import APIClientConnectedFactory, RunCompiledFunction
+
+
+@pytest.mark.asyncio
+async def test_loop_interval_default_not_pulled_forward(
+    yaml_config: str,
+    run_compiled: RunCompiledFunction,
+    api_client_connected: APIClientConnectedFactory,
+) -> None:
+    """Fast scheduler item must not pull component phase past default ~62 Hz."""
+    loop = asyncio.get_running_loop()
+    measurement_done: asyncio.Future[int] = loop.create_future()
+
+    def on_log_line(line: str) -> None:
+        match = re.search(r"MEASUREMENT_DONE loop_delta=(\d+)", line)
+        if match and not measurement_done.done():
+            measurement_done.set_result(int(match.group(1)))
+
+    async with (
+        run_compiled(yaml_config, line_callback=on_log_line),
+        api_client_connected() as client,
+    ):
+        device_info = await client.device_info()
+        assert device_info is not None
+        assert device_info.name == "loop-default-not-pulled"
+
+        try:
+            loop_delta = await asyncio.wait_for(measurement_done, timeout=10.0)
+        except TimeoutError:
+            pytest.fail("MEASUREMENT_DONE marker never appeared")
+
+        # Observation window = 2s, loop_interval_ default = 16ms → ~62 Hz →
+        # ~125 component-phase iterations expected.
+        # Pre-fix behavior: the 5 ms scheduler interval tripped the old
+        # delay_time/2 = 8 ms floor, pulling the phase to ~128 Hz → ~256.
+        # Upper bound 180 is comfortably below the ~256 pre-fix rate but
+        # above the ~125 nominal with CI jitter.
+        # Lower bound 80 covers very slow CI hosts without permitting a
+        # complete regression.
+        assert 80 <= loop_delta <= 180, (
+            f"Component loop at default loop_interval_ should fire ~125 times "
+            f"in 2s (≈62 Hz × 2s); got {loop_delta}. Values >200 indicate the "
+            f"scheduler is again pulling the component phase forward."
+        )

tests/integration/test_runtime_stats.py

@@ -26,6 +26,7 @@ async def test_runtime_stats(
 
     # Track component stats
     component_stats_found = set()
+    main_loop_lines: list[dict[str, str]] = []
 
     # Patterns to match - need to handle ANSI color codes and timestamps
     # The log format is: [HH:MM:SS][color codes][I][tag]: message
@@ -34,6 +35,14 @@ async def test_runtime_stats(
     component_pattern = re.compile(
         r"^\[[^\]]+\].*?\s+([\w.]+):\s+count=(\d+),\s+avg=([\d.]+)ms"
     )
+    # Main loop overhead line emitted by runtime_stats
+    main_loop_pattern = re.compile(
+        r"main_loop:\s+iters=(?P<iters>\d+),\s+"
+        r"active_avg=(?P<active_avg>[\d.]+)ms,\s+"
+        r"active_max=(?P<active_max>[\d.]+)ms,\s+"
+        r"active_total=(?P<active_total>[\d.]+)ms,\s+"
+        r"overhead_total=(?P<overhead_total>[\d.]+)ms"
+    )
 
     def check_output(line: str) -> None:
         """Check log output for runtime stats messages."""
@@ -54,6 +63,11 @@ async def test_runtime_stats(
             component_name = match.group(1)
             component_stats_found.add(component_name)
 
+        # Check for main_loop overhead line
+        ml_match = main_loop_pattern.search(line)
+        if ml_match:
+            main_loop_lines.append(ml_match.groupdict())
+
     async with (
         run_compiled(yaml_config, line_callback=check_output),
         api_client_connected() as client,
@@ -86,3 +100,22 @@ async def test_runtime_stats(
         assert "template.switch" in component_stats_found, (
             f"Expected template.switch stats, found: {component_stats_found}"
         )
+
+        # Verify the main_loop overhead line is emitted (at least once for
+        # the period section and once for the total section, per log cycle).
+        assert len(main_loop_lines) >= 2, (
+            f"Expected at least 2 main_loop lines, got {len(main_loop_lines)}"
+        )
+        for fields in main_loop_lines:
+            assert int(fields["iters"]) > 0, f"iters should be > 0: {fields}"
+            assert float(fields["active_total"]) > 0.0, (
+                f"active_total should be > 0: {fields}"
+            )
+            assert float(fields["active_avg"]) >= 0.0, (
+                f"active_avg should be >= 0: {fields}"
+            )
+            # overhead_total is derived and may be 0 if components dominate,
+            # but the field must still be present and parseable as a float.
+            assert float(fields["overhead_total"]) >= 0.0, (
+                f"overhead_total should be >= 0: {fields}"
+            )

