Use variables and test data

Keep the values your tests type and visit out of the test code. There are three common sources:

Environment variables for settings that change between environments, such as the app URL.
Fixtures for a known set of test data you reuse across tests.
Generated data for values that must be unique on every run.

To keep passwords and tokens out of logs as well, see Use secrets.

Read environment variables

Read settings from process.env so the same test runs against dev, staging, or production.

tests/home.test.mjs

import { expect, it } from 'vitest';
import { TestDriver } from 'testdriverai/vitest/hooks';

const appUrl = process.env.APP_URL ?? 'https://testdriver-sandbox.vercel.app';

it('shows the login form', async (context) => {
  const testdriver = TestDriver(context);
  await testdriver.provision.chrome({ url: `${appUrl}/login` });

  const result = await testdriver.assert('a login form is visible');
  expect(result).toBe(true);
});

Set the variable when you run the tests:

APP_URL=https://staging.example.com npx vitest run

TestDriver loads a .env file in your project root automatically, so you can also keep local values there:

.env

APP_URL=https://staging.example.com

Reuse test data with fixtures

Put shared test data in its own module and import it wherever you need it.

tests/fixtures/usernames.js

export const usernames = [
  { label: 'a typical username', value: 'standard_user' },
  { label: 'a username with a dot', value: 'jane.doe' },
  { label: 'a 32-character username', value: 'user_with_a_32_character_name_01' },
];

Use Vitest’s it.for() to run the same test once per fixture. Unlike it.each(), it.for() passes the test context as the second argument, which TestDriver(context) needs.

tests/login.test.mjs

import { expect, it } from 'vitest';
import { TestDriver } from 'testdriverai/vitest/hooks';
import { usernames } from './fixtures/usernames.js';

it.for(usernames)('accepts $label', async (username, context) => {
  const testdriver = TestDriver(context);
  await testdriver.provision.chrome({ url: 'https://testdriver-sandbox.vercel.app/login' });

  const usernameField = await testdriver.find('Username input field');
  await usernameField.click();
  await testdriver.type(username.value);

  const result = await testdriver.assert(`the username field contains "${username.value}"`);
  expect(result).toBe(true);
});

Each fixture becomes its own test with its own sandbox.

Generate unique data

When a test creates records, such as new accounts, generate fresh values on every run so they don’t collide with earlier runs. Faker is a common choice:

npm install --save-dev @faker-js/faker

tests/signup.test.mjs

import { faker } from '@faker-js/faker';
import { expect, it } from 'vitest';
import { TestDriver } from 'testdriverai/vitest/hooks';

it('creates an account', async (context) => {
  const testdriver = TestDriver(context);
  await testdriver.provision.chrome({ url: `${process.env.APP_URL}/signup` });

  const email = faker.internet.email();

  const emailField = await testdriver.find('Email input field');
  await emailField.click();
  await testdriver.type(email);

  const passwordField = await testdriver.find('Password input field');
  await passwordField.click();
  await testdriver.type(faker.internet.password({ length: 12 }), { secret: true });

  const createAccountButton = await testdriver.find('Create account button below the form');
  await createAccountButton.click();

  const result = await testdriver.assert('a welcome message is visible');
  expect(result).toBe(true);
});

Keep values out of descriptions

Pass changing values to type(), not to find(). The cache matches find() descriptions exactly. A description that contains a generated value misses the cache on every run:

// Misses the cache whenever the email changes
const emailField = await testdriver.find(`input next to ${email}`);

Describe the element itself, and type the value after you click it:

// Same description every run, so it can be cached
const emailField = await testdriver.find('Email input field');
await emailField.click();
await testdriver.type(email);

Next steps

Use secrets

Keep passwords and tokens out of code and logs.

Reuse code

Share helpers like a login step across tests.

Run in CI/CD

Pass environment variables to tests in your pipeline.

Caching

Write descriptions that reuse cached locations.

Overview

Using TestDriver

Building & maintaining tests

Advanced topics

Use variables and test data

Read environment variables

Reuse test data with fixtures

Generate unique data

Keep values out of descriptions

Next steps

Use secrets

Reuse code

Run in CI/CD

Caching

​Read environment variables

​Reuse test data with fixtures

​Generate unique data

​Keep values out of descriptions

​Next steps

Use secrets

Reuse code

Run in CI/CD

Caching

Read environment variables

Reuse test data with fixtures

Generate unique data

Keep values out of descriptions

Next steps