25 KiB
id | title |
---|---|
test-fixtures | Advanced: fixtures |
Playwright Test is based on the concept of test fixtures. Test fixtures are used to establish environment for each test, giving the test everything it needs and nothing else. Test fixtures are isolated between tests. With fixtures, you can group tests based on their meaning, instead of their common setup.
Built-in fixtures
You have already used test fixtures in your first test.
const { test, expect } = require('@playwright/test');
test('basic test', async ({ page }) => {
await page.goto('https://playwright.dev/');
await expect(page).toHaveTitle(/Playwright/);
});
import { test, expect } from '@playwright/test';
test('basic test', async ({ page }) => {
await page.goto('https://playwright.dev/');
await expect(page).toHaveTitle(/Playwright/);
});
The { page }
argument tells Playwright Test to setup the page
fixture and provide it to your test function.
Here is a list of the pre-defined fixtures that you are likely to use most of the time:
Fixture | Type | Description |
---|---|---|
page | [Page] | Isolated page for this test run. |
context | [BrowserContext] | Isolated context for this test run. The page fixture belongs to this context as well. Learn how to configure context. |
browser | [Browser] | Browsers are shared across tests to optimize resources. Learn how to configure browser. |
browserName | [string] | The name of the browser currently running the test. Either chromium , firefox or webkit . |
request | [APIRequestContext] | Isolated APIRequestContext instance for this test run. |
Without fixtures
Here is how typical test environment setup differs between traditional test style and the fixture-based one.
We assume a TodoPage
class that helps interacting with a "todo list" page of the web app, following the Page Object Model pattern. It uses Playwright's page
internally.
// todo.spec.js
const { test } = require('@playwright/test');
const { TodoPage } = require('./todo-page');
test.describe('todo tests', () => {
let todoPage;
test.beforeEach(async ({ page }) => {
todoPage = new TodoPage(page);
await todoPage.goto();
await todoPage.addToDo('item1');
await todoPage.addToDo('item2');
});
test.afterEach(async () => {
await todoPage.removeAll();
});
test('should add an item', async () => {
await todoPage.addToDo('my item');
// ...
});
test('should remove an item', async () => {
await todoPage.remove('item1');
// ...
});
});
With fixtures
Fixtures have a number of advantages over before/after hooks:
- Fixtures encapsulate setup and teardown in the same place so it is easier to write.
- Fixtures are reusable between test files - you can define them once and use in all your tests. That's how Playwright's built-in
page
fixture works. - Fixtures are on-demand - you can define as many fixtures as you'd like, and Playwright Test will setup only the ones needed by your test and nothing else.
- Fixtures are composable - they can depend on each other to provide complex behaviors.
- Fixtures are flexible. Tests can use any combinations of the fixtures to tailor precise environment they need, without affecting other tests.
- Fixtures simplify grouping. You no longer need to wrap tests in
describe
s that set up environment, and are free to group your tests by their meaning instead.
// todo.spec.js
const base = require('@playwright/test');
const { TodoPage } = require('./todo-page');
// Extend basic test by providing a "todoPage" fixture.
const test = base.test.extend({
todoPage: async ({ page }, use) => {
const todoPage = new TodoPage(page);
await todoPage.goto();
await todoPage.addToDo('item1');
await todoPage.addToDo('item2');
await use(todoPage);
await todoPage.removeAll();
},
});
test('should add an item', async ({ todoPage }) => {
await todoPage.addToDo('my item');
// ...
});
test('should remove an item', async ({ todoPage }) => {
await todoPage.remove('item1');
// ...
});
// example.spec.ts
import { test as base } from '@playwright/test';
import { TodoPage } from './todo-page';
// Extend basic test by providing a "todoPage" fixture.
const test = base.extend<{ todoPage: TodoPage }>({
todoPage: async ({ page }, use) => {
const todoPage = new TodoPage(page);
await todoPage.goto();
await todoPage.addToDo('item1');
await todoPage.addToDo('item2');
await use(todoPage);
await todoPage.removeAll();
},
});
test('should add an item', async ({ todoPage }) => {
await todoPage.addToDo('my item');
// ...
});
test('should remove an item', async ({ todoPage }) => {
await todoPage.remove('item1');
// ...
});
Creating a fixture
To create your own fixture, use [method: Test.extend
] to create a new test
object that will include it.
