---
title: "Scalability"
description: "From small projects to enterprise test suites with thousands of tests"
icon: "arrow-up-right-dots"
---

TestDriver scales effortlessly from your first test to enterprise suites with thousands of tests running in parallel across multiple platforms.

## Code Snippets for Reusability

Scale your test suite with reusable code snippets to reduce duplication and maintain consistency:

<Tabs>
  <Tab title="Helper Functions">
    ```javascript test/helpers/auth.js
    // Reusable authentication helpers
    export async function login(testdriver, { email, password }) {
      await testdriver.find('email input').type(email);
      await testdriver.find('password input').type(password);
      await testdriver.find('login button').click();
      await testdriver.assert('logged in successfully');
    }

    export async function logout(testdriver) {
      await testdriver.find('user menu').click();
      await testdriver.find('logout button').click();
    }
    ```

    <Warning>
      **Avoid hardcoding dynamic values in element descriptions.** Element selectors should describe the *type* of element, not specific content that might change.

      **❌ Bad:** `await testdriver.find('profile name TestDriver in the top right')`  
      **✅ Good:** `await testdriver.find('user profile name in the top right')`

      Hardcoded values like usernames, product names, or prices will cause tests to fail when the data changes. Use generic descriptions that work regardless of the specific content displayed.
    </Warning>

    ```javascript test/checkout.test.js
    import { login } from './helpers/auth.js';

    test('checkout flow', async (context) => {
      const { testdriver } = await chrome(context, { url });
      await login(testdriver, { 
        email: 'user@example.com',
        password: 'password123' 
      });
      // Continue with checkout test
    });
    ```
  </Tab>

  <Tab title="Page Objects">
    ```javascript test/pages/LoginPage.js
    export class LoginPage {
      constructor(testdriver) {
        this.testdriver = testdriver;
      }

      async login(email, password) {
        await this.testdriver.find('email input').type(email);
        await this.testdriver.find('password input').type(password);
        await this.testdriver.find('submit button').click();
      }

      async assertError(message) {
        await this.testdriver.assert(`error message shows "${message}"`);
      }
    }
    ```

    ```javascript test/auth.test.js
    import { LoginPage } from './pages/LoginPage.js';

    test('invalid login shows error', async (context) => {
      const { testdriver } = await chrome(context, { url });
      const loginPage = new LoginPage(testdriver);
      
      await loginPage.login('invalid@test.com', 'wrong');
      await loginPage.assertError('Invalid credentials');
    });
    ```
  </Tab>

  <Tab title="Custom Commands">
    ```javascript test/commands/navigation.js
    export function addNavigationCommands(testdriver) {
      testdriver.navigateTo = async (section) => {
        await testdriver.find(`${section} nav link`).click();
        await testdriver.assert(`${section} page is loaded`);
      };

      testdriver.searchFor = async (query) => {
        await testdriver.find('search input').type(query);
        await testdriver.find('search button').click();
        await testdriver.assert('search results are displayed');
      };

      return testdriver;
    }
    ```

    ```javascript test/search.test.js
    import { addNavigationCommands } from './commands/navigation.js';

    test('search functionality', async (context) => {
      let { testdriver } = await chrome(context, { url });
      testdriver = addNavigationCommands(testdriver);
      
      await testdriver.searchFor('laptop');
      // Custom command used
    });
    ```
  </Tab>
</Tabs>

<Check>
  Reusable snippets reduce test maintenance time by up to 70% in large test suites.
</Check>

## Dynamic Variables for Data-Driven Tests

Scale your testing with dynamic data to cover more scenarios:

<Tabs>
  <Tab title="Environment Variables">
    ```javascript
    import { test } from 'vitest';
    import { chrome } from 'testdriverai/presets';

    test('multi-environment testing', async (context) => {
      const env = process.env.TEST_ENV || 'staging';
      const urls = {
        dev: 'https://dev.myapp.com',
        staging: 'https://staging.myapp.com',
        production: 'https://myapp.com'
      };

      const { testdriver } = await chrome(context, { 
        url: urls[env] 
      });

      await testdriver.assert('app is running');
    });
    ```

    ```bash
    # Run against different environments
    TEST_ENV=dev vitest run
    TEST_ENV=staging vitest run
    TEST_ENV=production vitest run
    ```
  </Tab>

  <Tab title="Test Fixtures">
    ```javascript test/fixtures/users.js
    export const testUsers = [
      { email: 'admin@test.com', role: 'admin' },
      { email: 'user@test.com', role: 'user' },
      { email: 'guest@test.com', role: 'guest' }
    ];

    export const products = [
      { name: 'Laptop', price: 999 },
      { name: 'Mouse', price: 29 },
      { name: 'Keyboard', price: 89 }
    ];
    ```

    ```javascript test/permissions.test.js
    import { test } from 'vitest';
    import { chrome } from 'testdriverai/presets';
    import { testUsers } from './fixtures/users.js';

    test.each(testUsers)('$role can access dashboard', async ({ email, role }, context) => {
      const { testdriver } = await chrome(context, { url });
      
      await testdriver.find('email input').type(email);
      await testdriver.find('password input').type('password123');
      await testdriver.find('login button').click();
      
      if (role === 'admin') {
        await testdriver.assert('admin panel is visible');
      } else {
        await testdriver.assert('user dashboard is visible');
      }
    });
    ```
  </Tab>

  <Tab title="Dynamic Data Generation">
    ```javascript
    import { test } from 'vitest';
    import { chrome } from 'testdriverai/presets';
    import { faker } from '@faker-js/faker';

    test('user registration with dynamic data', async (context) => {
      const { testdriver } = await chrome(context, { url });

      // Generate unique test data for each run
      const userData = {
        firstName: faker.person.firstName(),
        lastName: faker.person.lastName(),
        email: faker.internet.email(),
        password: faker.internet.password({ length: 12 })
      };

      await testdriver.find('first name input').type(userData.firstName);
      await testdriver.find('last name input').type(userData.lastName);
      await testdriver.find('email input').type(userData.email);
      await testdriver.find('password input').type(userData.password);
      await testdriver.find('register button').click();

      await testdriver.assert('registration successful');
      console.log('Registered user:', userData.email);
    });
    ```

    ```bash
    npm install --save-dev @faker-js/faker
    ```
  </Tab>
</Tabs>

<Card title="Dynamic Variables Best Practices" icon="lightbulb">
  - **Environment configs:** Store URLs, credentials, and settings in env vars
  - **Test fixtures:** Maintain reusable test data in separate files
  - **Data generators:** Use libraries like Faker for unique test data
  - **Parameterization:** Test multiple scenarios with `test.each()`
  - **CI/CD integration:** Pass dynamic values via environment variables
</Card>

## Works with Vitest

Full integration with Vitest's powerful features:

```javascript vitest.config.mjs
import { defineConfig } from 'vitest/config';

export default defineConfig({
  test: {
    testTimeout: 120000,
    hookTimeout: 120000,
    maxConcurrency: 10,      // Run 10 tests in parallel
    minThreads: 2,
    maxThreads: 10,
  },
});
```

<CardGroup cols={2}>
  <Card title="Parallel Execution" icon="layer-group">
    Run multiple tests simultaneously for maximum throughput:

    ```bash
    # Run all tests in parallel
    vitest run

    # Control concurrency
    vitest run --max-concurrency=5
    ```
  </Card>

  <Card title="Watch Mode" icon="eye">
    Instant feedback during development:

    ```bash
    # Run in watch mode
    vitest

    # Only run changed tests
    vitest --changed
    ```
  </Card>
</CardGroup>

[See complete Vitest integration guide](/v7/guides/vitest)

## CI/CD Compatible

TestDriver integrates seamlessly with all major CI/CD platforms:

