Keep lambda parameters on a single line

Summary
--

This PR changes our formatting of `lambda` expressions to keep the parameters on
a single line, at least if there are no comments. This fixes #8179.

Black formatting and this PR's formatting:

```py
def a():
    return b(
        c,
        d,
        e,
        f=lambda self, *args, **kwargs: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa(
            *args, **kwargs
        ),
    )
```

Stable Ruff formatting

```py
def a():
    return b(
        c,
        d,
        e,
        f=lambda self,
        *args,
        **kwargs: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa(*args, **kwargs),
    )
```

I split this off from #21385 because it seemed like the simpler change and
helpful to isolate from the body parenthesization ecosystem and performance
changes. However, as Micha pointed out, we need the formatting from #21385 to
land first, so this branch is currently stacked on that one.

Test Plan
--

New formatting on tests from #8465 and #21385

Author: ntBre

crates/ruff_python_formatter/src/expression/expr_lambda.rs

@@ -1,3 +1,4 @@
+use ruff_formatter::RemoveSoftLinesBuffer;
 use ruff_formatter::write;
 use ruff_python_ast::AnyNodeRef;
 use ruff_python_ast::ExprLambda;
@@ -10,6 +11,7 @@ use crate::expression::parentheses::{
 };
 use crate::other::parameters::ParametersParentheses;
 use crate::prelude::*;
+use crate::preview::is_force_single_line_lambda_parameters_enabled;
 use crate::preview::is_parenthesize_lambda_bodies_enabled;
 
 #[derive(Default)]
@@ -41,12 +43,25 @@ impl FormatNodeRule<ExprLambda> for FormatExprLambda {
                 write!(f, [dangling_comments(dangling_before_parameters)])?;
             }
 
-            write!(
-                f,
-                [parameters
-                    .format()
-                    .with_options(ParametersParentheses::Never)]
-            )?;
+            // Try to keep the parameters on a single line, unless there are intervening comments.
+            if is_force_single_line_lambda_parameters_enabled(f.context())
+                && !comments.contains_comments(parameters.as_ref().into())
+            {
+                let mut buffer = RemoveSoftLinesBuffer::new(f);
+                write!(
+                    buffer,
+                    [parameters
+                        .format()
+                        .with_options(ParametersParentheses::Never)]
+                )?;
+            } else {
+                write!(
+                    f,
+                    [parameters
+                        .format()
+                        .with_options(ParametersParentheses::Never)]
+                )?;
+            }
 
             write!(f, [token(":")])?;
 

crates/ruff_python_formatter/src/preview.rs

@@ -59,3 +59,12 @@ pub(crate) const fn is_avoid_parens_for_long_as_captures_enabled(
 pub(crate) const fn is_parenthesize_lambda_bodies_enabled(context: &PyFormatContext) -> bool {
     context.is_preview()
 }
+
+/// Returns `true` if the
+/// [`force_single_line_lambda_parameters`](https://github.com/astral-sh/ruff/pull/21385) preview
+/// style is enabled.
+pub(crate) const fn is_force_single_line_lambda_parameters_enabled(
+    context: &PyFormatContext,
+) -> bool {
+    context.is_preview()
+}

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

@@ -757,7 +757,52 @@ msg = (
  )  # Trailing
  
  
-@@ -320,9 +324,9 @@
+@@ -280,9 +284,9 @@
+ ]  # Trailing
+ # Trailing
+ 
+-lambda self, araa, kkkwargs=aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa(
+-    *args, **kwargs
+-), e=1, f=2, g=2: d
++lambda self, araa, kkkwargs=aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa(*args, **kwargs), e=1, f=2, g=2: (
++    d
++)
+ 
+ 
+ # Regression tests for https://github.com/astral-sh/ruff/issues/8179
+@@ -291,9 +295,9 @@
+         c,
+         d,
+         e,
+-        f=lambda self,
+-        *args,
+-        **kwargs: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa(*args, **kwargs),
++        f=lambda self, *args, **kwargs: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa(
++            *args, **kwargs
++        ),
+     )
+ 
+ 
+@@ -302,15 +306,9 @@
+         c,
+         d,
+         e,
+-        f=lambda self,
+-        araa,
+-        kkkwargs,
+-        aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa,
+-        args,
+-        kwargs,
+-        e=1,
+-        f=2,
+-        g=2: d,
++        f=lambda self, araa, kkkwargs, aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa, args, kwargs, e=1, f=2, g=2: (
++            d
++        ),
+         g=10,
+     )
+ 
+@@ -320,9 +318,9 @@
          c,
          d,
          e,
@@ -770,7 +815,7 @@ msg = (
      )
  
  
-@@ -337,6 +341,6 @@
+@@ -337,6 +335,6 @@
  
  
  # temporary copy of a test from preview_long_strings.py