tests/integration/test_scheduler_interval_zero_coerced.py

@@ -0,0 +1,67 @@
+"""Test that Scheduler::set_timer_common_ coerces interval=0 to 1ms.
+
+Regression test for the scheduler busy-loop when interval=0 was passed
+literally. Without the coercion, Scheduler::call() would spin forever
+because the item's next_execution == now_64 after re-scheduling, failing
+the loop's `> now_64` break condition. The device would fail to yield
+back to the main loop and trigger a WDT reset.
+
+With the coercion, interval=0 becomes interval=1 and the scheduler
+fires at ~1kHz (bounded by the loop), the main loop continues to run,
+and the device stays responsive to API calls.
+"""
+
+from __future__ import annotations
+
+import asyncio
+
+import pytest
+
+from .types import APIClientConnectedFactory, RunCompiledFunction
+
+
+@pytest.mark.asyncio
+async def test_scheduler_interval_zero_coerced(
+    yaml_config: str,
+    run_compiled: RunCompiledFunction,
+    api_client_connected: APIClientConnectedFactory,
+) -> None:
+    """interval=0ms must be coerced to 1ms and not starve the main loop."""
+    loop = asyncio.get_running_loop()
+    reached_50: asyncio.Future[None] = loop.create_future()
+    coerce_warning: asyncio.Future[None] = loop.create_future()
+
+    def on_log_line(line: str) -> None:
+        if "ZERO_INTERVAL_50_FIRES_REACHED" in line and not reached_50.done():
+            reached_50.set_result(None)
+        if "would spin main loop" in line and not coerce_warning.done():
+            coerce_warning.set_result(None)
+
+    async with (
+        run_compiled(yaml_config, line_callback=on_log_line),
+        api_client_connected() as client,
+    ):
+        # The API-client connection itself is evidence that the main loop
+        # is not starved — if set_interval(0) were spinning we could not
+        # get here at all.
+        device_info = await client.device_info()
+        assert device_info is not None
+        assert device_info.name == "sched-interval-zero"
+
+        # Coerce warning must fire at registration
+        try:
+            await asyncio.wait_for(coerce_warning, timeout=5.0)
+        except TimeoutError:
+            pytest.fail("Expected coerce warning 'would spin main loop' not seen")
+
+        # The coerced 1ms interval should fire 50 times quickly — this
+        # confirms the callback actually runs (not just registered) and the
+        # scheduler yields back to the main loop each time.
+        try:
+            await asyncio.wait_for(reached_50, timeout=5.0)
+        except TimeoutError:
+            pytest.fail(
+                "Coerced interval=0→1ms did not reach 50 fires within 5s, "
+                "which would indicate either the coercion failed or the "
+                "main loop is still being starved."
+            )

tests/integration/test_uart_mock_ld2412.py

@@ -325,9 +325,13 @@ async def test_uart_mock_ld2412_engineering_truncated(
         ],
     )
 
-    # Signal when we see Phase 3 recovery values (gate_0_move=50)
+    # Signal when we see ALL Phase 3 recovery values to avoid race where some
+    # arrive after the waiter fires but before we index into the lists
     recovery_received = collector.add_waiter(
-        lambda: pytest.approx(50.0) in collector.sensor_states["gate_0_move_energy"]
+        lambda: (
+            pytest.approx(50.0) in collector.sensor_states["gate_0_move_energy"]
+            and pytest.approx(42.0) in collector.sensor_states["light"]
+        )
     )
 
