typescript-e2e-testing

What this skill does

# E2E Testing Skill

E2E testing validates complete workflows from user perspective, using real infrastructure via Docker.

---

## Workflows

For comprehensive step-by-step guidance, use the appropriate workflow:

| Workflow | When to Use |
|----------|-------------|
| [Setup E2E Test](workflows/setup/workflow.md) | Setting up E2E infrastructure for a new or existing project |
| [Writing E2E Test](workflows/writing/workflow.md) | Creating new E2E test cases with proper GWT pattern |
| [Review E2E Test](workflows/review/workflow.md) | Reviewing existing tests for quality and correctness |
| [Running E2E Test](workflows/running/workflow.md) | Executing tests with proper verification |
| [Debugging E2E Test](workflows/debugging/workflow.md) | Systematically fixing failing tests |
| [Optimize E2E Test](workflows/optimize/workflow.md) | Improving test suite performance |

## Workflow Selection Guide

**IMPORTANT**: Before starting any E2E testing task, identify the user's intent and load the appropriate workflow.

### Detect User Intent → Select Workflow

| User Says / Wants | Workflow to Load | File |
|-------------------|------------------|------|
| "Set up E2E tests", "configure docker-compose", "add E2E to project", "create test helpers" | **Setup** | `workflows/setup/workflow.md` |
| "Write E2E tests", "add integration tests", "test this endpoint", "create e2e-spec" | **Writing** | `workflows/writing/workflow.md` |
| "Review E2E tests", "check test quality", "audit tests", "is this test correct?" | **Reviewing** | `workflows/review/workflow.md` |
| "Run E2E tests", "execute tests", "start docker and test", "check if tests pass" | **Running** | `workflows/running/workflow.md` |
| "Fix E2E tests", "debug tests", "tests are failing", "flaky test", "connection error" | **Debugging** | `workflows/debugging/workflow.md` |
| "Speed up E2E tests", "optimize tests", "tests are slow", "reduce test time" | **Optimizing** | `workflows/optimize/workflow.md` |

### Workflow Execution Protocol

1. **ALWAYS load the workflow file first** - Read the full workflow before taking action
2. **Follow each step in order** - Complete checkpoints before proceeding
3. **Load knowledge files as directed** - Each workflow specifies which `references/` files to read
4. **Verify compliance after completion** - Re-read relevant reference files to ensure quality

**Important**: Each workflow includes instructions to load relevant knowledge from the `references/` folder before and after completing tasks.

---

## Knowledge Base Structure

```
references/
├── common/              # Shared testing fundamentals
│   ├── knowledge.md     # Core E2E concepts and test pyramid
│   ├── rules.md         # Mandatory testing rules (GWT, timeouts, logging)
│   ├── best-practices.md # Test design and cleanup patterns
│   ├── test-case-creation-guide.md # GWT templates for all scenarios
│   ├── nestjs-setup.md  # NestJS app bootstrap and Jest config
│   ├── debugging.md     # VS Code config and log analysis
│   └── examples.md      # Comprehensive examples by category
│
├── kafka/               # Kafka-specific testing
│   ├── knowledge.md     # Why common approaches fail, architecture
│   ├── rules.md         # Kafka-specific testing rules
│   ├── test-helper.md   # KafkaTestHelper implementation
│   ├── docker-setup.md  # Redpanda/Kafka Docker configs
│   ├── performance.md   # Optimization techniques
│   ├── isolation.md     # Pre-subscription pattern details
│   └── examples.md      # Kafka test examples
│
├── postgres/            # PostgreSQL-specific testing
│   ├── knowledge.md     # PostgreSQL testing concepts
│   ├── rules.md         # Cleanup, transaction, assertion rules
│   ├── test-helper.md   # PostgresTestHelper implementation
│   └── examples.md      # CRUD, transaction, constraint examples
│
├── mongodb/             # MongoDB-specific testing
│   ├── knowledge.md     # MongoDB testing concepts
│   ├── rules.md         # Document cleanup and assertion rules
│   ├── test-helper.md   # MongoDbTestHelper implementation
│   ├── docker-setup.md  # Docker and Memory Server setup
│   └── examples.md      # Document and aggregation examples
│
├── redis/               # Redis-specific testing
│   ├── knowledge.md     # Redis testing concepts
│   ├── rules.md         # TTL and pub/sub rules
│   ├── test-helper.md   # RedisTestHelper implementation
│   ├── docker-setup.md  # Docker configuration
│   └── examples.md      # Cache, session, rate limit examples
│
└── api/                 # API testing (REST, GraphQL, gRPC)
    ├── knowledge.md     # API testing concepts
    ├── rules.md         # Request/response assertion rules
    ├── test-helper.md   # Auth and Supertest helpers
    ├── examples.md      # REST, GraphQL, validation examples
    └── mocking.md       # MSW and Nock external API mocking
```

