Format ExprIfExp (ternary operator) (#5597)

## Summary

Format `ExprIfExp`, also known as the ternary operator or inline `if`.
It can look like
```python
a1 = 1 if True else 2
```
but also
```python
b1 = (
    # We return "a" ...
    "a" # that's our True value
    # ... if this condition matches ...
    if True # that's our test
    # ... otherwise we return "b§
    else "b" # that's our False value
)
```

This also fixes a visitor order bug.

The jaccard index on django goes from 0.911 to 0.915.

## Test Plan

I added fixtures without and with comments in strange places.

crates/ruff_python_ast/src/visitor/preorder.rs

@@ -476,8 +476,9 @@ where
             orelse,
             range: _range,
         }) => {
-            visitor.visit_expr(test);
+            // `body if test else orelse`
             visitor.visit_expr(body);
+            visitor.visit_expr(test);
             visitor.visit_expr(orelse);
         }
 

crates/ruff_python_formatter/resources/test/fixtures/ruff/expression/if.py

@@ -0,0 +1,33 @@
+a1 = 1 if True else 2
+
+a2 = "this is a very long text that will make the group break to check that parentheses are added" if True else 2
+
+# These comment should be kept in place
+b1 = (
+    # We return "a" ...
+    "a" # that's our True value
+    # ... if this condition matches ...
+    if True # that's our test
+    # ... otherwise we return "b"
+    else "b" # that's our False value
+)
+
+# These only need to be stable, bonus is we also keep the order
+c1 = (
+    "a" # 1
+    if # 2
+    True # 3
+    else # 4
+    "b" # 5
+)
+c2 = (
+    "a" # 1
+    # 2
+    if # 3
+    # 4
+    True # 5
+    # 6
+    else # 7
+    # 8
+    "b" # 9
+)

crates/ruff_python_formatter/src/comments/placement.rs

@@ -1,8 +1,8 @@
 use std::cmp::Ordering;
 
-use ruff_text_size::TextRange;
+use ruff_text_size::{TextLen, TextRange};
 use rustpython_parser::ast;
-use rustpython_parser::ast::{Expr, ExprSlice, Ranged};
+use rustpython_parser::ast::{Expr, ExprIfExp, ExprSlice, Ranged};
 
 use ruff_python_ast::node::{AnyNodeRef, AstNode};
 use ruff_python_ast::source_code::Locator;
@@ -14,7 +14,9 @@ use crate::expression::expr_slice::{assign_comment_in_slice, ExprSliceCommentSec
 use crate::other::arguments::{
     assign_argument_separator_comment_placement, find_argument_separators,
 };
-use crate::trivia::{first_non_trivia_token_rev, SimpleTokenizer, Token, TokenKind};
+use crate::trivia::{
+    first_non_trivia_token, first_non_trivia_token_rev, SimpleTokenizer, Token, TokenKind,
+};
 
 /// Implements the custom comment placement logic.
 pub(super) fn place_comment<'a>(
@@ -37,6 +39,7 @@ pub(super) fn place_comment<'a>(
         handle_dict_unpacking_comment,
         handle_slice_comments,
         handle_attribute_comment,
+        handle_expr_if_comment,
     ];
     for handler in HANDLERS {
         comment = match handler(comment, locator) {
@@ -1154,6 +1157,82 @@ fn handle_attribute_comment<'a>(
     }
 }
 
