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Version: 1.17

API testing

Playwright can be used to get access to the REST API of your application.

Sometimes you may want to send requests to the server directly from Node.js without loading a page and running js code in it. A few examples where it may come in handy:

  • Test your server API.
  • Prepare server side state before visiting the web application in a test.
  • Validate server side post-conditions after running some actions in the browser.

All of that could be achieved via APIRequestContext methods.

Writing API Test

APIRequestContext can send all kinds of HTTP(S) requests over network.

The following example demonstrates how to use Playwright to test issues creation via GitHub API. The test suite will do the following:

  • Create a new repository before running tests.
  • Create a few issues and validate server state.
  • Delete the repository after running tests.

Configuration

GitHub API requires authorization, so we'll configure the token once for all tests. While at it, we'll also set the baseURL to simplify the tests. You can either put them in the configuration file, or in the test file with test.use().

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

const config: PlaywrightTestConfig = {
use: {
// All requests we send go to this API endpoint.
baseURL: 'https://api.github.com',
extraHTTPHeaders: {
// We set this header per GitHub guidelines.
'Accept': 'application/vnd.github.v3+json',
// Add authorization token to all requests.
// Assuming personal access token available in the environment.
'Authorization': `token ${process.env.API_TOKEN}`,
},
}
};
export default config;

Writing tests

Playwright Test comes with the built-in request fixture that respects configuration options like baseURL or extraHTTPHeaders we specified and is ready to send some requests.

Now we can add a few tests that will create new issues in the repository.

const REPO = 'test-repo-1';
const USER = 'github-username';

test('should create a bug report', async ({ request }) => {
const newIssue = await request.post(`/repos/${USER}/${REPO}/issues`, {
data: {
title: '[Bug] report 1',
body: 'Bug description',
}
});
expect(newIssue.ok()).toBeTruthy();

const issues = await request.get(`/repos/${USER}/${REPO}/issues`);
expect(issues.ok()).toBeTruthy();
expect(await issues.json()).toContainEqual(expect.objectContaining({
title: '[Bug] report 1',
body: 'Bug description'
}));
});

test('should create a feature request', async ({ request }) => {
const newIssue = await request.post(`/repos/${USER}/${REPO}/issues`, {
data: {
title: '[Feature] request 1',
body: 'Feature description',
}
});
expect(newIssue.ok()).toBeTruthy();

const issues = await request.get(`/repos/${USER}/${REPO}/issues`);
expect(issues.ok()).toBeTruthy();
expect(await issues.json()).toContainEqual(expect.objectContaining({
title: '[Feature] request 1',
body: 'Feature description'
}));
});

Setup and teardown

These tests assume that repository exists. You probably want to create a new one before running tests and delete it afterwards. Use beforeAll and afterAll hooks for that.

test.beforeAll(async ({ request }) => {
// Create a new repository
const response = await request.post('/user/repos', {
data: {
name: REPO
}
});
expect(response.ok()).toBeTruthy();
});

test.afterAll(async ({ request }) => {
// Delete the repository
const response = await request.delete(`/repos/${USER}/${REPO}`);
expect(response.ok()).toBeTruthy();
});

Using request context

Behind the scenes, request fixture will actually call apiRequest.newContext([options]). You can always do that manually if you'd like more control. Below is a standalone script that does the same as beforeAll and afterAll from above.

const { request } = require('@playwright/test');
const REPO = 'test-repo-1';
const USER = 'github-username';

(async () => {
// Create a context that will issue http requests.
const context = await request.newContext({
baseURL: 'https://api.github.com',
});

// Create a repository.
await context.post('/user/repos', {
headers: {
'Accept': 'application/vnd.github.v3+json',
// Add GitHub personal access token.
'Authorization': `token ${process.env.API_TOKEN}`,
},
data: {
name: REPO
}
});

// Delete a repository.
await context.delete(`/repos/${USER}/${REPO}`{
headers: {
'Accept': 'application/vnd.github.v3+json',
// Add GitHub personal access token.
'Authorization': `token ${process.env.API_TOKEN}`,
}
});
})()

Sending API requests from UI tests

While running tests inside browsers you may want to make calls to the HTTP API of your application. It may be helpful if you need to prepare server state before running a test or to check some postconditions on the server after performing some actions in the browser. All of that could be achieved via APIRequestContext methods.