Below we create two fixtures todoPage
and settingsPage
that follow the Page Object Model pattern.
// my-test.js
const base = require('@playwright/test');
const { TodoPage } = require('./todo-page');
const { SettingsPage } = require('./settings-page');
// Extend base test by providing "todoPage" and "settingsPage".
// This new "test" can be used in multiple test files, and each of them will get the fixtures.
exports.test = base.test.extend({
todoPage: async ({ page }, use) => {
// Set up the fixture.
const todoPage = new TodoPage(page);
await todoPage.goto();
await todoPage.addToDo('item1');
await todoPage.addToDo('item2');
// Use the fixture value in the test.
await use(todoPage);
// Clean up the fixture.
await todoPage.removeAll();
},
settingsPage: async ({ page }, use) => {
await use(new SettingsPage(page));
},
});
exports.expect = base.expect;
// my-test.ts
import { test as base } from '@playwright/test';
import { TodoPage } from './todo-page';
import { SettingsPage } from './settings-page';
// Declare the types of your fixtures.
type MyFixtures = {
todoPage: TodoPage;
settingsPage: SettingsPage;
};
// Extend base test by providing "todoPage" and "settingsPage".
// This new "test" can be used in multiple test files, and each of them will get the fixtures.
export const test = base.extend<MyFixtures>({
todoPage: async ({ page }, use) => {
// Set up the fixture.
const todoPage = new TodoPage(page);
await todoPage.goto();
await todoPage.addToDo('item1');
await todoPage.addToDo('item2');
// Use the fixture value in the test.
await use(todoPage);
// Clean up the fixture.
await todoPage.removeAll();
},
settingsPage: async ({ page }, use) => {
await use(new SettingsPage(page));
},
});
export { expect } from '@playwright/test';
:::note Custom fixture names should start with a letter or underscore, and can contain only letters, numbers, underscores. :::
Using a fixture
Just mention fixture in your test function argument, and test runner will take care of it. Fixtures are also available in hooks and other fixtures. If you use TypeScript, fixtures will have the right type.
Below we use the todoPage
and settingsPage
fixtures defined above.
const { test, expect } = require('./my-test');
test.beforeEach(async ({ settingsPage }) => {
await settingsPage.switchToDarkMode();
});
test('basic test', async ({ todoPage, page }) => {
await todoPage.addToDo('something nice');
await expect(page.getByTestId('todo-title')).toContainText(['something nice']);
});
import { test, expect } from './my-test';
test.beforeEach(async ({ settingsPage }) => {
await settingsPage.switchToDarkMode();
});
test('basic test', async ({ todoPage, page }) => {
await todoPage.addToDo('something nice');
await expect(page.getByTestId('todo-title')).toContainText(['something nice']);
});
Overriding fixtures
In addition to creating your own fixtures, you can also override existing fixtures to fit your needs. Consider the following example which overrides the page
fixture by automatically navigating to some baseURL
:
const base = require('@playwright/test');
exports.test = base.test.extend({
page: async ({ baseURL, page }, use) => {
await page.goto(baseURL);
await use(page);
},
});
import { test as base } from '@playwright/test';
export const test = base.extend({
page: async ({ baseURL, page }, use) => {
await page.goto(baseURL);
await use(page);
},
});
Notice that in this example, the page
fixture is able to depend on other built-in fixtures such as [property: TestOptions.baseURL
]. We can now configure baseURL
in the configuration file, or locally in the test file with [method: Test.use
].
// example.spec.js
test.use({ baseURL: 'https://playwright.dev' });
// example.spec.ts
test.use({ baseURL: 'https://playwright.dev' });
Fixtures can also be overridden where the base fixture is completely replaced with something different. For example, we could override the [property: TestOptions.storageState
] fixture to provide our own data.
const base = require('@playwright/test');
exports.test = base.test.extend({
storageState: async ({}, use) => {
const cookie = await getAuthCookie();
await use({ cookies: [cookie] });
},
});
import { test as base } from '@playwright/test';
export const test = base.extend({
storageState: async ({}, use) => {
const cookie = await getAuthCookie();
await use({ cookies: [cookie] });
},
});
Worker-scoped fixtures
Playwright Test uses worker processes to run test files. Similarly to how test fixtures are set up for individual test runs, worker fixtures are set up for each worker process. That's where you can set up services, run servers, etc. Playwright Test will reuse the worker process for as many test files as it can, provided their worker fixtures match and hence environments are identical.
