diff --git a/mypy/checkexpr.py b/mypy/checkexpr.py index 1b10370b08cb..6e0915179f90 100644 --- a/mypy/checkexpr.py +++ b/mypy/checkexpr.py @@ -5350,9 +5350,9 @@ def visit_dict_expr(self, e: DictExpr) -> Type: # an error, but returns the TypedDict type that matches the literal it found # that would cause a second error when that TypedDict type is returned upstream # to avoid the second error, we always return TypedDict type that was requested - typeddict_contexts = self.find_typeddict_context(self.type_context[-1], e) + typeddict_contexts, exhaustive = self.find_typeddict_context(self.type_context[-1], e) if typeddict_contexts: - if len(typeddict_contexts) == 1: + if len(typeddict_contexts) == 1 and exhaustive: return self.check_typeddict_literal_in_context(e, typeddict_contexts[0]) # Multiple items union, check if at least one of them matches cleanly. for typeddict_context in typeddict_contexts: @@ -5363,7 +5363,8 @@ def visit_dict_expr(self, e: DictExpr) -> Type: self.chk.store_types(tmap) return ret_type # No item matched without an error, so we can't unambiguously choose the item. - self.msg.typeddict_context_ambiguous(typeddict_contexts, e) + if exhaustive: + self.msg.typeddict_context_ambiguous(typeddict_contexts, e) # fast path attempt dt = self.fast_dict_type(e) @@ -5425,22 +5426,29 @@ def visit_dict_expr(self, e: DictExpr) -> Type: def find_typeddict_context( self, context: Type | None, dict_expr: DictExpr - ) -> list[TypedDictType]: + ) -> tuple[list[TypedDictType], bool]: + """Extract `TypedDict` members of the enclosing context. + + Returns: + a 2-tuple, (found_candidates, is_exhaustive) + """ context = get_proper_type(context) if isinstance(context, TypedDictType): - return [context] + return [context], True elif isinstance(context, UnionType): items = [] + exhaustive = True for item in context.items: - item_contexts = self.find_typeddict_context(item, dict_expr) + item_contexts, item_exhaustive = self.find_typeddict_context(item, dict_expr) for item_context in item_contexts: if self.match_typeddict_call_with_dict( item_context, dict_expr.items, dict_expr ): items.append(item_context) - return items + exhaustive = exhaustive and item_exhaustive + return items, exhaustive # No TypedDict type in context. - return [] + return [], False def visit_lambda_expr(self, e: LambdaExpr) -> Type: """Type check lambda expression.""" diff --git a/test-data/unit/check-typeddict.test b/test-data/unit/check-typeddict.test index be5a6c655d8c..34cae74d795b 100644 --- a/test-data/unit/check-typeddict.test +++ b/test-data/unit/check-typeddict.test @@ -4289,3 +4289,21 @@ inputs: Sequence[Component] = [{ }] [builtins fixtures/dict.pyi] [typing fixtures/typing-typeddict.pyi] + +[case testTypedDictAssignableToWiderContext] +from typing import TypedDict, Union + +class TD(TypedDict): + x: int + +x: Union[TD, dict[str, str]] = {"x": "foo"} +y: Union[TD, dict[str, int]] = {"x": "foo"} # E: Dict entry 0 has incompatible type "str": "str"; expected "str": "int" + +def ok(d: Union[TD, dict[str, str]]) -> None: ... +ok({"x": "foo"}) + +def bad(d: Union[TD, dict[str, int]]) -> None: ... +bad({"x": "foo"}) # E: Dict entry 0 has incompatible type "str": "str"; expected "str": "int" + +[builtins fixtures/dict.pyi] +[typing fixtures/typing-typeddict.pyi]