Test data

Test data lives in data builders — small classes that generate everything a test needs: URLs, credentials, form values. Tests stay readable because the "what" (data) is separated from the "how" (steps).

Using a data builder

Pass a builder to E2ESetup, then read it with getTestData():

import { TavolaDataBuilder } from '../databuilders/tavola-data-builder.js';

const { getTestData, getDevices } = E2ESetup({
  databuilder: TavolaDataBuilder(),
  devices: { device: createChromeE2EApi({}) },
});

test('User can sign in', async () => {
  const { device } = getDevices();
  const { loginUrl, username, password } = getTestData();

  await device.navigate(loginUrl);
  await device.type('login-username', username);
  await device.type('login-password', password);
  // ...
});

Writing a data builder

Extend BaseDataBuilder and implement genImp() — it runs in the constructor and populates the instance:

databuilders/shop-data-builder.js

import { BaseDataBuilder } from './base-data-builder.js';

class genShopDataBuilder extends BaseDataBuilder {
  constructor() {
    super();
    this.name = 'ShopDataBuilder';
    this.version = '1';
    this.genImp();
  }

  /** @override */
  genImp() {
    this.baseUrl = 'https://shop.example.com';
    this.loginUrl = `${this.baseUrl}/login`;

    this.username = 'test-user';
    this.password = 'test-password';

    // Dynamic data: generate what must be unique per run
    const stamp = Date.now();
    this.newAccountEmail = `e2e-${stamp}@example.com`;

    return this;
  }
}

export function ShopDataBuilder() {
  return new genShopDataBuilder();
}

Export a factory function (not the class) so each test file gets a fresh instance.

Guidelines

Compute dates, don't hardcode them. A hardcoded "future" date becomes a past date eventually:

const future = new Date(Date.now() + 3 * 24 * 60 * 60 * 1000);
this.reservationDate = future.toISOString().slice(0, 10); // always 3 days ahead

Make unique what must be unique. Sign-up flows fail on the second run if the email is fixed — derive it from a timestamp.

Keep environment URLs in one place. When the staging URL changes, you edit one builder, not twenty tests.

Don't put steps in builders. Builders hold data. Page interactions belong in tests.