What is API/Web Service Testing?
Application Programming Interface (API) is a set of rules and mechanisms by which one application or component interacts with another. API can return data in a convenient format such as JSON, XML, etc. APIs for web applications are often referred as Web services.
Testing these APIs directly as part of integration testing to determine if they meet the expectations for functionality, reliability, performance, and security is known as API Testing.
API testing is performed at the business layer and can validate application logic. This is different from browser based Graphical User Interface (GUI) testing. API testing doesn’t concentrate on the look and feel of an application.
Why is API testing important?
From past few years the software development process has evolved using micro services and CI/CD pipelines to support frequent release of the working software to the end users. Hence increasing the use of Integration testing (API testing). According to Google trends, the interest in API testing has increased considerably from last five years.
How to test REST API?
API testing is sending different requests to the API server and verifying the responses from the server. API testing requires a tool/framework that can send requests to the API and display the response from server.
API testing tools
There are number of open-source and commercial tools available for API testing. The below mind map shows the 10 best tools for REST API testing.
Having the right process, tools and solutions for API automation testing are more critical than ever. Finding the perfect tool is a tough job. It is important to carefully consider the project requirements, pros and cons of each tool. It is a good idea to try and create a POC with more than one tool from your shortlist. This gives you a better knowledge of the tool and it’s suitability for your project.