## Summary
Allows for proper lexing of tokens like `->`.
The main challenge is to ensure that our forward and backwards
representations are the same for cases like `===`. Specifically, we want
that to lex as `==` followed by `=` regardless of whether it's a
forwards or backwards lex. To do so, we identify the range of the
sequential characters (the full span of `===`), lex it forwards, then
return the last token.
## Test Plan
`cargo test`
## Summary
This PR adds support for parenthesized comments. A parenthesized comment
is a comment that appears within a parenthesis, but not within the range
of the expression enclosed by the parenthesis. For example, the comment
here is a parenthesized comment:
```python
if (
# comment
True
):
...
```
The parentheses enclose the `True`, but the range of `True` doesn’t
include the `# comment`.
There are at least two problems associated with parenthesized comments:
(1) associating the comment with the correct (i.e., enclosed) node; and
(2) formatting the comment correctly, once it has been associated with
the enclosed node.
The solution proposed here for (1) is to search for parentheses between
preceding and following node, and use open and close parentheses to
break ties, rather than always assigning to the preceding node.
For (2), we handle these special parenthesized comments in `FormatExpr`.
The biggest risk with this approach is that we forget some codepath that
force-disables parenthesization (by passing in `Parentheses::Never`).
I've audited all usages of that enum and added additional handling +
test coverage for such cases.
Closes https://github.com/astral-sh/ruff/issues/6390.
## Test Plan
`cargo test` with new cases.
Before:
| project | similarity index |
|--------------|------------------|
| build | 0.75623 |
| cpython | 0.75472 |
| django | 0.99804 |
| transformers | 0.99618 |
| typeshed | 0.74233 |
| warehouse | 0.99601 |
| zulip | 0.99727 |
After:
| project | similarity index |
|--------------|------------------|
| build | 0.75623 |
| cpython | 0.75472 |
| django | 0.99804 |
| transformers | 0.99618 |
| typeshed | 0.74237 |
| warehouse | 0.99601 |
| zulip | 0.99727 |
## Summary
Instead, we set an `is_star` flag on `Stmt::Try`. This is similar to the
pattern we've migrated towards for `Stmt::For` (removing
`Stmt::AsyncFor`) and friends. While these are significant differences
for an interpreter, we tend to handle these cases identically or nearly
identically.
## Test Plan
`cargo test`
## Summary
This PR adds handling for comments on open parentheses in parenthesized
context managers. For example, given:
```python
with ( # comment
CtxManager1() as example1,
CtxManager2() as example2,
CtxManager3() as example3,
):
...
```
We want to preserve that formatting. (Black does the same.) On `main`,
we format as:
```python
with (
# comment
CtxManager1() as example1,
CtxManager2() as example2,
CtxManager3() as example3,
):
...
```
It's very similar to how `StmtImportFrom` is handled.
Note that this case _isn't_ covered by the "parenthesized comment"
proposal, since this is a common on the statement that would typically
be attached to the first `WithItem`, and the `WithItem` _itself_ can
have parenthesized comments, like:
```python
with ( # comment
(
CtxManager1() # comment
) as example1,
CtxManager2() as example2,
CtxManager3() as example3,
):
...
```
## Test Plan
`cargo test`
Confirmed no change in similarity score.
## Summary
The bracketed-end-of-line comment rule is meant to assign comments like
this as "immediately following the bracket":
```python
f( # comment
1
)
```
However, the logic was such that we treated this equivalently:
```python
f(
( # comment
1
)
)
```
This PR modifies the placement logic to ensure that we only skip the
opening bracket, and not any nested brackets. The above is now formatted
as:
```python
f(
(
# comment
1
)
)
```
(But will be corrected once we handle parenthesized comments properly.)
## Test Plan
`cargo test`
Confirmed no change in similarity score.
## Summary
This PR adds formatting support for `MatchCase` node with subs for the
`Pattern`
nodes.
## Test Plan
Added test cases for case node handling with comments, newlines.
resolves: #6299
## Summary
The bug was happening in this
[loop](75f402eb82/crates/ruff_python_formatter/src/comments/placement.rs (L545)).
