7 Best Practices for Testing APIs: A Practical Guide for Developers
28 Sep

7 Best Practices for Testing APIs: A Practical Guide for Developers

Mahipal Nehra

When building an API, developers need to make sure that it is secure and reliable. To do this, they must test it thoroughly before releasing it to the public. But where should they start? What are some best practices for testing APIs?

Testing is one of the most important parts of any development process. Before you release your API to the public, you need to make sure that it's well-tested and secure. It's critical that you cover all of the different aspects of your API in order for it to function properly.

Here are 7 practical tips for developing a successful API in no time, and for more in-depth information on API testing.

Test Your API with a Consumer

Before you release your API, you need to make sure that it works properly for the end-user. The first step is to use an end-user. (Don’t worry — your end users are probably developers!)

Read: API VS Web Services VS Microservices

You can use your own users to test your API or you can use external tools. You can also look for volunteers to test your API. The more testers, the better.

To test your API, you need some feedback. A small sample of users will provide a good measure of data about the end-user experience. It’s ideal to use real users that you’ve signed up for an account with your service.

Provide the consumer with a file and instructions on how to test your API. A sample of your API documentation should be provided so that the end-user can test your API. You can ask your customers to test the API by clicking a link in your email campaign. It’s an effective way to get early feedback.

Read: Microservices vs API

Most importantly, test your API with a minimal number of users to ensure that your user’s experience is predictable. You don’t want to limit your end user’s access to your API by setting too many things up. Your user experience should be consistent and understandable.

Make Sure the Problem is Being Resolved

If a user is unable to use your API, it could be because they are unable to find what they’re looking for or they can’t connect. The first step is to have someone look for errors in the API documentation. You may also want to make sure that the data in the data store is in the format required for your API, or that your forms are valid and functioning.

In the end, it’s a good idea to have at least two end users using your API at the same time. These two users should use the same logins so they can see what each other is doing and fix problems as they occur.

Read: API vs Web Services

If a problem is being resolved, you want to make sure that it’s the right way.

Create a Mock Server

Test this by creating a mock server. This will allow you to run code as if it’s actually working and can demonstrate to your end-user that the API is working as expected.

Make sure that you can test the following:

  • The GET method of your API (e.g. GET /username )

  • The POST method of your API (e.g. POST /user )

  • The PUT method of your API

  • The DELETE method of your API

Once you’re happy with your tests, you can run them on a server with the same IP address as the real API.

Use Acceptance Tests

Acceptance tests are tests that aren’t as comprehensive as unit tests. They usually focus on certain aspects of your API and make sure that those areas are working properly. They help you determine if your API has the right functionality and if it’s performing as expected. They should also make sure that the functions in your API are returning the expected results.

You can create acceptance tests in many ways. The most popular way to create acceptance tests is by using an acceptance test framework. There are a number of open-source acceptance test frameworks you can use to help you build your tests.

Read: What is an API and How it works?

You can also create acceptance tests by writing your own. You can look at the WebUnit test framework for guidance. Some frameworks have good documentation, and it’s easy to find documentation and examples for your platform.

Run Your Acceptance Tests Using Output Functions

The last step in testing your API is to run your acceptance tests using the output functions you defined. This way, you can see what your API is doing.

If your API is producing data, your test should output that data to a text file. If your tests are failing because your data is not being produced as expected, then you may need to make changes in your API or contact your users and resolve the issue.

If the tests are passing, then the API is working as expected.

Avoid Test Failures

Make sure that all your tests pass before you release your API. Otherwise, you may have a user registration program or login feature that works perfectly on your development server but fails when your end-users try to use it.

If your API is going to be used by real people rather than just in development environments, consider adopting a case statement in your test code. This can help you catch more types of errors that might be associated with real-world applications.

Read: What is API Testing, Types & Benefits?

After you have completed all of your testings, it’s time to implement it into your API.

Consider SQLite Testing

Many frameworks require that you run tests against a database. SQLite is a great alternative that’s fast, efficient, and easy to use. SQLite supports API testing with just a few lines of code. It’s particularly useful for testing projects that support multiple client platforms.

SQLite should provide you with a strong set of testing tools. There’s no need to install an external database or download additional code. When running SQLite tests, you can use the same SQLite database that you’re testing.

SQLite runs very quickly and has a friendly and easy-to-use interface. It integrates with the whole programming environment, so you can also see the results of your tests in a text editor without having to run them on a database server.


You’ve successfully tested your API. You should be able to demonstrate that it’s fast, efficient, and easy to use.

If you haven’t tested your API or if you have no documentation, then you may have issues that could cause real-world problems. You should consider implementing your API tests. At the very least, you can learn from your failures and identify issues early.

Posted by Mahipal Nehra | Posted at 28 Sep, 2021 Web