api-test-patterns

API Test Patterns

Write comprehensive API tests that ensure reliability and contract compliance.

When to Use

• Testing REST or GraphQL APIs
• Validating API contracts
• Integration testing between services
• Testing error handling and edge cases
• Performance testing API endpoints

REST API Testing

Using Playwright API Testing

// tests/api/users.spec.ts
import { test, expect } from '@playwright/test';

test.describe('Users API', () => {
  const baseURL = process.env.API_URL || 'http://localhost:3000';

  test('GET /users returns list of users', async ({ request }) => {
    const response = await request.get(`${baseURL}/api/users`);

    expect(response.ok()).toBeTruthy();
    expect(response.status()).toBe(200);

    const users = await response.json();
    expect(Array.isArray(users)).toBeTruthy();
    expect(users.length).toBeGreaterThan(0);

    // Validate schema
    expect(users[0]).toMatchObject({
      id: expect.any(Number),
      email: expect.any(String),
      name: expect.any(String),
    });
  });

  test('POST /users creates new user', async ({ request }) => {
    const newUser = {
      email: '[email protected]',
      name: 'Test User',
      password: 'securepassword123',
    };

    const response = await request.post(`${baseURL}/api/users`, {
      data: newUser,
    });

    expect(response.status()).toBe(201);

    const created = await response.json();
    expect(created.email).toBe(newUser.email);
    expect(created.name).toBe(newUser.name);
    expect(created).not.toHaveProperty('password');
  });

  test('GET /users/:id returns single user', async ({ request }) => {
    const response = await request.get(`${baseURL}/api/users/1`);

    expect(response.ok()).toBeTruthy();

    const user = await response.json();
    expect(user.id).toBe(1);
  });

  test('PUT /users/:id updates user', async ({ request }) => {
    const updates = { name: 'Updated Name' };

    const response = await request.put(`${baseURL}/api/users/1`, {
      data: updates,
    });

    expect(response.ok()).toBeTruthy();

    const user = await response.json();
    expect(user.name).toBe('Updated Name');
  });

  test('DELETE /users/:id removes user', async ({ request }) => {
    const response = await request.delete(`${baseURL}/api/users/1`);

    expect(response.status()).toBe(204);

    // Verify deleted
    const getResponse = await request.get(`${baseURL}/api/users/1`);
    expect(getResponse.status()).toBe(404);
  });
});