write-e2e-test

name	write-e2e-test
description	Write Playwright E2E tests following project patterns for components and user interactions. Use when adding tests for new features, testing accessibility, or validating responsive behavior.

Write E2E Test

Create Playwright E2E tests for agentconfig.org following project patterns.

Test File Location

All E2E tests live in site/tests/e2e/:

site/tests/e2e/
├── app.spec.ts
├── comparison.spec.ts
├── fileTree.spec.ts
├── navigation.spec.ts
├── primitiveCards.spec.ts
└── theme.spec.ts

Test File Structure

import { test, expect } from '@playwright/test'

test.describe('Feature Name', () => {
  test.beforeEach(async ({ page }) => {
    await page.goto('/')
  })

  test('should do something specific', async ({ page }) => {
    // Arrange
    const element = page.getByRole('button', { name: 'Click me' })

    // Act
    await element.click()

    // Assert
    await expect(page.getByText('Success')).toBeVisible()
  })
})

Locator Strategy (Priority Order)

Use the most resilient locators, in this order of preference:

1. Role + Name (most resilient)

page.getByRole('button', { name: 'Submit' })
page.getByRole('heading', { name: 'Welcome' })
page.getByRole('navigation')

2. Label/Placeholder (for form elements)

page.getByLabel('Email address')
page.getByPlaceholder('Enter your email')

3. Text content (for static text)

page.getByText('Learn more')
page.getByText(/welcome/i)  // regex for flexible matching

4. Test ID (when others don't work)

page.getByTestId('file-tree-node')

5. CSS selectors (last resort)

page.locator('.custom-component')

Common Test Patterns

Navigation

test('should scroll to section when nav link is clicked', async ({ page }) => {
  const navLink = page.getByRole('link', { name: 'File Tree' })
  const section = page.getByRole('region', { name: 'File Tree' })

  await navLink.click()

  await expect(section).toBeInViewport()
})

Theme Toggle

test('should toggle between light and dark mode', async ({ page }) => {
  const toggle = page.getByRole('button', { name: /theme/i })

  await expect(page.locator('html')).toHaveAttribute('data-theme', 'light')

  await toggle.click()

  await expect(page.locator('html')).toHaveAttribute('data-theme', 'dark')
})

Expandable Content

test('should expand tree node on click', async ({ page }) => {
  const treeNode = page.getByRole('button', { name: '.github/' })
  const childNode = page.getByRole('button', { name: 'copilot-instructions.md' })

  await expect(childNode).not.toBeVisible()

  await treeNode.click()

  await expect(childNode).toBeVisible()
})

Copy to Clipboard

test('should copy template to clipboard', async ({ page, context }) => {
  await context.grantPermissions(['clipboard-read', 'clipboard-write'])

  const copyButton = page.getByRole('button', { name: 'Copy template' })
  await copyButton.click()

  const clipboardText = await page.evaluate(() => navigator.clipboard.readText())
  expect(clipboardText).toContain('expected content')
})

Responsive Testing

Test at multiple viewport sizes:

test.describe('Mobile viewport', () => {
  test.use({ viewport: { width: 375, height: 667 } })

  test('should show mobile navigation', async ({ page }) => {
    await expect(page.getByRole('button', { name: 'Menu' })).toBeVisible()
  })
})

test.describe('Desktop viewport', () => {
  test.use({ viewport: { width: 1280, height: 720 } })

  test('should show full navigation', async ({ page }) => {
    await expect(page.getByRole('navigation')).toBeVisible()
  })
})

Theme Testing

Test both light and dark modes:

test.describe('Dark mode', () => {
  test.use({ colorScheme: 'dark' })

  test('should render with dark theme colors', async ({ page }) => {
    // Verify dark mode specific styling
  })
})

test.describe('Light mode', () => {
  test.use({ colorScheme: 'light' })

  test('should render with light theme colors', async ({ page }) => {
    // Verify light mode specific styling
  })
})

Test Independence

Each test must be independent:

• Don't rely on state from previous tests
• Use beforeEach for common setup
• Clean up any side effects

Assertions

Use Playwright's built-in assertions (auto-waiting):

// Good - auto-waits for element
await expect(page.getByText('Hello')).toBeVisible()
await expect(page.getByRole('button')).toBeEnabled()
await expect(page.locator('.item')).toHaveCount(3)
await expect(page.getByRole('link')).toHaveAttribute('href', '/about')

// Bad - doesn't auto-wait
const text = await page.textContent('.item')
expect(text).toBe('Hello')

Test Naming

Use descriptive names that explain the expected behavior:

// Good
test('should expand tree node when clicked', ...)
test('should scroll to File Tree section when nav link is clicked', ...)
test('should display error message when copy fails', ...)

// Bad
test('click test', ...)
test('tree works', ...)
test('test 1', ...)

Running Tests

cd site
bun run test              # Run all tests
bun run test:ui           # Interactive test UI

Checklist

Before considering tests complete:

• Uses resilient locators (role > text > testid > css)
• Each test is independent
• Test name describes expected behavior
• Uses Playwright auto-waiting assertions
• Covers happy path and edge cases
• Tests responsive behavior if relevant
• Tests both themes if relevant
• No hardcoded waits (page.waitForTimeout)