[ci] Only run integration tests for changed components (#14776)

tests/script/test_helpers.py

@@ -36,6 +36,7 @@ def clear_helpers_cache() -> None:
     """Clear cached functions before each test."""
     helpers._get_github_event_data.cache_clear()
     helpers._get_changed_files_github_actions.cache_clear()
+    helpers.get_components_per_integration_fixture.cache_clear()
 
 
 @pytest.mark.parametrize(
@@ -1111,7 +1112,7 @@ def test_get_components_from_integration_fixtures() -> None:
         "gpio",
     }
 
-    mock_yaml_file = Mock()
+    mock_yaml_file = Mock(stem="test_fixture")
 
     with (
         patch("pathlib.Path.glob") as mock_glob,
@@ -1133,7 +1134,7 @@ def test_get_components_from_integration_fixtures_skips_yaml_anchors() -> None:
         ".binary_filters": {"filters": [{"settle": "50ms"}]},
     }
 
-    mock_yaml_file = Mock()
+    mock_yaml_file = Mock(stem="test_fixture")
 
     with (
         patch("pathlib.Path.glob") as mock_glob,
@@ -1148,6 +1149,31 @@ def test_get_components_from_integration_fixtures_skips_yaml_anchors() -> None:
         assert components == {"sensor", "esphome", "template"}
 
 
+def test_get_integration_test_files_for_components_real_fixtures() -> None:
+    """Test that component changes map to the correct real integration test files.
+
+    This test uses real fixtures to verify the mapping stays correct
+    as new tests are added.
+    """
+    # modbus should include at least the modbus test
+    modbus_tests = helpers.get_integration_test_files_for_components({"modbus"})
+    assert "tests/integration/test_uart_mock_modbus.py" in modbus_tests
+
+    # ld2410 should include at least the ld2410 test
+    ld2410_tests = helpers.get_integration_test_files_for_components({"ld2410"})
+    assert "tests/integration/test_uart_mock_ld2410.py" in ld2410_tests
+
+    # syslog should include at least the syslog test
+    syslog_tests = helpers.get_integration_test_files_for_components({"syslog"})
+    assert "tests/integration/test_syslog.py" in syslog_tests
+
+    # A component not used by any fixture should return nothing
+    fake_tests = helpers.get_integration_test_files_for_components(
+        {"nonexistent_component_xyz"}
+    )
+    assert fake_tests == []
+
+
 @pytest.mark.parametrize(
     "output,expected",
     [