## Summary
For imports, we enforce that there's _at least_ one empty line after an
import (assuming the next statement is _not_ an import), but allow up to
two at the module level.
Closes https://github.com/astral-sh/ruff/issues/6760.
## Test Plan
`cargo test`
Avoid the nesting in a macro by using the new `WithNodeLevel` to
`PyFormatter` deref. No changes otherwise.
I wanted to follow this up with quickly fixing the typeshed empty line
rules but they turned out a lot more complex than i had anticipated.
## Summary
We're using LibCST to ensure that we return the full parenthesized range
of an expression, for display purposes. We can just use
`parenthesized_range` which is more efficient and removes one LibCST
dependency.
## Test Plan
`cargo test`
## Summary
The motivating code here was:
```python
with test as (
# test
foo):
pass
```
Which we were formatting as:
```python
with test as
# test
(foo):
pass
```
`with` statements are oddly difficult. This PR makes a bunch of subtle
modifications and adds a more extensive test suite. For example, we now
only preserve parentheses if there's more than one `WithItem` _or_ a
trailing comma; before, we always preserved.
Our formatting is_not_ the same as Black, but here's a diff of our
formatted code vs. Black's for the `with.py` test suite. The primary
difference is that we tend to break parentheses when they contain
comments rather than move them to the end of the life (this is a
consistent difference that we make across the codebase):
```diff
diff --git a/crates/ruff_python_formatter/foo.py b/crates/ruff_python_formatter/foo.py
index 85e761080..31625c876 100644
--- a/crates/ruff_python_formatter/foo.py
+++ b/crates/ruff_python_formatter/foo.py
@@ -1,6 +1,4 @@
-with (
- aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
-), aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa:
+with aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa, aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa:
...
# trailing
@@ -16,28 +14,33 @@ with (
# trailing
-with a, b: # a # comma # c # colon
+with (
+ a, # a # comma
+ b, # c
+): # colon
...
with (
- a as # a # as
- # own line
- b, # b # comma
+ a as ( # a # as
+ # own line
+ b
+ ), # b # comma
c, # c
): # colon
... # body
# body trailing own
-with (
- a as # a # as
+with a as ( # a # as
# own line
- bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb # b
-):
+ bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
+): # b
pass
-with (a,): # magic trailing comma
+with (
+ a,
+): # magic trailing comma
...
@@ -47,6 +50,7 @@ with a: # should remove brackets
with aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb as c:
...
+
with (
# leading comment
a
@@ -74,8 +78,7 @@ with (
with (
a # trailing same line comment
# trailing own line comment
- as b
-):
+) as b:
...
with (
@@ -87,7 +90,9 @@ with (
with (
a
# trailing own line comment
-) as b: # trailing as same line comment # trailing b same line comment
+) as ( # trailing as same line comment
+ b
+): # trailing b same line comment
...
with (
@@ -124,18 +129,24 @@ with ( # comment
...
with ( # outer comment
- CtxManager1() as example1, # inner comment
+ ( # inner comment
+ CtxManager1()
+ ) as example1,
CtxManager2() as example2,
CtxManager3() as example3,
):
...
-with CtxManager() as example: # outer comment
+with ( # outer comment
+ CtxManager()
+) as example:
...
with ( # outer comment
CtxManager()
-) as example, CtxManager2() as example2: # inner comment
+) as example, ( # inner comment
+ CtxManager2()
+) as example2:
...
with ( # outer comment
@@ -145,7 +156,9 @@ with ( # outer comment
...
with ( # outer comment
- (CtxManager1()), # inner comment
+ ( # inner comment
+ CtxManager1()
+ ),
CtxManager2(),
) as example:
...
@@ -179,7 +192,9 @@ with (
):
pass
-with a as (b): # foo
+with a as ( # foo
+ b
+):
pass
with f(
@@ -209,17 +224,13 @@ with f(
) as b, c as d:
pass
-with (
- aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
-) as b:
+with aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb as b:
pass
with aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb as b:
pass
-with (
- aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
-) as b, c as d:
+with aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb as b, c as d:
pass
with (
@@ -230,6 +241,8 @@ with (
pass
with (
- aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
-) as b, c as d:
+ aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
+ + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb as b,
+ c as d,
+):
pass
```
Closes https://github.com/astral-sh/ruff/issues/6600.