Below we'll create an account
fixture that will be shared by all tests in the same worker, and override the page
fixture to login into this account for each test. To generate unique accounts, we'll use the [property: WorkerInfo.workerIndex
] that is available to any test or fixture. Note the tuple-like syntax for the worker fixture - we have to pass {scope: 'worker'}
so that test runner sets up this fixture once per worker.
// my-test.js
const base = require('@playwright/test');
exports.test = base.test.extend({
account: [async ({ browser }, use, workerInfo) => {
// Unique username.
const username = 'user' + workerInfo.workerIndex;
const password = 'verysecure';
// Create the account with Playwright.
const page = await browser.newPage();
await page.goto('/signup');
await page.getByLabel('User Name').fill(username);
await page.getByLabel('Password').fill(password);
await page.getByText('Sign up').click();
// Make sure everything is ok.
await expect(page.locator('#result')).toHaveText('Success');
// Do not forget to cleanup.
await page.close();
// Use the account value.
await use({ username, password });
}, { scope: 'worker' }],
page: async ({ page, account }, use) => {
// Sign in with our account.
const { username, password } = account;
await page.goto('/signin');
await page.getByLabel('User Name').fill(username);
await page.getByLabel('Password').fill(password);
await page.getByText('Sign in').click();
await expect(page.getByTestId('userinfo')).toHaveText(username);
// Use signed-in page in the test.
await use(page);
},
});
exports.expect = base.expect;
// my-test.ts
import { test as base } from '@playwright/test';
type Account = {
username: string;
password: string;
};
// Note that we pass worker fixture types as a second template parameter.
export const test = base.extend<{}, { account: Account }>({
account: [async ({ browser }, use, workerInfo) => {
// Unique username.
const username = 'user' + workerInfo.workerIndex;
const password = 'verysecure';
// Create the account with Playwright.
const page = await browser.newPage();
await page.goto('/signup');
await page.getByLabel('User Name').fill(username);
await page.getByLabel('Password').fill(password);
await page.getByText('Sign up').click();
// Make sure everything is ok.
await expect(page.getByTestId('result')).toHaveText('Success');
// Do not forget to cleanup.
await page.close();
// Use the account value.
await use({ username, password });
}, { scope: 'worker' }],
page: async ({ page, account }, use) => {
// Sign in with our account.
const { username, password } = account;
await page.goto('/signin');
await page.getByLabel('User Name').fill(username);
await page.getByLabel('Password').fill(password);
await page.getByText('Sign in').click();
await expect(page.getByTestId('userinfo')).toHaveText(username);
// Use signed-in page in the test.
await use(page);
},
});
export { expect } from '@playwright/test';
Automatic fixtures
Automatic fixtures are set up for each test/worker, even when the test does not list them directly. To create an automatic fixture, use the tuple syntax and pass { auto: true }
.
Here is an example fixture that automatically attaches debug logs when the test fails, so we can later review the logs in the reporter. Note how it uses [TestInfo] object that is available in each test/fixture to retrieve metadata about the test being run.
// my-test.js
const debug = require('debug');
const fs = require('fs');
const base = require('@playwright/test');
exports.test = base.test.extend({
saveLogs: [async ({}, use, testInfo) => {
// Collecting logs during the test.
const logs = [];
debug.log = (...args) => logs.push(args.map(String).join(''));
debug.enable('myserver');
await use();
// After the test we can check whether the test passed or failed.
if (testInfo.status !== testInfo.expectedStatus) {
// outputPath() API guarantees a unique file name.
const logFile = testInfo.outputPath('logs.txt');
await fs.promises.writeFile(logFile, logs.join('\n'), 'utf8');
testInfo.attachments.push({ name: 'logs', contentType: 'text/plain', path: logFile });
}
}, { auto: true }],
});
// my-test.ts
import * as debug from 'debug';
import * as fs from 'fs';
import { test as base } from '@playwright/test';
export const test = base.extend<{ saveLogs: void }>({
saveLogs: [async ({}, use, testInfo) => {
// Collecting logs during the test.
const logs = [];
debug.log = (...args) => logs.push(args.map(String).join(''));
debug.enable('myserver');
await use();
// After the test we can check whether the test passed or failed.
if (testInfo.status !== testInfo.expectedStatus) {
// outputPath() API guarantees a unique file name.
