Remove logic converting empty or falsy YAML to empty dict (#103912)

* Correct logic converting empty YAML to empty dict

* Modify according to github comments

* Add load_yaml_dict helper

* Update check_config script

* Update tests

homeassistant/components/blueprint/models.py

@@ -215,7 +215,7 @@ class DomainBlueprints:
     def _load_blueprint(self, blueprint_path) -> Blueprint:
         """Load a blueprint."""
         try:
-            blueprint_data = yaml.load_yaml(self.blueprint_folder / blueprint_path)
+            blueprint_data = yaml.load_yaml_dict(self.blueprint_folder / blueprint_path)
         except FileNotFoundError as err:
             raise FailedToLoad(
                 self.domain,
@@ -225,7 +225,6 @@ class DomainBlueprints:
         except HomeAssistantError as err:
             raise FailedToLoad(self.domain, blueprint_path, err) from err
 
-        assert isinstance(blueprint_data, dict)
         return Blueprint(
             blueprint_data, expected_domain=self.domain, path=blueprint_path
         )

homeassistant/components/lovelace/dashboard.py

@@ -14,7 +14,7 @@ from homeassistant.const import CONF_FILENAME
 from homeassistant.core import callback
 from homeassistant.exceptions import HomeAssistantError
 from homeassistant.helpers import collection, storage
-from homeassistant.util.yaml import Secrets, load_yaml
+from homeassistant.util.yaml import Secrets, load_yaml_dict
 
 from .const import (
     CONF_ICON,
@@ -201,7 +201,9 @@ class LovelaceYAML(LovelaceConfig):
         is_updated = self._cache is not None
 
         try:
-            config = load_yaml(self.path, Secrets(Path(self.hass.config.config_dir)))
+            config = load_yaml_dict(
+                self.path, Secrets(Path(self.hass.config.config_dir))
+            )
         except FileNotFoundError:
             raise ConfigNotFound from None
 

homeassistant/components/notify/legacy.py

@@ -17,7 +17,7 @@ from homeassistant.helpers.typing import ConfigType, DiscoveryInfoType
 from homeassistant.loader import async_get_integration, bind_hass
 from homeassistant.setup import async_prepare_setup_platform, async_start_setup
 from homeassistant.util import slugify
-from homeassistant.util.yaml import load_yaml
+from homeassistant.util.yaml import load_yaml_dict
 
 from .const import (
     ATTR_DATA,
@@ -280,8 +280,8 @@ class BaseNotificationService:
         # Load service descriptions from notify/services.yaml
         integration = await async_get_integration(hass, DOMAIN)
         services_yaml = integration.file_path / "services.yaml"
-        self.services_dict = cast(
+        self.services_dict = await hass.async_add_executor_job(
-            dict, await hass.async_add_executor_job(load_yaml, str(services_yaml))
+            load_yaml_dict, str(services_yaml)
         )
 
     async def async_register_services(self) -> None:

homeassistant/components/python_script/__init__.py

@@ -27,7 +27,7 @@ from homeassistant.helpers.typing import ConfigType
 from homeassistant.loader import bind_hass
 from homeassistant.util import raise_if_invalid_filename
 import homeassistant.util.dt as dt_util
-from homeassistant.util.yaml.loader import load_yaml
+from homeassistant.util.yaml.loader import load_yaml_dict
 
 _LOGGER = logging.getLogger(__name__)
 
@@ -120,7 +120,7 @@ def discover_scripts(hass):
     # Load user-provided service descriptions from python_scripts/services.yaml
     services_yaml = os.path.join(path, "services.yaml")
     if os.path.exists(services_yaml):
-        services_dict = load_yaml(services_yaml)
+        services_dict = load_yaml_dict(services_yaml)
     else:
         services_dict = {}
 

homeassistant/components/tts/legacy.py

@@ -6,7 +6,7 @@ from collections.abc import Coroutine, Mapping
 from functools import partial
 import logging
 from pathlib import Path
-from typing import TYPE_CHECKING, Any, cast
+from typing import TYPE_CHECKING, Any
 
 import voluptuous as vol
 
@@ -31,7 +31,7 @@ import homeassistant.helpers.config_validation as cv
 from homeassistant.helpers.service import async_set_service_schema
 from homeassistant.helpers.typing import ConfigType, DiscoveryInfoType
 from homeassistant.setup import async_prepare_setup_platform
-from homeassistant.util.yaml import load_yaml
+from homeassistant.util.yaml import load_yaml_dict
 
 from .const import (
     ATTR_CACHE,
@@ -104,8 +104,8 @@ async def async_setup_legacy(
 