+/// Assign comments between `if` and `test` and `else` and `orelse` as leading to the respective
+/// node.
+///
+/// ```python
+/// x = (
+///     "a"
+///     if # leading comment of `True`
+///     True
+///     else # leading comment of `"b"`
+///     "b"
+/// )
+/// ```
+///
+/// This placement ensures comments remain in their previous order. This an edge case that only
+/// happens if the comments are in a weird position but it also doesn't hurt handling it.
+fn handle_expr_if_comment<'a>(
+    comment: DecoratedComment<'a>,
+    locator: &Locator,
+) -> CommentPlacement<'a> {
+    let Some(expr_if) = comment.enclosing_node().expr_if_exp() else {
+        return CommentPlacement::Default(comment);
+    };
+    let ExprIfExp {
+        range: _,
+        test,
+        body,
+        orelse,
+    } = expr_if;
+
+    if comment.line_position().is_own_line() {
+        return CommentPlacement::Default(comment);
+    }
+
+    // Find the if and the else
+    let if_token =
+        find_only_token_str_in_range(TextRange::new(body.end(), test.start()), locator, "if");
+    let else_token =
+        find_only_token_str_in_range(TextRange::new(test.end(), orelse.start()), locator, "else");
+
+    // Between `if` and `test`
+    if if_token.range.start() < comment.slice().start() && comment.slice().start() < test.start() {
+        return CommentPlacement::leading(test.as_ref().into(), comment);
+    }
+
+    // Between `else` and `orelse`
+    if else_token.range.start() < comment.slice().start()
+        && comment.slice().start() < orelse.start()
+    {
+        return CommentPlacement::leading(orelse.as_ref().into(), comment);
+    }
+
+    CommentPlacement::Default(comment)
+}
+
+/// Looks for a multi char token in the range that contains no other tokens. `SimpleTokenizer` only
+/// works with single char tokens so we check that we have the right token by string comparison.
+fn find_only_token_str_in_range(range: TextRange, locator: &Locator, token_str: &str) -> Token {
+    let token =
+        first_non_trivia_token(range.start(), locator.contents()).expect("Expected a token");
+    debug_assert!(
+        locator.after(token.start()).starts_with(token_str),
+        "expected a `{token_str}` token",
+    );
+    debug_assert!(
+        SimpleTokenizer::new(
+            locator.contents(),
+            TextRange::new(token.start() + token_str.text_len(), range.end())
+        )
+        .skip_trivia()
+        .next()
+        .is_none(),
+        "Didn't expect any other token"
+    );
+    token
+}
+
 /// Returns `true` if `right` is `Some` and `left` and `right` are referentially equal.
 fn are_same_optional<'a, T>(left: AnyNodeRef, right: Option<T>) -> bool
 where

crates/ruff_python_formatter/src/expression/expr_if_exp.rs

@@ -1,21 +1,42 @@
-use crate::comments::Comments;
+use crate::comments::{leading_comments, Comments};
 use crate::expression::parentheses::{
     default_expression_needs_parentheses, NeedsParentheses, Parentheses, Parenthesize,
 };
-use crate::{not_yet_implemented_custom_text, FormatNodeRule, PyFormatter};
+use crate::{AsFormat, FormatNodeRule, PyFormatter};
-use ruff_formatter::{write, Buffer, FormatResult};
+use ruff_formatter::prelude::{group, soft_line_break_or_space, space, text};
+use ruff_formatter::{format_args, write, Buffer, FormatResult};
 use rustpython_parser::ast::ExprIfExp;
 
 #[derive(Default)]
 pub struct FormatExprIfExp;
 
 impl FormatNodeRule<ExprIfExp> for FormatExprIfExp {
-    fn fmt_fields(&self, _item: &ExprIfExp, f: &mut PyFormatter) -> FormatResult<()> {
+    fn fmt_fields(&self, item: &ExprIfExp, f: &mut PyFormatter) -> FormatResult<()> {
+        let ExprIfExp {
+            range: _,
+            test,
+            body,
+            orelse,
+        } = item;
+        let comments = f.context().comments().clone();
+        // We place `if test` and `else orelse` on a single line, so the `test` and `orelse` leading
+        // comments go on the line before the `if` or `else` instead of directly ahead `test` or
+        // `orelse`
         write!(
             f,
-            [not_yet_implemented_custom_text(
+            [group(&format_args![
-                "NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false"
+                body.format(),
-            )]
+                soft_line_break_or_space(),
+                leading_comments(comments.leading_comments(test.as_ref())),
+                text("if"),
+                space(),
+                test.format(),
+                soft_line_break_or_space(),
+                leading_comments(comments.leading_comments(orelse.as_ref())),
+                text("else"),
+                space(),
+                orelse.format()
+            ])]
         )
     }
 }

crates/ruff_python_formatter/tests/snapshots/black_compatibility@conditional_expression.py.snap