Basically, In the first iteration of the loop, the `comment_indentation`
is bigger than `child_indentation` (`comment_indentation` is 7 and
`child_indentation` is 4) making the `Ordering::Greater` branch execute.
Inside the `Ordering::Greater` branch, the `if` block gets executed,
resulting in the update of these variables.
```rust
parent_body = current_body;
current_body = Some(last_child_in_current_body);
last_child_in_current_body = nested_child;
```
In the second iteration of the loop, `comment_indentation` is smaller
than `child_indentation` (`comment_indentation` is 7 and
`child_indentation` is 8) making the `Ordering::Less` branch execute.
Inside the `Ordering::Less` branch, the `if` block gets executed, this
is where the bug was happening. At this point `parent_body` should be a
`StmtFunctionDef` but it was a `StmtClassDef`. Causing the comment to be
incorrectly formatted.
That happened for the following code:
```python
class A:
def f():
pass
# strangely indented comment
print()
```
There is only one problem that I couldn't figure it out a solution, the
variable `current_body` in this
[line](75f402eb82/crates/ruff_python_formatter/src/comments/placement.rs (L542C5-L542C49))
now gives this warning _"value assigned to `current_body` is never read
maybe it is overwritten before being read?"_
Any tips on how to solve that?
Closes#5337
## Test Plan
Add new test case.
---------
Co-authored-by: konstin <konstin@mailbox.org>
We currently don't format all comments as match statements are not yet implemented. We can work around this for the top level match statement by setting them manually formatted but the mocked-out top level match doesn't call into its children so they would still have unformatted comments
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## Summary
This PR fixes the issue where the FString formatting dropped dangling comments between the string parts.
```python
result_f = (
f' File "{__file__}", line {lineno_f+1}, in f\n'
' f()\n'
# XXX: The following line changes depending on whether the tests
# are run through the interactive interpreter or with -m
# It also varies depending on the platform (stack size)
# Fortunately, we don't care about exactness here, so we use regex
r' \[Previous line repeated (\d+) more times\]' '\n'
'RecursionError: maximum recursion depth exceeded\n'
)
```
The solution here isn't ideal because it re-introduces the `enclosing_parent` on `DecoratedComment` but it is the easiest fix that I could come up.
I didn't spend more time finding another solution becaues I think we have to re-write most of the fstring formatting with the upcoming Python 3.12 support (because lexing the individual parts as we do now will no longer work).
closes#6440
<!-- What's the purpose of the change? What does it do, and why? -->
## Test Plan
`cargo test`
The child PR testing that all comments are formatted should now pass
## Summary
Given:
```python
def double(a: int) -> ( # Hello
int
):
return 2*a
```
We currently treat `# Hello` as a trailing comment on the parameters
(`(a: int)`). This PR adds a placement method to instead treat it as a
dangling comment on the function definition itself, so that it gets
formatted at the end of the definition, like:
```python
def double(a: int) -> int: # Hello
return 2*a
```
The formatting in this case is unchanged, but it's incorrect IMO for
that to be a trailing comment on the parameters, and that placement
leads to an instability after changing the grouping in #6410.
Fixing this led to a _different_ instability related to tuple return
type annotations, like:
```python
def zrevrangebylex(self, name: _Key, max: _Value, min: _Value, start: int | None = None, num: int | None = None) -> ( # type: ignore[override]
):
...
```
(This is a real example.)
To fix, I had to special-case tuples in that spot, though I'm not
certain that's correct.
## Summary
This PR adds support for `StmtMatch` with subs for `MatchCase`.
## Test Plan
Add a few additional test cases around `match` statement, comments, line
breaks.
resolves: #6298
## Summary
I noticed some deviations in how we treat dangling comments that hug the
opening parenthesis for function definitions.
For example, given:
```python
def f( # first
# second
): # third
...
```
We currently format as:
```python
def f(
# first
# second
): # third
...
```
This PR adds the proper opening-parenthesis dangling comment handling
for function parameters. Specifically, as with all other parenthesized
nodes, we now detect that dangling comment in `placement.rs` and handle
it in `parameters.rs`. We have to take some care in that file, since we
have multiple "kinds" of dangling comments, but I added a bunch of test
cases that we now format identically to Black.
