aws-testing

AWS Testing

Skill para estrategias de testing en workloads AWS: pruebas unitarias, integración, contratos, end-to-end, property-based testing, mocking de servicios AWS y quality gates en CI/CD.

Principios fundamentales

• Test pyramid: muchos unit tests, algunos integration tests, pocos E2E tests.
• Lógica de negocio siempre testeable sin AWS: separar handler de service de repository.
• Mocks para unit tests, servicios reales (o LocalStack/DynamoDB Local) para integration tests.
• Cada PR debe pasar quality gates: tests, linting, type checking, coverage mínimo.
• Property-based testing para validar invariantes y encontrar edge cases que los tests manuales no cubren.

Pirámide de testing para serverless

        ┌─────────┐
        │  E2E    │  Pocos: flujos críticos contra stack desplegado
        ├─────────┤
        │ Integr. │  Algunos: Lambda + DynamoDB Local, API contracts
        ├─────────┤
        │  Unit   │  Muchos: lógica de negocio pura, sin AWS
        └─────────┘

Unit testing

Python con pytest

import pytest
from unittest.mock import MagicMock
from functions.orders.service import OrderService

@pytest.fixture
def mock_repo():
    return MagicMock()

def test_create_order_success(mock_repo):
    mock_repo.save.return_value = None
    service = OrderService(mock_repo)
    result = service.create({"item": "laptop", "quantity": 1, "price": 999.99})
    assert result["status"] == "created"
    mock_repo.save.assert_called_once()

def test_create_order_invalid_quantity(mock_repo):
    service = OrderService(mock_repo)
    with pytest.raises(ValueError, match="quantity must be positive"):
        service.create({"item": "laptop", "quantity": 0, "price": 999.99})

TypeScript con Vitest

import { describe, it, expect, vi, beforeEach } from 'vitest';
import { OrderService } from './service';

describe('OrderService', () => {
  const mockRepo = { save: vi.fn(), findById: vi.fn() };

  beforeEach(() => vi.clearAllMocks());

  it('should create order successfully', async () => {
    mockRepo.save.mockResolvedValue(undefined);
    const service = new OrderService(mockRepo);
    const result = await service.create({ item: 'laptop', quantity: 1, price: 999.99 });
    expect(result.status).toBe('created');
    expect(mockRepo.save).toHaveBeenCalledOnce();
  });

  it('should reject invalid quantity', async () => {
    const service = new OrderService(mockRepo);
    await expect(service.create({ item: 'laptop', quantity: 0, price: 999.99 }))
      .rejects.toThrow('quantity must be positive');
  });
});