Dynamic assertion values in Postman - Test Execution Trace

Test Overview

This test sends a GET request to a user API endpoint and verifies that the returned user ID matches the expected dynamic value from the response. It checks that the user name is not empty and the status code is 200.

Test Code - Postman

Postman

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

pm.test("User ID matches dynamic value", function () {
    const jsonData = pm.response.json();
    const expectedUserId = jsonData.data.id;
    pm.expect(jsonData.data.id).to.eql(expectedUserId);
});

pm.test("User name is not empty", function () {
    const jsonData = pm.response.json();
    pm.expect(jsonData.data.name).to.not.be.empty;
});

Execution Trace - 4 Steps

Step	Action	System State	Assertion	Result
1	Send GET request to https://api.example.com/users/123	Request sent, waiting for response	-	PASS
2	Receive response with status code 200 and JSON body containing user data	Response received: {"data":{"id":123,"name":"Alice"}}	Check that status code is 200	PASS
3	Extract user ID from response JSON and assign to expectedUserId	expectedUserId = 123	Verify that response user ID equals expectedUserId	PASS
4	Check that user name field is not empty	User name is 'Alice'	Verify user name is not empty	PASS

Failure Scenario

Failing Condition: Response user ID does not match the dynamically extracted expectedUserId

Execution Trace Quiz - 3 Questions

What does the test verify about the user ID?

A It is always 123 regardless of response

B It matches the dynamic value extracted from the response

C It is not checked in the test

D It is compared to a hardcoded value 456

Key Result

Using dynamic values from the response in assertions makes tests flexible and reliable, avoiding hardcoded checks that can break with data changes.