     # Load service descriptions from tts/services.yaml
     services_yaml = Path(__file__).parent / "services.yaml"
-    services_dict = cast(
+    services_dict = await hass.async_add_executor_job(
-        dict, await hass.async_add_executor_job(load_yaml, str(services_yaml))
+        load_yaml_dict, str(services_yaml)
     )
 
     async def async_setup_platform(

homeassistant/config.py

@@ -66,7 +66,7 @@ from .loader import ComponentProtocol, Integration, IntegrationNotFound
 from .requirements import RequirementsNotFound, async_get_integration_with_requirements
 from .util.package import is_docker_env
 from .util.unit_system import get_unit_system, validate_unit_system
-from .util.yaml import SECRET_YAML, Secrets, load_yaml
+from .util.yaml import SECRET_YAML, Secrets, YamlTypeError, load_yaml_dict
 
 _LOGGER = logging.getLogger(__name__)
 
@@ -476,15 +476,15 @@ def load_yaml_config_file(
 
     This method needs to run in an executor.
     """
-    conf_dict = load_yaml(config_path, secrets)
+    try:
-
+        conf_dict = load_yaml_dict(config_path, secrets)
-    if not isinstance(conf_dict, dict):
+    except YamlTypeError as exc:
         msg = (
             f"The configuration file {os.path.basename(config_path)} "
             "does not contain a dictionary"
         )
         _LOGGER.error(msg)
-        raise HomeAssistantError(msg)
+        raise HomeAssistantError(msg) from exc
 
     # Convert values to dictionaries if they are None
     for key, value in conf_dict.items():

homeassistant/helpers/service.py

@@ -42,7 +42,7 @@ from homeassistant.exceptions import (
     UnknownUser,
 )
 from homeassistant.loader import Integration, async_get_integrations, bind_hass
-from homeassistant.util.yaml import load_yaml
+from homeassistant.util.yaml import load_yaml_dict
 from homeassistant.util.yaml.loader import JSON_TYPE
 
 from . import (
@@ -542,7 +542,9 @@ def _load_services_file(hass: HomeAssistant, integration: Integration) -> JSON_T
     try:
         return cast(
             JSON_TYPE,
-            _SERVICES_SCHEMA(load_yaml(str(integration.file_path / "services.yaml"))),
+            _SERVICES_SCHEMA(
+                load_yaml_dict(str(integration.file_path / "services.yaml"))
+            ),
         )
     except FileNotFoundError:
         _LOGGER.warning(

homeassistant/scripts/check_config.py

@@ -32,7 +32,7 @@ REQUIREMENTS = ("colorlog==6.7.0",)
 _LOGGER = logging.getLogger(__name__)
 MOCKS: dict[str, tuple[str, Callable]] = {
     "load": ("homeassistant.util.yaml.loader.load_yaml", yaml_loader.load_yaml),
-    "load*": ("homeassistant.config.load_yaml", yaml_loader.load_yaml),
+    "load*": ("homeassistant.config.load_yaml_dict", yaml_loader.load_yaml_dict),
     "secrets": ("homeassistant.util.yaml.loader.secret_yaml", yaml_loader.secret_yaml),
 }
 

homeassistant/util/yaml/__init__.py

@@ -2,7 +2,14 @@
 from .const import SECRET_YAML
 from .dumper import dump, save_yaml
 from .input import UndefinedSubstitution, extract_inputs, substitute
-from .loader import Secrets, load_yaml, parse_yaml, secret_yaml
+from .loader import (
+    Secrets,
+    YamlTypeError,
+    load_yaml,
+    load_yaml_dict,
+    parse_yaml,
+    secret_yaml,
+)
 from .objects import Input
 
 __all__ = [
@@ -11,7 +18,9 @@ __all__ = [
     "dump",
     "save_yaml",
     "Secrets",
+    "YamlTypeError",
     "load_yaml",
+    "load_yaml_dict",
     "secret_yaml",
     "parse_yaml",
     "UndefinedSubstitution",

homeassistant/util/yaml/loader.py

@@ -36,6 +36,10 @@ _DictT = TypeVar("_DictT", bound=dict)
 _LOGGER = logging.getLogger(__name__)
 
 
+class YamlTypeError(HomeAssistantError):
+    """Raised by load_yaml_dict if top level data is not a dict."""
+
+
 class Secrets:
     """Store secrets while loading YAML."""
 
