[BUG] Intermittent Issue where fixture is not returning unique data

Context:

• Playwright Version: 1.26.1
• Operating System: Mac
• Node.js version: v16.15.0
• Browser: N/A
• Extra: MacBook Pro M1 Pro

System:

• OS: macOS 13.0
• Memory: 576.33 MB / 32.00 GB

Binaries:

• Node: 16.15.0 - ~/.nvm/versions/node/v16.15.0/bin/node
• Yarn: 1.22.19 - /opt/homebrew/bin/yarn
• npm: 8.5.5 - ~/.nvm/versions/node/v16.15.0/bin/npm

Languages:

• Bash: 3.2.57 - /bin/bash

Help us help you! Put down a short code snippet that illustrates your bug and that we can run and debug locally. For example:

FIXTURE

import { test as base } from '@playwright/test';
import { faker } from '@faker-js/faker';

type Email = {
  email: string;
};

export const test = base.extend<{}, { email: Email }>({
  email: [async ({ browser }, use, workerInfo) => {
    const email = faker.internet.exampleEmail();
    await use({ email });
  }, { scope: 'worker' }],

});

export default test;
export const expect = test.expect;

TEST

import test, { expect } from '../../fixtures/testFixture';

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

test('Test One', async ({email}) => {
  console.log(email.email);
});

test('Test Two', async ({email}) => {
  console.log(email.email);
});

OUTPUT

Running 2 tests using 2 workers
[e-mail]
·[e-mail]
·

  2 passed (1s)
➜  play-on-e2e npm run test

> play-on-e2e@1.0.0 test
> npx playwright test


Running 2 tests using 2 workers
[e-mail]
[e-mail]
··

Describe the bug This example is a simplified version of the real issue I am facing in my actual e2e test project. I am using faker to generate fake data and passing this through to the test. The tests are running in parallel when this issue occurs. As you can see from the output where I print the fake email address on the first run the emails are the same but on the 2nd run the emails are unique.

I believe that the desired behaviour is the emails being unique. I would expect this because they run on separate workers. At the very least I would expect the results to be consistent.

Please can you look into it for me?

Add any other details about the problem here.

The reason this is an issue in my real tests is firebase is returning a 400 for 1 of the 2 requests when creating a user as they have to have unique email addresses.

It passes on some occasions which explains the intermittent behaviour.

Hope this helps. Thanks

[costag1982]

I have found a solution where I generate a random number to pass into the faker seed

import { test as base } from '@playwright/test';
import { faker } from '@faker-js/faker';

const randomIntFromInterval = (min: number, max: number): number => {
  return Math.floor(Math.random() * (max - min + 1) + min)
}

type Email = {
  email: string;
};

export const test = base.extend<{}, { email: Email }>({
  email: [async ({ browser }, use, workerInfo) => {
    const randomNum = randomIntFromInterval(0, 10000);
    faker.seed(randomNum);
    const email = faker.internet.exampleEmail();
    await use({ email });
  }, { scope: 'worker' }],

});

export default test;
export const expect = test.expect;

This seems to return unique emails now every time

> npx playwright test


Running 2 tests using 2 workers
{ email: '[e-mail]' }
·{ email: '[e-mail]' }
·

  2 passed (3s)
➜  play-on-e2e 

Once again thanks for your help

[pavelfeldman]

Closing as per above, please feel free to open a new issue if this does not cover your use case.