Master the art of Network Interception in Playwright for Mocking API Responses

Rationale for Network Interception

Network interception serves several critical purposes:

• Mocking API Responses: Facilitate the replacement of server responses with tailored data for controlled testing.
• Simulating Fault Scenarios: Enable the evaluation of application behavior under failed API conditions.
• Validating Frontend Logic: Assess application responses to varied backend data inputs.
• Enhancing Test Efficiency: Reduce dependency on live servers, thereby accelerating and stabilizing test execution.

Configuring Network Interception

Playwright’s page.route() function allows precise interception by matching URL patterns and implementing custom logic to modify responses dynamically.

Foundational Configuration

Below is an example of intercepting and mocking an API response:

const { test, expect } = require('@playwright/test');

test('Mock API response with Playwright', async ({ page }) => {
    // Intercept the API request
    await page.route('https://api.example.com/data', async route => {
        // Define mock response
        const mockData = {
            status: 'success',
            items: [
                { id: 1, name: 'Mock Item 1' },
                {…