from typing import Literal, assert_never, reveal_type
def main(some: Literal['a']) -> None:
if some != 'a':
assigned = 'b'
reveal_type(assigned)
assert_never(assigned)INFO revealed type: Literal['b'] [reveal-type]
--> t.py:6:20
|
6 | reveal_type(assigned)
| ----------
|
ERROR Argument `Literal['b']` is not assignable to parameter `arg` with type `Never` in function `typing.assert_never` [bad-argument-type]
--> t.py:7:22
|
7 | assert_never(assigned)
| ^^^^^^^^
|
INFO 1 error
info[revealed-type]: Revealed type
--> t.py:6:21
|
6 | reveal_type(assigned)
| ^^^^^^^^ `Never`
|
Found 1 diagnostic
Describe the Bug
mypy and pyright just don't report on this path at all
ty gives
Sandbox Link
https://pyrefly.org/sandbox/?project=N4IgZglgNgpgziAXKOBDAdgEwEYHsAeAdAA4CeS4ATrgLYAEALqcROgOZ0Q3G6UN0AZCAxiVUUADR1UcOKIYB9dDABuoqZVUxxCpsRgAddEcwwwdGqlYAKOLRiJBw0eIDaAclTuAugEo6ALQAfHQAcrjKiEZ0MZzmdjQwdACEALx0nu5R6LG50rIQbMqYdOnu2O7ReTGaajp6MNYycIXFvlXVzfJKWpRNBUUwmL4gEiBkmmBQpIQMtFAUAMR0AAqkk9N0aFh4%2BHQAxhGQbACuYgwQEYRGywDKMEkAFgwMxHCIAPQfE2bThLxsD4wdAfTC4fZwD6HdDHM6oC4RD50MC8aQqKxQVDYWAHI6FOEInK4YiEuDXdBkBiPCIBNSUFoRUp0AwgADMhAAjAAmFlGVyiaj07xGE7oLg8PhDAKYCCafYXNRM9ytXgwSrodC4BgBTQARxOsqlAGsYKQAqh9vt4HAlQB3VCUdDqkAAXzGFoVMAAYtAYBRtjgCCRyC6gA
(Only applicable for extension issues) IDE Information
No response