Mohammad Waseem

Posted on Jan 30

Streamlining Authentication Flow Automation in Node.js Without Documentation

#automation #node #qa

In modern software development, automating authentication flows is crucial for ensuring robust, repeatable testing and deployment processes. However, as a Lead QA Engineer, I faced the challenge of implementing this automation in Node.js despite minimal or nonexistent documentation. This post outlines my approach, lessons learned, and best practices for tackling such scenarios.

Understanding the Authentication Flow

Initially, the absence of documentation meant I needed to reverse-engineer the existing authentication process. I started by analyzing network traffic using tools like Chrome DevTools or Wireshark to inspect the login request and response patterns. For example, I noticed that the login process involved a POST request to /api/auth/login with credentials in JSON format:

{
  "username": "testuser",
  "password": "password123"
}

and received a response containing a session token:

{
  "token": "abcdef1234567890"
}

This key insight set the foundation for automating the flow.

Building the Automation with Node.js

Leveraging Node.js with popular libraries such as axios for HTTP requests and jest for assertions, I constructed a script to handle login, token retrieval, and subsequent authenticated requests.

Step 1: Setup Dependencies

npm init -y
npm install axios jest

Step 2: Implementing the Login Function

const axios = require('axios');

async function login(username, password) {
  const response = await axios.post('https://example.com/api/auth/login', {
    username,
    password
  });
  return response.data.token;
}

This function captures the authentication token needed for further requests.

Step 3: Automate Authenticated Requests

async function getUserProfile(token) {
  const response = await axios.get('https://example.com/api/user/profile', {
    headers: {
      Authorization: `Bearer ${token}`
    }
  });
  return response.data;
}

Step 4: Testing the Flow

Create a test script with jest.

const { login, getUserProfile } = require('./auth');

test('Authentication flow works correctly', async () => {
  const token = await login('testuser', 'password123');
  expect(token).toBeDefined();
  const profile = await getUserProfile(token);
  expect(profile).toHaveProperty('username', 'testuser');
});

Handling Challenges

Without proper documentation, maintaining and scaling these tests can be difficult. To mitigate this, I relied heavily on inspecting live APIs and leveraging network captures. Additionally, creating a minimal internal documentation or comments within my scripts helped future team members understand the flow.

Lessons Learned

Reverse Engineering is Key: Network traffic analysis provides invaluable clues when documentation is lacking.
Modular Code: Isolating login and data-fetching logic improves maintainability.
Token Management: Securely storing and renewing tokens is vital for extended tests.
Continuous Questions: Always verify if the API contracts change, necessitating script updates.

Conclusion

Automating auth flows without documentation is challenging but feasible with a methodical approach. Network inspection combined with modular, well-structured Node.js scripts allows QA teams to develop reliable automation, ultimately leading to more resilient deployment pipelines and thorough testing coverage. As a best practice, investing in proper API documentation reduces effort in the long term, but when absent, reverse engineering remains a powerful tool for QA automation.

Note: Keep your scripts adaptable, and always validate token handling and API updates to ensure your automation remains effective.

🛠️ QA Tip

To test this safely without using real user data, I use TempoMail USA.

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