This solves an instability when formatting cpython. It also introduces
another one, but i think it's still a worthwhile change for now.
There's no proper testing since this is just a dummy.
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## Summary
format StmtFor
still trying to learn how to help out with the formatter. trying
something slightly more advanced than [break](#5158)
mostly copied form StmtWhile
## Test Plan
snapshots
## Summary
This is a complete rewrite of the handling of `/` and `*` comment
handling in function signatures. The key problem is that slash and star
don't have a note. We now parse out the positions of slash and star and
their respective preceding and following note. I've left code comments
for each possible case of function signature structure and comment
placement
## Test Plan
I extended the function statement fixtures with cases that i found. If
you have more weird edge cases your input would be appreciated.
## Summary
This fixes two problems discovered when trying to format the cpython
repo with `cargo run --bin ruff_dev -- check-formatter-stability
projects/cpython`:
The first is to ignore try/except trailing comments for now since they
lead to unstable formatting on the dummy.
The second is to avoid dropping trailing if comments through placement:
This changes the placement to keep a comment trailing an if-elif or
if-elif-else to keep the comment a trailing comment on the entire if.
Previously the last comment would have been lost.
```python
if "first if":
pass
elif "first elif":
pass
```
The last remaining problem in cpython so far is function signature
argument separator comment placement which is its own PR on top of this.
## Test Plan
I added test fixtures of minimized examples with links back to the
original cpython location
This formats slice expressions and subscript expressions.
Spaces around the colons follows the same rules as black
(https://black.readthedocs.io/en/stable/the_black_code_style/current_style.html#slices):
```python
e00 = "e"[:]
e01 = "e"[:1]
e02 = "e"[: a()]
e10 = "e"[1:]
e11 = "e"[1:1]
e12 = "e"[1 : a()]
e20 = "e"[a() :]
e21 = "e"[a() : 1]
e22 = "e"[a() : a()]
e200 = "e"[a() : :]
e201 = "e"[a() :: 1]
e202 = "e"[a() :: a()]
e210 = "e"[a() : 1 :]
```
Comment placement is different due to our very different infrastructure.
If we have explicit bounds (e.g. `x[1:2]`) all comments get assigned as
leading or trailing to the bound expression. If a bound is missing
`[:]`, comments get marked as dangling and placed in the same section as
they were originally in:
```python
x = "x"[ # a
# b
: # c
# d
]
```
to
```python
x = "x"[
# a
# b
:
# c
# d
]
```
Except for the potential trailing end-of-line comments, all comments get
formatted on their own line. This can be improved by keeping end-of-line
comments after the opening bracket or after a colon as such but the
changes were already complex enough.
I added tests for comment placement and spaces.
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## Summary
This PR adds basic formatting for unary expressions.
<!-- What's the purpose of the change? What does it do, and why? -->
## Test Plan
I added a new `unary.py` with custom test cases
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## Summary
Black supports for layouts when it comes to breaking binary expressions:
```rust
#[derive(Copy, Clone, Debug, Eq, PartialEq)]
enum BinaryLayout {
/// Put each operand on their own line if either side expands
Default,
/// Try to expand the left to make it fit. Add parentheses if the left or right don't fit.
///
///```python
/// [
/// a,
/// b
/// ] & c
///```
ExpandLeft,
/// Try to expand the right to make it fix. Add parentheses if the left or right don't fit.
///
/// ```python
/// a & [
/// b,
/// c
/// ]
/// ```
ExpandRight,
/// Both the left and right side can be expanded. Try in the following order:
/// * expand the right side
/// * expand the left side
/// * expand both sides
///
/// to make the expression fit
///
/// ```python
/// [
/// a,
/// b
/// ] & [
/// c,
/// d
/// ]
/// ```
ExpandRightThenLeft,
}
```
Our current implementation only handles `ExpandRight` and `Default` correctly. This PR adds support for `ExpandRightThenLeft` and `ExpandLeft`.
## Test Plan
I added tests that play through all 4 binary expression layouts.
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## Summary
Format `continue` statement.
## Test Plan
`continue` is used already in some tests, but if a new test is needed I
could add it.
---------
Co-authored-by: konstin <konstin@mailbox.org>
## 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.
This implements formatting ExprTuple, including magic trailing comma. I
intentionally didn't change the settings mechanism but just added a
dummy global const flag.
Besides the snapshots, I added custom breaking/joining tests and a
deeply nested test case. The diffs look better than previously, proper
black compatibility depends on parentheses handling.
---------
Co-authored-by: Micha Reiser <micha@reiser.io>
* Implement StmtPass
This implements StmtPass as `pass`.
The snapshot diff is small because pass mainly occurs in bodies and function (#4951) and if/for bodies.
* Implement StmtReturn
This implements StmtReturn as `return` or `return {value}`.
The snapshot diff is small because return occurs in functions (#4951)
* 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?
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## Summary
This issue fixes the removal of empty lines between a leading comment and the previous statement:
```python
a = 20
# leading comment
b = 10
```
Ruff removed the empty line between `a` and `b` because:
* The leading comments formatting does not preserve leading newlines (to avoid adding new lines at the top of a body)
* The `JoinNodesBuilder` counted the lines before `b`, which is 1 -> Doesn't insert a new line
This is fixed by changing the `JoinNodesBuilder` to count the lines instead *after* the last node. This correctly gives 1, and the `# leading comment` will insert the empty lines between any other leading comment or the node.
## Test Plan
I added a new test for empty lines.
* Implement module formatting using JoinNodesBuilder
This uses JoinNodesBuilder to implement module formatting for #4800
See the snapshots for the changed behaviour. See one PR up for a CLI that i used to verify the trailing new line behaviour
### Summary
This PR adds custom logic to handle end-of-line comments of the last statement in a body.
For example:
```python
while True:
if something.changed:
do.stuff() # trailing comment
b
```
The `# trailing comment` is a trailing comment of the `do.stuff()` expression statement. We incorrectly attached the comment as a trailing comment of the enclosing `while` statement because the comment is between the end of the while statement (the `while` statement ends right after `do.stuff()`) and before the `b` statement.
This PR fixes the placement to correctly attach these comments to the last statement in a body (recursively).
## Test Plan
I reviewed the snapshots and they now look correct. This may appear odd because a lot comments have now disappeared. This is the expected result because we use `verbatim` formatting for the block statements (like `while`) and that means that it only formats the inner content of the block, but not any trailing comments. The comments were visible before, because they were associated with the block statement (e.g. `while`).
* Add Format for Stmt
* Implement basic module formatting
This implements formatting each statement in a module with a hard line break in between, so that we can start formatting statements.
Basic testing is done by the snapshots
