Header assertions in Postman - Test Execution Trace

Test Overview

This test sends a GET request to an API endpoint and verifies that the response headers contain the expected content type and server information.

Test Code - Postman

Postman

pm.test("Response has correct Content-Type header", function () {
    pm.response.to.have.header("Content-Type");
    pm.expect(pm.response.headers.get("Content-Type")).to.include("application/json");
});

pm.test("Response has Server header", function () {
    pm.response.to.have.header("Server");
    pm.expect(pm.response.headers.get("Server")).to.equal("nginx/1.18.0");
});

Execution Trace - 5 Steps

Step	Action	System State	Assertion	Result
1	Send GET request to the API endpoint	Request sent, waiting for response	-	PASS
2	Check if response has 'Content-Type' header	Response received with headers	Verify 'Content-Type' header exists	PASS
3	Verify 'Content-Type' header includes 'application/json'	Header value is 'application/json; charset=utf-8'	Check header value contains 'application/json'	PASS
4	Check if response has 'Server' header	Response headers available	Verify 'Server' header exists	PASS
5	Verify 'Server' header equals 'nginx/1.18.0'	Header value is 'nginx/1.18.0'	Check header value equals expected string	PASS

Failure Scenario

Failing Condition: The response does not include the expected 'Content-Type' or 'Server' headers or their values differ

Execution Trace Quiz - 3 Questions

What does the test check first after receiving the response?

A If the response body is empty

B If the 'Content-Type' header exists

C If the status code is 404

D If the 'Authorization' header is present

Key Result

Always verify both the presence and the exact value or pattern of response headers to ensure the API behaves as expected.