Book Image

API Testing and Development with Postman

By : Dave Westerveld
1 (1)
Book Image

API Testing and Development with Postman

1 (1)
By: Dave Westerveld

Overview of this book

Postman enables the exploration and testing of web APIs, helping testers and developers figure out how an API works. With Postman, you can create effective test automation for any APIs. If you want to put your knowledge of APIs to work quickly, this practical guide to using Postman will help you get started. The book provides a hands-on approach to learning the implementation and associated methodologies that will have you up and running with Postman in no time. Complete with step-by-step explanations of essential concepts, practical examples, and self-assessment questions, this book begins by taking you through the principles of effective API testing. A combination of theory coupled with real-world examples will help you learn how to use Postman to create well-designed, documented, and tested APIs. You'll then be able to try some hands-on projects that will teach you how to add test automation to an already existing API with Postman, and guide you in using Postman to create a well-designed API from scratch. By the end of this book, you'll be able to use Postman to set up and run API tests for any API that you are working with.
Table of Contents (19 chapters)
1
Section 1: API Testing Theory and Terminology
6
Section 2: Using Postman When Working with an Existing API
13
Section 3: Using Postman to Develop an API

Chapter 6: Creating Test Validation Scripts

At one company that I worked at, I was trying to figure out the value of some of the test automation scripts that we had. In order to do this, I was analyzing the test results to see which scripts were giving us the most information. One of the rules I used to determine which scripts might not be adding value was to look at scripts that had never failed. My hypothesis was that if a script had been running for some time and had never failed, it was unlikely to fail in the future and so was not giving us valuable information. I had identified several test scripts that had never failed and was looking through them. Imagine my surprise when in several of them I found assertions that where checking things such as whether true==true or 5 == 5? No wonder the tests had never failed. It was impossible for them to fail.

Although these were egregious examples, the reality is that often a well-designed test suite will fail to deliver on its promise...