<Tabs>
  <Tab title="GitHub Actions">
    ```yaml .github/workflows/test.yml
    name: E2E Tests

    on: [push, pull_request]

    jobs:
      test:
        runs-on: ubuntu-latest
        steps:
          - uses: actions/checkout@v3
          - uses: actions/setup-node@v3
          - run: npm install
          - run: vitest run
            env:
              TD_API_KEY: ${{ secrets.TD_API_KEY }}
    ```

    [GitHub Actions guide](/v7/guides/ci-cd/github-actions)
  </Tab>

  <Tab title="GitLab CI">
    ```yaml .gitlab-ci.yml
    test:
      image: node:20
      script:
        - npm install
        - vitest run
      variables:
        TD_API_KEY: $TD_API_KEY
    ```

    [GitLab CI guide](/v7/guides/ci-cd/gitlab)
  </Tab>

  <Tab title="CircleCI">
    ```yaml .circleci/config.yml
    version: 2.1
    jobs:
      test:
        docker:
          - image: cimg/node:20.0
        steps:
          - checkout
          - run: npm install
          - run: vitest run
    ```

    [CircleCI guide](/v7/guides/ci-cd/circleci)
  </Tab>

  <Tab title="Jenkins">
    ```groovy Jenkinsfile
    pipeline {
      agent any
      stages {
        stage('Test') {
          steps {
            sh 'npm install'
            sh 'vitest run'
          }
        }
      }
    }
    ```

    [Jenkins guide](/v7/guides/ci-cd/jenkins)
  </Tab>
</Tabs>

## JUnit Reports

Generate JUnit XML reports for test result aggregation and CI/CD integration.

### Basic Setup

Configure Vitest to output JUnit reports by adding a reporter to your config:

```javascript vitest.config.mjs
import { defineConfig } from 'vitest/config';

export default defineConfig({
  test: {
    testTimeout: 120000,
    hookTimeout: 120000,
    reporters: ['default', 'junit'],
    outputFile: {
      junit: 'test-report.junit.xml'
    }
  },
});
```

Or run from the command line:

```bash
vitest run --reporter=junit --outputFile=test-results.xml
```

This generates a standard JUnit XML report:

```xml test-results.xml
<?xml version="1.0" encoding="UTF-8"?>
<testsuites name="vitest tests" tests="12" failures="0" errors="0" time="125.3">
  <testsuite name="login.test.js" tests="3" failures="0" time="31.2">
    <testcase name="user can login" time="12.4" />
    <testcase name="invalid credentials show error" time="9.8" />
    <testcase name="password reset works" time="9.0" />
  </testsuite>
</testsuites>
```

### GitHub Actions PR Comments

Use JUnit reports to automatically post test results as comments on pull requests. This provides immediate visibility into test failures without leaving GitHub.

```yaml .github/workflows/test.yml
name: E2E Tests

on:
  pull_request:
    branches: [main]

permissions:
  contents: read
  pull-requests: write
  checks: write

jobs:
  test:
    runs-on: ubuntu-latest
    
    steps:
      - uses: actions/checkout@v4
      
      - name: Setup Node.js
        uses: actions/setup-node@v4
        with:
          node-version: '20'
          cache: 'npm'
      
      - name: Install dependencies
        run: npm ci
      
      - name: Run tests
        run: vitest run
        env:
          TD_API_KEY: ${{ secrets.TD_API_KEY }}

      - name: Publish Test Results
        uses: EnricoMi/publish-unit-test-result-action@v2
        if: always()
        with:
          files: test-report.junit.xml
          comment_mode: always
          check_name: Test Results
```

<Note>
  The `if: always()` ensures test results are published even when tests fail, so you always see what went wrong.
</Note>

The [publish-unit-test-result-action](https://github.com/EnricoMi/publish-unit-test-result-action) creates:

- **PR comments** with a summary table of passed/failed tests
- **Check runs** visible in the GitHub PR checks tab
- **Annotations** highlighting failed tests in the diff view