@@ -79,7 +79,7 @@ def something():
 ```diff
 --- Black
 +++ Ruff
-@@ -1,90 +1,50 @@
+@@ -1,20 +1,16 @@
  long_kwargs_single_line = my_function(
      foo="test, this is a sample value",
 -    bar=(
@@ -87,7 +87,9 @@ def something():
 -        if some_boolean_variable
 -        else some_fallback_value_foo_bar_baz
 -    ),
-+    bar=NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false,
++    bar=some_long_value_name_foo_bar_baz
++    if some_boolean_variable
++    else some_fallback_value_foo_bar_baz,
      baz="hello, this is a another value",
  )
  
@@ -98,33 +100,13 @@ def something():
 -        if some_boolean_variable
 -        else some_fallback_value_foo_bar_baz
 -    ),
-+    bar=NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false,
++    bar=some_long_value_name_foo_bar_baz
++    if some_boolean_variable
++    else some_fallback_value_foo_bar_baz,
      baz="hello, this is a another value",
  )
  
- imploding_kwargs = my_function(
+@@ -40,11 +36,9 @@
-     foo="test, this is a sample value",
--    bar=a if foo else b,
-+    bar=NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false,
-     baz="hello, this is a another value",
- )
- 
--imploding_line = 1 if 1 + 1 == 2 else 0
-+imploding_line = NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false
- 
--exploding_line = (
--    "hello this is a slightly long string"
--    if some_long_value_name_foo_bar_baz
--    else "this one is a little shorter"
--)
-+exploding_line = NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false
- 
- positional_argument_test(
--    some_long_value_name_foo_bar_baz
--    if some_boolean_variable
--    else some_fallback_value_foo_bar_baz
-+    NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false
- )
  
  
  def weird_default_argument(
@@ -133,21 +115,15 @@ def something():
 -        if SOME_CONSTANT
 -        else some_fallback_value_foo_bar_baz
 -    ),
-+    x=NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false
++    x=some_long_value_name_foo_bar_baz
++    if SOME_CONSTANT
++    else some_fallback_value_foo_bar_baz,
  ):
      pass
  
- 
+@@ -59,26 +53,14 @@
--nested = (
+     else "this one is a little shorter"
--    "hello this is a slightly long string"
+ )
--    if (
--        some_long_value_name_foo_bar_baz
--        if nesting_test_expressions
--        else some_fallback_value_foo_bar_baz
--    )
--    else "this one is a little shorter"
--)
-+nested = NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false
  
 -generator_expression = (
 -    (
@@ -174,13 +150,6 @@ def something():
      )
  
  
- def something():
-     clone._iterable_class = (
--        NamedValuesListIterable
--        if named
--        else FlatValuesListIterable if flat else ValuesListIterable
-+        NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false
-     )
 ```
 
 ## Ruff Output
@@ -188,38 +157,58 @@ def something():
 ```py
 long_kwargs_single_line = my_function(
     foo="test, this is a sample value",
-    bar=NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false,
+    bar=some_long_value_name_foo_bar_baz
+    if some_boolean_variable
+    else some_fallback_value_foo_bar_baz,
     baz="hello, this is a another value",
 )
 
 multiline_kwargs_indented = my_function(
     foo="test, this is a sample value",
-    bar=NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false,
+    bar=some_long_value_name_foo_bar_baz
+    if some_boolean_variable
+    else some_fallback_value_foo_bar_baz,
     baz="hello, this is a another value",
 )
 
 imploding_kwargs = my_function(
     foo="test, this is a sample value",
-    bar=NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false,
+    bar=a if foo else b,
     baz="hello, this is a another value",
 )
 
-imploding_line = NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false
+imploding_line = 1 if 1 + 1 == 2 else 0
 
-exploding_line = NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false
+exploding_line = (
+    "hello this is a slightly long string"
+    if some_long_value_name_foo_bar_baz
+    else "this one is a little shorter"
+)
 
 positional_argument_test(
-    NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false
+    some_long_value_name_foo_bar_baz
+    if some_boolean_variable
+    else some_fallback_value_foo_bar_baz
 )
 
 
 def weird_default_argument(
-    x=NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false
+    x=some_long_value_name_foo_bar_baz
+    if SOME_CONSTANT
+    else some_fallback_value_foo_bar_baz,
 ):
     pass
 
 
-nested = NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false
+nested = (
+    "hello this is a slightly long string"
+    if (
+        some_long_value_name_foo_bar_baz
+        if nesting_test_expressions
+        else some_fallback_value_foo_bar_baz
+    )
+    else "this one is a little shorter"
+)
 
 generator_expression = (NOT_YET_IMPLEMENTED_generator_key for NOT_YET_IMPLEMENTED_generator_key in [])
 
@@ -234,7 +223,9 @@ def limit_offset_sql(self, low_mark, high_mark):
 
 def something():
     clone._iterable_class = (
-        NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false
+        NamedValuesListIterable
+        if named
+        else FlatValuesListIterable if flat else ValuesListIterable
     )
 ```
 

crates/ruff_python_formatter/tests/snapshots/black_compatibility@simple_cases__expression.py.snap