## Test Plan
`cargo test`
Before:
- `zulip`: 0.99388
- `django`: 0.99784
- `warehouse`: 0.99504
- `transformers`: 0.99404
- `cpython`: 0.75913
- `typeshed`: 0.74364
After:
- `zulip`: 0.99386
- `django`: 0.99784
- `warehouse`: 0.99504
- `transformers`: 0.99404
- `cpython`: 0.75913
- `typeshed`: 0.74409
Meaningful improvement on `typeshed`, minor decrease on `zulip`.
## Summary
Per the suggestion in
https://github.com/astral-sh/ruff/discussions/6183, this PR removes
`AsyncWith`, `AsyncFor`, and `AsyncFunctionDef`, replacing them with an
`is_async` field on the non-async variants of those structs. Unlike an
interpreter, we _generally_ have identical handling for these nodes, so
separating them into distinct variants adds complexity from which we
don't really benefit. This can be seen below, where we get to remove a
_ton_ of code related to adding generic `Any*` wrappers, and a ton of
duplicate branches for these cases.
## Test Plan
`cargo test` is unchanged, apart from parser snapshots.
## Summary
Given:
```python
[ # comment
first,
second,
third
] # another comment
```
We were adding a hard line break as part of the formatting of `#
comment`, which led to the following formatting:
```python
[first, second, third] # comment
# another comment
```
Closes https://github.com/astral-sh/ruff/issues/6367.
Implement fluent style/call chains. See the `call_chains.py` formatting
for examples.
This isn't fully like black because in `raise A from B` they allow `A`
breaking can influence the formatting of `B` even if it is already
multiline.
Similarity index:
| project | main | PR |
|--------------|-------|-------|
| build | ??? | 0.753 |
| django | 0.991 | 0.998 |
| transformers | 0.993 | 0.994 |
| typeshed | 0.723 | 0.723 |
| warehouse | 0.978 | 0.994 |
| zulip | 0.992 | 0.994 |
Call chain formatting is affected by
https://github.com/astral-sh/ruff/issues/627, but i'm cutting scope
here.
Closes#5343
**Test Plan**:
* Added a dedicated call chains test file
* The ecosystem checks found some bugs
* I manually check django and zulip formatting
---------
Co-authored-by: Micha Reiser <micha@reiser.io>
## 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
This PR adds an API for chaining comment placement methods based on the
[`then_with`](https://doc.rust-lang.org/std/cmp/enum.Ordering.html#method.then_with)
from `Ordering` in the standard library.
For example, you can now do:
```rust
try_some_case(comment).then_with(|comment| try_some_other_case_if_still_default(comment))
```
This lets us avoid this kind of pattern, which I've seen in
`placement.rs` and used myself before:
```rust
let comment = match handle_own_line_comment_between_branches(comment, preceding, locator) {
CommentPlacement::Default(comment) => comment,
placement => return placement,
};
```
## Summary
This ensures that we treat `# comment` as parenthesized in contexts
like:
```python
while (
True
# comment
):
pass
```
The same logic applies equally to `for`, `async for`, `if`, `with`, and
`async with`. The general pattern is that you have an expression which
precedes a colon-separated suite.
Part of #5062
Closes https://github.com/astral-sh/ruff/issues/5931
Implements formatting of a sequence of type parameters in a dedicated
struct for reuse by classes, functions, and type aliases (preparing for
#5929). Adds formatting of type parameters in class and function
definitions — previously, they were just elided.
## Summary
This PR leverages the `Arguments` AST node introduced in #6259 in the
formatter, which ensures that we correctly handle trailing comments in
calls, like:
```python
f(
1,
# comment
)
pass
```
(Previously, this was treated as a leading comment on `pass`.)
This also allows us to unify the argument handling across calls and
class definitions.
## Test Plan
A bunch of new fixture tests, plus improved Black compatibility.
