From 44c27caf8b0801c91b28eb968b47f031a99af4f2 Mon Sep 17 00:00:00 2001
From: Qingyu Wang <wangqingyu.c0l1n@bytedance.com>
Date: Fri, 27 Feb 2026 15:39:15 +0800
Subject: [PATCH] test: verify cjs module compatibility

---
 test/cjs-compat/index.test.ts | 26 ++++++++++++++++++++++++++
 test/cjs-compat/src/index.js  |  6 ++++++
 test/cjs-compat/src/lib.cjs   |  4 ++++
 3 files changed, 36 insertions(+)
 create mode 100644 test/cjs-compat/index.test.ts
 create mode 100644 test/cjs-compat/src/index.js
 create mode 100644 test/cjs-compat/src/lib.cjs

diff --git a/test/cjs-compat/index.test.ts b/test/cjs-compat/index.test.ts
new file mode 100644
index 0000000..b4ec712
--- /dev/null
+++ b/test/cjs-compat/index.test.ts
@@ -0,0 +1,26 @@
+import { dirname } from 'node:path';
+import { fileURLToPath } from 'node:url';
+import { expect, test } from '@playwright/test';
+import { createRsbuild } from '@rsbuild/core';
+import { pluginTailwindCSS } from '../../src';
+
+const __dirname = dirname(fileURLToPath(import.meta.url));
+
+test('should not interfere with CJS modules', async ({ page }) => {
+  const rsbuild = await createRsbuild({
+    cwd: __dirname,
+    rsbuildConfig: {
+      plugins: [pluginTailwindCSS()],
+    },
+  });
+
+  await rsbuild.build();
+  const { server, urls } = await rsbuild.preview();
+
+  await page.goto(urls[0]);
+
+  const locator = page.locator('#cjs-output');
+  await expect(locator).toHaveText('Hello from CJS');
+
+  await server.close();
+});
diff --git a/test/cjs-compat/src/index.js b/test/cjs-compat/src/index.js
new file mode 100644
index 0000000..9c69427
--- /dev/null
+++ b/test/cjs-compat/src/index.js
@@ -0,0 +1,6 @@
+import lib from './lib.cjs';
+
+const div = document.createElement('div');
+div.id = 'cjs-output';
+div.textContent = lib.message;
+document.body.appendChild(div);
diff --git a/test/cjs-compat/src/lib.cjs b/test/cjs-compat/src/lib.cjs
new file mode 100644
index 0000000..da42510
--- /dev/null
+++ b/test/cjs-compat/src/lib.cjs
@@ -0,0 +1,4 @@
+module.exports = {
+  message: 'Hello from CJS',
+  data: Array.from({ length: 1000 }, (_, i) => i), // Some data to make it "large"
+};