invalid-formatter-suppression-comment (RUF028)

Fix is always available.

This rule is unstable and in preview. The --preview flag is required for use.

What it does

Checks for formatter suppression comments that are ineffective or incompatible with Ruff's formatter.

Why is this bad?

Suppression comments that do not actually prevent formatting could cause unintended changes when the formatter is run.

Examples

In the following example, all suppression comments would cause a rule violation.

def decorator():
    pass


@decorator
# fmt: off
def example():
    if True:
        # fmt: skip
        expression = [
            # fmt: off
            1,
            2,
        ]
        # yapf: disable
    # fmt: on
    # yapf: enable