## Summary
This PR adds comment handling for comments between the `=` and the
`value` for keywords, as in the following cases:
```python
func(
x # dangling
= # dangling
# dangling
1,
** # dangling
y
)
```
(Comments after the `**` were already handled in some cases, but I've
unified the handling with the `=` handling.)
Note that, previously, comments between the `**` and its value were
rendered as trailing comments on the value (so they'd appear after `y`).
This struck me as odd since it effectively re-ordered the comment with
respect to its closest AST node (the value). I've made them leading
comments, though I don't know that that's a significant improvement. I
could also imagine us leaving them where they are.
## Summary
The motivation here is that this enables us to implement `Ranged` in
crates that don't depend on `ruff_python_ast`.
Largely a mechanical refactor with a lot of regex, Clippy help, and
manual fixups.
## Test Plan
`cargo test`
## Summary
This PR moves `empty_parenthesized` such that it's peer to
`parenthesized`, and changes the API to better match that of
`parenthesized` (takes `&str` rather than `StaticText`, has a
`with_dangling_comments` method, etc.).
It may be intentionally _not_ part of `parentheses.rs`, but to me
they're so similar that it makes more sense for them to be in the same
module, with the same API, etc.
## Summary
We already support preserving the end-of-line comment in calls and type
parameters, as in:
```python
foo( # comment
bar,
)
```
This PR adds the same behavior for lists, sets, comprehensions, etc.,
such that we preserve:
```python
[ # comment
1,
2,
3,
]
```
And related cases.
**Summary** Add a `EmptyWithDanglingComments` format helper that formats
comments inside empty parentheses, brackets or curly braces. Previously,
this was implemented separately, and partially incorrectly, for each use
case.
Empty `()`, `[]` and `{}` are special because there can be dangling
comments, and they can be in
two positions:
```python
x = [ # end-of-line
# own line
]
```
These comments are dangling because they can't be assigned to any
element inside as they would
in all other cases.
**Test Plan** Added a regression test.
145 (from previously 149) instances of unstable formatting remaining.
```
$ cargo run --bin ruff_dev --release -- format-dev --stability-check --error-file formatter-ecosystem-errors.txt --multi-project target/checkouts > formatter-ecosystem-progress.txt
$ rg "Unstable formatting" target/formatter-ecosystem-errors.txt | wc -l
145
```
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## Summary
I started working on this because I assumed that I would need access to options inside of `NeedsParantheses` but it then turned out that I won't.
Anyway, it kind of felt nice to pass fewer arguments. So I'm gonna put this out here to get your feedback if you prefer this over passing individual fiels.
Oh, I sneeked in another change. I renamed `context.contents` to `source`. `contents` is too generic and doesn't tell you anything.
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## Test Plan
It compiles
## Summary
This is small refactoring to reuse the code that detects the magic
trailing comma across functions. I make this change now to avoid copying
code in a later PR. @MichaReiser is planning on making a larger
refactoring later that integrates with the join nodes builder
## Test Plan
No functional changes. The magic trailing comma behaviour is checked by
the fixtures.
## Summary
This fixes a number of problems in the formatter that showed up with
various files in the [cpython](https://github.com/python/cpython)
repository. These problems surfaced as unstable formatting and invalid
code. This is not the entirety of problems discovered through cpython,
but a big enough chunk to separate it. Individual fixes are generally
individual commits. They were discovered with #5055, which i update as i
work through the output
## Test Plan
I added regression tests with links to cpython for each entry, except
for the two stubs that also got comment stubs since they'll be
implemented properly later.
* A basic StmtAssign formatter and better dummies for expressions
The goal of this PR was formatting StmtAssign since many nodes in the black tests (and in python in general) are after an assignment. This caused unstable formatting: The spacing of power op spacing depends on the type of the two involved expressions, but each expression was formatted as dummy string and re-parsed as a ExprName, so in the second round the different rules of ExprName were applied, causing unstable formatting.
This PR does not necessarily bring us closer to black's style, but it unlocks a good porting of black's test suite and is a basis for implementing the Expr nodes.
* fmt
* Review
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## Summary
This PR replaces the `verbatim_text` builder with a `not_yet_implemented` builder that emits `NOT_YET_IMPLEMENTED_<NodeKind>` for not yet implemented nodes.
The motivation for this change is that partially formatting compound statements can result in incorrectly indented code, which is a syntax error:
```python
def func_no_args():
a; b; c
if True: raise RuntimeError
if False: ...
for i in range(10):
print(i)
continue
```
Get's reformatted to
```python
def func_no_args():
a; b; c
if True: raise RuntimeError
if False: ...
for i in range(10):
print(i)
continue
```
because our formatter does not yet support `for` statements and just inserts the text from the source.
## Downsides
Using an identifier will not work in all situations. For example, an identifier is invalid in an `Arguments ` position. That's why I kept `verbatim_text` around and e.g. use it in the `Arguments` formatting logic where incorrect indentations are impossible (to my knowledge). Meaning, `verbatim_text` we can opt in to `verbatim_text` when we want to iterate quickly on nodes that we don't want to provide a full implementation yet and using an identifier would be invalid.
## Upsides
Running this on main discovered stability issues with the newline handling that were previously "hidden" because of the verbatim formatting. I guess that's an upside :)
## Test Plan
None?