## Summary
This PR renames a few AST nodes for clarity:
- `Arguments` is now `Parameters`
- `Arg` is now `Parameter`
- `ArgWithDefault` is now `ParameterWithDefault`
For now, the attribute names that reference `Parameters` directly are
changed (e.g., on `StmtFunctionDef`), but the attributes on `Parameters`
itself are not (e.g., `vararg`). We may revisit that decision in the
future.
For context, the AST node formerly known as `Arguments` is used in
function definitions. Formally (outside of the Python context),
"arguments" typically refers to "the values passed to a function", while
"parameters" typically refers to "the variables used in a function
definition". E.g., if you Google "arguments vs parameters", you'll get
some explanation like:
> A parameter is a variable in a function definition. It is a
placeholder and hence does not have a concrete value. An argument is a
value passed during function invocation.
We're thus deviating from Python's nomenclature in favor of a scheme
that we find to be more precise.
**Summary** Allow passing any node to `CommentPlacement::{leading,
trailing, dangling}` without manually converting. Conversely, Restrict
the comment to the only type we actually pass.
**Test Plan** No changes.
## Summary
This PR protects against code like:
```python
from typing import Optional
import bar # ruff: noqa
import baz
class Foo:
x: Optional[str] = None
```
In which the user wrote `# ruff: noqa` to ignore a specific error, not
realizing that it was a file-level exemption that thus turned off all
lint rules.
Specifically, if a `# ruff: noqa` directive is not at the start of a
line, we now ignore it and warn, since this is almost certainly a
mistake.
## Summary
This is a rewrite of the main comment placement logic. `place_comment`
now has three parts:
- place own line comments
- between branches
- after a branch
- place end-of-line comments
- after colon
- after a branch
- place comments for specific nodes (that include module level comments)
The rewrite fixed three bugs: `class A: # trailing comment` comments now
stay end-of-line, `try: # comment` remains end-of-line and deeply
indented try-else-finally comments remain with the right nested
statement.
It will be much easier to give more alternative branches nodes since
this is abstracted away by `is_node_with_body` and the first/last child
helpers. Adding new node types can now be done by adding an entry to the
`place_comment` match. The code went from 1526 lines before #6033 to
1213 lines now.
It thinks it easier to just read the new `placement.rs` rather than
reviewing the diff.
## Test Plan
The existing fixtures staying the same or improving plus new ones for
the bug fixes.
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## Summary
<!-- What's the purpose of the change? What does it do, and why? -->
Part of #5062
Requires https://github.com/astral-sh/RustPython-Parser/pull/32
Adds visitation of type alias statements and type parameters in class
and function definitions.
Duplicates tests for `PreorderVisitor` into `Visitor` with new
snapshots. Testing required node implementations for the `TypeParam`
enum, which is a chunk of the diff and the reason we need `Ranged`
implementations in
https://github.com/astral-sh/RustPython-Parser/pull/32.
## Test Plan
<!-- How was it tested? -->
Adds unit tests with snapshots.
## Summary
This PR is a refactoring of placement.rs. The code got more consistent,
some comments were updated and some dead code was removed or replaced
with debug assertions. It also contains a bugfix for the placement of
end-of-branch comments with nested bodies inside try statements that
occurred when refactoring the nested body loop.
## Test Plan
The existing test cases don't change. I added a couple of cases that i
think should be tested but weren't, and a regression test for the bugfix
**Summary** Fix an instability in with statement formatter when there is
an own line comment as the `as`
```python
with (
a as
# bad comment
b):
```
**Test Plan** Added the comment to the test cases.
## Summary
This crate now contains utilities for dealing with trivia more broadly:
whitespace, newlines, "simple" trivia lexing, etc. So renaming it to
reflect its increased responsibilities.
To avoid conflicts, I've also renamed `Token` and `TokenKind` to
`SimpleToken` and `SimpleTokenKind`.
**Summary** Add a static string error message to the formatter syntax
error so we can disambiguate where the syntax error came from
**Test Plan** No fixed tests, we don't expect this to occur, but it
helped with transformers syntax error debugging:
```
Error: Failed to format node
Caused by:
syntax error: slice first colon token was not a colon
```
