Mypy plugin for settings

pydantic/mypy.py

@@ -440,7 +440,7 @@ def transform(self) -> bool:
 
         is_settings = any(base.fullname == BASESETTINGS_FULLNAME for base in info.mro[:-1])
         self.add_initializer(fields, config, is_settings)
-        self.add_model_construct_method(fields, config)
+        self.add_model_construct_method(fields, config, is_settings)
         self.set_frozen(fields, frozen=config.frozen is True)
 
         self.adjust_decorator_signatures()
@@ -781,18 +781,37 @@ def add_initializer(self, fields: list[PydanticModelField], config: ModelConfigD
 
         typed = self.plugin_config.init_typed
         use_alias = config.populate_by_name is not True
-        force_all_optional = is_settings or bool(config.has_alias_generator and not config.populate_by_name)
+        requires_dynamic_aliases = bool(config.has_alias_generator and not config.populate_by_name)
         with state.strict_optional_set(self._api.options.strict_optional):
             args = self.get_field_arguments(
-                fields, typed=typed, force_all_optional=force_all_optional, use_alias=use_alias
+                fields,
+                typed=typed,
+                requires_dynamic_aliases=requires_dynamic_aliases,
+                use_alias=use_alias,
+                is_settings=is_settings,
             )
+            if is_settings:
+                base_settings_info = self._api.lookup_fully_qualified(BASESETTINGS_FULLNAME).node.defn.info
+                base_settings_init_arguments = base_settings_info.names['__init__'].node.arguments
+                settings_init_arguments = []
+                a: Argument
+                for a in base_settings_init_arguments:
+                    if a.variable.name.startswith('__') or not a.variable.name.startswith('_'):
+                        continue
+                    analyzed_variable_type = self._api.anal_type(a.variable.type)
+                    variable = Var(a.variable.name, analyzed_variable_type)
+                    settings_init_arguments.append(Argument(variable, analyzed_variable_type, None, ARG_OPT))
+                args.extend(settings_init_arguments)
+
         if not self.should_init_forbid_extra(fields, config):
             var = Var('kwargs')
             args.append(Argument(var, AnyType(TypeOfAny.explicit), None, ARG_STAR2))
 
         add_method(self._api, self._cls, '__init__', args=args, return_type=NoneType())
 
-    def add_model_construct_method(self, fields: list[PydanticModelField], config: ModelConfigData) -> None:
+    def add_model_construct_method(
+        self, fields: list[PydanticModelField], config: ModelConfigData, is_settings: bool
+    ) -> None:
         """Adds a fully typed `model_construct` classmethod to the class.
 
         Similar to the fields-aware __init__ method, but always uses the field names (not aliases),
@@ -802,7 +821,9 @@ def add_model_construct_method(self, fields: list[PydanticModelField], config: M
         optional_set_str = UnionType([set_str, NoneType()])
         fields_set_argument = Argument(Var('_fields_set', optional_set_str), optional_set_str, None, ARG_OPT)
         with state.strict_optional_set(self._api.options.strict_optional):
-            args = self.get_field_arguments(fields, typed=True, force_all_optional=False, use_alias=False)
+            args = self.get_field_arguments(
+                fields, typed=True, requires_dynamic_aliases=False, use_alias=False, is_settings=is_settings
+            )
         if not self.should_init_forbid_extra(fields, config):
             var = Var('kwargs')
             args.append(Argument(var, AnyType(TypeOfAny.explicit), None, ARG_STAR2))
@@ -926,15 +947,22 @@ def get_alias_info(stmt: AssignmentStmt) -> tuple[str | None, bool]:
         return None, False
 
     def get_field_arguments(
-        self, fields: list[PydanticModelField], typed: bool, force_all_optional: bool, use_alias: bool
+        self,
+        fields: list[PydanticModelField],
+        typed: bool,
+        use_alias: bool,
+        requires_dynamic_aliases: bool,
+        is_settings: bool,
     ) -> list[Argument]:
         """Helper function used during the construction of the `__init__` and `model_construct` method signatures.
 
         Returns a list of mypy Argument instances for use in the generated signatures.
         """
         info = self._cls.info
         arguments = [
-            field.to_argument(info, typed=typed, force_optional=force_all_optional, use_alias=use_alias)
+            field.to_argument(
+                info, typed=typed, force_optional=requires_dynamic_aliases or is_settings, use_alias=use_alias
+            )
             for field in fields
             if not (use_alias and field.has_dynamic_alias)
         ]

tests/mypy/modules/pydantic_settings.py

@@ -6,3 +6,7 @@ class Settings(BaseSettings):
 
 
 s = Settings()
+
+s = Settings(foo='test', _case_sensitive=True, _env_prefix='test__', _env_file='test')
+
+s = Settings(foo='test', _case_sensitive=1, _env_prefix=2, _env_file=3)