@@ -211,7 +215,7 @@ class SafeLineLoader(PythonSafeLoader):
 LoaderType = FastSafeLoader | PythonSafeLoader
 
 
-def load_yaml(fname: str, secrets: Secrets | None = None) -> JSON_TYPE:
+def load_yaml(fname: str, secrets: Secrets | None = None) -> JSON_TYPE | None:
     """Load a YAML file."""
     try:
         with open(fname, encoding="utf-8") as conf_file:
@@ -221,6 +225,20 @@ def load_yaml(fname: str, secrets: Secrets | None = None) -> JSON_TYPE:
         raise HomeAssistantError(exc) from exc
 
 
+def load_yaml_dict(fname: str, secrets: Secrets | None = None) -> dict:
+    """Load a YAML file and ensure the top level is a dict.
+
+    Raise if the top level is not a dict.
+    Return an empty dict if the file is empty.
+    """
+    loaded_yaml = load_yaml(fname, secrets)
+    if loaded_yaml is None:
+        loaded_yaml = {}
+    if not isinstance(loaded_yaml, dict):
+        raise YamlTypeError(f"YAML file {fname} does not contain a dict")
+    return loaded_yaml
+
+
 def parse_yaml(
     content: str | TextIO | StringIO, secrets: Secrets | None = None
 ) -> JSON_TYPE:
@@ -255,12 +273,7 @@ def _parse_yaml(
     secrets: Secrets | None = None,
 ) -> JSON_TYPE:
     """Load a YAML file."""
-    # If configuration file is empty YAML returns None
+    return yaml.load(content, Loader=lambda stream: loader(stream, secrets))  # type: ignore[arg-type]
-    # We convert that to an empty dict
-    return (
-        yaml.load(content, Loader=lambda stream: loader(stream, secrets))  # type: ignore[arg-type]
-        or NodeDictClass()
-    )
 
 
 @overload
@@ -309,7 +322,10 @@ def _include_yaml(loader: LoaderType, node: yaml.nodes.Node) -> JSON_TYPE:
     """
     fname = os.path.join(os.path.dirname(loader.get_name()), node.value)
     try:
-        return _add_reference(load_yaml(fname, loader.secrets), loader, node)
+        loaded_yaml = load_yaml(fname, loader.secrets)
+        if loaded_yaml is None:
+            loaded_yaml = NodeDictClass()
+        return _add_reference(loaded_yaml, loader, node)
     except FileNotFoundError as exc:
         raise HomeAssistantError(
             f"{node.start_mark}: Unable to read file {fname}."
@@ -339,7 +355,10 @@ def _include_dir_named_yaml(loader: LoaderType, node: yaml.nodes.Node) -> NodeDi
         filename = os.path.splitext(os.path.basename(fname))[0]
         if os.path.basename(fname) == SECRET_YAML:
             continue
-        mapping[filename] = load_yaml(fname, loader.secrets)
+        loaded_yaml = load_yaml(fname, loader.secrets)
+        if loaded_yaml is None:
+            continue
+        mapping[filename] = loaded_yaml
     return _add_reference(mapping, loader, node)
 
 
@@ -364,9 +383,10 @@ def _include_dir_list_yaml(
     """Load multiple files from directory as a list."""
     loc = os.path.join(os.path.dirname(loader.get_name()), node.value)
     return [
-        load_yaml(f, loader.secrets)
+        loaded_yaml
         for f in _find_files(loc, "*.yaml")
         if os.path.basename(f) != SECRET_YAML
+        and (loaded_yaml := load_yaml(f, loader.secrets)) is not None
     ]
 