     async with (

tests/integration/test_wake_loop_forces_phase_b.py

@@ -0,0 +1,76 @@
+"""Test that wake_loop_threadsafe() forces a component-phase iteration.
+
+Regression test for the wake-request flag added to Application::loop()'s
+Phase A / Phase B gate. Background producers (MQTT RX, USB RX, BLE event,
+etc.) call App.wake_loop_threadsafe() expecting their component's loop()
+to drain queued work; if the component phase stays gated by loop_interval_,
+the work waits up to loop_interval_ ms instead of running on the next tick.
+
+Setup:
+- App.set_loop_interval(2000) — a wide gate that would clearly mask the bug.
+- A test component spawns a detached std::thread that sleeps 50 ms and then
+  calls App.wake_loop_threadsafe() from a non-main thread.
+- The on_boot block snapshots the component's loop counter before/after a
+  500 ms observation window.
+
+Without the fix, delta=0 (the gate holds Phase B for ~2 s).
+With the fix, delta>=1 (the wake forces Phase B within one tick of the wake).
+"""
+
+from __future__ import annotations
+
+import asyncio
+from pathlib import Path
+import re
+
+import pytest
+
+from .types import APIClientConnectedFactory, RunCompiledFunction
+
+
+@pytest.mark.asyncio
+async def test_wake_loop_forces_phase_b(
+    yaml_config: str,
+    run_compiled: RunCompiledFunction,
+    api_client_connected: APIClientConnectedFactory,
+) -> None:
+    """A wake_loop_threadsafe() call from a background thread must trigger the
+    component phase within the next tick, even when loop_interval_ is raised
+    well above the observation window."""
+    external_components_path = str(
+        Path(__file__).parent / "fixtures" / "external_components"
+    )
+    yaml_config = yaml_config.replace(
+        "EXTERNAL_COMPONENT_PATH", external_components_path
+    )
+
+    loop = asyncio.get_running_loop()
+    result: asyncio.Future[tuple[int, int]] = loop.create_future()
+
+    def on_log_line(line: str) -> None:
+        match = re.search(r"WAKE_RESULT delta=(\d+) elapsed=(\d+)", line)
+        if match and not result.done():
+            result.set_result((int(match.group(1)), int(match.group(2))))
+
+    async with (
+        run_compiled(yaml_config, line_callback=on_log_line),
+        api_client_connected() as client,
+    ):
+        device_info = await client.device_info()
+        assert device_info is not None
+        assert device_info.name == "wake-loop-phase-b"
+
+        try:
+            delta, elapsed = await asyncio.wait_for(result, timeout=15.0)
+        except TimeoutError:
+            pytest.fail("WAKE_RESULT marker never appeared")
+
+        # Without the fix, delta would be 0 — loop_interval_=2000ms held
+        # Phase B off for the full 500ms observation window. With the fix
+        # the wake from the background thread (~50ms after start) forces
+        # Phase B on the next tick, so the counter increments at least once.
+        assert delta >= 1, (
+            f"wake_loop_threadsafe() from a background thread should force "
+            f"Phase B within the next tick; observed delta={delta} after "
+            f"{elapsed}ms with loop_interval_=2000ms"
+        )

