Error: require() of ES Module in Playwright

[kettanaito]

Reproduction steps

1. Create a Playwright test.

import { createTestHttpServer } from '@epic-web/test-server/http'
import { test, expect } from '../playwright.extend'

test('', () => {
  createTestHttpServer()
})

2. Run the text via npx playwright test.
3. See the following error:

Error: require() of ES Module /node_modules/.pnpm/@epic-web+test-server@0.1.0/node_modules/@epic-web/test-server/lib/http.js from /test/browser/sse-api/sse.server.connect.test.ts not supported.
Instead change the require of http.js in /test/browser/sse-api/sse.server.connect.test.ts to a dynamic import() which is available in all CommonJS modules.

Expected behavior

There must be no error, the test should compile and run.

Context

The error is a bit odd because the package is ESM, and there's no require() statements. I suspect what's happening is Playwright transpiles the ESM test to CJS, and because the imported package is ESM-only, it fails?

• Related: [Feature] Add a way to handle CJS/ESM module hell microsoft/playwright#23662

[kettanaito]

This seems to be an issue with Playwright not digesting ESM modules correctly. This can be fixed by running the tests like this

NODE_OPTIONS=--experimental-require-module npx playwright test

Note: this requires Node.js v20+.