[Bug]: Example spec uses CommonJS instead of ESM, even though type:module is set in package.json (JavaScript project)

[aral]

Version

1.48.1

Steps to reproduce

1. Clone my repo at https://codeberg.org/kitten/app
2. Run npm init playwright@latest
3. Run npx playwright test
4. Select JavaScript for project type and enter tests/e2e as the test folder.

Expected behavior

The automatically created example spec should run without errors.

Actual behavior

ReferenceError: require is not defined in ES module scope, you can use import instead
This file is being treated as an ES module because it has a '.js' file extension and '/Users/aral/Projects/kitten/app/package.json' contains "type": "module". To treat it as a CommonJS script, rename it to use the '.cjs' file extension.
    at file:///Users/aral/Projects/kitten/app/playwright.config.js:2:35
    at ModuleJob.run (node:internal/modules/esm/module_job:218:25)
    at ModuleLoader.import (node:internal/modules/esm/loader:329:24)
    at importModuleDynamicallyWrapper (node:internal/vm/module:431:15)
    at requireOrImport (/Users/aral/Projects/kitten/app/node_modules/playwright/lib/transform/transform.js:230:24)
    at loadUserConfig (/Users/aral/Projects/kitten/app/node_modules/playwright/lib/common/configLoader.js:94:46)
    at loadConfig (/Users/aral/Projects/kitten/app/node_modules/playwright/lib/common/configLoader.js:105:22)
    at loadConfigFromFileRestartIfNeeded (/Users/aral/Projects/kitten/app/node_modules/playwright/lib/common/configLoader.js:273:10)
    at runTests (/Users/aral/Projects/kitten/app/node_modules/playwright/lib/program.js:199:18)
    at t.<anonymous> (/Users/aral/Projects/kitten/app/node_modules/playwright/lib/program.js:54:7)

Additional context

The test being created uses CommonJS instead of ESM, even though type:module is set in package.json.

Fix

Convert example.spec.js and playwright.config.js to use ESM.

example.spec.js

// @ts-check
import { test, expect } from '@playwright/test';

test('has title', async ({ page }) => {
  await page.goto('https://playwright.dev/');

  // Expect a title "to contain" a substring.
  await expect(page).toHaveTitle(/Playwright/);
});

test('get started link', async ({ page }) => {
  await page.goto('https://playwright.dev/');

  // Click the get started link.
  await page.getByRole('link', { name: 'Get started' }).click();

  // Expects page to have a heading with the name of Installation.
  await expect(page.getByRole('heading', { name: 'Installation' })).toBeVisible();
});

playwright.config.js

// @ts-check
import { defineConfig, devices } from '@playwright/test';

/**
 * Read environment variables from file.
 * https://github.com/motdotla/dotenv
 */
// require('dotenv').config({ path: path.resolve(__dirname, '.env') });

/**
 * @see https://playwright.dev/docs/test-configuration
 */
export default defineConfig({
  testDir: './tests/e2e',
  /* Run tests in files in parallel */
  fullyParallel: true,
  /* Fail the build on CI if you accidentally left test.only in the source code. */
  forbidOnly: !!process.env.CI,
  /* Retry on CI only */
  retries: process.env.CI ? 2 : 0,
  /* Opt out of parallel tests on CI. */
  workers: process.env.CI ? 1 : undefined,
  /* Reporter to use. See https://playwright.dev/docs/test-reporters */
  reporter: 'html',
  /* Shared settings for all the projects below. See https://playwright.dev/docs/api/class-testoptions. */
  use: {
    /* Base URL to use in actions like `await page.goto('/')`. */
    // baseURL: 'http://127.0.0.1:3000',

    /* Collect trace when retrying the failed test. See https://playwright.dev/docs/trace-viewer */
    trace: 'on-first-retry',
  },

  /* Configure projects for major browsers */
  projects: [
    {
      name: 'chromium',
      use: { ...devices['Desktop Chrome'] },
    },

    {
      name: 'firefox',
      use: { ...devices['Desktop Firefox'] },
    },

    {
      name: 'webkit',
      use: { ...devices['Desktop Safari'] },
    },

    /* Test against mobile viewports. */
    // {
    //   name: 'Mobile Chrome',
    //   use: { ...devices['Pixel 5'] },
    // },
    // {
    //   name: 'Mobile Safari',
    //   use: { ...devices['iPhone 12'] },
    // },

    /* Test against branded browsers. */
    // {
    //   name: 'Microsoft Edge',
    //   use: { ...devices['Desktop Edge'], channel: 'msedge' },
    // },
    // {
    //   name: 'Google Chrome',
    //   use: { ...devices['Desktop Chrome'], channel: 'chrome' },
    // },
  ],

  /* Run your local dev server before starting the tests */
  // webServer: {
  //   command: 'npm run start',
  //   url: 'http://127.0.0.1:3000',
  //   reuseExistingServer: !process.env.CI,
  // },
});

Environment

System:
OS: macOS 14.6.1
CPU: (8) x64 Intel(R) Core(TM) i5-8279U CPU @ 2.40GHz
Memory: 368.51 MB / 16.00 GB
Binaries:
Node: 20.11.1 - ~/.local/share/nvm/v20.11.1/bin/node
npm: 10.2.4 - ~/.local/share/nvm/v20.11.1/bin/npm
Languages:
Bash: 5.2.37 - /usr/local/bin/bash
npmPackages:
@playwright/test: ^1.48.1 => 1.48.1