Assigning a variable to the result of an untyped method removes any existing type constraints #3724
Description
from typing import Any, Optional
def foo() -> Optional[int]:
return 42
raz: Any
def bar() -> int:
x = foo()
if isinstance(x, int):
reveal_type(x)
x = raz()
reveal_type(x)
x = x + 42
return 0$ python3.6 -m mypy --strict-optional test_optional_assign.py
test_optional_assign.py:11: error: Revealed type is 'builtins.int'
test_optional_assign.py:13: error: Revealed type is 'Union[builtins.int, builtins.None]'
test_optional_assign.py:14: error: Unsupported operand types for + ("Optional[int]" and "int")I would have expected the revealed type at like 13 to be Any.