Handle generics (except for TypeAlias without explicit params - that does not work?

Author: sterliakov

mypy/semanal_typeddict.py

@@ -139,23 +139,18 @@ def analyze_typeddict_classdef(self, defn: ClassDef) -> tuple[bool, TypeInfo | N
                     typeddict_bases_set.add("TypedDict")
                 else:
                     self.fail('Duplicate base class "TypedDict"', defn)
-            elif isinstance(expr, RefExpr) and self.is_typeddict(expr):
-                assert expr.fullname
-                if expr.fullname not in typeddict_bases_set:
-                    typeddict_bases_set.add(expr.fullname)
+            elif (
+                isinstance(expr, RefExpr)
+                and self.is_typeddict(expr)
+                or isinstance(expr, IndexExpr)
+                and self.is_typeddict(expr.base)
+            ):
+                info = self._parse_typeddict_base(expr, defn)
+                if info.fullname not in typeddict_bases_set:
+                    typeddict_bases_set.add(info.fullname)
                     typeddict_bases.append(expr)
                 else:
-                    assert isinstance(expr.node, TypeInfo)
-                    self.fail(f'Duplicate base class "{expr.node.name}"', defn)
-            elif isinstance(expr, IndexExpr) and self.is_typeddict(expr.base):
-                assert isinstance(expr.base, RefExpr)
-                assert expr.base.fullname
-                if expr.base.fullname not in typeddict_bases_set:
-                    typeddict_bases_set.add(expr.base.fullname)
-                    typeddict_bases.append(expr)
-                else:
-                    assert isinstance(expr.base.node, TypeInfo)
-                    self.fail(f'Duplicate base class "{expr.base.node.name}"', defn)
+                    self.fail(f'Duplicate base class "{info.name}"', defn)
             else:
                 self.fail("All bases of a new TypedDict must be TypedDict types", defn)
 
@@ -192,30 +187,13 @@ def add_keys_and_types_from_base(
         readonly_keys: set[str],
         ctx: Context,
     ) -> None:
+        info = self._parse_typeddict_base(base, ctx)
         base_args: list[Type] = []
-        if isinstance(base, RefExpr):
-            if isinstance(base.node, TypeAlias):
-                # Only old TypeAlias / plain assignment, PEP695 `type` stmt
-                # cannot be used as a base class
-                target = get_proper_type(base.node.target)
-                assert isinstance(target, TypedDictType)
-                info = target.fallback.type
-            elif isinstance(base.node, TypeInfo):
-                info = base.node
-            else:
-                assert False
-        elif isinstance(base, IndexExpr):
-            assert isinstance(base.base, RefExpr)
-            assert isinstance(base.base.node, TypeInfo)
-            info = base.base.node
+        if isinstance(base, IndexExpr):
             args = self.analyze_base_args(base, ctx)
             if args is None:
                 return
             base_args = args
-        else:
-            assert isinstance(base, CallExpr)
-            assert isinstance(base.analyzed, TypedDictExpr)
-            info = base.analyzed.info
 
         assert info.typeddict_type is not None
         base_typed_dict = info.typeddict_type
@@ -241,6 +219,26 @@ def add_keys_and_types_from_base(
         required_keys.update(base_typed_dict.required_keys)
         readonly_keys.update(base_typed_dict.readonly_keys)
 
+    def _parse_typeddict_base(self, base: Expression, ctx: Context) -> TypeInfo:
+        if isinstance(base, RefExpr):
+            if isinstance(base.node, TypeInfo):
+                return base.node
+            elif isinstance(base.node, TypeAlias):
+                # Only old TypeAlias / plain assignment, PEP695 `type` stmt
+                # cannot be used as a base class
+                target = get_proper_type(base.node.target)
+                assert isinstance(target, TypedDictType)
+                return target.fallback.type
+            else:
+                assert False
+        elif isinstance(base, IndexExpr):
+            assert isinstance(base.base, RefExpr)
+            return self._parse_typeddict_base(base.base, ctx)
+        else:
+            assert isinstance(base, CallExpr)
+            assert isinstance(base.analyzed, TypedDictExpr)
+            return base.analyzed.info
+
     def analyze_base_args(self, base: IndexExpr, ctx: Context) -> list[Type] | None:
         """Analyze arguments of base type expressions as types.
 