## Test Plan
Before:
| project | similarity index |
|--------------|------------------|
| cpython | 0.75473 |
| django | 0.99804 |
| transformers | 0.99618 |
| twine | 0.99876 |
| typeshed | 0.74292 |
| warehouse | 0.99601 |
| zulip | 0.99727 |
After:
| project | similarity index |
|--------------|------------------|
| cpython | 0.75473 |
| django | 0.99804 |
| transformers | 0.99618 |
| twine | 0.99876 |
| typeshed | 0.74292 |
| warehouse | 0.99601 |
| zulip | 0.99727 |
`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
Unlike other statements, Black always adds a trailing comma if an
import-from statement breaks with a single import member. I believe this
is for compatibility with isort -- see
09f5ee3a19,
https://github.com/psf/black/issues/127, or
66648c528a/src/black/linegen.py (L1452)
for the current version.
## Test Plan
`cargo test`, notice that a big chunk of the compatibility suite is
removed.
Before:
| project | similarity index |
|--------------|------------------|
| cpython | 0.75472 |
| django | 0.99804 |
| transformers | 0.99618 |
| twine | 0.99876 |
| typeshed | 0.74233 |
| warehouse | 0.99601 |
| zulip | 0.99727 |
After:
| project | similarity index |
|--------------|------------------|
| cpython | 0.75472 |
| django | 0.99804 |
| transformers | 0.99618 |
| twine | 0.99876 |
| typeshed | 0.74260 |
| 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
In https://github.com/astral-sh/ruff/pull/6512, we added a flag to the
AST to mark implicitly-concatenated string expressions. This PR makes
use of that flag to remove the `is_implicit_concatenation` method.
## Test Plan
`cargo test`
**Summary** Implement docstring formatting
**Test Plan** Matches black's `docstring.py` fixture exactly, added some
new cases for what is hard to debug with black and with what black
doesn't cover.
similarity index:
main:
zulip: 0.99702
django: 0.99784
warehouse: 0.99585
build: 0.75623
transformers: 0.99469
cpython: 0.75989
typeshed: 0.74853
this branch:
zulip: 0.99702
django: 0.99784
warehouse: 0.99585
build: 0.75623
transformers: 0.99464
cpython: 0.75517
typeshed: 0.74853
The regression in transformers is actually an improvement in a file they
don't format with black (they run `black examples tests src utils
setup.py conftest.py`, the difference is in hubconf.py). cpython doesn't
use black.
Closes#6196
## Summary
This PR modifies our logic for wrapping return type annotations.
Previously, we _always_ wrapped the annotation in parentheses if it
expanded; however, Black only exhibits this behavior when the function
parameters is empty (i.e., it doesn't and can't break). In other cases,
it uses the normal parenthesization rules, allowing nodes to bring their
own parentheses.
For example, given:
```python
def xxxxxxxxxxxxxxxxxxxxxxxxxxxx() -> Set[
"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
]:
...
def xxxxxxxxxxxxxxxxxxxxxxxxxxxx(x) -> Set[
"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
]:
...
```
Black will format as:
```python
def xxxxxxxxxxxxxxxxxxxxxxxxxxxx() -> (
Set[
"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
]
):
...
def xxxxxxxxxxxxxxxxxxxxxxxxxxxx(
x,
) -> Set[
"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
]:
...
```
Whereas, prior to this PR, Ruff would format as:
```python
def xxxxxxxxxxxxxxxxxxxxxxxxxxxx() -> (
Set[
"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
]
):
...
def xxxxxxxxxxxxxxxxxxxxxxxxxxxx(
x,
) -> (
Set[
"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
]
):
...
```
Closes https://github.com/astral-sh/ruff/issues/6431.