const logFile = testInfo.outputPath('logs.txt');
await fs.promises.writeFile(logFile, logs.join('\n'), 'utf8');
testInfo.attachments.push({ name: 'logs', contentType: 'text/plain', path: logFile });
}
}, { auto: true }],
});
export { expect } from '@playwright/test';
Fixture timeout
By default, fixture shares timeout with the test. However, for slow fixtures, especially worker-scoped ones, it is convenient to have a separate timeout. This way you can keep the overall test timeout small, and give the slow fixture more time.
const { test: base, expect } = require('@playwright/test');
const test = base.extend({
slowFixture: [async ({}, use) => {
// ... perform a slow operation ...
await use('hello');
}, { timeout: 60000 }]
});
test('example test', async ({ slowFixture }) => {
// ...
});
import { test as base, expect } from '@playwright/test';
const test = base.extend<{ slowFixture: string }>({
slowFixture: [async ({}, use) => {
// ... perform a slow operation ...
await use('hello');
}, { timeout: 60000 }]
});
test('example test', async ({ slowFixture }) => {
// ...
});
Fixtures-options
:::note Overriding custom fixtures in the config file has changed in version 1.18. Learn more. :::
Playwright Test supports running multiple test projects that can be separately configured. You can use "option" fixtures to make your configuration options declarative and type-checked. Learn more about parametrizing tests.
Below we'll create a defaultItem
option in addition to the todoPage
fixture from other examples. This option will be set in configuration file. Note the tuple syntax and { option: true }
argument.
// my-test.js
const base = require('@playwright/test');
const { TodoPage } = require('./todo-page');
exports.test = base.test.extend({
// Define an option and provide a default value.
// We can later override it in the config.
defaultItem: ['Something nice', { option: true }],
// Our "todoPage" fixture depends on the option.
todoPage: async ({ page, defaultItem }, use) => {
const todoPage = new TodoPage(page);
await todoPage.goto();
await todoPage.addToDo(defaultItem);
await use(todoPage);
await todoPage.removeAll();
},
});
exports.expect = base.expect;
// my-test.ts
import { test as base } from '@playwright/test';
import { TodoPage } from './todo-page';
// Declare your options to type-check your configuration.
export type MyOptions = {
defaultItem: string;
};
type MyFixtures = {
todoPage: TodoPage;
};
// Specify both option and fixture types.
export const test = base.extend<MyOptions & MyFixtures>({
// Define an option and provide a default value.
// We can later override it in the config.
defaultItem: ['Something nice', { option: true }],
// Our "todoPage" fixture depends on the option.
todoPage: async ({ page, defaultItem }, use) => {
const todoPage = new TodoPage(page);
await todoPage.goto();
await todoPage.addToDo(defaultItem);
await use(todoPage);
await todoPage.removeAll();
},
});
export { expect } from '@playwright/test';
We can now use todoPage
fixture as usual, and set the defaultItem
option in the config file.
// playwright.config.js
// @ts-check
const { defineConfig } = require('@playwright/test');
module.exports = defineConfig({
projects: [
{
name: 'shopping',
use: { defaultItem: 'Buy milk' },
},
{
name: 'wellbeing',
use: { defaultItem: 'Exercise!' },
},
]
});
// playwright.config.ts
import { defineConfig } from '@playwright/test';
import { MyOptions } from './my-test';
export default defineConfig({
projects: [
{
name: 'shopping',
use: { defaultItem: 'Buy milk' },
},
{
name: 'wellbeing',
use: { defaultItem: 'Exercise!' },
},
]
});
Execution order
Each fixture has a setup and teardown phase separated by the await use()
call in the fixture. Setup is executed before the fixture is used by the test/hook, and teardown is executed when the fixture will not be used by the test/hook anymore.
Fixtures follow these rules to determine the execution order:
- When fixture A depends on fixture B: B is always set up before A and teared down after A.
- Non-automatic fixtures are executed lazily, only when the test/hook needs them.
- Test-scoped fixtures are teared down after each test, while worker-scoped fixtures are only teared down when the worker process executing tests is shutdown.
Consider the following example:
const { test: base } = require('@playwright/test');
const test = base.extend({
workerFixture: [async ({ browser }) => {
// workerFixture setup...
await use('workerFixture');
// workerFixture teardown...
