Use SettingsErrors for invalid file source

Some file formats (at least yaml) allow to represent non dictionnary
values. In such situation we can't add the values read from those files.
Instead of raising a ValueError, we now raise a SettingsError and
indicate we can't parse the related config file.

Author: Julian Vanden Broeck

pydantic_settings/sources.py

@@ -1917,7 +1917,11 @@ def _read_files(self, files: PathType | None) -> dict[str, Any]:
         for file in files:
             file_path = Path(file).expanduser()
             if file_path.is_file():
-                vars.update(self._read_file(file_path))
+                try:
+                    settings = self._read_file(file_path)
+                except ValueError as e:
+                    raise SettingsError(f'Failed to parse settings from {file_path}, {e}')
+                vars.update(settings)
         return vars
 
     @abstractmethod

tests/test_source_json.py

@@ -13,6 +13,7 @@
     JsonConfigSettingsSource,
     PydanticBaseSettingsSource,
     SettingsConfigDict,
+    SettingsError,
 )
 
 
@@ -91,7 +92,7 @@ def settings_customise_sources(
         ) -> Tuple[PydanticBaseSettingsSource, ...]:
             return (JsonConfigSettingsSource(settings_cls),)
 
-    with pytest.raises(ValueError):
+    with pytest.raises(SettingsError, match='Failed to parse settings from .*, expecting an object'):
         Settings()
 
 

tests/test_source_toml.py

@@ -12,6 +12,7 @@
     BaseSettings,
     PydanticBaseSettingsSource,
     SettingsConfigDict,
+    SettingsError,
     TomlConfigSettingsSource,
 )
 
@@ -97,7 +98,7 @@ def settings_customise_sources(
         ) -> Tuple[PydanticBaseSettingsSource, ...]:
             return (TomlConfigSettingsSource(settings_cls, pyproject),)
 
-    with pytest.raises(ValueError):
+    with pytest.raises(SettingsError, match='Failed to parse settings from'):
         Settings()
 
 

tests/test_source_yaml.py

@@ -11,6 +11,7 @@
     BaseSettings,
     PydanticBaseSettingsSource,
     SettingsConfigDict,
+    SettingsError,
     YamlConfigSettingsSource,
 )
 
@@ -105,7 +106,7 @@ def settings_customise_sources(
         ) -> Tuple[PydanticBaseSettingsSource, ...]:
             return (YamlConfigSettingsSource(settings_cls),)
 
-    with pytest.raises(ValueError):
+    with pytest.raises(SettingsError, match='Failed to parse settings from .*, expecting an object'):
         Settings()