fix(autofmt): preserve indentation of commented-out RSX blocks (#5464)

* test: add failing idempotency tests for commented-out RSX blocks

Two variants of the regression introduced in v0.7.4 (#5257):
- commented_rsx_block: first line keeps indent, rest gets dedented
- commented_rsx_block_nested: entire block gets dedented

See #5463

* fix(autofmt): preserve indentation of commented-out RSX blocks

Trailing comments before `}` in write_rsx_block were indented at
parent level instead of child level. Truncate the tab from
tabbed_line() and bump indent to child level before
apply_line_comments, same approach as write_trailing_body_comments.

Fixes #5463

packages/autofmt/src/writer.rs

@@ -426,7 +426,13 @@ impl<'a> Writer<'a> {
         {
             let comments = self.accumulate_full_line_comments(brace.span.span().end());
             if !comments.is_empty() {
+                // Undo the tab from tabbed_line(). It positioned for the closing
+                // brace, but trailing comments need child-level indentation
+                let tab_width = self.out.indent.indent_str().len() * self.out.indent_level;
+                self.out.buf.truncate(self.out.buf.len() - tab_width);
+                self.out.indent_level += 1;
                 self.apply_line_comments(comments)?;
+                self.out.indent_level -= 1;
                 self.out.tab()?;
             }
         }

packages/autofmt/tests/samples.rs

@@ -69,6 +69,11 @@ twoway![
     blank_lines,
     blank_lines_preserved,
     forloop_tuple,
+    commented_rsx_block,
+    commented_rsx_block_nested,
+    commented_rsx_block_only,
+    commented_rsx_block_between,
+    commented_rsx_block_deep,
 ];
 
 fn assert_idempotent(src: &str) {

packages/autofmt/tests/samples/commented_rsx_block.rsx

@@ -0,0 +1,9 @@
+rsx! {
+    div {
+        h2 { "Title" }
+        // div { class: "wrapper",
+        //     p { "A" }
+        //     p { "B" }
+        // }
+    }
+}

packages/autofmt/tests/samples/commented_rsx_block_between.rsx

@@ -0,0 +1,9 @@
+rsx! {
+    div {
+        h1 { "Before" }
+        // div { class: "commented",
+        //     p { "A" }
+        // }
+        h2 { "After" }
+    }
+}

packages/autofmt/tests/samples/commented_rsx_block_deep.rsx

@@ -0,0 +1,12 @@
+rsx! {
+    div {
+        div {
+            div {
+                h2 { "Title" }
+                // div { class: "deep",
+                //     p { "A" }
+                // }
+            }
+        }
+    }
+}

packages/autofmt/tests/samples/commented_rsx_block_nested.rsx

@@ -0,0 +1,13 @@
+rsx! {
+    Component {
+        field: rsx! {
+            div {
+                h2 { "Title" }
+                // div { class: "wrapper",
+                //     // nested comment
+                //     p { "A" }
+                // }
+            }
+        },
+    }
+}

packages/autofmt/tests/samples/commented_rsx_block_only.rsx

@@ -0,0 +1,6 @@
+rsx! {
+    div {
+        // p { "A" }
+        // p { "B" }
+    }
+}