@@ -274,7 +274,7 @@ last_call()
  Name
  None
  True
-@@ -31,33 +31,39 @@
+@@ -31,18 +31,15 @@
  -1
  ~int and not v1 ^ 123 + v2 | True
  (~int) and (not ((v1 ^ (123 + v2)) | True))
@@ -291,16 +291,6 @@ last_call()
 -    "port1": port1_resource,
 -    "port2": port2_resource,
 -}[port_id]
--1 if True else 2
--str or None if True else str or bytes or None
--(str or None) if True else (str or bytes or None)
--str or None if (1 if True else 2) else str or bytes or None
--(str or None) if (1 if True else 2) else (str or bytes or None)
--(
--    (super_long_variable_name or None)
--    if (1 if super_long_test_name else 2)
--    else (str or bytes or None)
--)
 +lambda x: True
 +lambda x: True
 +lambda x: True
@@ -308,25 +298,14 @@ last_call()
 +lambda x: True
 +manylambdas = lambda x: True
 +foo = lambda x: True
-+NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false
+ 1 if True else 2
-+NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false
+ str or None if True else str or bytes or None
-+NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false
+ (str or None) if True else (str or bytes or None)
-+NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false
+@@ -57,7 +54,13 @@
-+NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false
-+(NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false)
- {"2.7": dead, "3.7": (long_live or die_hard)}
  {"2.7": dead, "3.7": (long_live or die_hard), **{"3.6": verygood}}
  {**a, **b, **c}
--{"2.7", "3.6", "3.7", "3.8", "3.9", ("4.0" if gilectomy else "3.10")}
+ {"2.7", "3.6", "3.7", "3.8", "3.9", ("4.0" if gilectomy else "3.10")}
 -({"a": "b"}, (True or False), (+value), "string", b"bytes") or None
-+{
-+    "2.7",
-+    "3.6",
-+    "3.7",
-+    "3.8",
-+    "3.9",
-+    (NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false),
-+}
 +(
 +    {"a": "b"},
 +    (True or False),
@@ -337,7 +316,7 @@ last_call()
  ()
  (1,)
  (1, 2)
-@@ -69,40 +75,37 @@
+@@ -69,40 +72,37 @@
      2,
      3,
  ]
@@ -396,7 +375,7 @@ last_call()
  Python3 > Python2 > COBOL
  Life is Life
  call()
-@@ -115,10 +118,10 @@
+@@ -115,10 +115,10 @@
      arg,
      another,
      kwarg="hey",
@@ -410,7 +389,7 @@ last_call()
  call(**self.screen_kwargs)
  call(b, **self.screen_kwargs)
  lukasz.langa.pl
-@@ -131,34 +134,28 @@
+@@ -131,34 +131,28 @@
  tuple[str, ...]
  tuple[str, int, float, dict[str, int]]
  tuple[
@@ -458,26 +437,16 @@ last_call()
  numpy[0, :]
  numpy[:, i]
  numpy[0, :2]
-@@ -172,20 +169,27 @@
+@@ -172,7 +166,7 @@
  numpy[1 : c + 1, c]
  numpy[-(c + 1) :, d]
  numpy[:, l[-2]]
 -numpy[:, ::-1]
 +numpy[:,  :: -1]
  numpy[np.newaxis, :]
--(str or None) if (sys.version_info[0] > (3,)) else (str or bytes or None)
+ (str or None) if (sys.version_info[0] > (3,)) else (str or bytes or None)
-+NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false
  {"2.7": dead, "3.7": long_live or die_hard}
--{"2.7", "3.6", "3.7", "3.8", "3.9", "4.0" if gilectomy else "3.10"}
+@@ -181,11 +175,11 @@
-+{
-+    "2.7",
-+    "3.6",
-+    "3.7",
-+    "3.8",
-+    "3.9",
-+    NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false,
-+}
- [1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or A, 11 or B, 12 or C]
  (SomeName)
  SomeName
  (Good, Bad, Ugly)
@@ -494,7 +463,7 @@ last_call()
  {
      "id": "1",
      "type": "type",
-@@ -200,32 +204,22 @@
+@@ -200,32 +194,22 @@
  c = 1
  d = (1,) + a + (2,)
  e = (1,).count(1)
@@ -537,7 +506,7 @@ last_call()
  Ø = set()
  authors.łukasz.say_thanks()
  mapping = {
-@@ -237,29 +231,29 @@
+@@ -237,29 +221,33 @@
  
