What to Test in API Testing?

This article highlights the benefits of performing API testing on software applications for mobile or web. it also covers what exactly is covered in API testing.

What is API testing? 

Application Programming Interface or API is a set of routines and protocols that are used to test and interact with protocols. It describes how one software program interacts with other software programs.

API testing involves testing various API directly and to check whether the API used to interact between software programs is working as per expected functionality or not. API testing is performed on the basis of performance, the security of an application. This testing is done on multiple API of the software. It is different from GUI testing as it emphasis the functionality of API rather than the look and feel of the mobile or web software.

API testing includes the various types of testing performed for the following 

reasons:

Unit Testing: It is done to test the individual components of the software in the form of a unit. A unit is a single function that can have one or two inputs to deliver a single output.

Functional Testing: It is done to check the accuracy of output from each feature or function of the software. The output from the software application is tested and evaluated on the basis of the result expected. 

Load Testing: It is done to check the behavior and result of the application under specific stress conditions. Load testing is performed under normal and at peak conditions when mobile or web application gets more than expected traffic.  

Runtime/ Error Detection: It checks and evaluates the application to identify problems such as various exceptions and command issues. 

Security Testing: It is done to check the implementation of API to external threats. It checks the system vulnerabilities of the system against the possible intrusion that can take place in the system. 

UI Testing: This is performed to check the overall look and feel of various components of the software and their interface to be user-friendly. 

Penetration Testing: It is performed to find the various vulnerable spots in the software or web application by trying to intrude into the system. 

The benefits of API testing are:

• It is time effective and offers better results compared to other GUI testing. 

• API testing can be automated for faster and better test coverage. 

• It reduces the total cost of testing as it helps in finding the major and critical bugs before GUI testing. 

• It is not language-dependent.

• It checks the functionality of an application, unlike GUI that tests the APIs interface. GUI testing can be done after API testing. 

• It reduces the risk of application failure.

Author's Note

API testing helps in finding major problems and errors that can cause application failure.

Reviews

[JayG]

Way too generic. programmers don't need it and amateurs won't care. And it makes the deadly mistake of testing for success. Guaranteed, no matter how carefully you test to be certain it does what the book says it should do, the end used will screw it up by not following the directions; by mistyping; by inattention and inept usage.

Not testing for the ways in which such failure can be induced is common, and why the first thing you do on installing new software is download the fixes for things missed by testing only for success.