 

script/hassfest/services.py

@@ -13,7 +13,7 @@ from voluptuous.humanize import humanize_error
 from homeassistant.const import CONF_SELECTOR
 from homeassistant.exceptions import HomeAssistantError
 from homeassistant.helpers import config_validation as cv, selector, service
-from homeassistant.util.yaml import load_yaml
+from homeassistant.util.yaml import load_yaml_dict
 
 from .model import Config, Integration
 
@@ -107,7 +107,7 @@ def grep_dir(path: pathlib.Path, glob_pattern: str, search_pattern: str) -> bool
 def validate_services(config: Config, integration: Integration) -> None:
     """Validate services."""
     try:
-        data = load_yaml(str(integration.path / "services.yaml"))
+        data = load_yaml_dict(str(integration.path / "services.yaml"))
     except FileNotFoundError:
         # Find if integration uses services
         has_services = grep_dir(
@@ -122,7 +122,7 @@ def validate_services(config: Config, integration: Integration) -> None:
             )
         return
     except HomeAssistantError:
-        integration.add_error("services", "Unable to load services.yaml")
+        integration.add_error("services", "Invalid services.yaml")
         return
 
     try:

tests/components/automation/test_init.py

@@ -1102,7 +1102,7 @@ async def test_reload_automation_when_blueprint_changes(
             autospec=True,
             return_value=config,
         ), patch(
-            "homeassistant.components.blueprint.models.yaml.load_yaml",
+            "homeassistant.components.blueprint.models.yaml.load_yaml_dict",
             autospec=True,
             return_value=blueprint_config,
         ):

tests/components/lovelace/test_cast.py

@@ -44,7 +44,7 @@ async def mock_yaml_dashboard(hass):
     )
 
     with patch(
-        "homeassistant.components.lovelace.dashboard.load_yaml",
+        "homeassistant.components.lovelace.dashboard.load_yaml_dict",
         return_value={
             "title": "YAML Title",
             "views": [

tests/components/lovelace/test_dashboard.py

@@ -141,7 +141,7 @@ async def test_lovelace_from_yaml(
     events = async_capture_events(hass, const.EVENT_LOVELACE_UPDATED)
 
     with patch(
-        "homeassistant.components.lovelace.dashboard.load_yaml",
+        "homeassistant.components.lovelace.dashboard.load_yaml_dict",
         return_value={"hello": "yo"},
     ):
         await client.send_json({"id": 7, "type": "lovelace/config"})
@@ -154,7 +154,7 @@ async def test_lovelace_from_yaml(
 
     # Fake new data to see we fire event
     with patch(
-        "homeassistant.components.lovelace.dashboard.load_yaml",
+        "homeassistant.components.lovelace.dashboard.load_yaml_dict",
         return_value={"hello": "yo2"},
     ):
         await client.send_json({"id": 8, "type": "lovelace/config", "force": True})
@@ -245,7 +245,7 @@ async def test_dashboard_from_yaml(
     events = async_capture_events(hass, const.EVENT_LOVELACE_UPDATED)
 
     with patch(
-        "homeassistant.components.lovelace.dashboard.load_yaml",
+        "homeassistant.components.lovelace.dashboard.load_yaml_dict",
         return_value={"hello": "yo"},
     ):
         await client.send_json(
@@ -260,7 +260,7 @@ async def test_dashboard_from_yaml(
 
     # Fake new data to see we fire event
     with patch(
-        "homeassistant.components.lovelace.dashboard.load_yaml",
+        "homeassistant.components.lovelace.dashboard.load_yaml_dict",
         return_value={"hello": "yo2"},
     ):
         await client.send_json(

tests/components/lovelace/test_resources.py

@@ -38,7 +38,7 @@ async def test_yaml_resources_backwards(
 ) -> None:
     """Test defining resources in YAML ll config (legacy)."""
     with patch(
-        "homeassistant.components.lovelace.dashboard.load_yaml",
+        "homeassistant.components.lovelace.dashboard.load_yaml_dict",
         return_value={"resources": RESOURCE_EXAMPLES},
     ):
         assert await async_setup_component(

tests/components/lovelace/test_system_health.py

@@ -39,7 +39,7 @@ async def test_system_health_info_yaml(hass: HomeAssistant) -> None:
     assert await async_setup_component(hass, "lovelace", {"lovelace": {"mode": "YAML"}})
     await hass.async_block_till_done()
     with patch(
-        "homeassistant.components.lovelace.dashboard.load_yaml",
+        "homeassistant.components.lovelace.dashboard.load_yaml_dict",
         return_value={"views": [{"cards": []}]},
     ):
         info = await get_system_health_info(hass, "lovelace")

tests/components/samsungtv/test_trigger.py

@@ -57,7 +57,7 @@ async def test_turn_on_trigger_device_id(
     assert calls[0].data["some"] == device.id
     assert calls[0].data["id"] == 0
 