tests/mypy/outputs/1.0.1/mypy-default_ini/pydantic_settings.py

@@ -6,3 +6,10 @@ class Settings(BaseSettings):
 
 
 s = Settings()
+
+s = Settings(foo='test', _case_sensitive=True, _env_prefix='test__', _env_file='test')
+
+s = Settings(foo='test', _case_sensitive=1, _env_prefix=2, _env_file=3)
+# MYPY: error: Argument "_case_sensitive" to "Settings" has incompatible type "int"; expected "Optional[bool]"  [arg-type]
+# MYPY: error: Argument "_env_prefix" to "Settings" has incompatible type "int"; expected "Optional[str]"  [arg-type]
+# MYPY: error: Argument "_env_file" to "Settings" has incompatible type "int"; expected "Optional[Union[Path, str, List[Union[Path, str]], Tuple[Union[Path, str], ...]]]"  [arg-type]

tests/mypy/outputs/1.0.1/mypy-plugin_ini/pydantic_settings.py

@@ -6,3 +6,10 @@ class Settings(BaseSettings):
 
 
 s = Settings()
+
+s = Settings(foo='test', _case_sensitive=True, _env_prefix='test__', _env_file='test')
+
+s = Settings(foo='test', _case_sensitive=1, _env_prefix=2, _env_file=3)
+# MYPY: error: Argument "_case_sensitive" to "Settings" has incompatible type "int"; expected "Optional[bool]"  [arg-type]
+# MYPY: error: Argument "_env_prefix" to "Settings" has incompatible type "int"; expected "Optional[str]"  [arg-type]
+# MYPY: error: Argument "_env_file" to "Settings" has incompatible type "int"; expected "Optional[Union[Path, str, List[Union[Path, str]], Tuple[Union[Path, str], ...]]]"  [arg-type]

tests/mypy/outputs/1.0.1/pyproject-default_toml/pydantic_settings.py

@@ -6,3 +6,10 @@ class Settings(BaseSettings):
 
 
 s = Settings()
+
+s = Settings(foo='test', _case_sensitive=True, _env_prefix='test__', _env_file='test')
+
+s = Settings(foo='test', _case_sensitive=1, _env_prefix=2, _env_file=3)
+# MYPY: error: Argument "_case_sensitive" to "Settings" has incompatible type "int"; expected "Optional[bool]"  [arg-type]
+# MYPY: error: Argument "_env_prefix" to "Settings" has incompatible type "int"; expected "Optional[str]"  [arg-type]
+# MYPY: error: Argument "_env_file" to "Settings" has incompatible type "int"; expected "Optional[Union[Path, str, List[Union[Path, str]], Tuple[Union[Path, str], ...]]]"  [arg-type]

tests/mypy/outputs/1.0.1/pyproject-plugin_toml/pydantic_settings.py

@@ -6,3 +6,10 @@ class Settings(BaseSettings):
 
 
 s = Settings()
+
+s = Settings(foo='test', _case_sensitive=True, _env_prefix='test__', _env_file='test')
+
+s = Settings(foo='test', _case_sensitive=1, _env_prefix=2, _env_file=3)
+# MYPY: error: Argument "_case_sensitive" to "Settings" has incompatible type "int"; expected "Optional[bool]"  [arg-type]
+# MYPY: error: Argument "_env_prefix" to "Settings" has incompatible type "int"; expected "Optional[str]"  [arg-type]
+# MYPY: error: Argument "_env_file" to "Settings" has incompatible type "int"; expected "Optional[Union[Path, str, List[Union[Path, str]], Tuple[Union[Path, str], ...]]]"  [arg-type]

tests/mypy/outputs/1.1.1/mypy-default_ini/pydantic_settings.py

@@ -7,3 +7,13 @@ class Settings(BaseSettings):
 
 s = Settings()
 # MYPY: error: Missing named argument "foo" for "Settings"  [call-arg]
+
+s = Settings(foo='test', _case_sensitive=True, _env_prefix='test__', _env_file='test')
+# MYPY: error: Unexpected keyword argument "_case_sensitive" for "Settings"  [call-arg]
+# MYPY: error: Unexpected keyword argument "_env_prefix" for "Settings"  [call-arg]
+# MYPY: error: Unexpected keyword argument "_env_file" for "Settings"  [call-arg]
+
+s = Settings(foo='test', _case_sensitive=1, _env_prefix=2, _env_file=3)
+# MYPY: error: Unexpected keyword argument "_case_sensitive" for "Settings"  [call-arg]
+# MYPY: error: Unexpected keyword argument "_env_prefix" for "Settings"  [call-arg]
+# MYPY: error: Unexpected keyword argument "_env_file" for "Settings"  [call-arg]

