possibly-used-before-assignment does not understand assert_never

[efroemling]

Bug description

The new possibly-used-before-assignment checker does not seem to understand assert_never(), which is useful these days with type checkers for exhaustive conditional handling/etc.

"""Code for bad.py"""

from enum import Enum
from typing import assert_never

class MyEnum(Enum):
    """A lovely enum."""
    VAL1 = 1
    VAL2 = 2
    VAL3 = 3

# Pylint correctly gives 'possibly-used-before-assignment' for this.
def do_thing(val: MyEnum) -> None:
    """Do a thing."""
    if val is MyEnum.VAL1:
        note = 'got 1'
    elif val is MyEnum.VAL2:
        note = 'got 2'
    elif val is MyEnum.VAL3:
        note = 'got 3'

    print('Note:', note)

# Pylint understands this correction.
def do_thing_2(val: MyEnum) -> None:
    """Do a thing."""
    if val is MyEnum.VAL1:
        note = 'got 1'
    elif val is MyEnum.VAL2:
        note = 'got 2'
    elif val is MyEnum.VAL3:
        note = 'got 3'
    else:
        raise ValueError('Should never get here.')

    print('Note:', note)

# But not this one (which integrates better with type checkers).
def do_thing_3(val: MyEnum) -> None:
    """Do a thing."""
    if val is MyEnum.VAL1:
        note = 'got 1'
    elif val is MyEnum.VAL2:
        note = 'got 2'
    elif val is MyEnum.VAL3:
        note = 'got 3'
    else:
        assert_never(val)

    print('Note:', note)

Configuration

No response

Command used

pylint bad.py

Pylint output

bad.py:22:19: E0606: Possibly using variable 'note' before assignment (possibly-used-before-assignment)
bad.py:50:19: E0606: Possibly using variable 'note' before assignment (possibly-used-before-assignment)

Expected behavior

assert_never should prevent the error in do_thing_3, just as the exception does for do_thing_2

Pylint version

pylint 3.2.0
astroid 3.2.1
Python 3.12.3 (main, Apr  9 2024, 08:09:14) [Clang 15.0.0 (clang-1500.3.9.4)]

OS / Environment

macOS 14.5

Additional dependencies

No response