fix(codegen): print comments in JSX expression containers and spread attributes (#19701)

## Summary

Closes #17266

- Print leading comments attached to expressions inside `JSXExpressionContainer` (e.g. `{/*before*/ x}`, `{/*before*/ "y"}`, `{/*before*/ true}`)
- Print comments between `{` and `...` in `JSXSpreadAttribute` (e.g. `{/*before*/ ...x}`)
- Add `print_comments_in_range` helper for finding comments attached to positions not directly represented in the AST (needed for the `...` token in spread attributes)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

crates/oxc_codegen/src/comment.rs

@@ -64,6 +64,22 @@ impl Codegen<'_> {
         }
     }
 
+    /// Print comments attached to any position in the given range `(start, end)` (exclusive).
+    /// Returns `true` if any comments were printed.
+    pub(crate) fn print_comments_in_range(&mut self, start: u32, end: u32) -> bool {
+        if self.comments.is_empty() {
+            return false;
+        }
+        // Find and remove the first key in the range.
+        let key = self.comments.keys().find(|&&k| k > start && k < end).copied();
+        if let Some(key) = key {
+            let comments = self.comments.remove(&key).unwrap();
+            self.print_comments(&comments);
+            return true;
+        }
+        false
+    }
+
     pub(crate) fn print_expr_comments(&mut self, start: u32) -> bool {
         if self.comments.is_empty() {
             return false;

crates/oxc_codegen/src/gen.rs

@@ -2482,9 +2482,16 @@ impl Gen for JSXEmptyExpression {
 
 impl Gen for JSXExpression<'_> {
     fn r#gen(&self, p: &mut Codegen, ctx: Context) {
-        match self {
-            Self::EmptyExpression(expr) => expr.print(p, ctx),
-            _ => p.print_expression(self.to_expression()),
+        if let Self::EmptyExpression(expr) = self {
+            expr.print(p, ctx);
+        } else {
+            let expr = self.to_expression();
+            let start = expr.span().start;
+            if p.has_comment(start) {
+                p.print_comments_at(start);
+                p.print_indent();
+            }
+            p.print_expression(expr);
         }
     }
 }
@@ -2515,7 +2522,11 @@ impl Gen for JSXAttributeValue<'_> {
 
 impl Gen for JSXSpreadAttribute<'_> {
     fn r#gen(&self, p: &mut Codegen, _ctx: Context) {
-        p.print_str("{...");
+        p.print_ascii_byte(b'{');
+        if p.print_comments_in_range(self.span.start, self.argument.span().start) {
+            p.print_indent();
+        }
+        p.print_str("...");
         self.argument.print_expr(p, Precedence::Comma, Context::empty());
         p.print_ascii_byte(b'}');
     }

crates/oxc_codegen/tests/integration/comments.rs

@@ -20,6 +20,16 @@ fn test_comment_at_top_of_file() {
 #[test]
 fn unit() {
     test_same("<div>{/* Hello */}</div>;\n");
+    // https://github.com/oxc-project/oxc/issues/17266
+    test("console.log(<div x={/*before*/ x} />)", "console.log(<div x={/*before*/ x} />);\n");
+    test(
+        "console.log(<div x={/*before*/ \"y\"} />)",
+        "console.log(<div x={/*before*/ \"y\"} />);\n",
+    );
+    test("console.log(<div x={/*before*/ true} />)", "console.log(<div x={/*before*/ true} />);\n");
+    test("console.log(<div {/*before*/ ...x} />)", "console.log(<div {/*before*/ ...x} />);\n");
+    test("console.log(<div>{/*before*/ x}</div>)", "console.log(<div>{/*before*/ x}</div>);\n");
+    test("console.log(<>{/*before*/ x}</>)", "console.log(<>{/*before*/ x}</>);\n");
     // https://lingui.dev/ref/macro#definemessage
     test("const message = /*i18n*/{};", "const message = (/*i18n*/ {});\n");
     test(