[flake8-comprehensions] Parenthesize sorted when needed for `unne…

…cessary-call-around-sorted` (`C413`) (#15825)

If there is any `ParenthesizedWhitespace` (in the sense of LibCST) after
the function name `sorted` and before the arguments, then we must wrap
`sorted` with parentheses after removing the surrounding function.

Closes #15789

crates/ruff_linter/resources/test/fixtures/flake8_comprehensions/C413.py

@@ -17,3 +17,13 @@
 # Regression test for: https://github.com/astral-sh/ruff/issues/10335
 reversed(sorted([1, 2, 3], reverse=False or True))
 reversed(sorted([1, 2, 3], reverse=(False or True)))
+
+# These fixes need to be parenthesized to avoid syntax errors and behavior
+# changes.
+# See https://github.com/astral-sh/ruff/issues/15789
+reversed(sorted
+(""))
+list(sorted
+    (""))
+list(sorted
+("xy"))

crates/ruff_linter/src/rules/flake8_comprehensions/fixes.rs

@@ -416,9 +416,17 @@ pub(crate) fn fix_unnecessary_call_around_sorted(
         }
     };
 
+    let inner_needs_parens = matches!(
+        inner_call.whitespace_after_func,
+        ParenthesizableWhitespace::ParenthesizedWhitespace(_)
+    );
+
     if let Expression::Name(outer_name) = &*outer_call.func {
         if outer_name.value == "list" {
             tree = Expression::Call(Box::new((*inner_call).clone()));
+            if inner_needs_parens {
+                tree = tree.with_parens(LeftParen::default(), RightParen::default());
+            };
         } else {
             // If the `reverse` argument is used...
             let args = if inner_call.args.iter().any(|arg| {
@@ -503,6 +511,9 @@ pub(crate) fn fix_unnecessary_call_around_sorted(
                 whitespace_after_func: inner_call.whitespace_after_func.clone(),
                 whitespace_before_args: inner_call.whitespace_before_args.clone(),
             }));
+            if inner_needs_parens {
+                tree = tree.with_parens(LeftParen::default(), RightParen::default());
+            }
         }
     }
 

crates/ruff_linter/src/rules/flake8_comprehensions/snapshots/ruff_linter__rules__flake8_comprehensions__tests__C413_C413.py.snap

@@ -244,13 +244,17 @@ C413.py:18:1: C413 [*] Unnecessary `reversed()` call around `sorted()`
 18    |-reversed(sorted([1, 2, 3], reverse=False or True))
    18 |+sorted([1, 2, 3], reverse=not (False or True))
 19 19 | reversed(sorted([1, 2, 3], reverse=(False or True)))
+20 20 | 
+21 21 | # These fixes need to be parenthesized to avoid syntax errors and behavior
 
 C413.py:19:1: C413 [*] Unnecessary `reversed()` call around `sorted()`
    |
 17 | # Regression test for: https://github.com/astral-sh/ruff/issues/10335
 18 | reversed(sorted([1, 2, 3], reverse=False or True))
 19 | reversed(sorted([1, 2, 3], reverse=(False or True)))
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ C413
+20 |
+21 | # These fixes need to be parenthesized to avoid syntax errors and behavior
    |
    = help: Remove unnecessary `reversed()` call
 
@@ -260,3 +264,70 @@ C413.py:19:1: C413 [*] Unnecessary `reversed()` call around `sorted()`
 18 18 | reversed(sorted([1, 2, 3], reverse=False or True))
 19    |-reversed(sorted([1, 2, 3], reverse=(False or True)))
    19 |+sorted([1, 2, 3], reverse=not (False or True))
+20 20 | 
+21 21 | # These fixes need to be parenthesized to avoid syntax errors and behavior
+22 22 | # changes.
+
+C413.py:24:1: C413 [*] Unnecessary `reversed()` call around `sorted()`
+   |
+22 |   # changes.
+23 |   # See https://github.com/astral-sh/ruff/issues/15789
+24 | / reversed(sorted
+25 | | (""))
+   | |_____^ C413
+26 |   list(sorted
+27 |       (""))
+   |
+   = help: Remove unnecessary `reversed()` call
+
+ℹ Unsafe fix
+21 21 | # These fixes need to be parenthesized to avoid syntax errors and behavior
+22 22 | # changes.
+23 23 | # See https://github.com/astral-sh/ruff/issues/15789
+24    |-reversed(sorted
+25    |-(""))
+   24 |+(sorted
+   25 |+("", reverse=True))
+26 26 | list(sorted
+27 27 |     (""))
+28 28 | list(sorted
+
+C413.py:26:1: C413 [*] Unnecessary `list()` call around `sorted()`
+   |
+24 |   reversed(sorted
+25 |   (""))
+26 | / list(sorted
+27 | |     (""))
+   | |_________^ C413
+28 |   list(sorted
+29 |   ("xy"))
+   |
+   = help: Remove unnecessary `list()` call
+
+ℹ Safe fix
+23 23 | # See https://github.com/astral-sh/ruff/issues/15789
+24 24 | reversed(sorted
+25 25 | (""))
+26    |-list(sorted
+   26 |+(sorted
+27 27 |     (""))
+28 28 | list(sorted
+29 29 | ("xy"))
+
+C413.py:28:1: C413 [*] Unnecessary `list()` call around `sorted()`
+   |
+26 |   list(sorted
+27 |       (""))
+28 | / list(sorted
+29 | | ("xy"))
+   | |_______^ C413
+   |
+   = help: Remove unnecessary `list()` call
+
+ℹ Safe fix
+25 25 | (""))
+26 26 | list(sorted
+27 27 |     (""))
+28    |-list(sorted
+   28 |+(sorted
+29 29 | ("xy"))