## Quick Reference by Task

> **Tip**: For detailed step-by-step guidance, use the [Workflows](#workflows) section above.

### Setup New E2E Structure
**Workflow**: [Setup E2E Test](workflows/setup/workflow.md)
1. Read `references/common/knowledge.md` - Understand E2E fundamentals
2. Read `references/common/nestjs-setup.md` - Project setup
3. Read technology-specific `docker-setup.md` files as needed

### Write Test Cases
**Workflow**: [Writing E2E Test](workflows/writing/workflow.md)
1. **MANDATORY**: Read `references/common/rules.md` - GWT pattern, timeouts
2. Read `references/common/test-case-creation-guide.md` - Templates
3. Read technology-specific files:
   - **Kafka**: `references/kafka/knowledge.md` → `test-helper.md` → `isolation.md`
   - **PostgreSQL**: `references/postgres/rules.md` → `test-helper.md`
   - **MongoDB**: `references/mongodb/rules.md` → `test-helper.md`
   - **Redis**: `references/redis/rules.md` → `test-helper.md`
   - **API**: `references/api/rules.md` → `test-helper.md`

### Review Test Quality
**Workflow**: [Review E2E Test](workflows/review/workflow.md)
1. Read `references/common/rules.md` - Check against mandatory patterns
2. Read `references/common/best-practices.md` - Quality standards
3. Read technology-specific `rules.md` files

### Run E2E Tests
**Workflow**: [Running E2E Test](workflows/running/workflow.md)
1. Verify Docker infrastructure is running
2. Run tests sequentially with `npm run test:e2e > /tmp/e2e-${E2E_SESSION}-output.log 2>&1`
3. Follow failure protocol if tests fail

### Debug Failing Tests
**Workflow**: [Debugging E2E Test](workflows/debugging/workflow.md)
1. Read `references/common/debugging.md`
2. Create `/tmp/e2e-${E2E_SESSION}-failures.md` tracking file
3. Fix ONE test at a time

### Optimize Test Performance
**Workflow**: [Optimize E2E Test](workflows/optimize/workflow.md)
1. Read `references/common/best-practices.md` - Performance patterns
2. Read `references/kafka/performance.md` for Kafka tests
3. Measure baseline before making changes

### Examples
- Read `references/common/examples.md` for general patterns
- Read technology-specific `examples.md` for detailed scenarios

---

## Core Principles

### 0. Context Efficiency (Temp File Output)
**ALWAYS redirect E2E test output to temp files, NOT console**. E2E output is verbose and bloats agent context.

**IMPORTANT**: Redirect output to temp files only (NO console output). Use unique session ID to prevent conflicts.

```bash
# Generate unique session ID at start of debugging session
export E2E_SESSION=$(date +%s)-$$

# Standard pattern - redirect to file only (no console output)
npm run test:e2e > /tmp/e2e-${E2E_SESSION}-output.log 2>&1

# Read summary only (last 50 lines)
tail -50 /tmp/e2e-${E2E_SESSION}-output.log

# Get failure details
grep -B 2 -A 15 "FAIL\|✕" /tmp/e2e-${E2E_SESSION}-output.log

# Cleanup when done
rm -f /tmp/e2e-${E2E_SESSION}-*.log /tmp/e2e-${E2E_SESSION}-*.md
```

**Temp Files** (with `${E2E_SESSION}` unique per agent):
- `/tmp/e2e-${E2E_SESSION}-output.log` - Full test output
- `/tmp/e2e-${E2E_SESSION}-failures.log` - Filtered failure output
- `/tmp/e2e-${E2