# Backend Testing

> Testing API endpoints and database operations

## 📋 Overview

This guide covers testing tRPC procedures, database queries, and API endpoints.

## 🧪 Setup

```bash
cd apps/api
pnpm add -D vitest @testcontainers/postgresql
```

## 📝 Testing tRPC Procedures

```typescript
import { describe, it, expect } from 'vitest'
import { appRouter } from '@izri/trpc/routers'
import { createTestContext } from './utils'

describe('projectsRouter', () => {
  it('lists user projects', async () => {
    const ctx = await createTestContext()
    const caller = appRouter.createCaller(ctx)
    
    const projects = await caller.projects.list()
    
    expect(projects).toEqual([])
  })
  
  it('creates a project', async () => {
    const ctx = await createTestContext()
    const caller = appRouter.createCaller(ctx)
    
    const project = await caller.projects.create({
      name: 'Test Project',
      repository: 'https://github.com/test/repo',
    })
    
    expect(project.name).toBe('Test Project')
  })
})
```

## 🗄️ Database Testing

```typescript
import { PostgreSqlContainer } from '@testcontainers/postgresql'
import { drizzle } from 'drizzle-orm/postgres-js'
import postgres from 'postgres'

let container: PostgreSqlContainer

beforeAll(async () => {
  container = await new PostgreSqlContainer().start()
  const connection = postgres(container.getConnectionUri())
  const db = drizzle(connection)
  
  // Run migrations
  await migrate(db, { migrationsFolder: './migrations' })
}, 60000)

afterAll(async () => {
  await container.stop()
})
```

## 📊 Test Utilities

```typescript
// test/utils.ts
export async function createTestContext() {
  const db = await getTestDatabase()
  const userId = 'test-user-' + Math.random()
  
  return {
    db,
    userId,
  }
}
```

## 🚀 Running Tests

```bash
# Run all tests
pnpm test

# Watch mode
pnpm test:watch

# Coverage
pnpm test:coverage
```

## 🔗 Related Documentation

- [Testing Guide](../../development/testing.md) - General testing
- [tRPC Server](./trpc-server.md) - tRPC patterns
- [Database Queries](./database-queries.md) - Database patterns

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**Section 05 (Backend) complete!** Next: [Packages documentation](../packages/README.md)