REST API Testing in 2024: Definition & Challenges

APIs have become the cornerstones of the software world as 90%¹of developers rely on APIs. As APIs become prevalent, API incidents also rise; as of 2020, 40%²of API users have reported API breakages. Given the wide use of APIs and their importance, ensuring consistent functionality is crucial for businesses. This article will examine the importance of REST APIs and REST API testing, practices, and challenges.

Why are REST APIs important?

Representational State Transfer (REST) or RESTful APIs is by far the most used format as %94³of developers use them, and they make up 80% of public web APIs. RESTful APIs are the most common method for companies because they:

• Provide flexibility: RESTful APIs can send data in many forms, such as SON, XLT, HTML, XML or simple text, providing flexibility

The video below does a good job of summarizing the popularity of REST APIs.

What is REST API testing?

REST API testing is a test automation technique to ensure the stability of RESTful APIs for web applications. Given their importance and popularity, developers use REST API testing to check if they are working correctly or not.

In REST API testing, the tester records the response of a REST API by sending HTTP or HTTP/s requests. REST API Testing uses the following methods for the testing process:

• GET: Reads or retrieves information from the destination server 
• POST: Sends data to a server using HTML forms or creates new resources.
• PATCH: Updates or modifies an existing resource.
• DELETE: Deletes a resource identified by a Uniform Resource Identifier (URI) 

It does not matter whether the APIs use RESTful or SOAP protocols, API testing is the backbone of QA because the cost of errors found in the testing stage is less than in the later stages. For more detailed information on API testing, refer to API Testing: 3 Benefits & 8 Different Types. 

Sponsored

There are several open-source and commercial tools for API testing. PULSE is an API test automation tool created by TESTIFI. By examining an API’s documentation, it generates tests. Afterward, the AI analyzes the results and reports back the dashboard style. PULSE can reduce cycle time and cost by 50% and improve documentation. Well-known companies like BMW and Amazon use TESTIFI services.  

Challenges of REST API Testing

A large number of parameters

Since many parameters need to be covered in RESTful API testing, a specific combination could expose errors, making the API vulnerable to security threats or not functioning at all. Such errors can cause the failure of service operations, which can cause an organization to face financial and trust losses ⁵. Testers must ensure that the input is valid before executing the REST to overcome the issue mentioned above⁶.

Testing set-up process 

While testing cycles of REST API testing can be automated, setting up such test cycles requires manual effort, which can be time-consuming. Considering that there isn’t a wide choice of testing tools for generating unit tests for RESTful APIs, this also presents a challenge ⁷.

Complex Input Types

RESTful APIs of today enable communication between hybrid networks, backends, and all types of devices. Sending data is possible anytime, and it can be anything from a single file or collection of files to basic integers and texts. In order to test RESTful APIs, the framework for creating tests must have the ability to infer test input values, which is especially challenging when dealing with complicated types ⁸.

If you have a specific business challenge or want to learn more about API testing, you can reach us:

External Links

• 1. https://nordicapis.com/apis-have-taken-over-software-development/
• 2. Statista. https://www.statista.com/statistics/1083219/worldwide-api-performance/
• 3. https://nordicapis.com/20-impressive-api-economy-statistics/
• 4. https://venubotlaqa.co.uk/2019/10/25/restful-web-service-testing-for-beginners/
• 5. Ehsan A, Abuhaliqa MAME, Catal C, Mishra D. RESTful API Testing Methodologies: Rationale, Challenges, and Solution Directions. Applied Sciences. 2022. https://www.mdpi.com/2076-3417/12/9/4369#cite
• 6. Mirabella, A.G.; Martin-Lopez, A.; Segura, S.; Valencia-Cabrera, L.; Ruiz-Cortes, A. Deep Learning-Based Prediction of Test Input Validity for RESTful APIs.https://personal.us.es/amarlop/wp-content/uploads/2021/04/Deep-Learning-Based-Prediction-of-Test-Input-Validity-for-RESTful-APIs.pdf
• 7. Segura, S.; Parejo, J.A.; Troya, J.; Ruiz-Cortes, A. Metamorphic Testing of RESTful Web APIs. IEEE Trans. Softw. Eng. 2017, 44,1083–1099.https://dl.acm.org/doi/10.1145/3180155.3182528
• 8. Ehsan A, Abuhaliqa MAME, Catal C, Mishra D. RESTful API Testing Methodologies: Rationale, Challenges, and Solution Directions. Applied Sciences. 2022. https://www.mdpi.com/2076-3417/12/9/4369#cite