How QA Engineers Validate Status Codes, Responses, and Tokens

When QA engineers start writing Postman test scripts, one of the first questions they face is how much validation is actually required. Should every response body be checked? Should tokens be hardcoded? And what does a “good” Postman test look like in real QA practice?

This article explains how professional QA engineers use pm.test in Postman, what they always validate, what they validate selectively, and how tokens are handled correctly using variables.

1. Status Code Validation Is Mandatory

In real QA workflows, validating the HTTP status code is non negotiable. It is the first and most reliable indicator that an API behaves according to its contract.

A basic status check looks like this:

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

Every test case, whether positive or negative, should include a status assertion. Without it, a test does not clearly express its expectation and is harder to interpret in CI pipelines.

Status code validation is considered the minimum requirement for any API test.

2. Response Body Validation Is Context Dependent

Unlike status codes, response body validation is not always required. In practice, QA engineers validate response bodies only when the content carries business meaning or affects subsequent test steps.

When response validation is required

Response body assertions are necessary when:

Example: