Maximizing Test Efficiency: Playwright's Parallel Execution with Cross-Browser Support

Introduction:

Automated testing has become an integral part of software development processes. It ensures that software is tested thoroughly, and the bugs are caught early, thus reducing the chances of issues arising later. 

One crucial aspect of automated testing is testing across multiple browsers, which can be time-consuming and resource-intensive. That's where Playwright's Parallel Execution comes into play. 

In this blog post, we'll explore in-depth how Playwright's Parallel Execution feature can be used to run tests against different browsers in parallel, saving time and resources.

What is Playwright:

Playwright is an open-source Node.js library for automating web browsers. It is a relatively new library that is gaining popularity because of its simplicity, reliability, and powerful API. 

Playwright supports multiple programming languages such as JavaScript, TypeScript, Java, C# and Python, which makes it easy for developers to write automation scripts in their preferred language. It provides an excellent API for interacting with web pages and allows testing against multiple browsers.

What is Playwright – How it is different from other Frameworks?

What is Parallel Execution?

Parallel Execution is a feature in Playwright that allows you to run tests against multiple browsers simultaneously. 

This feature allows you to write a test once and run it against different browsers, such as Chrome, Firefox, and Safari, simultaneously. 

This can save a significant amount of time and resources because you no longer have to run tests against each browser individually. Instead, you can run the tests against all the browsers concurrently, which can significantly reduce the time required to execute the tests.

How to use Parallel Execution in Playwright?

Playwright makes it easy to use Parallel Execution in your automation scripts. The following steps show how you can use Parallel Execution to run tests against different browsers.

Step 1: Create a new Project

$ npm init -y

Step 2: Install Typescript

$ npm install typescript

Step 3: Install Playwright

$ npm install playwright

Step 4: Install Playwright Runner

$ npm install @playwright/test

Step 5: Open Project in Visual Studio Code

$ code .

Once Project is opened in Visual Studio Code, Create folder called "src"- We are going to add test cases in this folder.

package.json 

{

  "name": "playwright-parallel",

  "version": "1.0.0",

  "description": "",

  "main": "index.js",

  "scripts": {

    "test": "echo \"Error: no test specified\" && exit 1"

  },

  "keywords": [],

  "author": "",

  "license": "ISC",

  "dependencies": {

    "@playwright/test": "^1.32.1",

    "playwright": "^1.32.1",

    "typescript": "^5.0.3"

  }

}

Step 6: Add playwright.config.ts file in the project

Add below code snippet -

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

export default defineConfig({

  projects: [

    /* Test against desktop browsers */

    {

      name: 'chromium',

      use: { ...devices['Desktop Chrome'] },

      fullyParallel: true,

    },

    {

      name: 'firefox',

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

      fullyParallel: true,

    },

    {

      name: 'webkit',

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

      fullyParallel: true,

    },

    /* Test against mobile viewports. */

    {

      name: 'Mobile Chrome',

      use: { ...devices['Pixel 5'] },

    },

    {

      name: 'Mobile Safari',

      use: { ...devices['iPhone 12'] },

    },

    /* Test against branded browsers. */

    {

      name: 'Google Chrome',

      use: { ...devices['Desktop Chrome'], channel: 'chrome' }, // or 'chrome-beta'

    },

    {

      name: 'Microsoft Edge',

      use: { ...devices['Desktop Edge'], channel: 'msedge' }, // or 'msedge-dev'

    },

  ],

});

Playwright can run your tests in multiple browsers and configurations by setting up projects in the config. You can also add different options for each project.

Step 7: Create parallel.test.ts file under src folder.

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

test.describe.configure({ mode: 'parallel' });

test('runs in parallel 1', async ({ browser }) => {

        const context = await browser.newContext();

        const page = await context.newPage();

        await page.goto("https://automationassist.blogspot.com");

        await page.close();

        await browser.close();

});

In this case we are using playwright/test runner to describe test with mode as parallel.

When we run these tests, Tests will be executed in parallel against all the browsers provided in config files 

Step 8: Run test

$ npx playwright test

Conclusion:

Playwright's Parallel Execution feature makes it easy to run tests against different browsers simultaneously, saving you time and resources. 

Whether you're testing your website or application for cross-browser compatibility or simply want to speed up your test runs, Parallel Execution is a powerful tool in your automation arsenal. Try it out in your next Playwright project and see the benefits for yourself!