}, { scope: 'worker' }],
autoWorkerFixture: [async ({ browser }) => {
// autoWorkerFixture setup...
await use('autoWorkerFixture');
// autoWorkerFixture teardown...
}, { scope: 'worker', auto: true }],
testFixture: [async ({ page, workerFixture }) => {
// testFixture setup...
await use('testFixture');
// testFixture teardown...
}, { scope: 'test' }],
autoTestFixture: [async () => {
// autoTestFixture setup...
await use('autoTestFixture');
// autoTestFixture teardown...
}, { scope: 'test', auto: true }],
unusedFixture: [async ({ page }) => {
// unusedFixture setup...
await use('unusedFixture');
// unusedFixture teardown...
}, { scope: 'test' }],
});
test.beforeAll(async () => { /* ... */ });
test.beforeEach(async ({ page }) => { /* ... */ });
test('first test', async ({ page }) => { /* ... */ });
test('second test', async ({ testFixture }) => { /* ... */ });
test.afterEach(async () => { /* ... */ });
test.afterAll(async () => { /* ... */ });
import { test as base } from '@playwright/test';
const test = base.extend<{
testFixture: string,
autoTestFixture: string,
unusedFixture: string,
}, {
workerFixture: string,
autoWorkerFixture: string,
}>({
workerFixture: [async ({ browser }) => {
// workerFixture setup...
await use('workerFixture');
// workerFixture teardown...
}, { scope: 'worker' }],
autoWorkerFixture: [async ({ browser }) => {
// autoWorkerFixture setup...
await use('autoWorkerFixture');
// autoWorkerFixture teardown...
}, { scope: 'worker', auto: true }],
testFixture: [async ({ page, workerFixture }) => {
// testFixture setup...
await use('testFixture');
// testFixture teardown...
}, { scope: 'test' }],
autoTestFixture: [async () => {
// autoTestFixture setup...
await use('autoTestFixture');
// autoTestFixture teardown...
}, { scope: 'test', auto: true }],
unusedFixture: [async ({ page }) => {
// unusedFixture setup...
await use('unusedFixture');
// unusedFixture teardown...
}, { scope: 'test' }],
});
test.beforeAll(async () => { /* ... */ });
test.beforeEach(async ({ page }) => { /* ... */ });
test('first test', async ({ page }) => { /* ... */ });
test('second test', async ({ testFixture }) => { /* ... */ });
test.afterEach(async () => { /* ... */ });
test.afterAll(async () => { /* ... */ });
Normally, if all tests pass and no errors are thrown, the order of execution is as following.
- worker setup and
beforeAll
section:browser
setup because it is required byautoWorkerFixture
.autoWorkerFixture
setup because automatic worker fixtures are always set up before anything else.beforeAll
runs.
first test
section:autoTestFixture
setup because automatic test fixtures are always set up before test andbeforeEach
hooks.page
setup because it is required inbeforeEach
hook.beforeEach
runs.first test
runs.afterEach
runs.page
teardown because it is a test-scoped fixture and should be teared down after the test finishes.autoTestFixture
teardown because it is a test-scoped fixture and should be teared down after the test finishes.
second test
section:autoTestFixture
setup because automatic test fixtures are always set up before test andbeforeEach
hooks.page
setup because it is required inbeforeEach
hook.beforeEach
runs.workerFixture
setup because it is required bytestFixture
that is required by thesecond test
.testFixture
setup because it is required by thesecond test
.second test
runs.afterEach
runs.testFixture
teardown because it is a test-scoped fixture and should be teared down after the test finishes.page
teardown because it is a test-scoped fixture and should be teared down after the test finishes.autoTestFixture
teardown because it is a test-scoped fixture and should be teared down after the test finishes.
afterAll
and worker teardown section:afterAll
runs.workerFixture
teardown because it is a workers-scoped fixture and should be teared down once at the end.autoWorkerFixture
teardown because it is a workers-scoped fixture and should be teared down once at the end.browser
teardown because it is a workers-scoped fixture and should be teared down once at the end.
A few observations:
page
andautoTestFixture
are set up and teared down for each test, as test-scoped fixtures.unusedFixture
is never set up because it is not used by any tests/hooks.testFixture
depends onworkerFixture
and triggers its setup.workerFixture
is lazily set up before the second test, but teared down once during worker shutdown, as a worker-scoped fixture.autoWorkerFixture
is set up forbeforeAll
hook, butautoTestFixture
is not.