### Multi-Platform Testing with JUnit

When testing across multiple platforms, use separate check names to distinguish results:

```yaml .github/workflows/test.yml
jobs:
  test-linux:
    runs-on: ubuntu-latest
    steps:
      # ... setup steps ...
      
      - name: Run Linux tests
        run: vitest run
        env:
          TD_API_KEY: ${{ secrets.TD_API_KEY }}
          TD_OS: linux

      - name: Publish Test Results
        uses: EnricoMi/publish-unit-test-result-action@v2
        if: always()
        with:
          files: test-report.junit.xml
          comment_mode: always
          check_name: Test Results (Linux)

  test-windows:
    runs-on: ubuntu-latest
    steps:
      # ... setup steps ...
      
      - name: Run Windows tests
        run: vitest run
        env:
          TD_API_KEY: ${{ secrets.TD_API_KEY }}
          TD_OS: windows

      - name: Publish Test Results
        uses: EnricoMi/publish-unit-test-result-action@v2
        if: always()
        with:
          files: test-report.junit.xml
          comment_mode: always
          check_name: Test Results (Windows)
```

<Check>
  JUnit reports integrate with Jenkins, Azure DevOps, TeamCity, GitLab, and other CI platforms for test result visualization.
</Check>

## Familiar Test Syntax

TestDriver works with the test frameworks you already know:

<Tabs>
  <Tab title="Vitest">
    ```javascript
    import { test, describe, beforeAll, afterAll } from 'vitest';
    import { chrome } from 'testdriverai/presets';

    describe('My Feature', () => {
      test('should work', async (context) => {
        const { testdriver } = await chrome(context, { url });
        await testdriver.find('button').click();
      });
    });
    ```
  </Tab>

  <Tab title="Jest">
    ```javascript
    import { chrome } from 'testdriverai/presets';

    describe('My Feature', () => {
      test('should work', async () => {
        const { testdriver } = await chrome({ url });
        await testdriver.find('button').click();
      });
    });
    ```
  </Tab>

  <Tab title="Mocha">
    ```javascript
    import { chrome } from 'testdriverai/presets';

    describe('My Feature', function() {
      it('should work', async function() {
        const { testdriver } = await chrome(this, { url });
        await testdriver.find('button').click();
      });
    });
    ```
  </Tab>
</Tabs>

## Existing Systems Integration

Drop TestDriver into your current workflow without disruption:

```javascript
import { test, expect } from 'vitest';
import { chrome } from 'testdriverai/presets';

test('integrates with existing assertions', async (context) => {
  const { testdriver } = await chrome(context, { url });

  // Use TestDriver's AI assertions
  await testdriver.assert('welcome message is visible');

  // Or use traditional assertions
  const button = await testdriver.find('submit button');
  expect(button.coordinates).toBeDefined();
  expect(button.text).toContain('Submit');

  // Mix and match as needed
  const element = await testdriver.exec('js', 'document.title');
  expect(element).toBe('My App');
});
```

## Scale to Thousands of Tests

TestDriver handles large test suites efficiently:

<Card title="Enterprise Test Suite Example" icon="building">
  ```
  Project: E-commerce Platform
  Total tests: 3,847
  Test files: 412
  Parallel runners: 20
  Total duration: 18 minutes

  Breakdown:
  - Unit tests: 2,134 (3 min)
  - Integration: 891 (7 min)
  - E2E (TestDriver): 822 (18 min)

  Cost per run: $4.32
  Runs per day: 50
  Monthly cost: $6,480
  ```

  With caching enabled:
  ```
  E2E duration: 8 minutes (2.25x faster)
  Cost per run: $1.89 (56% reduction)
  Monthly cost: $2,835 (saves $3,645/month)
  ```
</Card>

## Test Sharding

Distribute tests across multiple machines:

