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name: webapp-testing description: Web application testing principles. E2E, Playwright, deep audit strategies.

Web App Testing

Discover and test everything. Leave no route untested.

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1. Deep Audit Approach

Discovery First

Target	How to Find
Routes	Scan app/, pages/, router files
API endpoints	Grep for HTTP methods
Components	Find component directories
Features	Read documentation

Systematic Testing

1. Map - List all routes/APIs
2. Scan - Verify they respond
3. Test - Cover critical paths

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2. Testing Pyramid for Web

        /\          E2E (Few)
       /  \         Critical user flows
      /----\
     /      \       Integration (Some)
    /--------\      API, data flow
   /          \
  /------------\    Component (Many)
                    Individual UI pieces

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3. E2E Test Principles

What to Test

Priority	Tests
1	Happy path user flows
2	Authentication flows
3	Critical business actions
4	Error handling

E2E Best Practices

Practice	Why
Use data-testid	Stable selectors
Wait for elements	Avoid flaky tests
Clean state	Independent tests
Avoid implementation details	Test user behavior

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4. Playwright Principles

Core Concepts

Concept	Use
Page Object Model	Encapsulate page logic
Fixtures	Reusable test setup
Assertions	Built-in auto-wait
Trace Viewer	Debug failures

Configuration

Setting	Recommendation
Retries	2 on CI
Trace	on-first-retry
Screenshots	on-failure
Video	retain-on-failure

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5. Visual Testing

When to Use

Scenario	Value
Design system	High
Marketing pages	High
Component library	Medium
Dynamic content	Lower

Strategy

• Baseline screenshots
• Compare on changes
• Review visual diffs
• Update intentional changes

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6. API Testing Principles

Coverage Areas

Area	Tests
Status codes	200, 400, 404, 500
Response shape	Matches schema
Error messages	User-friendly
Edge cases	Empty, large, special chars

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7. Test Organization

File Structure

tests/
├── e2e/           # Full user flows
├── integration/   # API, data
├── component/     # UI units
└── fixtures/      # Shared data

Naming Convention

Pattern	Example
Feature-based	login.spec.ts
Descriptive	user-can-checkout.spec.ts

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8. CI Integration

Pipeline Steps

1. Install dependencies
2. Install browsers
3. Run tests
4. Upload artifacts (traces, screenshots)

Parallelization

Strategy	Use
Per file	Playwright default
Sharding	Large suites
Workers	Multiple browsers

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9. Anti-Patterns

❌ Don't	✅ Do
Test implementation	Test behavior
Hardcode waits	Use auto-wait
Skip cleanup	Isolate tests
Ignore flaky tests	Fix root cause

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Remember: E2E tests are expensive. Use them for critical paths only.