## Test Plan
Before:
- `zulip`: 0.99702
- `django`: 0.99784
- `warehouse`: 0.99585
- `build`: 0.75623
- `transformers`: 0.99470
- `cpython`: 0.75988
- `typeshed`: 0.74853
After:
- `zulip`: 0.99724
- `django`: 0.99791
- `warehouse`: 0.99586
- `build`: 0.75623
- `transformers`: 0.99474
- `cpython`: 0.75956
- `typeshed`: 0.74857
## Summary
This PR fixes some misformattings around optional parentheses for
expressions.
I first noticed that we were misformatting this:
```python
return (
unicodedata.normalize("NFKC", s1).casefold()
== unicodedata.normalize("NFKC", s2).casefold()
)
```
The above is stable Black formatting, but we were doing:
```python
return unicodedata.normalize("NFKC", s1).casefold() == unicodedata.normalize(
"NFKC", s2
).casefold()
```
Above, the "last" expression is a function call, so our
`can_omit_optional_parentheses` was returning `true`...
However, it turns out that Black treats function calls differently
depending on whether or not they have arguments -- presumedly because
they'll never split empty parentheses, and so they're functionally
non-useful. On further investigation, I believe this applies to all
parenthesized expressions. If Black can't split on the parentheses, it
doesn't leverage them when removing optional parentheses.
## Test Plan
Nice increase in similarity scores.
Before:
- `zulip`: 0.99702
- `django`: 0.99784
- `warehouse`: 0.99585
- `build`: 0.75623
- `transformers`: 0.99470
- `cpython`: 0.75989
- `typeshed`: 0.74853
After:
- `zulip`: 0.99705
- `django`: 0.99795
- `warehouse`: 0.99600
- `build`: 0.75623
- `transformers`: 0.99471
- `cpython`: 0.75989
- `typeshed`: 0.74853
## 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
This PR renames the `MagicCommand` token to `IpyEscapeCommand` token and
`MagicKind` to `IpyEscapeKind` type to better reflect the purpose of the
token and type. Similarly, it renames the AST nodes from `LineMagic` to
`IpyEscapeCommand` prefixed with `Stmt`/`Expr` wherever necessary.
It also makes renames from using `jupyter_magic` to
`ipython_escape_commands` in various function names.
The mode value is still `Mode::Jupyter` because the escape commands are
part of the IPython syntax but the lexing/parsing is done for a Jupyter
notebook.
### Motivation behind the rename:
* IPython codebase defines it as "EscapeCommand" / "Escape Sequences":
* Escape Sequences:
292e3a2345/IPython/core/inputtransformer2.py (L329-L333)
* Escape command:
292e3a2345/IPython/core/inputtransformer2.py (L410-L411)
* The word "magic" is used mainly for the actual magic commands i.e.,
the ones starting with `%`/`%%`
(https://ipython.readthedocs.io/en/stable/interactive/reference.html#magic-command-system).
So, this avoids any confusion between the Magic token (`%`, `%%`) and
the escape command itself.
## Test Plan
* `cargo test` to make sure all renames are done correctly.
* `grep` for `jupyter_escape`/`magic` to make sure all renames are done
correctly.
## Summary
This PR removes the group around function definition parameters, instead
grouping the parameters with the type parameters and return type
annotation.
This increases Zulip's similarity score from 0.99385 to 0.99699, so it's
a meaningful improvement. However, there's at least one stability error
that I'm working on, and I'm really just looking for high-level feedback
at this point, because I'm not happy with the solution.
Closes https://github.com/astral-sh/ruff/issues/6352.
## Test Plan
Before:
- `zulip`: 0.99396
- `django`: 0.99784
- `warehouse`: 0.99578
- `build`: 0.75436
- `transformers`: 0.99407
- `cpython`: 0.75987
- `typeshed`: 0.74432
After:
- `zulip`: 0.99702
- `django`: 0.99784
- `warehouse`: 0.99585
- `build`: 0.75623
- `transformers`: 0.99470
- `cpython`: 0.75988
- `typeshed`: 0.74853
## 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
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.
