Why Postman supports non-functional testing - Automation Benefits in Action

Verify API response time and status code using Postman

Preconditions (2)

Step 1: Open Postman and create a new GET request

Step 2: Enter the API endpoint URL in the request URL field

Step 3: Click the Send button to send the request

Step 4: Observe the response status code and response time displayed in Postman

✅ Expected Result: The response status code should be 200 OK and the response time should be less than 2000 milliseconds

Automation Requirements - Postman Test Scripts (JavaScript)

Assertions Needed:

Verify response status code is 200

Verify response time is less than 2000 ms

Best Practices:

Use pm.response.to.have.status() for status code assertion

Use pm.response.responseTime to check response time

Write clear and simple test scripts inside the Tests tab

Avoid hardcoding values; use environment variables if needed

Automated Solution

Postman

pm.test('Status code is 200', () => {
    pm.response.to.have.status(200);
});

pm.test('Response time is less than 2000ms', () => {
    pm.expect(pm.response.responseTime).to.be.below(2000);
});

The first test checks if the API response status code is exactly 200, which means the request was successful.

The second test checks if the response time is less than 2000 milliseconds, ensuring the API is fast enough.

Both tests use Postman's built-in pm object and assertion methods for clarity and reliability.

Common Mistakes - 3 Pitfalls

Not checking the response time in tests

Hardcoding API URLs and values directly in test scripts

Using incorrect assertion syntax like pm.response.status instead of pm.response.to.have.status()

Bonus Challenge

Now add tests to verify the API response contains a specific JSON field with expected value for 3 different endpoints

Show Hint