test(fmt): cover postprocess normalization

Author: SoonIter

packages/rstack/tests/fmt/swcNextPlugin.test.ts

@@ -144,6 +144,12 @@ test.each([
     source: 'type Value = (((string | number)));',
     expected: 'type Value = string | number;\n',
   },
+  {
+    name: 'single-member unions with comments',
+    parser: 'swc-next-ts' as const,
+    source: 'type Value = | // value\nstring;',
+    expected: 'type Value =\n  // value\n  string;\n',
+  },
   {
     name: 'TypeScript template expressions',
     parser: 'swc-next-ts' as const,
@@ -167,6 +173,20 @@ test.each([
   ).resolves.toBe(fixture.expected);
 });
 
+test.each(['swc-next', 'swc-next-ts'] as const)(
+  'normalizes nested template expressions with %s',
+  async (parser) => {
+    const source =
+      'const result=`outer ${(`inner ${(a || (b || c))}`)} ${/** @type {Foo} */ (value)}`';
+    const formatted = await formatWithSwcNext(source, { parser });
+
+    expect(formatted).toBe(
+      'const result = `outer ${`inner ${a || b || c}`} ${/** @type {Foo} */ (value)}`;\n',
+    );
+    expect(await formatWithSwcNext(formatted, { parser })).toBe(formatted);
+  },
+);
+
 test('reuses Prettier options and pragma handling', async () => {
   await expect(
     formatWithSwcNext('/** @format */\nconst value={answer:"yes"}', {
@@ -355,15 +375,6 @@ test('reports SWC Next diagnostics with Prettier locations', async () => {
   });
 });
 
-test.each(['swc-next', 'swc-next-ts'] as const)(
-  'rejects malformed template literals with %s diagnostics',
-  async (parser) => {
-    await expect(
-      formatWithSwcNext('const value = `value: ${}`', { parser }),
-    ).rejects.toBeInstanceOf(SyntaxError);
-  },
-);
-
 test.each(['js', 'jsx', 'ts', 'tsx'])(
   'uses SWC Next by default for .%s files',
   async (extension) => {