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
Builds on #6170 to break `global` and `nonlocal` statements, such that
we get:
```python
def f():
global \
analyze_featuremap_layer, \
analyze_featuremapcompression_layer, \
analyze_latencies_post, \
analyze_motions_layer, \
analyze_size_model
```
Instead of:
```python
def f():
global analyze_featuremap_layer, analyze_featuremapcompression_layer, analyze_latencies_post, analyze_motions_layer, analyze_size_model
```
Notably, we avoid applying this formatting if the statement ends in a
comment. Otherwise, the comment would _need_ to be placed after the last
item, like:
```python
def f():
global \
analyze_featuremap_layer, \
analyze_featuremapcompression_layer, \
analyze_latencies_post, \
analyze_motions_layer, \
analyze_size_model # noqa
```
To me, this seems wrong (and would break the `# noqa` comment). Ideally,
the items would be parenthesized, and the comment would be on the inner
parenthesis, like:
```python
def f():
global ( # noqa
analyze_featuremap_layer,
analyze_featuremapcompression_layer,
analyze_latencies_post,
analyze_motions_layer,
analyze_size_model
)
```
But that's not valid syntax.
## Summary
This PR boxes the `TypeParams` and `Arguments` fields on the class
definition node. These fields are optional and often emitted, and given
that class definition is our largest enum variant, we pay the cost of
including them for every statement in the AST. Boxing these types
reduces the statement size by 40 bytes, which seems like a good tradeoff
given how infrequently these are accessed.
## Test Plan
Need to benchmark, but no behavior changes.
## 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 adds a new `Arguments` AST node, which we can use for function
calls and class definitions.
The `Arguments` node spans from the left (open) to right (close)
parentheses inclusive.
In the case of classes, the `Arguments` is an option, to differentiate
between:
```python
# None
class C: ...
# Some, with empty vectors
class C(): ...
```
In this PR, we don't really leverage this change (except that a few
rules get much simpler, since we don't need to lex to find the start and
end ranges of the parentheses, e.g.,
`crates/ruff/src/rules/pyupgrade/rules/lru_cache_without_parameters.rs`,
`crates/ruff/src/rules/pyupgrade/rules/unnecessary_class_parentheses.rs`).
In future PRs, this will be especially helpful for the formatter, since
we can track comments enclosed on the node itself.
## Test Plan
`cargo test`
## Summary
Black allows up to one blank line _before_ a class docstring, and
enforces one blank line _after_ a class docstring. This PR implements
that handling. The cases in
`crates/ruff_python_formatter/resources/test/fixtures/ruff/statement/class_definition.py`
match Black identically.
## Summary
This PR ensures that if a function or class is the first statement in a
nested suite that _isn't_ a function or class body, we insert a leading
newline.
For example, given:
```python
def f():
if True:
def register_type():
pass
```
We _want_ to preserve the newline, whereas today, we remove it.
Note that this only applies when the function or class doesn't have any
leading comments.
Closes https://github.com/astral-sh/ruff/issues/6066.
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## Summary
This PR removes the `type_comment` field which our parser doesn't support.
<!-- What's the purpose of the change? What does it do, and why? -->
## Test Plan
`cargo test`
<!-- How was it tested? -->
## Summary
This PR moves the "insert empty lines" behavior out of
`JoinNodesBuilder` and into the `Suite` formatter. I find it a little
confusing that the logic is split between those two formatters right
now, and since this is _only_ used in that one place, IMO it is a bit
simpler to just inline it and use a single approach to tracking state
(right now, both are stateful).
The only other place this was used was for decorators. As a side effect,
we now remove blank lines in both of these cases, which is a known but
intentional deviation from Black (which preserves the empty line before
the comment in the first case):
```python
@foo
# Hello
@bar
def baz():
pass
@foo
@bar
def baz():
pass
```
## Summary
Adds `global` and `nonlocal` formatting, without the "deviation from
black" outlined in the linked issue, which I'll do separately.
See: https://github.com/astral-sh/ruff/issues/4798.
## Test Plan
Added a fixture in the Ruff-specific directory since the Black fixtures
don't seem to cover this.
## 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.
