Mastering Automated Authentication Flows with JavaScript Under Tight Deadlines

In rapid-paced development environments, ensuring the robustness of authentication flows via automated testing often becomes a critical yet challenging task. As a Lead QA Engineer, I encountered an urgent need to implement reliable automated auth flow tests using JavaScript, aiming to deliver under a strict deadline without compromising quality.

Understanding the Challenge

Authentication processes involve multiple steps—login, token refresh, logout—and often interact with various external systems and APIs. Automating these flows requires handling asynchronous calls, managing tokens, and simulating user interactions, all within a framework that is fast, reliable, and maintainable.

Strategy and Approach

Given the limited timeframe, I prioritized building a modular and reusable testing framework leveraging popular tools like JavaScript, Playwright, and JWT libraries. My goal was to rapidly develop scripts capable of executing login, verifying tokens, and handling session expirations.

Implementation Details

Setting Up the Environment

First, I set up Playwright—a powerful browser automation library—along with necessary dependencies:

npm init -y
npm install playwright jsonwebtoken axios

Creating Utility Functions

These utilities focus on encapsulating common operations such as login, token validation, and token refresh.

const { chromium } = require('playwright');
const jwt = require('jsonwebtoken');
const axios = require('axios');

async function performLogin(username, password) {
  const browser = await chromium.launch();
  const page = await browser.newPage();
  await page.goto('https://example.com/login');
  await page.fill('#username', username);
  await page.fill('#password', password);
  await page.click('#loginButton');
  // Wait for navigation or token storage
  await page.waitForSelector('#dashboard');
  // Extract token from storage or response
  const token = await page.evaluate(() => localStorage.getItem('authToken'));
  await browser.close();
  return token;
}

function validateToken(token) {
  try {
    const decoded = jwt.decode(token);
    const now = Math.floor(Date.now() / 1000);
    if (decoded.exp > now) {
      return true;
    }
    return false;
  } catch (error) {
    return false;
  }
}

async function refreshToken(refreshToken) {
  const response = await axios.post('https://api.example.com/auth/refresh', { refreshToken });
  return response.data.newToken;
}

Automating the Auth Flow

The core script performs login, checks token validity, and handles refresh logic.

(async () => {
  let token = await performLogin('[e-mail]', 'password123');

  if (validateToken(token)) {
    console.log('Token is valid. Proceeding with tests...');
  } else {
    console.log('Token expired, attempting refresh...');
    // For demonstration, assume refresh token stored elsewhere
    const refreshToken = 'stored-refresh-token';
    token = await refreshToken(refreshToken);
    if (validateToken(token)) {
      console.log('Token refreshed successfully. Continuing...');
    } else {
      console.error('Failed to refresh token. Re-login required.');
    }
  }
  // Further automated tests can be added here using the valid token
})();

Lessons Learned

1. Modularity is key—separating login, validate, and refresh prevents code duplication and eases maintenance.
2. Asynchronous handling is crucial—auth flows are inherently async, so using async/await ensures reliability.
3. Rapid prototyping with Playwright enables fast, reliable interaction with web pages, simulating real user actions.
4. Token validation prevents false positives, ensuring only valid tokens allow test continuation.

Final Thoughts

Automating complex auth flows under tight deadlines demands a well-structured, scalable approach. By leveraging JavaScript, Playwright, and JWT libraries, I created a resilient testing pipeline that accommodates token handling intricacies. This methodology supports quick turnarounds, reduces manual testing burden, and enhances overall application security validation.

---

Automated auth testing is an ongoing process—continuously refine your scripts, incorporate error handling, and adapt to evolving security protocols to maintain robustness and efficiency.

---

🛠️ QA Tip

I rely on TempoMail USA to keep my test environments clean.