## Summary
This is another attempt at https://github.com/astral-sh/ruff/pull/21410
that fixes https://github.com/astral-sh/ruff/issues/19226.
@MichaReiser helped me get something working in a very helpful pairing
session. I pushed one additional commit moving the comments back from
leading comments to trailing comments, which I think retains more of the
input formatting.
I was inspired by Dylan's PR (#21185) to make one of these tables:
<table>
<thead>
<tr>
<th scope="col">Input</th>
<th scope="col">Main</th>
<th scope="col">PR</th>
</tr>
</thead>
<tbody>
<tr>
<td><pre lang="python">
if (
not
# comment
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa +
bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
):
pass
</pre></td>
<td><pre lang="python">
if (
# comment
not aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
+ bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
):
pass
</pre></td>
<td><pre lang="python">
if (
not
# comment
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
+ bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
):
pass
</pre></td>
</tr>
<tr>
<td><pre lang="python">
if (
# unary comment
not
# operand comment
(
# comment
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
+ bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
)
):
pass
</pre></td>
<td><pre lang="python">
if (
# unary comment
# operand comment
not (
# comment
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
+ bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
)
):
pass
</pre></td>
<td><pre lang="python">
if (
# unary comment
not
# operand comment
(
# comment
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
+ bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
)
):
pass
</pre></td>
</tr>
<tr>
<td><pre lang="python">
if (
not # comment
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
+ bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
):
pass
</pre></td>
<td><pre lang="python">
if ( # comment
not aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
+ bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
):
pass
</pre></td>
<td><pre lang="python">
if (
not aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa # comment
+ bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
):
pass
</pre></td>
</tr>
</tbody>
</table>
hopefully it helps even though the snippets are much wider here.
The two main differences are (1) that we now retain own-line comments
between the unary operator and its operand instead of moving these to
leading comments on the operator itself, and (2) that we move
end-of-line comments between the operator and operand to dangling
end-of-line comments on the operand (the last example in the table).
## Test Plan
Existing tests, plus new ones based on the issue. As I noted below, I
also ran the output from main on the unary.py file back through this
branch to check that we don't reformat code from main. This made me feel
a bit better about not preview-gating the changes in this PR.
```shell
> git show main:crates/ruff_python_formatter/resources/test/fixtures/ruff/expression/unary.py | ruff format - | ./target/debug/ruff format --diff -
> echo $?
0
```
---------
Co-authored-by: Micha Reiser <micha@reiser.io>
Co-authored-by: Takayuki Maeda <takoyaki0316@gmail.com>