## Summary
This PR fixes a bug where Ruff would raise `E203` for f-string debug
expression. This isn't valid because whitespaces are important for debug
expressions.
fixes: #12023
## Test Plan
Add test case and make sure there are no snapshot changes.
## Summary
This PR removes most of the syntax errors from the test cases. This
would create noise when https://github.com/astral-sh/ruff/pull/11901 is
complete. These syntax errors are also just noise for the test itself.
## Test Plan
Update the snapshots and verify that they're still the same.
## Summary
The fix for E203 now produces the same result as ruff format in cases
where a slice ends on a colon and the closing square bracket is on the
following line.
Refers to https://github.com/astral-sh/ruff/issues/10973
## Test Plan
The minimal reproduction case in the ticket was added as test case
producing no error. Additional cases with multiple spaces or a tab
before the colon where added to make sure that the rule still finds
these.
## Summary
The code later in this file that checks for slices relies on the stack
of brackets to determine the position. I'm not sure why format strings
were being excluded from this, but the tests still pass with these match
guards removed.
Closes#10278
## Test Plan
~Still needs a test.~ Test case added for this example.
## Summary
This PR makes `whitespace-before-punctuation` (`E203`) compatible with
the formatter by relaxing the rule a bit, as compared to the pycodestyle
implementation. It's also more consistent with PEP 8, which says:
> However, in a slice the colon acts like a binary operator, and should
have equal amounts on either side (treating it as the operator with the
lowest priority).
Closes https://github.com/astral-sh/ruff/issues/7259.
Closes https://github.com/astral-sh/ruff/issues/8642.
## Test Plan
`cargo test`
