Extracting data from responses in Postman - Test Execution Trace

Test Overview

This test sends a GET request to a sample API endpoint and extracts a specific value from the JSON response. It verifies that the extracted value matches the expected result.

Test Code - Postman

Postman

pm.test("Extract user ID from response", function () {
    pm.sendRequest('https://jsonplaceholder.typicode.com/users/1', function (err, res) {
        pm.expect(err).to.be.null;
        pm.expect(res).to.have.property('status', 200);
        const jsonData = res.json();
        const userId = jsonData.id;
        pm.expect(userId).to.eql(1);
        pm.environment.set('extractedUserId', userId);
    });
});

Execution Trace - 5 Steps

Step	Action	System State	Assertion	Result
1	Test starts and sends GET request to 'https://jsonplaceholder.typicode.com/users/1'	Postman sends HTTP GET request to the API endpoint	-	PASS
2	Receives HTTP response with status code 200 and JSON body	Response contains user data JSON with id, name, username, etc.	Check that response status code is 200	PASS
3	Parses JSON response and extracts 'id' field value	Extracted userId = 1	Verify extracted userId equals 1	PASS
4	Stores extracted userId in environment variable 'extractedUserId'	Environment variable 'extractedUserId' set to 1	-	PASS
5	Test completes successfully	Test result marked as passed in Postman test runner	-	PASS

Failure Scenario

Failing Condition: Response status code is not 200 or 'id' field is missing or incorrect

Execution Trace Quiz - 3 Questions

What does the test verify after receiving the response?

A That the response body is empty

B That the request method is POST

C That the response status code is 200 and 'id' equals 1

D That the environment variable is deleted

Key Result

Always verify the response status code before extracting data, and store extracted values in environment variables for reuse in subsequent requests.