In this article we’ll share and explore the best methods to automate your API testing process. The use of Application Programming Interfaces or APIs in the creation of software applications is a widespread practice in the global software developing community. This is mainly because APIs allow developers to efficiently and easily define how the separate software components of their applications communicate with each other in standardized language. As such, developers are free to focus on refining what makes their application unique and innovative, rather than having to code interfaces from scratch.
The Importance of API Testing
This widespread use and integration in software development make API testing all the more important. In addition to ensuring that the essential components of the application function properly, API testing helps root out critical errors and deficiencies in the API that could negatively affect the application’s performance and functionality in general. These errors may include security vulnerabilities, an inability to deal with the wrong type of data input or high volumes of load, and more.
The Challenges of API Testing and How API Automation Resolves Them
However, manually testing for all of these can be quite the challenge, as you would be required to code a separate application to test for every single potential issue. This is especially true if your development schedule is tight and without much leeway.
In this scenario, automated API testing is a more efficient option. Automated API testing involves the use of tools that can be programmed to perform repetitive tests automatically. When you choose to run a comprehensive API testing tool to perform your API tests, you leave yourself free to do other development tasks on the side while you monitor the results. This allows for a more agile and efficient development cycle.
Eight Easy Steps for Automating API Testing
To help you in this regard, here is an easy step-by-step guide on how to automate your API testing process, using a single API execution and automation test case for basic API functional testing.
1 Pick a comprehensive testing tool
There are many API automation testing tools available online. Most of them offer similar features with some extras to help make your testing a bit more convenient. Some, like Postman, can be used free of charge, while others are locked behind a paywall. Whichever you pick, check to see that it meets your testing requirements before using it.
2 Select the Method Type and input the API URL
Since this is a functional test—i.e. making sure that the API itself works—we need to select the method involved and input the URL of your API. Look for the API runner feature of your selected tool, select the method you want, and input the URL of the API being tested.
3 Add additional information for the API request
To successfully run the request, some additional parameters may appear, such as headers, a body, and so on. To add these parameters, look for the parameters tab in the API runner window and then click the Add Parameter test button, or the equivalent in your chosen API automation tool. You will then be given a field to add the key and the value of the parameters you desire.
4 Input authentication credentials
On the occasion that your hosted API requires authentication before you can run a request on it. You should enter the credentials needed first. Your chosen API automation tool should have an Authorization tab that will let you choose the Authentication type from a drop-down list. This will supply you with fields to input a username and password.
5 Input assertions
Next, you need to add assertions to the test. Assertions allow you to specify what kind of data or information the API should respond with during the test. If the API does not deliver the kind of response the assertion demands. The test itself can be a failure. Go to your tool’s Assertion tab in its API Runner window. Moreover, choose the response and the assertion condition from the drop-down list. Then input the value at the value field. To add more assertions, simply click the Add Assertions button or the equivalent in your automation tool.
6 Input variables
Finally, adding variables to the test allow you to store the values that the API sends in response to the test request. You can then use the values as an expected assertion for subsequent tests. As a result, allowing for a more complete functionality testing experience. To add a variable, simply go to the Variables tab in your automation tool. In addition, input the variable name and the JSON path of the value to be data from the API’s response. To add more variables, you can also click on the Add Variable button or equivalent.
7 Run the API request and check the results
Give everything one last check before initiating the test. This will save the test into the tool’s memory and run it. You should be able to run the same test without having to input all the previous values, as well as see the results in the API execution history.
8 Repeat as necessary API testing process
Make new tests with your API testing tool and repeat them as necessary to get the results you need. With the completion of that last step. You have successfully automated a single API test case using an API testing tool. You are now ready to run tests in higher intensities and repetitions to truly refine and polish your application’s.