[`ruff`] Parenthesize generator expressions in f-strings (`RUF010`) (#19434)

## Summary

Fixes #19433

---------

Co-authored-by: Brent Westbrook <36778786+ntBre@users.noreply.github.com>

crates/ruff_linter/resources/test/fixtures/ruff/RUF010.py

@@ -52,3 +52,7 @@ f"{repr(lambda: 1)}"
 f"{repr(x := 2)}"
 
 f"{str(object=3)}"
+
+f"{str(x for x in [])}"
+
+f"{str((x for x in []))}"

crates/ruff_linter/src/rules/ruff/rules/explicit_f_string_type_conversion.rs

@@ -149,8 +149,7 @@ fn convert_call_to_conversion_flag(
             formatted_string_expression.whitespace_before_expression = space();
         }
 
-        formatted_string_expression.expression = if needs_paren(OperatorPrecedence::from_expr(arg))
-        {
+        formatted_string_expression.expression = if needs_paren_expr(arg) {
             call.args[0]
                 .value
                 .clone()
@@ -178,6 +177,16 @@ fn needs_paren(precedence: OperatorPrecedence) -> bool {
     precedence <= OperatorPrecedence::Lambda
 }
 
+fn needs_paren_expr(arg: &Expr) -> bool {
+    // Generator expressions need to be parenthesized in f-string expressions
+    if let Some(generator) = arg.as_generator_expr() {
+        return !generator.parenthesized;
+    }
+
+    // Check precedence for other expressions
+    needs_paren(OperatorPrecedence::from_expr(arg))
+}
+
 /// Represents the three built-in Python conversion functions that can be replaced
 /// with f-string conversion flags.
 #[derive(Copy, Clone)]

crates/ruff_linter/src/rules/ruff/snapshots/ruff_linter__rules__ruff__tests__RUF010_RUF010.py.snap

@@ -359,6 +359,7 @@ RUF010.py:52:4: RUF010 [*] Use explicit conversion flag
    52 |+f"{(x := 2)!r}"
 53 53 | 
 54 54 | f"{str(object=3)}"
+55 55 | 
 
 RUF010.py:54:4: RUF010 [*] Use explicit conversion flag
    |
@@ -366,6 +367,8 @@ RUF010.py:54:4: RUF010 [*] Use explicit conversion flag
 53 |
 54 | f"{str(object=3)}"
    |    ^^^^^^^^^^^^^ RUF010
+55 |
+56 | f"{str(x for x in [])}"
    |
    = help: Replace with conversion flag
 
@@ -375,3 +378,42 @@ RUF010.py:54:4: RUF010 [*] Use explicit conversion flag
 53 53 | 
 54    |-f"{str(object=3)}"
    54 |+f"{3!s}"
+55 55 | 
+56 56 | f"{str(x for x in [])}"
+57 57 | 
+
+RUF010.py:56:4: RUF010 [*] Use explicit conversion flag
+   |
+54 | f"{str(object=3)}"
+55 |
+56 | f"{str(x for x in [])}"
+   |    ^^^^^^^^^^^^^^^^^^ RUF010
+57 |
+58 | f"{str((x for x in []))}"
+   |
+   = help: Replace with conversion flag
+
+ℹ Safe fix
+53 53 | 
+54 54 | f"{str(object=3)}"
+55 55 | 
+56    |-f"{str(x for x in [])}"
+   56 |+f"{(x for x in [])!s}"
+57 57 | 
+58 58 | f"{str((x for x in []))}"
+
+RUF010.py:58:4: RUF010 [*] Use explicit conversion flag
+   |
+56 | f"{str(x for x in [])}"
+57 |
+58 | f"{str((x for x in []))}"
+   |    ^^^^^^^^^^^^^^^^^^^^ RUF010
+   |
+   = help: Replace with conversion flag
+
+ℹ Safe fix
+55 55 | 
+56 56 | f"{str(x for x in [])}"
+57 57 | 
+58    |-f"{str((x for x in []))}"
+   58 |+f"{(x for x in [])!s}"