<Tabs>
  <Tab title="GitHub Actions Matrix">
    ```yaml .github/workflows/test.yml
    strategy:
      matrix:
        shard: [1, 2, 3, 4, 5]
    steps:
      - run: vitest run --shard=${{ matrix.shard }}/5
    ```

    Runs 5 parallel jobs, each handling 1/5 of tests.
  </Tab>

  <Tab title="GitLab CI Parallel">
    ```yaml .gitlab-ci.yml
    test:
      parallel: 5
      script:
        - vitest run --shard=$CI_NODE_INDEX/$CI_NODE_TOTAL
    ```
  </Tab>

  <Tab title="Manual Sharding">
    ```bash
    # Machine 1
    vitest run --shard=1/4

    # Machine 2
    vitest run --shard=2/4

    # Machine 3
    vitest run --shard=3/4

    # Machine 4
    vitest run --shard=4/4
    ```
  </Tab>
</Tabs>

## Team Collaboration

Built for teams with multiple developers:

<AccordionGroup>
  <Accordion title="Shared Test Cache">
    Tests automatically benefit from each other's cache entries:

    ```javascript
    // Developer A runs test
    await testdriver.find('submit button').click();
    // Creates cache entry

    // Developer B runs test later
    await testdriver.find('submit button').click();
    // Uses Developer A's cache ⚡
    ```

    Per-team cache sharing accelerates everyone's tests.
  </Accordion>

  <Accordion title="Dashcam Replays">
    Share test replays with your team:

    ```javascript
    test('shareable replay', async (context) => {
      const { testdriver, dashcam } = await chrome(context, { url });

      await testdriver.find('button').click();

      // Share replay URL with team
      console.log('Replay:', dashcam.url);
      // https://console.testdriver.ai/dashcam/abc123
    });
    ```

    View replays at [app.testdriver.ai](https://app.testdriver.ai)
  </Accordion>

  <Accordion title="Sandbox Management">
    Long-running sandboxes for team debugging:

    ```bash
    # Spawn a sandbox for the team
    testdriver sandbox spawn --timeout 7200000

    # Team members can connect
    export TESTDRIVER_SANDBOX_ID=i-0abc123def
    vitest run
    ```

    [Learn about sandbox management](/v7/guides/sandbox-management)
  </Accordion>
</AccordionGroup>

## Cost Optimization

TestDriver scales cost-effectively:

<Card title="Pricing Model" icon="dollar-sign">
  - **API calls:** Pay per AI vision analysis
  - **Sandbox time:** Pay per minute of VM usage
  - **Caching:** Reduces both costs dramatically
  - **Shared cache:** Team benefits from collective cache

  **Example costs:**
  - Single test run: $0.04 - $0.12
  - 100-test suite: $4 - $12 (first run)
  - Cached suite: $0.50 - $2 (90%+ savings)
</Card>

## Enterprise Scale

TestDriver supports the largest testing operations:

- **Unlimited tests** in enterprise plans
- **Unlimited sandbox hours** for large suites
- **Unlimited team members** for collaboration
- **Priority infrastructure** for faster execution
- **Dedicated support** for optimization help
- **Custom SLA** for guaranteed uptime

[Contact sales](https://testdriver.ai/enterprise) for enterprise pricing.

## Learn More

<CardGroup cols={2}>
  <Card
    title="Vitest Integration"
    icon="flask-vial"
    href="/v7/guides/vitest"
  >
    Complete Vitest guide
  </Card>

  <Card
    title="CI/CD Setup"
    icon="arrows-spin"
    href="/v7/guides/ci-cd/overview"
  >
    CI/CD integration guides
  </Card>

  <Card
    title="Performance Optimization"
    icon="gauge-high"
    href="/v7/guides/performance"
  >
    Optimize test performance
  </Card>

  <Card
    title="Self-Hosting"
    icon="server"
    href="/v7/guides/self-hosting"
  >
    Run on your infrastructure
  </Card>
</CardGroup>