tests/script/test_helpers.py

@@ -1468,3 +1468,159 @@ def test_cache_miss_corrupted_json(
         result = helpers.create_components_graph()
         # Should handle corruption gracefully and rebuild
         assert result == {}
+
+
+# ---------------------------------------------------------------------------
+# parse_component_metadata / split_conflicting_groups
+# ---------------------------------------------------------------------------
+
+
+@pytest.fixture
+def fake_components(tmp_path: Path) -> Path:
+    """Create a fake esphome/components/ tree and return the repo root.
+
+    Component layout (tested against split_conflicting_groups):
+
+        alpha          -- CONFLICTS_WITH=["beta"]
+        beta           -- CONFLICTS_WITH=["alpha"]
+        beta_variant   -- AUTO_LOAD=["beta"]
+        gamma          -- (no metadata)
+        one_sided      -- CONFLICTS_WITH=["plain"]  (plain does not reject back)
+        plain          -- no CONFLICTS_WITH
+        callable_auto  -- AUTO_LOAD is a function (not a list literal) -> ignored
+        broken         -- __init__.py has a SyntaxError
+    """
+    components = tmp_path / "esphome" / "components"
+    components.mkdir(parents=True)
+
+    def write(name: str, body: str) -> None:
+        (components / name).mkdir()
+        (components / name / "__init__.py").write_text(body)
+
+    write("alpha", 'CONFLICTS_WITH = ["beta"]\n')
+    write("beta", 'CONFLICTS_WITH = ["alpha"]\n')
+    write("beta_variant", 'AUTO_LOAD = ["beta"]\n')
+    write("gamma", "")
+    write("one_sided", 'CONFLICTS_WITH = ["plain"]\n')
+    write("plain", "")
+    write("callable_auto", "def AUTO_LOAD():\n    return ['beta']\n")
+    write("broken", "this is not valid python !!!")
+    helpers.parse_component_metadata.cache_clear()
+    return tmp_path
+
+
+def test_parse_component_metadata_list_literals(
+    fake_components: Path, monkeypatch: MonkeyPatch
+) -> None:
+    monkeypatch.setattr(helpers, "root_path", str(fake_components))
+    helpers.parse_component_metadata.cache_clear()
+
+    meta = helpers.parse_component_metadata("alpha")
+    assert meta.conflicts_with == frozenset({"beta"})
+    assert meta.auto_load == frozenset()
+
+    variant = helpers.parse_component_metadata("beta_variant")
+    assert variant.auto_load == frozenset({"beta"})
+    assert variant.conflicts_with == frozenset()
+
+
+def test_parse_component_metadata_missing_empty_and_callable(
+    fake_components: Path, monkeypatch: MonkeyPatch
+) -> None:
+    monkeypatch.setattr(helpers, "root_path", str(fake_components))
+    helpers.parse_component_metadata.cache_clear()
+
+    # Unknown component -> empty metadata, not an error.
+    unknown = helpers.parse_component_metadata("does_not_exist")
+    assert unknown == helpers.ComponentMetadata()
+
+    # Empty __init__.py -> empty metadata.
+    assert helpers.parse_component_metadata("gamma") == helpers.ComponentMetadata()
+
+    # Callable AUTO_LOAD cannot be statically evaluated -> empty.
+    callable_meta = helpers.parse_component_metadata("callable_auto")
+    assert callable_meta.auto_load == frozenset()
+
+    # SyntaxError in __init__.py must not raise.
+    assert helpers.parse_component_metadata("broken") == helpers.ComponentMetadata()
+
+
+def test_split_conflicting_groups_splits_direct_conflict(
+    fake_components: Path, monkeypatch: MonkeyPatch
+) -> None:
+    monkeypatch.setattr(helpers, "root_path", str(fake_components))
+    helpers.parse_component_metadata.cache_clear()
+
+    result = helpers.split_conflicting_groups(
+        {("esp32", "i2c"): ["alpha", "beta", "gamma"]}
+    )
+    # alpha and beta must end up in different buckets; gamma has no conflicts.
+    buckets = list(result.values())
+    assert any("alpha" in b for b in buckets)
+    assert any("beta" in b for b in buckets)
+    for bucket in buckets:
+        assert not ({"alpha", "beta"} <= set(bucket))
+    # Gamma sticks with whichever bucket it landed in first (alpha's).
+    all_members = {c for b in buckets for c in b}
+    assert all_members == {"alpha", "beta", "gamma"}
+
+
+def test_split_conflicting_groups_propagates_through_auto_load(
+    fake_components: Path, monkeypatch: MonkeyPatch
+) -> None:
+    """A component that AUTO_LOADs a conflicting one must also be split out."""
+    monkeypatch.setattr(helpers, "root_path", str(fake_components))
+    helpers.parse_component_metadata.cache_clear()
+
+    result = helpers.split_conflicting_groups(
+        {("esp32", "i2c"): ["alpha", "beta_variant"]}
+    )
+    buckets = list(result.values())
+    for bucket in buckets:
+        assert not ({"alpha", "beta_variant"} <= set(bucket))
+    assert sum(len(b) for b in buckets) == 2
+
+
+def test_split_conflicting_groups_symmetric_one_sided_declaration(
+    fake_components: Path, monkeypatch: MonkeyPatch
+) -> None:
+    """If only one side declares CONFLICTS_WITH, the pair must still be split."""
+    monkeypatch.setattr(helpers, "root_path", str(fake_components))
+    helpers.parse_component_metadata.cache_clear()
+
+    result = helpers.split_conflicting_groups(
+        {("esp32", "i2c"): ["one_sided", "plain"]}
+    )
+    buckets = list(result.values())
+    for bucket in buckets:
+        assert not ({"one_sided", "plain"} <= set(bucket))
+
+
+def test_split_conflicting_groups_preserves_non_conflicting_group(
+    fake_components: Path, monkeypatch: MonkeyPatch
+) -> None:
+    monkeypatch.setattr(helpers, "root_path", str(fake_components))
+    helpers.parse_component_metadata.cache_clear()
+
+    original = {("esp32", "i2c"): ["alpha", "gamma", "plain"]}
+    result = helpers.split_conflicting_groups(original)
+    # All three are mutually compatible -- the group must not be split.
+    assert result == original
+
+
+def test_split_conflicting_groups_preserves_original_signature_for_first_bucket(
+    fake_components: Path, monkeypatch: MonkeyPatch
+) -> None:
+    """When a group is split, the first bucket keeps the original signature key."""
+    monkeypatch.setattr(helpers, "root_path", str(fake_components))
+    helpers.parse_component_metadata.cache_clear()
+
+    result = helpers.split_conflicting_groups({("esp32", "i2c"): ["alpha", "beta"]})
+    keys = set(result.keys())
+    assert ("esp32", "i2c") in keys
+    # One additional bucket with a disambiguated signature.
+    extra = keys - {("esp32", "i2c")}
+    assert len(extra) == 1
+    platform, signature = next(iter(extra))
+    assert platform == "esp32"
+    assert signature.startswith("i2c__conflict")

