Can omit parentheses layout for patterns

[MichaReiser]

Ruff avoids adding parentheses to expressions that start or end with a parenthesized node (see can_omit_parentheses).

This is implemented by using optional_parentheses in conjunction with the in_parentheses_only_* builders. We need something similar for patterns to support

match test:
    case A | B | ["Aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", "bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb"]: ...

# Formatted
match test:
    case (
        A
        | B
        | ["Aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", "bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb"]
    ):
        ...

# Instead of
match test:
    case A | B | [
        "Aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
        "bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb",
    ]:
        ...

[dhruvmanila]

This seems to be fixed: https://play.ruff.rs/e7f95918-d71e-479f-8fae-29cdaa476463

Closing the issue but feel free to re-open it if you think otherwise.

[MichaReiser]

This isn't fixed yet. Notice how the expression gets wrapped in parentheses.

We need to avoid adding the parentheses in this case. I'm not sure why the function isn't using maybe_parenthesize(IfBreaks) directly

ruff/crates/ruff_python_formatter/src/other/match_case.rs

Lines 38 to 58 in c05e462

	if has_comments {
	pattern.format().with_options(Parentheses::Always).fmt(f)?;
	} else {
	match pattern.needs_parentheses(item.as_any_node_ref(), f.context()) {
	OptionalParentheses::Multiline => {
	parenthesize_if_expands(
	&pattern.format().with_options(Parentheses::Never),
	)
	.fmt(f)?;
	}
	OptionalParentheses::Always => {
	pattern.format().with_options(Parentheses::Always).fmt(f)?;
	}
	OptionalParentheses::Never => {
	pattern.format().with_options(Parentheses::Never).fmt(f)?;
	}
	OptionalParentheses::BestFit => {
	pattern.format().with_options(Parentheses::Never).fmt(f)?;
	}
	}
	}

[charliermarsh]

We want to make this change (it improves consistency), but it's not blocking for the Beta.

The challenge here is that we need to re-implement can_omit_parentheses for patterns, since that logic only applies to expressions.

[MichaReiser]

I'm going to remove this from the stable release since it hasn't come up often.