Nov 25, 2022 · Nov 4, 2022 · Nov 7, 2022 · Nov 7, 2022 · Nov 7, 2022 · Nov 24, 2022
diff --git a/mypy/server/aststrip.py b/mypy/server/aststrip.py
        node.analyzed = None  # May have been an alias or type application.
        super().visit_index_expr(node)

    def visit_op_expr(self, node: OpExpr) -> None:
        node.analyzed = None  # May have been an alias
        super().visit_op_expr(node)

    def strip_ref_expr(self, node: RefExpr) -> None:
        node.kind = None
        node.node = None
diff --git a/test-data/unit/fine-grained.test b/test-data/unit/fine-grained.test
 m.py:5: error: Invalid statement in TypedDict definition; expected "field_name: field_type"
 ==
 m.py:5: error: Invalid statement in TypedDict definition; expected "field_name: field_type"

 [case testTypeAliasWithNewStyleUnionChangedToVariable]
 # flags: --python-version 3.10
 import a

 [file a.py]
 from b import C, D
 A = C | D
 a: A
 reveal_type(a)

 [file b.py]
 C = int
 D = str

 [file b.py.2]
 C = "x"
 D = "y"

 [file b.py.3]
 C = str
 D = int
 [out]
 a.py:4: note: Revealed type is "Union[builtins.int, builtins.str]"
 ==
 a.py:2: error: Unsupported left operand type for | ("str")
 a.py:3: error: Variable "a.A" is not valid as a type
 a.py:3: note: See https://mypy.readthedocs.io/en/stable/common_issues.html#variables-vs-type-aliases
 a.py:4: note: Revealed type is "A?"
 ==
 a.py:4: note: Revealed type is "Union[builtins.str, builtins.int]"
Original file line number	Diff line number	Diff line change
Expand Up		@@ -222,6 +222,10 @@ def visit_index_expr(self, node: IndexExpr) -> None:
		node.analyzed = None # May have been an alias or type application.
		super().visit_index_expr(node)

		def visit_op_expr(self, node: OpExpr) -> None:
		node.analyzed = None # May have been an alias
		super().visit_op_expr(node)

		def strip_ref_expr(self, node: RefExpr) -> None:
		node.kind = None
		node.node = None
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -10277,3 +10277,34 @@ A = str
		m.py:5: error: Invalid statement in TypedDict definition; expected "field_name: field_type"
		==
		m.py:5: error: Invalid statement in TypedDict definition; expected "field_name: field_type"

		[case testTypeAliasWithNewStyleUnionChangedToVariable]
		# flags: --python-version 3.10
		import a

		[file a.py]
		from b import C, D
		A = C \| D
		a: A
		reveal_type(a)

		[file b.py]
		C = int
		D = str

		[file b.py.2]
		C = "x"
		D = "y"

		[file b.py.3]
		C = str
		D = int
		[out]
		a.py:4: note: Revealed type is "Union[builtins.int, builtins.str]"
		==
		a.py:2: error: Unsupported left operand type for \| ("str")
		a.py:3: error: Variable "a.A" is not valid as a type
		a.py:3: note: See https://mypy.readthedocs.io/en/stable/common_issues.html#variables-vs-type-aliases
		a.py:4: note: Revealed type is "A?"
		==
		a.py:4: note: Revealed type is "Union[builtins.str, builtins.int]"