Example requests and responses in Postman - Build an Automation Script

Verify GET request to fetch user details

Preconditions (2)

Step 1: Open Postman

Step 2: Create a new GET request

Step 3: Enter URL https://api.example.com/users/123

Step 4: Click Send button

Step 5: Observe the response body and status code

✅ Expected Result: Response status code is 200 and response body contains user details with id 123

Automation Requirements - Postman Tests (JavaScript)

Assertions Needed:

Verify response status code is 200

Verify response body contains user id 123

Verify response body has keys: id, name, email

Best Practices:

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

Use pm.expect with JSON parsing for body content

Write clear and simple test scripts inside Postman Tests tab

Automated Solution

Postman

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

pm.test('Response has user id 123', function () {
    const jsonData = pm.response.json();
    pm.expect(jsonData.id).to.eql(123);
});

pm.test('Response has required keys', function () {
    const jsonData = pm.response.json();
    pm.expect(jsonData).to.have.all.keys('id', 'name', 'email');
});

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

The second test parses the JSON response and verifies the user id is exactly 123.

The third test ensures the response JSON contains the keys 'id', 'name', and 'email', confirming the expected data structure.

All tests use Postman's pm and pm.expect APIs for clear and reliable assertions.

Common Mistakes - 3 Pitfalls

Not parsing response JSON before accessing properties

Checking status code with pm.response.code instead of pm.response.to.have.status

Hardcoding expected values without verifying response structure

Bonus Challenge

Now add tests for POST request to create a new user with 3 different user data inputs

Show Hint