playwright/docs/src/test-parameterize-js.md

id	title
test-parameterize	Parametrize tests

You can either parametrize tests on a test level or on a project level.

Parameterized Tests

// example.spec.js
const people = ['Alice', 'Bob'];
for (const name of people) {
  test(`testing with ${name}`, async () => {
    // ...
  });
  // You can also do it with test.describe() or with multiple tests as long the test name is unique.
}

// example.spec.ts
const people = ['Alice', 'Bob'];
for (const name of people) {
  test(`testing with ${name}`, async () => {
    // ...
  });
  // You can also do it with test.describe() or with multiple tests as long the test name is unique.
}

Parameterized Projects

Playwright Test supports running multiple test projects at the same time. In the following example, we'll run two projects with different options.

We declare the option person and set the value in the config. The first project runs with the value Alice and the second with the value Bob.

// my-test.js
const base = require('@playwright/test');

exports.test = base.test.extend({
  // Define an option and provide a default value.
  // We can later override it in the config.
  person: ['John', { option: true }],
});

// my-test.ts
import { test as base } from '@playwright/test';

export type TestOptions = {
  person: string;
};

export const test = base.extend<TestOptions>({
  // Define an option and provide a default value.
  // We can later override it in the config.
  person: ['John', { option: true }],
});

We can use this option in the test, similarly to fixtures.

// example.spec.js
const { test } = require('./my-test');

test('test 1', async ({ page, person }) => {
  await page.goto(`/index.html`);
  await expect(page.locator('#node')).toContainText(person);
  // ...
});

// example.spec.ts
import { test } from './my-test';

test('test 1', async ({ page, person }) => {
  await page.goto(`/index.html`);
  await expect(page.locator('#node')).toContainText(person);
  // ...
});

Now, we can run tests in multiple configurations by using projects.

// playwright.config.js
// @ts-check

/** @type {import('@playwright/test').PlaywrightTestConfig<{ person: string }>} */
const config = {
  projects: [
    {
      name: 'alice',
      use: { person: 'Alice' },
    },
    {
      name: 'bob',
      use: { person: 'Bob' },
    },
  ]
};

module.exports = config;

// playwright.config.ts
import { PlaywrightTestConfig } from '@playwright/test';
import { TestOptions } from './my-test';

const config: PlaywrightTestConfig<TestOptions> = {
  projects: [
    {
      name: 'alice',
      use: { person: 'Alice' },
    },
    {
      name: 'bob',
      use: { person: 'Bob' },
    },
  ]
};
export default config;

We can also use the option in a fixture. Learn more about fixtures.

// my-test.js
const base = require('@playwright/test');

exports.test = base.test.extend({
  // Define an option and provide a default value.
  // We can later override it in the config.
  person: ['John', { option: true }],

  // Override default "page" fixture.
  page: async ({ page, person }, use) => {
    await page.goto('/chat');
    // We use "person" parameter as a "name" for the chat room.
    await page.locator('#name').fill(person);
    await page.click('text=Enter chat room');
    // Each test will get a "page" that already has the person name.
    await use(page);
  },
});

// my-test.ts
import { test as base } from '@playwright/test';

export type TestOptions = {
  person: string;
};

export const test = base.test.extend<TestOptions>({
  // Define an option and provide a default value.
  // We can later override it in the config.
  person: ['John', { option: true }],

  // Override default "page" fixture.
  page: async ({ page, person }, use) => {
    await page.goto('/chat');
    // We use "person" parameter as a "name" for the chat room.
    await page.locator('#name').fill(person);
    await page.click('text=Enter chat room');
    // Each test will get a "page" that already has the person name.
    await use(page);
  },
});

:::note Parametrized projects behavior has changed in version 1.18. Learn more. :::