[core] Allow AUTO_LOAD to receive the component config to determine if it should load other components (#10961)

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: J. Nick Koston <nick@home-assistant.io>

tests/unit_tests/test_config_auto_load.py

@@ -0,0 +1,131 @@
+"""Tests for AUTO_LOAD functionality including dynamic AUTO_LOAD."""
+
+from pathlib import Path
+from typing import Any
+from unittest.mock import Mock
+
+import pytest
+
+from esphome import config, config_validation as cv, yaml_util
+from esphome.core import CORE
+
+
+@pytest.fixture
+def fixtures_dir() -> Path:
+    """Get the fixtures directory."""
+    return Path(__file__).parent / "fixtures"
+
+
+@pytest.fixture
+def default_component() -> Mock:
+    """Create a default mock component for unmocked components."""
+    return Mock(
+        auto_load=[],
+        is_platform_component=False,
+        is_platform=False,
+        multi_conf=False,
+        multi_conf_no_default=False,
+        dependencies=[],
+        conflicts_with=[],
+        config_schema=cv.Schema({}, extra=cv.ALLOW_EXTRA),
+    )
+
+
+@pytest.fixture
+def static_auto_load_component() -> Mock:
+    """Create a mock component with static AUTO_LOAD."""
+    return Mock(
+        auto_load=["logger"],
+        is_platform_component=False,
+        is_platform=False,
+        multi_conf=False,
+        multi_conf_no_default=False,
+        dependencies=[],
+        conflicts_with=[],
+        config_schema=cv.Schema({}, extra=cv.ALLOW_EXTRA),
+    )
+
+
+def test_static_auto_load_adds_components(
+    mock_get_component: Mock,
+    fixtures_dir: Path,
+    static_auto_load_component: Mock,
+    default_component: Mock,
+) -> None:
+    """Test that static AUTO_LOAD triggers loading of specified components."""
+    CORE.config_path = fixtures_dir / "auto_load_static.yaml"
+
+    config_file = fixtures_dir / "auto_load_static.yaml"
+    raw_config = yaml_util.load_yaml(config_file)
+
+    component_mocks = {"test_component": static_auto_load_component}
+    mock_get_component.side_effect = lambda name: component_mocks.get(
+        name, default_component
+    )
+
+    result = config.validate_config(raw_config, {})
+
+    # Check for validation errors
+    assert not result.errors, f"Validation errors: {result.errors}"
+
+    # Logger should have been auto-loaded by test_component
+    assert "logger" in result
+    assert "test_component" in result
+
+
+def test_dynamic_auto_load_with_config_param(
+    mock_get_component: Mock,
+    fixtures_dir: Path,
+    default_component: Mock,
+) -> None:
+    """Test that dynamic AUTO_LOAD evaluates based on configuration."""
+    CORE.config_path = fixtures_dir / "auto_load_dynamic.yaml"
+
+    config_file = fixtures_dir / "auto_load_dynamic.yaml"
+    raw_config = yaml_util.load_yaml(config_file)
+
+    # Track if auto_load was called with config
+    auto_load_calls = []
+
+    def dynamic_auto_load(conf: dict[str, Any]) -> list[str]:
+        """Dynamically load components based on config."""
+        auto_load_calls.append(conf)
+        component_map = {
+            "enable_logger": "logger",
+            "enable_api": "api",
+        }
+        return [comp for key, comp in component_map.items() if conf.get(key)]
+
+    dynamic_component = Mock(
+        auto_load=dynamic_auto_load,
+        is_platform_component=False,
+        is_platform=False,
+        multi_conf=False,
+        multi_conf_no_default=False,
+        dependencies=[],
+        conflicts_with=[],
+        config_schema=cv.Schema({}, extra=cv.ALLOW_EXTRA),
+    )
+
+    component_mocks = {"test_component": dynamic_component}
+    mock_get_component.side_effect = lambda name: component_mocks.get(
+        name, default_component
+    )
+
+    result = config.validate_config(raw_config, {})
+
+    # Check for validation errors
+    assert not result.errors, f"Validation errors: {result.errors}"
+
+    # Verify auto_load was called with the validated config
+    assert len(auto_load_calls) == 1, "auto_load should be called exactly once"
+    assert auto_load_calls[0].get("enable_logger") is True
+    assert auto_load_calls[0].get("enable_api") is False
+
+    # Only logger should be auto-loaded (enable_logger=true in YAML)
+    assert "logger" in result, (
+        f"Logger not found in result. Result keys: {list(result.keys())}"
+    )
+    # API should NOT be auto-loaded (enable_api=false in YAML)
+    assert "api" not in result
+    assert "test_component" in result