  
  def gen():
@@ -564,7 +533,11 @@ last_call()
 -), "Short message"
 -assert parens is TooMany
 +print(*NOT_YET_IMPLEMENTED_ExprStarred)
-+print(**NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false)
++print(
++    **{1: 3}
++    if False
++    else {NOT_IMPLEMENTED_dict_key: NOT_IMPLEMENTED_dict_value for key, value in NOT_IMPLEMENTED_dict}
++)
 +print(*NOT_YET_IMPLEMENTED_ExprStarred)
 +NOT_YET_IMPLEMENTED_StmtAssert
 +NOT_YET_IMPLEMENTED_StmtAssert
@@ -580,7 +553,7 @@ last_call()
      ...
  for i in call():
      ...
-@@ -328,13 +322,18 @@
+@@ -328,13 +316,18 @@
  ):
      return True
  if (
@@ -602,7 +575,7 @@ last_call()
      ^ aaaaaaaa.i << aaaaaaaa.k >> aaaaaaaa.l**aaaaaaaa.m // aaaaaaaa.n
  ):
      return True
-@@ -342,7 +341,8 @@
+@@ -342,7 +335,8 @@
      ~aaaaaaaaaaaaaaaa.a
      + aaaaaaaaaaaaaaaa.b
      - aaaaaaaaaaaaaaaa.c * aaaaaaaaaaaaaaaa.d @ aaaaaaaaaaaaaaaa.e
@@ -659,23 +632,20 @@ lambda x: True
 lambda x: True
 manylambdas = lambda x: True
 foo = lambda x: True
-NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false
+1 if True else 2
-NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false
+str or None if True else str or bytes or None
-NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false
+(str or None) if True else (str or bytes or None)
-NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false
+str or None if (1 if True else 2) else str or bytes or None
-NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false
+(str or None) if (1 if True else 2) else (str or bytes or None)
-(NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false)
+(
+    (super_long_variable_name or None)
+    if (1 if super_long_test_name else 2)
+    else (str or bytes or None)
+)
 {"2.7": dead, "3.7": (long_live or die_hard)}
 {"2.7": dead, "3.7": (long_live or die_hard), **{"3.6": verygood}}
 {**a, **b, **c}
-{
+{"2.7", "3.6", "3.7", "3.8", "3.9", ("4.0" if gilectomy else "3.10")}
-    "2.7",
-    "3.6",
-    "3.7",
-    "3.8",
-    "3.9",
-    (NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false),
-}
 (
     {"a": "b"},
     (True or False),
@@ -790,16 +760,9 @@ numpy[-(c + 1) :, d]
 numpy[:, l[-2]]
 numpy[:,  :: -1]
 numpy[np.newaxis, :]
-NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false
+(str or None) if (sys.version_info[0] > (3,)) else (str or bytes or None)
 {"2.7": dead, "3.7": long_live or die_hard}
-{
+{"2.7", "3.6", "3.7", "3.8", "3.9", "4.0" if gilectomy else "3.10"}
-    "2.7",
-    "3.6",
-    "3.7",
-    "3.8",
-    "3.9",
-    NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false,
-}
 [1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or A, 11 or B, 12 or C]
 (SomeName)
 SomeName
@@ -861,7 +824,11 @@ async def f():
 
 
 print(*NOT_YET_IMPLEMENTED_ExprStarred)
-print(**NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false)
+print(
+    **{1: 3}
+    if False
+    else {NOT_IMPLEMENTED_dict_key: NOT_IMPLEMENTED_dict_value for key, value in NOT_IMPLEMENTED_dict}
+)
 print(*NOT_YET_IMPLEMENTED_ExprStarred)
 NOT_YET_IMPLEMENTED_StmtAssert
 NOT_YET_IMPLEMENTED_StmtAssert

crates/ruff_python_formatter/tests/snapshots/black_compatibility@simple_cases__fmtonoff.py.snap

