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(馃悶) always-true/always-false doesn't activate until it's truth is checked聽#12325
Description
test.py:
from typing import Literal
def foo(a: Literal[True]) -> None:
...
FOO: bool
foo(FOO) # error: Argument 1 to "foo" has incompatible type "bool"; expected "Literal[True]" [arg-type]
reveal_type(FOO) # note: Revealed type is "builtins.bool"
if not FOO:
pass
reveal_type(FOO) # note: Revealed type is "Literal[True]"
if not FOO:
pass
import test2test2.py:
from test import FOO
reveal_type(FOO) # note: Revealed type is "builtins.bool"
if FOO:
pass
reveal_type(FOO) # note: Revealed type is "Literal[True]"> mypy --always-true FOO test.py
Activity
[-](馃悶) `always-true` doesn't activate until [/-][+](馃悶) `always-true`/`always-false` doesn't activate until it's truth is checked[/+]Zeckie commentedon Mar 13, 2022
Can you explain what you think is wrong, and why?
eg. is it that due to
--always-true FOOon command line, the variableFOOshould always be treated asLiteral[True]?Is this going to have flow on effects, such as having the code inside
if not FOO:being unreachable?KotlinIsland commentedon Mar 13, 2022
@Zeckie You can read about the expected functionality here
There are some negative consequences to this functionality, such as #11364