[core] Fix clean-all to handle custom build paths (#15146)

Co-authored-by: J. Nick Koston <nick+github@koston.org>

esphome/writer.py

@@ -18,7 +18,6 @@ from esphome.core import CORE, EsphomeError
 from esphome.helpers import (
     copy_file_if_changed,
     cpp_string_escape,
-    get_str_env,
     is_ha_addon,
     read_file,
     rmtree,
@@ -441,18 +440,42 @@ def clean_build(clear_pio_cache: bool = True):
             rmtree(cache_dir)
 
 
+def _get_custom_build_dir(item: Path, data_dir: Path) -> Path | None:
+    """Parse a YAML config to find a custom build directory."""
+    from esphome import yaml_util
+
+    try:
+        raw = yaml_util.load_yaml(item)
+    except (EsphomeError, OSError) as e:
+        _LOGGER.debug("Could not parse %s to find build_path: %s", item, e)
+        return None
+    if not isinstance(raw, dict):
+        return None
+    esphome_conf = raw.get("esphome", {})
+    if not isinstance(esphome_conf, dict):
+        return None
+    if build_path := esphome_conf.get("build_path"):
+        return data_dir / build_path
+    return None
+
+
 def clean_all(configuration: list[str]):
     data_dirs = []
     for config in configuration:
         item = Path(config)
         if item.is_file() and item.suffix in (".yaml", ".yml"):
-            data_dirs.append(item.parent / ".esphome")
+            data_dir = item.parent / ".esphome"
+            data_dirs.append(data_dir)
+            if custom := _get_custom_build_dir(item, data_dir):
+                data_dirs.append(custom)
         else:
             data_dirs.append(item / ".esphome")
     if is_ha_addon():
         data_dirs.append(Path("/data"))
-    if "ESPHOME_DATA_DIR" in os.environ:
-        data_dirs.append(Path(get_str_env("ESPHOME_DATA_DIR", None)))
+    if env_data_dir := os.environ.get("ESPHOME_DATA_DIR"):
+        data_dirs.append(Path(env_data_dir))
+    if env_build_path := os.environ.get("ESPHOME_BUILD_PATH"):
+        data_dirs.append(Path(env_build_path))
 
     # Clean build dir
     for dir in data_dirs:

tests/unit_tests/test_writer.py

@@ -866,6 +866,130 @@ def test_clean_all_with_yaml_file(
     assert str(build_dir) in caplog.text
 
 
+@patch("esphome.writer.CORE")
+def test_clean_all_with_yaml_build_path(
+    mock_core: MagicMock,
+    tmp_path: Path,
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """Test clean_all cleans absolute build_path specified in YAML config."""
+    config_dir = tmp_path / "config"
+    config_dir.mkdir()
+
+    # Create an absolute custom build path directory with contents
+    custom_build = tmp_path / "custom_build"
+    custom_build.mkdir()
+    (custom_build / "firmware.bin").write_text("x")
+    sub = custom_build / "subdir"
+    sub.mkdir()
+    (sub / "file.txt").write_text("x")
+
+    yaml_file = config_dir / "test.yaml"
+    # Absolute build_path: data_dir / absolute = absolute (Python Path behavior)
+    yaml_file.write_text(f"esphome:\n  name: test\n  build_path: {custom_build}\n")
+
+    # Also create the normal .esphome dir
+    build_dir = config_dir / ".esphome"
+    build_dir.mkdir()
+    (build_dir / "dummy.txt").write_text("x")
+
+    from esphome.writer import clean_all
+
+    with caplog.at_level("INFO"):
+        clean_all([str(yaml_file)])
+
+    # Both .esphome and custom build_path should be cleaned
+    assert build_dir.exists()
+    assert not (build_dir / "dummy.txt").exists()
+    assert custom_build.exists()
+    assert not (custom_build / "firmware.bin").exists()
+    assert not sub.exists()
+
+
+@patch("esphome.writer.CORE")
+def test_clean_all_with_yaml_parse_error(
+    mock_core: MagicMock,
+    tmp_path: Path,
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """Test clean_all still cleans .esphome when YAML parse fails."""
+    config_dir = tmp_path / "config"
+    config_dir.mkdir()
+    yaml_file = config_dir / "test.yaml"
+    yaml_file.write_text("invalid: yaml: content: [")
+
+    build_dir = config_dir / ".esphome"
+    build_dir.mkdir()
+    (build_dir / "dummy.txt").write_text("x")
+
+    from esphome.writer import clean_all
+
+    with caplog.at_level("INFO"):
+        clean_all([str(yaml_file)])
+
+    # .esphome should still be cleaned despite YAML parse failure
+    assert build_dir.exists()
+    assert not (build_dir / "dummy.txt").exists()
+
+
+@patch("esphome.writer.CORE")
+def test_clean_all_with_env_build_path(
+    mock_core: MagicMock,
+    tmp_path: Path,
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """Test clean_all cleans ESPHOME_BUILD_PATH directory."""
+    config_dir = tmp_path / "config"
+    config_dir.mkdir()
+
+    build_dir = config_dir / ".esphome"
+    build_dir.mkdir()
+    (build_dir / "dummy.txt").write_text("x")
+
+    # Create env build path directory
+    env_build = tmp_path / "env_build"
+    env_build.mkdir()
+    (env_build / "firmware.bin").write_text("x")
+
+    from esphome.writer import clean_all
+
+    with (
+        caplog.at_level("INFO"),
+        patch.dict(os.environ, {"ESPHOME_BUILD_PATH": str(env_build)}),
+    ):
+        clean_all([str(config_dir)])
+
+    # Both should be cleaned
+    assert not (build_dir / "dummy.txt").exists()
+    assert env_build.exists()
+    assert not (env_build / "firmware.bin").exists()
+
+
+@patch("esphome.writer.CORE")
+def test_clean_all_ignores_empty_env_vars(
+    mock_core: MagicMock,
+    tmp_path: Path,
+) -> None:
+    """Test clean_all ignores empty ESPHOME_BUILD_PATH/ESPHOME_DATA_DIR."""
+    config_dir = tmp_path / "config"
+    config_dir.mkdir()
+
+    # Create a file in cwd that must NOT be cleaned
+    marker = tmp_path / "important.txt"
+    marker.write_text("do not delete")
+
+    from esphome.writer import clean_all
+
+    with patch.dict(
+        os.environ,
+        {"ESPHOME_BUILD_PATH": "", "ESPHOME_DATA_DIR": ""},
+    ):
+        clean_all([str(config_dir)])
+
+    # Empty env vars must not cause cwd to be cleaned
+    assert marker.exists()
+
+
 @patch("esphome.writer.CORE")
 def test_clean_all(
     mock_core: MagicMock,