fix: never remove parens from prefix ops with valueless return/break/continue

crates/ide-assists/src/handlers/remove_parentheses.rs

@@ -162,6 +162,30 @@ mod tests {
         check_assist_not_applicable(remove_parentheses, r#"fn f() { if $0(return) {} }"#);
     }
 
+    #[test]
+    fn remove_parens_prefix_with_return_no_value() {
+        // removing `()` from !(return) would make `!return` which is invalid syntax
+        check_assist_not_applicable(
+            remove_parentheses,
+            r#"fn main() { let _x = true && !$0(return) || true; }"#,
+        );
+        check_assist_not_applicable(remove_parentheses, r#"fn f() { !$0(return) }"#);
+        check_assist_not_applicable(remove_parentheses, r#"fn f() { !$0(break) }"#);
+        check_assist_not_applicable(remove_parentheses, r#"fn f() { !$0(continue) }"#);
+
+        // Binary operators should still allow removal
+        check_assist(
+            remove_parentheses,
+            r#"fn f() { true || $0(return) }"#,
+            r#"fn f() { true || return }"#,
+        );
+        check_assist(
+            remove_parentheses,
+            r#"fn f() { cond && $0(return) }"#,
+            r#"fn f() { cond && return }"#,
+        );
+    }
+
     #[test]
     fn remove_parens_return_with_value_followed_by_block() {
         check_assist(

crates/syntax/src/ast/prec.rs

@@ -226,6 +226,12 @@ impl Expr {
             return false;
         }
 
+        // Special-case prefix operators with return/break/etc without value
+        // e.g., `!(return)` - parentheses are necessary
+        if self.is_ret_like_with_no_value() && parent.is_prefix() {
+            return true;
+        }
+
         if self.is_paren_like()
             || parent.is_paren_like()
             || self.is_prefix()