Establishing preconditions

The following test creates a new issue via API and then navigates to the list of all issues in the project to check that it appears at the top of the list.

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

const REPO = 'test-repo-1';
const USER = 'github-username';

// Request context is reused by all tests in the file.
let apiContext;

test.beforeAll(async ({ playwright }) => {
apiContext = await playwright.request.newContext({
// All requests we send go to this API endpoint.
baseURL: 'https://api.github.com',
extraHTTPHeaders: {
// We set this header per GitHub guidelines.
'Accept': 'application/vnd.github.v3+json',
// Add authorization token to all requests.
// Assuming personal access token available in the environment.
'Authorization': `token ${process.env.API_TOKEN}`,
},
});
})

test.afterAll(async ({ }) => {
// Dispose all responses.
await apiContext.dispose();
});

test('last created issue should be first in the list', async ({ page }) => {
const newIssue = await apiContext.post(`/repos/${USER}/${REPO}/issues`, {
data: {
title: '[Feature] request 1',
}
});
expect(newIssue.ok()).toBeTruthy();

await page.goto(`https://github.com/${USER}/${REPO}/issues`);
const firstIssue = page.locator(`a[data-hovercard-type='issue']`).first();
await expect(firstIssue).toHaveText('[Feature] request 1');
});

Validating postconditions

The following test creates a new issue via user interface in the browser and then uses checks if it was created via API:

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

const REPO = 'test-repo-1';
const USER = 'github-username';

// Request context is reused by all tests in the file.
let apiContext;

test.beforeAll(async ({ playwright }) => {
apiContext = await playwright.request.newContext({
// All requests we send go to this API endpoint.
baseURL: 'https://api.github.com',
extraHTTPHeaders: {
// We set this header per GitHub guidelines.
'Accept': 'application/vnd.github.v3+json',
// Add authorization token to all requests.
// Assuming personal access token available in the environment.
'Authorization': `token ${process.env.API_TOKEN}`,
},
});
})

test.afterAll(async ({ }) => {
// Dispose all responses.
await apiContext.dispose();
});

test('last created issue should be on the server', async ({ page, request }) => {
await page.goto(`https://github.com/${USER}/${REPO}/issues`);
await page.click('text=New Issue');
await page.fill('[aria-label="Title"]', 'Bug report 1');
await page.fill('[aria-label="Comment body"]', 'Bug description');
await page.click('text=Submit new issue');
const issueId = page.url().substr(page.url().lastIndexOf('/'));

const newIssue = await request.get(`https://api.github.com/repos/${USER}/${REPO}/issues/${issueId}`);
expect(newIssue.ok()).toBeTruthy();
expect(newIssue).toEqual(expect.objectContaining({
title: 'Bug report 1'
}));
});

Reusing authentication state

Web apps use cookie-based or token-based authentication, where authenticated state is stored as cookies. Playwright provides apiRequestContext.storageState([options]) method that can be used to retrieve storage state from an authenticated context and then create new contexts with that state.

Storage state is interchangeable between BrowserContext and APIRequestContext. You can use it to log in via API calls and then create a new context with cookies already there. The following code snippet retrieves state from an authenticated APIRequestContext and creates a new BrowserContext with that state.

const requestContext = await request.newContext({
httpCredentials: {
username: 'user',
password: 'passwd'
}
});
await requestContext.get(`https://api.example.com/login`);
// Save storage state into the file.
await requestContext.storageState({ path: 'state.json' });

// Create a new context with the saved storage state.
const context = await browser.newContext({ storageState: 'state.json' });