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How to Practice API Testing

woodjessica profile image Jessica Wood ・3 min read

Today the applications are getting more complex and a large amount of data is transferred across devices with the help of these applications, servers, and networks. It has become essentially important to validate that what information user wants is rendered to them accurately. This is where API testing plays its role.

It ensures that every request gets proper responses. Let us now try to understand this testing type in more detail and see how it is performed.

What is API testing?

API is a computing interface that acts as a guaranteed contract between two separate pieces of software systems. It allows one system to interact with other systems. In this test, the API is directly tested as a part of integration testing to determine whether or not it meets the expectation regarding functionality, reliability, security, performance, etc. This test is done to check the business or logic layer. During this test, the data is exchanged from XML or JSON through HTTP requests and responses.

Why is API Testing needed?

This test is needed due to following reasons:

It ensures that the APIs work as expected
It helps to fix defects early in the development lifecycle
It ensures that the application can handle the desired load
It helps teams to enable a better user experience
It ensures easier expansion of applications
To make sure the API provides the required functionality
It validates that the data passed through the API is as per compliance & security or not
It determines that all the business rules have been correctly implemented at the API level
It allows QA teams to integrate this test into the build server which in turn helps teams to provide quick feedback on the health of the application as soon as it is deployed

What are the types of API testing?

Below mentioned are different types of tests that come under this testing technique:

Functional Testing: It is done to ensure that all the APIs are up and working as expected.

Reliability Testing: It is done to ensure that API is working when connected to various devices and doesn’t get disconnected any time.

Load Testing: It is done to ensure that the API responds well when various servers send a request to an API.

Stress Testing: It is done to check that when more than set no. of requests is received by API how does it behave and how does it work.

Security Testing: It is done to check that no data leak or data breach occurs when API interacts with other devices. It is important to have proper authentication, permissions, and access controls.

Integration Testing: It is done to verify that all the connected APIs are communicating properly or not.

Usability Testing: It is done to ensure that APIs are user-friendly or not.

How to practice API testing?

Below mentioned are the steps that are involved while performing this test:

Understand testing requirements and prepare the test plan: To plan the test, first, you need to understand why this test is required, what are the test boundaries and accordingly you should prepare the test plan. The plan should cover all test scenarios and should clearly define the priority of scenarios, workflow, desired output, and pass/fail criteria. The plan should also include some of the common testing types like unit, integration, performance, security, and third-party API tests.

Establish the test environment: Now, set up the test environment with the required parameters that need to be configured for the given API. This includes the configuration of the server, database, and every resource the API interacts with.

Make an API call: In this step, an API call is made to ensure that there are no broken links in the testing process.

Combine data with API test: In this step, data is combined with the API test to ensure that the interface functions as expected with the provided parameters after being configured.

Evaluate the result: Now that you have executed the test, it is time to compare actual and expected results and see if any corrective measure needs to be taken.

Conclusion: Applications have several underlying API layers that need effective testing to ensure that they function properly and interact properly with each other. Since these API layers are complex and need effective testing businesses can leverage API testing from a next-gen QA and software testing services provider to get quality software.

About the author: I am a technical content writer and I write articles on various IT-related topics. In this article, I have tried to share my views on how to practice API testing.

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