Invalidate mypy cache if config changes

changes/5007-cdce8p.md

@@ -0,0 +1 @@
+Invalidate mypy cache if plugin config changes

pydantic/mypy.py

@@ -42,6 +42,7 @@
     FunctionContext,
     MethodContext,
     Plugin,
+    ReportConfigContext,
     SemanticAnalyzerPluginInterface,
 )
 from mypy.plugins import dataclasses
@@ -98,6 +99,7 @@ def plugin(version: str) -> 'TypingType[Plugin]':
 class PydanticPlugin(Plugin):
     def __init__(self, options: Options) -> None:
         self.plugin_config = PydanticPluginConfig(options)
+        self._plugin_data = self.plugin_config.to_data()
         super().__init__(options)
 
     def get_base_class_hook(self, fullname: str) -> 'Optional[Callable[[ClassDefContext], None]]':
@@ -124,6 +126,13 @@ def get_class_decorator_hook(self, fullname: str) -> Optional[Callable[[ClassDef
             return dataclasses.dataclass_class_maker_callback  # type: ignore[return-value]
         return None
 
+    def report_config_data(self, ctx: ReportConfigContext) -> Dict[str, Any]:
+        """Return all plugin config data.
+
+        Used by mypy to determine if cache needs to be discarded.
+        """
+        return self._plugin_data
+
     def _pydantic_model_class_maker_callback(self, ctx: ClassDefContext) -> None:
         transformer = PydanticModelTransformer(ctx, self.plugin_config)
         transformer.transform()
@@ -204,6 +213,9 @@ def __init__(self, options: Options) -> None:
                 setting = plugin_config.getboolean(CONFIGFILE_KEY, key, fallback=False)
                 setattr(self, key, setting)
 
+    def to_data(self) -> Dict[str, Any]:
+        return {key: getattr(self, key) for key in self.__slots__}
+
 
 def from_orm_callback(ctx: MethodContext) -> Type:
     """