tests/unit_tests/fixtures/bundle/bundle_test.yaml

@@ -11,9 +11,9 @@ esp32:
 logger:
   <<: !include common/base.yaml
 
-wifi:
-  ssid: !secret wifi_ssid
-  password: !secret wifi_password
+# Plain nested !include — deferred as an IncludeFile until the substitution
+# pass. The bundle must force-resolve it to pick up common/wifi.yaml.
+wifi: !include common/wifi.yaml
 
 api:
 

tests/unit_tests/fixtures/bundle/common/wifi.yaml

@@ -0,0 +1,2 @@
+ssid: !secret wifi_ssid
+password: !secret wifi_password

tests/unit_tests/fixtures/substitutions/15-substitutions_as_include.approved.yaml

@@ -0,0 +1,5 @@
+substitutions:
+  wifi_password: sub_password
+wifi:
+  ssid: main_ssid
+  password: sub_password

tests/unit_tests/fixtures/substitutions/15-substitutions_as_include.input.yaml

@@ -0,0 +1,5 @@
+substitutions: !include 15-substitutions_inc.yaml
+
+wifi:
+  ssid: main_ssid
+  password: $wifi_password

tests/unit_tests/fixtures/substitutions/15-substitutions_inc.yaml

@@ -0,0 +1 @@
+wifi_password: sub_password

tests/unit_tests/fixtures/substitutions/16-substitutions_as_include_with_packages.approved.yaml

@@ -0,0 +1,5 @@
+substitutions:
+  wifi_password: sub_password
+wifi:
+  ssid: main_ssid
+  password: sub_password

tests/unit_tests/fixtures/substitutions/16-substitutions_as_include_with_packages.input.yaml

@@ -0,0 +1,9 @@
+substitutions: !include 15-substitutions_inc.yaml
+
+packages:
+  wifi_pkg:
+    wifi:
+      password: $wifi_password
+
+wifi:
+  ssid: main_ssid

tests/unit_tests/fixtures/substitutions/17-substitutions_include_cli_var.approved.yaml

@@ -0,0 +1,6 @@
+substitutions:
+  subs_file: 15-substitutions_inc
+  wifi_password: sub_password
+wifi:
+  ssid: main_ssid
+  password: sub_password

tests/unit_tests/fixtures/substitutions/17-substitutions_include_cli_var.input.yaml

