API Testing

What is API Testing?

API testing is a type of testing that evaluates the ability of the developed APIs to provide the appropriate level of reliability, performance, and security for an application. API testing is considered one of the most challenging types of software testing. Since Application Programming Interfaces (APIs) are based on protocols and standards that your team might not be familiar with, testing them is a complicated task. As opposed to unit testing that is usually executed by a development team, API testing requires a separate QA specialist team.

How is API testing used?

How to ensure that the Application Programming Interface provides functionality, reliability, performance, and security for your application?

Here is a quick checklist for your convenience:

• • Define API testing requirements.
    Before you can run test cases, you need to document the requirements such as the purpose of the particular API, integrations it supports, API features, etc.
  • Configure database and server.
    Apply the list of requirements to set up a test environment including database and server configuration to meet the API testing requirements.
  • Involve application data.
    Integrate application data with the API tests to evaluate how well the API functions.
  • Choose the testing type.
    After establishing the requirements for the tests as well as the appropriate environment, decide which criteria you would like to test first. Through various API tests, you will discover missing functionalities, poor error handling procedures, multi-threaded issues, as well as unacceptable levels of reliability, security, performance, and functionality. Here are the most common types of API testing:Functionality testing assesses the functionality of an API and makes sure that it works the way it is supposed to.

    Reliability testing checks whether the API provides a consistent and stable connection.

    Load testing verifies whether the API performs well under average and high load.

    Security testing identifies possible security threats of the API.

    Validation testing evaluates the efficiency of the API.

 

• Create and execute test cases.
  The last step is to create tests based on the previously established requirements and execute them. Take into account the most valuable parameters for your users and incorporate them into test scenarios. Later, thoroughly document the procedures and results for future use.

5 Benefits of API Testing

Now that we have touched on the specific of API testing implementation, let’s dive into the main benefits of API testing:

1. Access without user interface

QA specialists can execute the tests without a UI or users which allows them to identify bottlenecks and fix them before they cause issues to the UI.

2. Broader test coverage

API tests are significantly broader and aim at all system components. They are designed to consider the full picture and make sure everything, including servers, databases, and interfaces functions as intended.

3. Time and cost effectiveness

API testing saves time because you can run API tests without GUI and begin testing early in the development cycle. API tests are also 35 times faster than UI tests since you will not spend time loading web pages and UI elements. The time efficiency results in cost-effectiveness and paired up with the concept of testing early, API testing becomes an important money saver.

4. Language independence

API tests are language independent and allow QA testers to use any programming language of their choice (JavaScript, Python, PHP, etc.)

5. Security and code integrity

Finally, API tests are important as they push the software and infrastructure to their limits, something that helps detect vulnerabilities and poor code integrity.

Further Reading: To learn more, read our Advanced Guide to API Performance Testing.

API Testing Tools

Running automated tests is one of the best practices when it comes to API testing. API automation can accelerate testing and drive up efficiency. To ensure test automation, you need an API testing tool such as RapidAPI Testing, PAW, SoapUI, or others. Manual API testing is also possible but requires writing code to test the APIs.

Learn more about the #1 API Load Testing Tool, WebLOAD. Get a Free Trial today.