Understanding the Principles of Web and API testing for beginners

Introduction

Today, most applications are built using In recent years there has been the rise of microservices and server less computing, with each service being a small component that can be deployed independently and scaled as needed. This leads to the integration points between applications, which leads back to API testing.

The black box testing technique checks how two applications communicate with each other, and ensures the app performs as expected.

To test mobile apps from the backend(for example, Facebook Messenger) or any application that has an API interface exposed to external entities.

API testing aims to ensure that the application performs well. It can be used to test backends of mobile apps (for example, Facebook Messenger) or any application that has an API interface exposed to external entities.

What is an API and Why it matters?

API testing is a type of performance testing in software testing that analyzes an application programming interface (API) to verify whether it fulfills its expected functionality, security, performance, and reliability. The tests are performed either directly on the API or as part of integration testing. APIs are used to share data between different systems or applications (e.g., sharing information about users). They can also be used to create mobile applications that use JSON requests and responses (JavaScript Object Notation) to communicate with distant servers or services via the internet.

Why is Everyone Talking about API Testing?

API testing is important for the quality of your web and mobile apps. It can be done with the help of the developers, QA engineers, and business analysts. It’s not just about testing the API endpoint and response, but also testing your mobile app or web app from the backend.

For example, it might make sense for your app’s backend server codebase (the part where all the logic happens) to have an API call into Yelp’s database for this feature to work properly — otherwise, it would just be sending the queries directly over cellular networks, which would be very slow! If you want to build an app that allows users to find the restaurants nearby on the mobile apps and order food through the app itself!

Here’s another real-life API testing example. Let’s say you doing mobile testing on the backend API of a mobile app that allows users to create and manage to-do lists. There are test cases that you should consider:

• Test API authentication: One needs to make sure that API requires authentication to access it. Verify whether a valid user can log in and receive the authentication token, while access is denied to an invalid user.
• Test API response codes: Make sure that the API returns the expected HTTP status codes for the requests like success (200), bad request (400), unauthorized (401), and not found (404).
• Test CRUD operations: Verify that users can create, read, update, and delete to-do lists and their associated tasks. For instance, make a new to-do list, make sure it shows up in the user’s to-do list, edit an existing item, and make sure the changes are reflected. in the backend.
• Test input validation: Ensure that the API properly deals with all the invalid input, such as empty fields or incorrect data types. Verify that the API returns error messages from these scenarios.
• Test API security: Verify that the API is secure and protected from security threats like SQL injection and cross-site scripting (XSS) attacks.
• Test API performance: Test the API’s response times and verify that it can tackle a huge volume of requests without hampering the performance.

By using these tests for the relevant scenarios, you can ensure that the API backend of the mobile app functions for better and more reliable performance.

Why API is Important?

API testing ensures the quality of your web and mobile apps. API testing can be done with the help of QA engineers, developers, and business analysts.

API testing is also about testing the backend of your mobile app.

Users can also perform API testing on a mobile device or an emulator. You can use your device to test the app, or you can use a cloud-based tool like Google Cloud Test Lab.

API testing is a crucial part of mobile app development. While building a mobile app, It is essential to make sure that the API endpoint works well with your backend.

How to test APIs?

There are a lot of ways to test APIs, like Postman API testing and curl command line tools, or even an API testing framework like SoapUI. The most popular method for web and mobile API testing is to use a tool like Karate, JMeter, Apigee, or Katalon, to automate API testing.

Conclusion

Testing is an integral part of the IT industry be it non-functional or functional testing as it allows us to make sure that our apps are working properly and are secure to use. It helps to identify the bugs and issues faced by the users. I hope now you have understood the significance of API testing and why it is important through this blog.