@@ -0,0 +1,8 @@
+command_line_substitutions:
+  subs_file: 15-substitutions_inc
+
+substitutions: !include ${subs_file}.yaml
+
+wifi:
+  ssid: main_ssid
+  password: $wifi_password

tests/unit_tests/test_bundle.py

@@ -5,8 +5,10 @@ from __future__ import annotations
 import io
 import json
 from pathlib import Path
+import shutil
 import tarfile
 from typing import Any
+from unittest.mock import patch
 
 import pytest
 
@@ -20,6 +22,7 @@ from esphome.bundle import (
     _add_bytes_to_tar,
     _default_target_dir,
     _find_used_secret_keys,
+    _force_load_include_files,
     extract_bundle,
     is_bundle_path,
     prepare_bundle_for_compile,
@@ -485,7 +488,7 @@ def test_read_bundle_manifest_minimal(tmp_path: Path) -> None:
 
     result = read_bundle_manifest(bundle_path)
     assert result.esphome_version == "unknown"
-    assert result.files == []
+    assert not result.files
     assert result.has_secrets is False
 
 
@@ -862,6 +865,117 @@ def test_discover_files_skips_missing_directory(tmp_path: Path) -> None:
     assert len(files) == 1
 
 
+def test_discover_files_nested_include(tmp_path: Path) -> None:
+    """Nested !include files (e.g. wifi: !include wifi.yaml) are bundled."""
+    config_dir = _setup_config_dir(tmp_path)
+    (config_dir / "test.yaml").write_text(
+        "esphome:\n  name: test\nwifi: !include wifi.yaml\n"
+    )
+    (config_dir / "wifi.yaml").write_text('ssid: "a"\npassword: "b"\n')
+
+    creator = ConfigBundleCreator({})
+    files = creator.discover_files()
+
+    paths = [f.path for f in files]
+    assert "test.yaml" in paths
+    assert "wifi.yaml" in paths
+
+
+def test_discover_files_deeply_nested_include(tmp_path: Path) -> None:
+    """Chains of !include (a includes b includes c) are fully resolved."""
+    config_dir = _setup_config_dir(tmp_path)
+    (config_dir / "test.yaml").write_text(
+        "esphome:\n  name: test\nwifi: !include level1.yaml\n"
+    )
+    (config_dir / "level1.yaml").write_text("nested: !include level2.yaml\n")
+    (config_dir / "level2.yaml").write_text('value: "leaf"\n')
+
+    creator = ConfigBundleCreator({})
+    files = creator.discover_files()
+
+    paths = [f.path for f in files]
+    assert "level1.yaml" in paths
+    assert "level2.yaml" in paths
+
+
+def test_discover_files_nested_include_unresolved_substitution(
+    tmp_path: Path,
+) -> None:
+    """!include with substitution vars in path cannot be resolved; skipped gracefully."""
+    config_dir = _setup_config_dir(tmp_path)
+    (config_dir / "test.yaml").write_text(
+        "esphome:\n  name: test\nwifi: !include ${platform}.yaml\n"
+    )
+
+    creator = ConfigBundleCreator({})
+    # Should not raise
+    files = creator.discover_files()
+
+    paths = [f.path for f in files]
+    assert "test.yaml" in paths
+
+
+def test_discover_files_nested_include_load_failure(
+    tmp_path: Path, caplog: pytest.LogCaptureFixture
+) -> None:
+    """A nested !include pointing at a missing file is logged and skipped."""
+    config_dir = _setup_config_dir(tmp_path)
+    (config_dir / "test.yaml").write_text(
+        "esphome:\n  name: test\nwifi: !include missing.yaml\n"
+    )
+
+    creator = ConfigBundleCreator({})
+    files = creator.discover_files()
+
+    paths = [f.path for f in files]
+    assert "test.yaml" in paths
+    assert any(
+        "failed to load !include" in r.message and "missing.yaml" in r.message
+        for r in caplog.records
+    )
+
+
+def test_force_load_skips_duplicate_include_file() -> None:
+    """The same IncludeFile referenced twice is only loaded once."""
+
+    class _StubInclude:
+        """Mimics yaml_util.IncludeFile minimally for _force_load testing."""
+
+        def __init__(self) -> None:
+            self.file = Path("dup.yaml")
+            self.parent_file = Path("root.yaml")
+            self.load_calls = 0
+
+        def has_unresolved_expressions(self) -> bool:
+            return False
+
+        def load(self) -> dict[str, Any]:
+            self.load_calls += 1
+            return {}
+
+    stub = _StubInclude()
+    # Same instance appears twice — second visit must hit the _seen guard.
+    tree = {"a": stub, "b": [stub]}
+
+    with patch("esphome.bundle.yaml_util.IncludeFile", _StubInclude):
+        _force_load_include_files(tree)
+
+    assert stub.load_calls == 1
+
+
+def test_force_load_handles_cyclic_containers() -> None:
+    """Cyclic dict/list references don't cause infinite recursion."""
+    cyclic_dict: dict[str, Any] = {}
+    cyclic_dict["self"] = cyclic_dict
+
+    cyclic_list: list[Any] = []
+    cyclic_list.append(cyclic_list)
+
+    # Should return without recursing forever
+    _force_load_include_files(cyclic_dict)
+    _force_load_include_files(cyclic_list)
+
+
 def test_discover_files_yaml_reload_failure(
     tmp_path: Path, monkeypatch: pytest.MonkeyPatch
 ) -> None:
@@ -1008,6 +1122,40 @@ def test_discover_files_walk_tuple_values(tmp_path: Path) -> None:
     assert "a.pem" in paths
 