@@ -211,7 +211,7 @@ d={'a':1,
  # Comment 1
  
  # Comment 2
-@@ -17,30 +16,54 @@
+@@ -17,30 +16,44 @@
  
  # fmt: off
  def func_no_args():
@@ -268,35 +268,15 @@ d={'a':1,
 +
 +
  # fmt: on
--def spaces(a=1, b=(), c=[], d={}, e=True, f=-1, g=1 if False else 2, h="", i=r""):
+ def spaces(a=1, b=(), c=[], d={}, e=True, f=-1, g=1 if False else 2, h="", i=r""):
 -    offset = attr.ib(default=attr.Factory(lambda: _r.uniform(1, 2)))
 -    assert task._cancel_stack[: len(old_stack)] == old_stack
-+def spaces(
-+    a=1,
-+    b=(),
-+    c=[],
-+    d={},
-+    e=True,
-+    f=-1,
-+    g=NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false,
-+    h="",
-+    i=r"",
-+):
 +    offset = attr.ib(default=attr.Factory(lambda x: True))
 +    NOT_YET_IMPLEMENTED_StmtAssert
  
  
  def spaces_types(
-@@ -50,7 +73,7 @@
+@@ -63,55 +76,54 @@
-     d: dict = {},
-     e: bool = True,
-     f: int = -1,
--    g: int = 1 if False else 2,
-+    g: int = NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false,
-     h: str = "",
-     i: str = r"",
- ):
-@@ -63,55 +86,54 @@
  
  something = {
      # fmt: off
@@ -371,7 +351,7 @@ d={'a':1,
      # fmt: on
  
  
-@@ -132,10 +154,10 @@
+@@ -132,10 +144,10 @@
      """Another known limitation."""
      # fmt: on
      # fmt: off
@@ -386,7 +366,7 @@ d={'a':1,
      # fmt: on
      # fmt: off
      # ...but comments still get reformatted even though they should not be
-@@ -153,9 +175,7 @@
+@@ -153,9 +165,7 @@
              )
          )
          # fmt: off
@@ -397,7 +377,7 @@ d={'a':1,
          # fmt: on
      _type_comment_re = re.compile(
          r"""
-@@ -178,7 +198,7 @@
+@@ -178,7 +188,7 @@
          $
          """,
          # fmt: off
@@ -406,7 +386,7 @@ d={'a':1,
          # fmt: on
      )
  
-@@ -216,8 +236,7 @@
+@@ -216,8 +226,7 @@
      xxxxxxxxxx_xxxxxxxxxxx_xxxxxxx_xxxxxxxxx=5,
  )
  # fmt: off
@@ -476,17 +456,7 @@ def function_signature_stress_test(
 
 
 # fmt: on
-def spaces(
+def spaces(a=1, b=(), c=[], d={}, e=True, f=-1, g=1 if False else 2, h="", i=r""):
-    a=1,
-    b=(),
-    c=[],
-    d={},
-    e=True,
-    f=-1,
-    g=NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false,
-    h="",
-    i=r"",
-):
     offset = attr.ib(default=attr.Factory(lambda x: True))
     NOT_YET_IMPLEMENTED_StmtAssert
 
@@ -498,7 +468,7 @@ def spaces_types(
     d: dict = {},
     e: bool = True,
     f: int = -1,
-    g: int = NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false,
+    g: int = 1 if False else 2,
     h: str = "",
     i: str = r"",
 ):

crates/ruff_python_formatter/tests/snapshots/black_compatibility@simple_cases__function.py.snap

@@ -126,7 +126,7 @@ def __await__(): return (yield)
      if False:
          ...
      for i in range(10):
-@@ -41,12 +40,22 @@
+@@ -41,12 +40,12 @@
      debug: bool = False,
      **kwargs,
  ) -> str:
@@ -134,35 +134,15 @@ def __await__(): return (yield)
 +    return text[number : -1]
  
