invalid-bool-returned / E0304

Message emitted:

__bool__ does not return bool

Description:

Used when a __bool__ method returns something which is not a bool

Problematic code:

class CustomBool:
    """__bool__ returns an int"""

    def __bool__(self):  # [invalid-bool-returned]
        return 1

Correct code:

class CustomBool:
    """__bool__ returns `bool`"""

    def __bool__(self):
        return True

Created by the classes checker.