E2E Testing - Bitwarden Clients

Overview

The Bitwarden clients repository uses Storybook as the primary tool for component-level E2E testing and visual regression testing. Storybook provides an isolated environment for developing and testing UI components.

Storybook Configuration

Available Commands

# Start Storybook development server
npm run storybook

# Build static Storybook for deployment
npm run build-storybook

# Build with webpack stats (for CI)
npm run build-storybook:ci

# Run Storybook tests
npm run test-stories

# Watch mode for story tests
npm run test-stories:watch

Storybook Dependencies

From package.json:

{
  "devDependencies": {
    "@storybook/addon-a11y": "9.1.16",
    "@storybook/addon-designs": "9.0.0-next.3",
    "@storybook/addon-docs": "9.1.16",
    "@storybook/addon-links": "9.1.16",
    "@storybook/addon-themes": "9.1.16",
    "@storybook/angular": "9.1.16",
    "@storybook/test-runner": "0.22.0",
    "@storybook/web-components-vite": "9.1.16",
    "storybook": "9.1.19"
  }
}

Storybook Features

1. Component Development

Storybook provides an isolated environment to develop components:

Live preview of component variations
Interactive controls for component props
Documentation alongside components
Accessibility testing via a11y addon

2. Visual Regression Testing

Using Chromatic for visual testing:

# Run Chromatic visual tests (if configured)
npx chromatic

The repository includes chromatic as a dependency for automated visual regression testing.

3. Accessibility Testing

The @storybook/addon-a11y addon automatically checks components for accessibility issues:

WCAG compliance violations
Color contrast issues
ARIA attribute problems
Keyboard navigation issues

Writing Stories

While the source files weren’t provided, typical Storybook stories in Angular projects follow this pattern:

Basic Component Story

import { Meta, StoryObj } from '@storybook/angular';
import { ButtonComponent } from './button.component';

const meta: Meta<ButtonComponent> = {
  title: 'Components/Button',
  component: ButtonComponent,
  tags: ['autodocs'],
  argTypes: {
    variant: {
      control: 'select',
      options: ['primary', 'secondary', 'danger'],
    },
    disabled: {
      control: 'boolean',
    },
  },
};

export default meta;
type Story = StoryObj<ButtonComponent>;

export const Primary: Story = {
  args: {
    variant: 'primary',
    label: 'Click me',
    disabled: false,
  },
};

export const Secondary: Story = {
  args: {
    variant: 'secondary',
    label: 'Click me',
  },
};

export const Disabled: Story = {
  args: {
    variant: 'primary',
    label: 'Disabled',
    disabled: true,
  },
};

Interactive Story with Actions

import { action } from '@storybook/addon-actions';

export const Interactive: Story = {
  args: {
    onClick: action('clicked'),
    onHover: action('hovered'),
  },
  render: (args) => ({
    props: args,
    template: `
      <app-button 
        [variant]="variant"
        (click)="onClick($event)"
        (mouseenter)="onHover($event)">
        {{ label }}
      </app-button>
    `,
  }),
};

Story with Multiple Components

import { moduleMetadata } from '@storybook/angular';
import { CommonModule } from '@angular/common';
import { FormBuilder, ReactiveFormsModule } from '@angular/forms';

const meta: Meta = {
  title: 'Forms/Login',
  decorators: [
    moduleMetadata({
      imports: [CommonModule, ReactiveFormsModule],
      providers: [FormBuilder],
    }),
  ],
};

export const LoginForm: Story = {
  render: () => ({
    template: `
      <form [formGroup]="loginForm">
        <app-input formControlName="email" label="Email" />
        <app-input formControlName="password" label="Password" type="password" />
        <app-button type="submit">Login</app-button>
      </form>
    `,
  }),
};

Test Runner

The Storybook test runner uses @storybook/test-runner to run automated tests:

Basic Test Configuration

Create a .storybook/test-runner.ts file:

import type { TestRunnerConfig } from '@storybook/test-runner';
import { checkA11y, injectAxe } from 'axe-playwright';

const config: TestRunnerConfig = {
  async preRender(page) {
    await injectAxe(page);
  },
  async postRender(page) {
    // Run accessibility tests on each story
    await checkA11y(page, '#storybook-root', {
      detailedReport: true,
      detailedReportOptions: {
        html: true,
      },
    });
  },
};

export default config;

Running Tests

# Make sure Storybook is running
npm run storybook

# In another terminal, run tests
npm run test-stories

# Or use the test URL directly
npm run test-stories -- --url http://localhost:6006

Testing Strategies

1. Visual Testing

Capture visual snapshots of components in different states:

export const AllStates: Story = {
  render: () => ({
    template: `
      <div style="display: grid; gap: 1rem;">
        <app-button variant="primary">Primary</app-button>
        <app-button variant="primary" disabled>Primary Disabled</app-button>
        <app-button variant="secondary">Secondary</app-button>
        <app-button variant="secondary" disabled>Secondary Disabled</app-button>
        <app-button variant="danger">Danger</app-button>
        <app-button variant="danger" disabled>Danger Disabled</app-button>
      </div>
    `,
  }),
};

2. Interaction Testing

Test user interactions with the @storybook/test library:

import { expect } from '@storybook/jest';
import { userEvent, within } from '@storybook/testing-library';

export const FilledForm: Story = {
  play: async ({ canvasElement }) => {
    const canvas = within(canvasElement);
    
    // Find form elements
    const emailInput = canvas.getByLabelText('Email');
    const passwordInput = canvas.getByLabelText('Password');
    const submitButton = canvas.getByRole('button', { name: /login/i });
    
    // Simulate user input
    await userEvent.type(emailInput, 'user@example.com');
    await userEvent.type(passwordInput, 'password123');
    