 
+# ---------------------------------------------------------------------------
+# ConfigBundleCreator - fixture-based end-to-end
+# ---------------------------------------------------------------------------
+
+
+def test_discover_files_fixture_config(fixture_path: Path, tmp_path: Path) -> None:
+    """Use the real ``fixtures/bundle/`` tree as an end-to-end reproducer.
+
+    The fixture config uses ``wifi: !include common/wifi.yaml`` — a plain
+    nested !include that is returned as a deferred ``IncludeFile`` and only
+    resolved during the substitution pass. Before this fix, bundle discovery
+    never ran substitutions, so ``common/wifi.yaml`` was silently missing
+    from the bundle.
+    """
+    # Copy the fixture tree into a tmp dir so the test doesn't rely on the
+    # source repo being writable and so we can set CORE.config_path freely.
+    src = fixture_path / "bundle"
+    dst = tmp_path / "bundle"
+    shutil.copytree(src, dst)
+
+    CORE.config_path = dst / "bundle_test.yaml"
+
+    creator = ConfigBundleCreator({})
+    files = creator.discover_files()
+    paths = {f.path for f in files}
+
+    # Root and top-level !secret-referenced files
+    assert "bundle_test.yaml" in paths
+    assert "secrets.yaml" in paths
+    # The nested !include — this is what regressed when IncludeFile became
+    # deferred (PR #12213).
+    assert "common/wifi.yaml" in paths
+
+
 # ---------------------------------------------------------------------------
 # ConfigBundleCreator - create_bundle
 # ---------------------------------------------------------------------------

tests/unit_tests/test_config_validation.py

@@ -24,6 +24,7 @@ from esphome.const import (
     PLATFORM_LN882X,
     PLATFORM_RP2040,
     PLATFORM_RTL87XX,
+    SCHEDULER_DONT_RUN,
 )
 from esphome.core import CORE, HexInt, Lambda
 
@@ -765,3 +766,30 @@ def test_percentage_validators__raw_number_above_one_without_percent_sign(
         config_validation.unbounded_percentage(value)
     with pytest.raises(Invalid, match="percent sign"):
         config_validation.unbounded_possibly_negative_percentage(value)
+
+
+def test_update_interval__coerces_zero_to_one_ms(
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """update_interval: 0ms must be coerced to 1ms (not rejected) because a
+    literal 0ms schedule causes Scheduler::call() to spin. Coercion keeps
+    existing configs compiling on upgrade while emitting a user-facing
+    warning that directs them to set a non-zero value."""
+    with caplog.at_level("WARNING"):
+        result = config_validation.update_interval("0ms")
+    assert result.total_milliseconds == 1
+    assert "update_interval of 0ms is not supported" in caplog.text
+    assert "1ms" in caplog.text
+
+
+def test_update_interval__preserves_nonzero_values() -> None:
+    """Non-zero update_interval values must pass through unchanged."""
+    assert config_validation.update_interval("1ms").total_milliseconds == 1
+    assert config_validation.update_interval("50ms").total_milliseconds == 50
+    assert config_validation.update_interval("60s").total_milliseconds == 60000
+
+
+def test_update_interval__never_passes_through() -> None:
+    """update_interval: never must still map to SCHEDULER_DONT_RUN."""
+    result = config_validation.update_interval("never")
+    assert result.total_milliseconds == SCHEDULER_DONT_RUN