-    with patch("homeassistant.config.load_yaml", return_value={}):
+    with patch("homeassistant.config.load_yaml_dict", return_value={}):
         await hass.services.async_call(automation.DOMAIN, SERVICE_RELOAD, blocking=True)
 
     calls.clear()

tests/components/webostv/test_trigger.py

@@ -60,7 +60,7 @@ async def test_webostv_turn_on_trigger_device_id(
     assert calls[0].data["some"] == device.id
     assert calls[0].data["id"] == 0
 
-    with patch("homeassistant.config.load_yaml", return_value={}):
+    with patch("homeassistant.config.load_yaml_dict", return_value={}):
         await hass.services.async_call(automation.DOMAIN, SERVICE_RELOAD, blocking=True)
 
     calls.clear()

tests/components/zwave_js/test_trigger.py

@@ -272,7 +272,7 @@ async def test_zwave_js_value_updated(
 
     clear_events()
 
-    with patch("homeassistant.config.load_yaml", return_value={}):
+    with patch("homeassistant.config.load_yaml_dict", return_value={}):
         await hass.services.async_call(automation.DOMAIN, SERVICE_RELOAD, blocking=True)
 
 
@@ -834,7 +834,7 @@ async def test_zwave_js_event(
 
     clear_events()
 
-    with patch("homeassistant.config.load_yaml", return_value={}):
+    with patch("homeassistant.config.load_yaml_dict", return_value={}):
         await hass.services.async_call(automation.DOMAIN, SERVICE_RELOAD, blocking=True)
 
 

tests/util/yaml/test_init.py

@@ -134,6 +134,7 @@ def test_include_yaml(
     [
         ({"/test/one.yaml": "one", "/test/two.yaml": "two"}, ["one", "two"]),
         ({"/test/one.yaml": "1", "/test/two.yaml": "2"}, [1, 2]),
+        ({"/test/one.yaml": "1", "/test/two.yaml": None}, [1]),
     ],
 )
 def test_include_dir_list(
@@ -190,6 +191,10 @@ def test_include_dir_list_recursive(
             {"/test/first.yaml": "1", "/test/second.yaml": "2"},
             {"first": 1, "second": 2},
         ),
+        (
+            {"/test/first.yaml": "1", "/test/second.yaml": None},
+            {"first": 1},
+        ),
     ],
 )
 def test_include_dir_named(
@@ -249,6 +254,10 @@ def test_include_dir_named_recursive(
             {"/test/first.yaml": "- 1", "/test/second.yaml": "- 2\n- 3"},
             [1, 2, 3],
         ),
+        (
+            {"/test/first.yaml": "- 1", "/test/second.yaml": None},
+            [1],
+        ),
     ],
 )
 def test_include_dir_merge_list(
@@ -311,6 +320,13 @@ def test_include_dir_merge_list_recursive(
             },
             {"key1": 1, "key2": 2, "key3": 3},
         ),
+        (
+            {
+                "/test/first.yaml": "key1: 1",
+                "/test/second.yaml": None,
+            },
+            {"key1": 1},
+        ),
     ],
 )
 def test_include_dir_merge_named(
@@ -686,3 +702,20 @@ def test_string_used_as_vol_schema(try_both_loaders) -> None:
     schema({"key_1": "value_1", "key_2": "value_2"})
     with pytest.raises(vol.Invalid):
         schema({"key_1": "value_2", "key_2": "value_1"})
+
+
+@pytest.mark.parametrize(
+    ("hass_config_yaml", "expected_data"), [("", {}), ("bla:", {"bla": None})]
+)
+def test_load_yaml_dict(
+    try_both_loaders, mock_hass_config_yaml: None, expected_data: Any
+) -> None:
+    """Test item without a key."""
+    assert yaml.load_yaml_dict(YAML_CONFIG_FILE) == expected_data
+
+
+@pytest.mark.parametrize("hass_config_yaml", ["abc", "123", "[]"])
+def test_load_yaml_dict_fail(try_both_loaders, mock_hass_config_yaml: None) -> None:
+    """Test item without a key."""
+    with pytest.raises(yaml_loader.YamlTypeError):
+        yaml_loader.load_yaml_dict(YAML_CONFIG_FILE)