@@ -537,7 +535,7 @@ def parse_typeddict_args(
                 return "", [], [], True, [], False
         dictexpr = args[1]
         tvar_defs = self.api.get_and_bind_all_tvars([t for k, t in dictexpr.items])
-        res = self.parse_typeddict_fields_with_types(dictexpr.items, call)
+        res = self.parse_typeddict_fields_with_types(dictexpr.items)
         if res is None:
             # One of the types is not ready, defer.
             return None
@@ -546,7 +544,7 @@ def parse_typeddict_args(
         return args[0].value, items, types, total, tvar_defs, ok
 
     def parse_typeddict_fields_with_types(
-        self, dict_items: list[tuple[Expression | None, Expression]], context: Context
+        self, dict_items: list[tuple[Expression | None, Expression]]
     ) -> tuple[list[str], list[Type], bool] | None:
         """Parse typed dict items passed as pairs (name expression, type expression).
 

test-data/unit/check-typeddict.test

@@ -4162,22 +4162,77 @@ c23: Child2 = {"foo": 0, "bar": 1, "baz": "error"}  # E: Extra key "baz" for Typ
 [builtins fixtures/dict.pyi]
 [typing fixtures/typing-typeddict.pyi]
 
-[case testTypedDictAliasMultiple]
+[case testTypedDictAliasInheritance]
 from typing import TypedDict
+from typing_extensions import TypeAlias
 
-class A(TypedDict, total=False):
-    y: int
-class B(TypedDict, total=False):
+class A(TypedDict):
     x: str
+class B(TypedDict):
+    y: int
+
+B1 = B
+B2: TypeAlias = B
 
-D = B
+class C(A, B1):
+    pass
+c1: C = {"y": 1}  # E: Missing key "x" for TypedDict "C"
+c2: C = {"x": "x", "y": 2}
+c3: C = {"x": 1, "y": 2}  # E: Incompatible types (expression has type "int", TypedDict item "x" has type "str")
 
-class C(A, D):
+class D(A, B2):
     pass
+d1: D = {"y": 1}  # E: Missing key "x" for TypedDict "D"
+d2: D = {"x": "x", "y": 2}
+d3: D = {"x": 1, "y": 2}  # E: Incompatible types (expression has type "int", TypedDict item "x" has type "str")
+[builtins fixtures/dict.pyi]
+[typing fixtures/typing-typeddict.pyi]
+
+[case testTypedDictAliasDuplicateBases]
+from typing import TypedDict
+from typing_extensions import TypeAlias
+
+class A(TypedDict):
+    x: str
+
+A1 = A
+A2 = A
+A3: TypeAlias = A
+
+class E(A1, A2): pass  # E: Duplicate base class "A"
+class F(A1, A3): pass # E: Duplicate base class "A"
+class G(A, A1): pass # E: Duplicate base class "A"
+
+class H(A, list): pass  # E: All bases of a new TypedDict must be TypedDict types
+[builtins fixtures/dict.pyi]
+[typing fixtures/typing-typeddict.pyi]
+
+[case testTypedDictAliasGeneric]
+from typing import Generic, TypedDict, TypeVar
+from typing_extensions import TypeAlias
 
-c1: C = {}
-c2: C = {"x": "x"}
-c3: C = {"y": 1}
-c4: C = {"x": "x", "y": 2}
+_T = TypeVar("_T")
+
+class A(Generic[_T], TypedDict):
+    x: _T
+
+A1 = A[_T]
+A2: TypeAlias = A[_T]
+Aint = A[int]
+
+class C(A1[_T]):
+    y: str
+c1: C[int] = {"x": 0, "y": "a"}
+c2: C[int] = {"x": "no", "y": "a"}  # E: Incompatible types (expression has type "str", TypedDict item "x" has type "int")
+
+class D(A2[_T]):
+    y: str
+d1: D[int] = {"x": 0, "y": "a"}
+d2: D[int] = {"x": "no", "y": "a"}  # E: Incompatible types (expression has type "str", TypedDict item "x" has type "int")
+
+class E(Aint):
+    y: str
+e1: E = {"x": 0, "y": "a"}
+e2: E = {"x": "no", "y": "a"}
 [builtins fixtures/dict.pyi]
 [typing fixtures/typing-typeddict.pyi]