Merge remote-tracking branch 'upstream/master' into generic-typeddict

ilevkivskyi · Aug 15, 2022 · Aug 11, 2022 · Aug 11, 2022 · Aug 11, 2022 · Aug 11, 2022
commit 8834fc260c61905a86f274e2fc0462346edd8905
diff --git a/mypy/checkexpr.py b/mypy/checkexpr.py
@@ -3768,6 +3768,9 @@ def visit_type_application(self, tapp: TypeApplication) -> Type:
             if isinstance(item, Instance):
                 tp = type_object_type(item.type, self.named_type)
                 return self.apply_type_arguments_to_callable(tp, item.args, tapp)
+            elif isinstance(item, TupleType) and item.partial_fallback.type.is_named_tuple:
+                tp = type_object_type(item.partial_fallback.type, self.named_type)
+                return self.apply_type_arguments_to_callable(tp, item.partial_fallback.args, tapp)
             elif isinstance(item, TypedDictType):
                 return self.typeddict_callable_from_context(item)
             else:

diff --git a/mypy/semanal.py b/mypy/semanal.py
@@ -1424,8 +1424,13 @@ def setup_alias_type_vars(self, defn: ClassDef) -> None:
         assert defn.info.special_alias is not None
         defn.info.special_alias.alias_tvars = list(defn.info.type_vars)
 >
-        assert isinstance(target, ProperType) and isinstance(target, TypedDictType)
-        target.fallback.args = tuple(defn.type_vars)
+        assert isinstance(target, ProperType)
+        if isinstance(target, TypedDictType):
+            target.fallback.args = tuple(defn.type_vars)
+        elif isinstance(target, TupleType):
+            target.partial_fallback.args = tuple(defn.type_vars)
+        else:
+            assert False, f"Unexpected special alias type: {type(target)}"
 
     def is_core_builtin_class(self, defn: ClassDef) -> bool:
         return self.cur_mod_id == "builtins" and defn.name in CORE_BUILTIN_CLASSES
@@ -1730,7 +1735,9 @@ def get_and_bind_all_tvars(self, type_exprs: List[Expression]) -> List[TypeVarLi
             tvar_defs.append(tvar_def)
         return tvar_defs
 
-    def prepare_class_def(self, defn: ClassDef, info: Optional[TypeInfo] = None) -> None:
+    def prepare_class_def(
+        self, defn: ClassDef, info: Optional[TypeInfo] = None, custom_names: bool = False
+    ) -> None:
         """Prepare for the analysis of a class definition.
 
         Create an empty TypeInfo and store it in a symbol table, or if the 'info'

diff --git a/test-data/unit/check-incremental.test b/test-data/unit/check-incremental.test
@@ -5911,6 +5911,29 @@ tmp/c.py:4: note: Revealed type is "TypedDict('a.N', {'r': Union[TypedDict('b.M'
 tmp/c.py:5: error: Incompatible types in assignment (expression has type "Optional[N]", variable has type "int")
 tmp/c.py:7: note: Revealed type is "TypedDict('a.N', {'r': Union[TypedDict('b.M', {'r': Union[..., None], 'x': builtins.int}), None], 'x': builtins.int})"
 
+[case testGenericNamedTupleSerialization]
+import b
+[file a.py]
+from typing import NamedTuple, Generic, TypeVar
+
+T = TypeVar("T")
+class NT(NamedTuple, Generic[T]):
+    key: int
+    value: T
+
+[file b.py]
+from a import NT
+nt = NT(key=0, value="yes")
+s: str = nt.value
+[file b.py.2]
+from a import NT
+nt = NT(key=0, value=42)
+s: str = nt.value
+[builtins fixtures/tuple.pyi]
+[out]
+[out2]
+tmp/b.py:3: error: Incompatible types in assignment (expression has type "int", variable has type "str")
+
 [case testGenericTypedDictSerialization]
 import b
 [file a.py]