tests/unit_tests/test_substitutions.py

@@ -14,6 +14,7 @@ from esphome.components.packages import (
     do_packages_pass,
     merge_packages,
 )
+from esphome.components.substitutions.jinja import UndefinedError
 from esphome.config import resolve_extend_remove
 from esphome.config_helpers import Extend, merge_config
 import esphome.config_validation as cv
@@ -675,6 +676,90 @@ def test_include_filename_substitution_undefined_var(tmp_path: Path) -> None:
         substitutions.do_substitution_pass(config)
 
 
+def test_raise_first_undefined_logs_extras_at_debug(
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """Only the first undefined error is raised; extras are logged at debug."""
+    errors: substitutions.ErrList = [
+        (UndefinedError("'a' is undefined"), ["url"], None),
+        (UndefinedError("'b' is undefined"), ["ref"], None),
+        (UndefinedError("'c' is undefined"), ["path"], None),
+    ]
+
+    with (
+        caplog.at_level(logging.DEBUG, logger="esphome.components.substitutions"),
+        pytest.raises(cv.Invalid) as exc_info,
+    ):
+        substitutions.raise_first_undefined(errors, None, "package definition")
+
+    # First error is surfaced as the cv.Invalid message.
+    raised = str(exc_info.value)
+    assert "'a' is undefined" in raised
+    assert "'b' is undefined" not in raised
+    assert "'c' is undefined" not in raised
+
+    # Remaining errors are captured via debug logging for troubleshooting.
+    assert "Additional undefined variables in package definition" in caplog.text
+    assert "'b' is undefined at 'ref'" in caplog.text
+    assert "'c' is undefined at 'path'" in caplog.text
+
+
+def test_raise_first_undefined_noop_on_empty() -> None:
+    """An empty errors list is a no-op — no exception, no log."""
+    substitutions.raise_first_undefined([], None, "package definition")
+
+
+def test_do_substitution_pass_included_substitutions_must_be_mapping(
+    tmp_path: Path,
+) -> None:
+    """`substitutions: !include list.yaml` where the file holds a list raises cv.Invalid.
+
+    Locks in the shape check that runs after the deferred IncludeFile has been
+    resolved.
+    """
+    parent = tmp_path / "main.yaml"
+    parent.write_text("")
+
+    def loader(path: Path):
+        return ["not", "a", "mapping"]
+
+    include = yaml_util.IncludeFile(parent, "subs.yaml", None, loader)
+    config = OrderedDict({CONF_SUBSTITUTIONS: include})
+
+    with pytest.raises(
+        cv.Invalid, match="Substitutions must be a key to value mapping"
+    ):
+        substitutions.do_substitution_pass(config)
+
+
+def test_do_packages_pass_included_substitutions_must_be_mapping(
+    tmp_path: Path,
+) -> None:
+    """`substitutions: !include list.yaml` alongside `packages:` raises cv.Invalid.
+
+    Without the shape check, ``UserDict(...)`` would surface a low-level
+    ``TypeError``; the explicit ``cv.Invalid`` points at the substitutions path.
+    """
+    parent = tmp_path / "main.yaml"
+    parent.write_text("")
+
+    def loader(path: Path):
+        return ["not", "a", "mapping"]
+
+    include = yaml_util.IncludeFile(parent, "subs.yaml", None, loader)
+    config = OrderedDict(
+        {
+            CONF_SUBSTITUTIONS: include,
+            "packages": {"noop": {"wifi": {"ssid": "main"}}},
+        }
+    )
+
+    with pytest.raises(
+        cv.Invalid, match="Substitutions must be a key to value mapping"
+    ):
+        do_packages_pass(config)
+
+
 def test_resolve_package_undefined_var_in_include_filename(tmp_path: Path) -> None:
     """An undefined substitution in a package include filename raises cv.Invalid.