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Adding Console and Network Logs in Playwright

Posted on: 2024-04-01

I will show you how to add console and network logs in Playwright. Logs are helpful when you have tests working locally but not on a CI/CD pipeline. You can use these logs to debug and understand what's happening.

The first step is to add the logs to the test. You can use the page.on('console') and page.on('request') functions to listen to the logs. To avoid repetitive code, you can add these logs into a fixture. A test fixture sets up the environment for the tests.

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

test('my test', async ({ page }) => {
  page.on('console', (msg) => {
    console.log('PAGE LOG:', msg.text());
  });
  page.on('request', (request) => {
    console.log('REQUEST:', request.url());
  });
  await page.goto('https://playwright.dev/');
  const title = page.locator('.navbar__title');
  await expect(title).toHaveText('Playwright');
});
export const wrapper = ()=>{
  const consoleLines:string[]=[];

  const test = base.extend<MyFixtures>({
    workerStorageState:[
      async ({browser}, use):Promise<void>=>{
        const page = await browser.newPage();
        page.on('console', (msg) => {
          consoleLines.push(msg.text());
        });

        page.on('request', async(request) => {
          consoleLines.push(request.url());
          if(request.failure()){
            consoleLines.push(request.failure().errorText);
          }
        });
      },
    ],
    
  });
  test.beforeEach(async()=>{
    consoleLines.lenght=0;
  });
  test.afterEach(async({page})=>{
    if(test.info().status !== test.info().expectedStatus){
      console.log("Output of console logs for: " + test.info().title);
      console.log(consoleLines.join("\n");
    }
  });
  return test;
};

The code above is a simplification of the potential. The goal is to extend the base test and return a test containing the event that collects the logs into an array. If one of the tests fails, the wrapper prints the log in the console.

const test = wrapper();
test('my test', async ({ page }) => {
  await page.goto('https://playwright.dev/');
  const title = page.locator('.navbar__title');
  await expect(title).toHaveText('Playwright');
});

Like the original test, the wrapper returns a function but has the events listening. The tests execute normally, but the logs are printed to the console if they fail. You can use the logs in a CI/CD pipeline to understand what's happening.