    // Verify form state
    await expect(emailInput).toHaveValue('user@example.com');
    await expect(passwordInput).toHaveValue('password123');
    
    // Submit form
    await userEvent.click(submitButton);
  },
};

3. Responsive Testing

Test components at different viewport sizes:

import { MINIMAL_VIEWPORTS } from '@storybook/addon-viewport';

const meta: Meta = {
  title: 'Components/ResponsiveCard',
  parameters: {
    viewport: {
      viewports: MINIMAL_VIEWPORTS,
    },
  },
};

export const Mobile: Story = {
  parameters: {
    viewport: {
      defaultViewport: 'mobile1',
    },
  },
};

export const Tablet: Story = {
  parameters: {
    viewport: {
      defaultViewport: 'tablet',
    },
  },
};

export const Desktop: Story = {
  parameters: {
    viewport: {
      defaultViewport: 'desktop',
    },
  },
};

4. Theme Testing

Test components with different themes using @storybook/addon-themes:

import { withThemeByClassName } from '@storybook/addon-themes';

const meta: Meta = {
  decorators: [
    withThemeByClassName({
      themes: {
        light: 'theme-light',
        dark: 'theme-dark',
      },
      defaultTheme: 'light',
    }),
  ],
};

Accessibility Testing

The @storybook/addon-a11y automatically runs accessibility checks:

const meta: Meta = {
  title: 'Components/AccessibleButton',
  parameters: {
    a11y: {
      // Configure accessibility rules
      config: {
        rules: [
          {
            id: 'color-contrast',
            enabled: true,
          },
        ],
      },
      // Optional: specify element to check
      element: '#root',
    },
  },
};

Using axe-playwright in test runner:

import { checkA11y } from 'axe-playwright';

export const Accessible: Story = {
  play: async ({ canvasElement }) => {
    // Component interactions
    const canvas = within(canvasElement);
    
    // Check accessibility
    await checkA11y(canvasElement, {
      rules: {
        'color-contrast': { enabled: true },
        'label': { enabled: true },
      },
    });
  },
};

Component Testing Workflow

1. Develop Component

# Start Storybook
npm run storybook

2. Create Stories

Create a .stories.ts file alongside your component:

components/
├── button/
│   ├── button.component.ts
│   ├── button.component.spec.ts  # Unit tests
│   └── button.stories.ts         # Storybook stories

3. Write Interaction Tests

Add play functions to test user interactions.

4. Run Tests

# Run all story tests
npm run test-stories

5. Visual Review

Use Chromatic or manual review to catch visual regressions.

Best Practices

1. Story Organization

Use clear story names: Primary, Disabled, WithError
Group related stories under the same title
Use autodocs tag to generate documentation

2. Component Variations

Create stories for all important states:

export const Default: Story = { args: {} };
export const Loading: Story = { args: { loading: true } };
export const Error: Story = { args: { error: 'Something went wrong' } };
export const Empty: Story = { args: { items: [] } };
export const WithData: Story = { args: { items: mockItems } };

3. Interaction Testing

Test happy paths
Test error states
Test form validation
Test async operations

4. Accessibility

Always enable a11y addon
Test keyboard navigation
Verify ARIA labels
Check color contrast

CI/CD Integration

GitHub Actions Example

name: Storybook Tests

on: [push, pull_request]

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - uses: actions/setup-node@v3
        with:
          node-version: '22'
      
      - name: Install dependencies
        run: npm ci
      
      - name: Build Storybook
        run: npm run build-storybook:ci
      
      - name: Run Storybook tests
        run: npm run test-stories
      
      - name: Run Chromatic
        uses: chromaui/action@v1
        with:
          projectToken: ${{ secrets.CHROMATIC_PROJECT_TOKEN }}
          buildScriptName: build-storybook

Troubleshooting

Storybook Won’t Start

Clear cache: rm -rf node_modules/.cache/storybook
Reinstall dependencies: npm ci
Check for port conflicts (default: 6006)

Test Runner Failing

Ensure Storybook is running: npm run storybook
Check the test URL: http://localhost:6006
Increase timeout for slow tests

Accessibility Violations

Review the a11y panel in Storybook UI
Fix violations in component code
Re-run tests to verify fixes

Alternative E2E Approaches

While Storybook is the primary E2E tool, other approaches include:

Browser Extension Testing

For the browser extension (apps/browser):

Manual testing in browser environments
Extension-specific test utilities
Browser automation with Puppeteer/Playwright (if configured)

Desktop App Testing

For Electron app (apps/desktop):

Spectron or Playwright Electron (if configured)
Manual testing in development mode

CLI Testing

For CLI app (apps/cli):

Integration tests with real commands
Mock API responses for offline testing

​Overview

​Storybook Configuration

​Available Commands

​Storybook Dependencies

​Storybook Features

​1. Component Development

​2. Visual Regression Testing

​3. Accessibility Testing

​Writing Stories

​Basic Component Story

​Interactive Story with Actions

​Story with Multiple Components

​Test Runner

​Basic Test Configuration

​Running Tests

​Testing Strategies

​1. Visual Testing

​2. Interaction Testing

​3. Responsive Testing

​4. Theme Testing

​Accessibility Testing

​Using the A11y Addon

​Programmatic A11y Testing

​Component Testing Workflow

​1. Develop Component

​2. Create Stories

​3. Write Interaction Tests

​4. Run Tests

​5. Visual Review

​Best Practices

​1. Story Organization

​2. Component Variations

​3. Interaction Testing

​4. Accessibility

​CI/CD Integration

​GitHub Actions Example

​Troubleshooting

​Storybook Won’t Start

​Test Runner Failing

​Accessibility Violations

​Alternative E2E Approaches

​Browser Extension Testing

​Desktop App Testing

​CLI Testing

​Resources