Stubtest: Fix __mypy-replace false positives

mypy/nodes.py

@@ -3746,6 +3746,10 @@ class SymbolTableNode:
         implicit: Was this defined by assignment to self attribute?
         plugin_generated: Was this symbol generated by a plugin?
             (And therefore needs to be removed in aststrip.)
+        internal_fictional: Flag to indicate that this is a node for internal
+            use only; it doesn't represent a method/attribute that actually
+            exists at runtime. (We generate some fictional methods for e.g.
+            dataclasses; stubtest needs to be able to spot these.)
         no_serialize: Do not serialize this node if True. This is used to prevent
             keys in the cache that refer to modules on which this file does not
             depend. Currently this can happen if there is a module not in build
@@ -3771,6 +3775,7 @@ class SymbolTableNode:
         "cross_ref",
         "implicit",
         "plugin_generated",
+        "internal_fictional",
         "no_serialize",
     )
 
@@ -3783,6 +3788,7 @@ def __init__(
         module_hidden: bool = False,
         *,
         plugin_generated: bool = False,
+        fictional_plugin_generated: bool = False,
         no_serialize: bool = False,
     ) -> None:
         self.kind = kind
@@ -3792,6 +3798,7 @@ def __init__(
         self.module_hidden = module_hidden
         self.cross_ref: str | None = None
         self.plugin_generated = plugin_generated
+        self.internal_fictional = internal_fictional
         self.no_serialize = no_serialize
 
     @property

mypy/plugins/common.py

@@ -219,6 +219,7 @@ def add_method_to_class(
     tvar_def: TypeVarType | None = None,
     is_classmethod: bool = False,
     is_staticmethod: bool = False,
+    internal_fictional: bool = False,
 ) -> None:
     """Adds a new method to a class definition."""
 
@@ -289,6 +290,7 @@ def add_method_to_class(
     else:
         sym = SymbolTableNode(MDEF, func)
     sym.plugin_generated = True
+    sym.internal_fictional = internal_fictional
     info.names[name] = sym
 
     info.defn.defs.body.append(func)

mypy/plugins/dataclasses.py

@@ -401,6 +401,7 @@ def _add_internal_replace_method(self, attributes: list[DataclassAttribute]) ->
             args=[attr.to_argument(self._cls.info, of="replace") for attr in attributes],
             return_type=NoneType(),
             is_staticmethod=True,
+            internal_fictional=True,
         )
 
     def _add_internal_post_init_method(self, attributes: list[DataclassAttribute]) -> None:
@@ -414,6 +415,7 @@ def _add_internal_post_init_method(self, attributes: list[DataclassAttribute]) -
                 if attr.is_init_var
             ],
             return_type=NoneType(),
+            internal_fictional=True,
         )
 
     def add_slots(

mypy/stubtest.py

@@ -495,8 +495,10 @@ def verify_typeinfo(
         stub, runtime, object_path, is_runtime_typeddict=is_runtime_typeddict
     )
 
-    # Check everything already defined on the stub class itself (i.e. not inherited)
-    to_check = set(stub.names)
+    # Check everything already defined on the stub class itself (i.e. not inherited),
+    # as long as it wasn't a fictional method generated by a plugin
+    # (__mypy-replace, __mypy-post_init, etc.)
+    to_check = {name for name, node in stub.names.items() if not node.internal_fictional}
     # Check all public things on the runtime class
     to_check.update(
         m for m in vars(runtime) if not is_probably_private(m) and m not in IGNORABLE_CLASS_DUNDERS