tests/mypy/outputs/1.1.1/mypy-plugin_ini/pydantic_settings.py

@@ -0,0 +1,15 @@
+from pydantic_settings import BaseSettings
+
+
+class Settings(BaseSettings):
+    foo: str
+
+
+s = Settings()
+
+s = Settings(foo='test', _case_sensitive=True, _env_prefix='test__', _env_file='test')
+
+s = Settings(foo='test', _case_sensitive=1, _env_prefix=2, _env_file=3)
+# MYPY: error: Argument "_case_sensitive" to "Settings" has incompatible type "int"; expected "Optional[bool]"  [arg-type]
+# MYPY: error: Argument "_env_prefix" to "Settings" has incompatible type "int"; expected "Optional[str]"  [arg-type]
+# MYPY: error: Argument "_env_file" to "Settings" has incompatible type "int"; expected "Optional[Union[Path, str, List[Union[Path, str]], Tuple[Union[Path, str], ...]]]"  [arg-type]

tests/mypy/outputs/1.1.1/pyproject-default_toml/pydantic_settings.py

@@ -7,3 +7,13 @@ class Settings(BaseSettings):
 
 s = Settings()
 # MYPY: error: Missing named argument "foo" for "Settings"  [call-arg]
+
+s = Settings(foo='test', _case_sensitive=True, _env_prefix='test__', _env_file='test')
+# MYPY: error: Unexpected keyword argument "_case_sensitive" for "Settings"  [call-arg]
+# MYPY: error: Unexpected keyword argument "_env_prefix" for "Settings"  [call-arg]
+# MYPY: error: Unexpected keyword argument "_env_file" for "Settings"  [call-arg]
+
+s = Settings(foo='test', _case_sensitive=1, _env_prefix=2, _env_file=3)
+# MYPY: error: Unexpected keyword argument "_case_sensitive" for "Settings"  [call-arg]
+# MYPY: error: Unexpected keyword argument "_env_prefix" for "Settings"  [call-arg]
+# MYPY: error: Unexpected keyword argument "_env_file" for "Settings"  [call-arg]

tests/mypy/outputs/1.1.1/pyproject-plugin_toml/pydantic_settings.py

@@ -0,0 +1,15 @@
+from pydantic_settings import BaseSettings
+
+
+class Settings(BaseSettings):
+    foo: str
+
+
+s = Settings()
+
+s = Settings(foo='test', _case_sensitive=True, _env_prefix='test__', _env_file='test')
+
+s = Settings(foo='test', _case_sensitive=1, _env_prefix=2, _env_file=3)
+# MYPY: error: Argument "_case_sensitive" to "Settings" has incompatible type "int"; expected "Optional[bool]"  [arg-type]
+# MYPY: error: Argument "_env_prefix" to "Settings" has incompatible type "int"; expected "Optional[str]"  [arg-type]
+# MYPY: error: Argument "_env_file" to "Settings" has incompatible type "int"; expected "Optional[Union[Path, str, List[Union[Path, str]], Tuple[Union[Path, str], ...]]]"  [arg-type]

tests/mypy/outputs/1.4.1/mypy-plugin_ini/pydantic_settings.py

@@ -0,0 +1,15 @@
+from pydantic_settings import BaseSettings
+
+
+class Settings(BaseSettings):
+    foo: str
+
+
+s = Settings()
+
+s = Settings(foo='test', _case_sensitive=True, _env_prefix='test__', _env_file='test')
+
+s = Settings(foo='test', _case_sensitive=1, _env_prefix=2, _env_file=3)
+# MYPY: error: Argument "_case_sensitive" to "Settings" has incompatible type "int"; expected "bool | None"  [arg-type]
+# MYPY: error: Argument "_env_prefix" to "Settings" has incompatible type "int"; expected "str | None"  [arg-type]
+# MYPY: error: Argument "_env_file" to "Settings" has incompatible type "int"; expected "Path | str | list[Path | str] | tuple[Path | str, ...] | None"  [arg-type]

tests/mypy/outputs/1.4.1/pyproject-plugin_toml/pydantic_settings.py

@@ -0,0 +1,15 @@
+from pydantic_settings import BaseSettings
+
+
+class Settings(BaseSettings):
+    foo: str
+
+
+s = Settings()
+
+s = Settings(foo='test', _case_sensitive=True, _env_prefix='test__', _env_file='test')
+
+s = Settings(foo='test', _case_sensitive=1, _env_prefix=2, _env_file=3)
+# MYPY: error: Argument "_case_sensitive" to "Settings" has incompatible type "int"; expected "bool | None"  [arg-type]
+# MYPY: error: Argument "_env_prefix" to "Settings" has incompatible type "int"; expected "str | None"  [arg-type]
+# MYPY: error: Argument "_env_file" to "Settings" has incompatible type "int"; expected "Path | str | list[Path | str] | tuple[Path | str, ...] | None"  [arg-type]