  
--def spaces(a=1, b=(), c=[], d={}, e=True, f=-1, g=1 if False else 2, h="", i=r""):
+ def spaces(a=1, b=(), c=[], d={}, e=True, f=-1, g=1 if False else 2, h="", i=r""):
 -    offset = attr.ib(default=attr.Factory(lambda: _r.uniform(10000, 200000)))
 -    assert task._cancel_stack[: len(old_stack)] == old_stack
-+def spaces(
-+    a=1,
-+    b=(),
-+    c=[],
-+    d={},
-+    e=True,
-+    f=-1,
-+    g=NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false,
-+    h="",
-+    i=r"",
-+):
 +    offset = attr.ib(default=attr.Factory(lambda x: True))
 +    NOT_YET_IMPLEMENTED_StmtAssert
  
  
  def spaces_types(
-@@ -56,7 +65,7 @@
+@@ -64,19 +63,17 @@
-     d: dict = {},
-     e: bool = True,
-     f: int = -1,
--    g: int = 1 if False else 2,
-+    g: int = NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false,
-     h: str = "",
-     i: str = r"",
- ):
-@@ -64,19 +73,17 @@
  
  
  def spaces2(result=_core.Value(None)):
@@ -190,7 +170,7 @@ def __await__(): return (yield)
  
  
  def long_lines():
-@@ -135,14 +142,8 @@
+@@ -135,14 +132,8 @@
      a,
      **kwargs,
  ) -> A:
@@ -257,17 +237,7 @@ def function_signature_stress_test(
     return text[number : -1]
 
 
-def spaces(
+def spaces(a=1, b=(), c=[], d={}, e=True, f=-1, g=1 if False else 2, h="", i=r""):
-    a=1,
-    b=(),
-    c=[],
-    d={},
-    e=True,
-    f=-1,
-    g=NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false,
-    h="",
-    i=r"",
-):
     offset = attr.ib(default=attr.Factory(lambda x: True))
     NOT_YET_IMPLEMENTED_StmtAssert
 
@@ -279,7 +249,7 @@ def spaces_types(
     d: dict = {},
     e: bool = True,
     f: int = -1,
-    g: int = NOT_IMPLEMENTED_true if NOT_IMPLEMENTED_cond else NOT_IMPLEMENTED_false,
+    g: int = 1 if False else 2,
     h: str = "",
     i: str = r"",
 ):

crates/ruff_python_formatter/tests/snapshots/format@expression__if.py.snap

@@ -0,0 +1,84 @@
+---
+source: crates/ruff_python_formatter/tests/fixtures.rs
+input_file: crates/ruff_python_formatter/resources/test/fixtures/ruff/expression/if.py
+---
+## Input
+```py
+a1 = 1 if True else 2
+
+a2 = "this is a very long text that will make the group break to check that parentheses are added" if True else 2
+
+# These comment should be kept in place
+b1 = (
+    # We return "a" ...
+    "a" # that's our True value
+    # ... if this condition matches ...
+    if True # that's our test
+    # ... otherwise we return "b"
+    else "b" # that's our False value
+)
+
+# These only need to be stable, bonus is we also keep the order
+c1 = (
+    "a" # 1
+    if # 2
+    True # 3
+    else # 4
+    "b" # 5
+)
+c2 = (
+    "a" # 1
+    # 2
+    if # 3
+    # 4
+    True # 5
+    # 6
+    else # 7
+    # 8
+    "b" # 9
+)
+```
+
+## Output
+```py
+a1 = 1 if True else 2
+
+a2 = (
+    "this is a very long text that will make the group break to check that parentheses are added"
+    if True
+    else 2
+)
+
+# These comment should be kept in place
+b1 = (
+    # We return "a" ...
+    "a"  # that's our True value
+    # ... if this condition matches ...
+    if True  # that's our test
+    # ... otherwise we return "b"
+    else "b"  # that's our False value
+)
+
+# These only need to be stable, bonus is we also keep the order
+c1 = (
+    "a"  # 1
+    # 2
+    if True  # 3
+    # 4
+    else "b"  # 5
+)
+c2 = (
+    "a"  # 1
+    # 2
+    # 3
+    # 4
+    if True  # 5
+    # 6
+    # 7
+    # 8
+    else "b"  # 9
+)
+```
+
+
+