Why response validation confirms correctness in Postman - Test Execution Impact

Test Overview

This test sends a request to an API endpoint and checks the response status and body content. It verifies that the API returns the expected data, confirming the correctness of the response.

Test Code - Postman Tests

Postman

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

pm.test("Response has expected user name", function () {
    const jsonData = pm.response.json();
    pm.expect(jsonData.name).to.eql("John Doe");
});

Execution Trace - 4 Steps

Step	Action	System State	Assertion	Result
1	Send GET request to API endpoint /users/123	Postman sends HTTP GET request to the server	-	PASS
2	Receive HTTP response from server	Response received with status code 200 and JSON body	-	PASS
3	Check if response status code is 200	Response status code is 200 OK	pm.response.to.have.status(200)	PASS
4	Parse response JSON and check if 'name' field equals 'John Doe'	Response JSON contains {"name": "John Doe", ...}	pm.expect(jsonData.name).to.eql("John Doe")	PASS

Failure Scenario

Failing Condition: Response status code is not 200 or 'name' field does not match 'John Doe'

Execution Trace Quiz - 3 Questions

What does the test check first after receiving the response?

A If the status code is 200

B If the response time is less than 1 second

C If the response body is empty

D If the server is reachable

Key Result

Validating both the response status code and key response data ensures the API behaves correctly and returns expected results, which confirms the correctness of the response.