Integration testing is the icing on the cake for many forms of software development. Knowing how to set up correct tests for React components can prove difficult and lead to inaccurate results if done incorrectly. This article answers some of the many questions regarding integration testing for React Apps. We explain integration testing in detail and then explore some of the significant benefits of adopting integration testing for React Apps. Also, we explain how React-testing-library is the ideal choice for carrying out integration tests while highlighting the steps involved in the testing process. Finally, the article covers some of the best practices for integration testing to ensure the process is as smooth as possible.
Many areas of software development can benefit from integration testing. When working with multiple third-party apps or APIs in a React application, it is essential to carry out integration tests because doing so ensures that everything works well and there are no bugs even after upgrades.
Setting up the proper tests for React components can be a hassle, leading to false positives and negatives if done incorrectly. Luckily, we're here to help out, so if you need help finding your way around integration testing, this article covers some tips to help you navigate the concept and get the best out of your React app.
To begin with, let's get acquainted with the term "integration testing."
What is Integration Testing?
Integration testing is the second step in the software testing process, which lies between unit testing and end-to-end testing. This form of testing helps to balance out the whole testing process. It guarantees that various software units or components are evaluated simultaneously and focuses on identifying problems in the communication between integrated units and components.
Integration tests are the ideal solution for dynamic websites like those created with React. Without adding the extra work of an end-to-end test, this test category verifies how a user interacts with your application. Several approaches are popular for integration tests, including Big Bang, Top Down, Bottom Up, and Incremental Integration Testing.
Other not-so-popular forms of integration testing are sandwich integration testing, Layer integration, backbone integration, distributed services integration, and high-frequency integration.
The program's complexity, cost, and other factors are all considered while determining the ideal technique. For example, you can test how well the units of an app work together and decide to mock specific aspects, like HTTP requests. This way, they take less time to write, you'd be confident in your work, and you may not need to carry out many unit tests.
However, remember that when writing integration tests, it's best to create them for critical use cases or particular scenarios and not as an exhaustive verification of an entire system’s functionality. When building integration tests for React apps, it is essential to keep test implementation details and shallow rendering to a minimum.
Significant Benefits of Integration Tests
While making changes to a React app, integration tests verify that the composition of components produces the intended UX. Integration testing is highly beneficial for developers at companies like Fetchly Labs, considering how it reduces the time and effort required for testing. React Integration Tests as a whole facilitate code maintenance while accelerating development.
Integration Tests with React Testing Library
React Testing Library is an ideal choice for carrying out integration tests for React apps. This is so because testing React components is done so that it simulates how an actual human would use the app or software's functions. React Testing Library can be used alongside other optional companion libraries to write tests that interact with the Document Object Model (DOM) and confirm that the software works as it should.
For a step-by-step guide on how to carry out a simple integration test in React, refer to this sample repository by Fetchly
, which also includes the app's implementation process.
Best Practices for Integration Testing
Adopting the best practices for integration testing will ensure that the testing process is as smooth as possible;
- Testing should be done early enough and as often as possible for quick updates in the development process.
- Carry out integration testing before unit testing. Though it may seem counterintuitive because the norm is to follow a prescribed procedure, bear in mind that in an agile environment like Fetchly, there's flexibility to make changes where necessary.
- Make use of the appropriate integration testing tools.
- The testing scripts and scenarios are helpful because they clearly define the details between units, and you can always refer to them in future.
- Try to automate tests for faster performance. For example, top-down and bottom-up integration approaches can be automated.
- Place priority on necessary units during the testing process for a detailed enough test on the app's interface.
- Avoid using integration tests for business logic, as unit tests are better suited. Unit tests target the fundamental correctness of code, so running them frequently in business logic is alright to detect bugs early and fix them. On the other hand, integration tests take longer to run, so they shouldn't be part of every build cycle.
- Go beyond integration tests as user experience goes beyond building the application. Consider how the app is deployed in the production environment and how it works with components like databases, mail servers, virtualization tools, load balancers, DNS servers, proxy servers, and many others. That being said, it's crucial to run system tests that accurately simulate the nature of the app.
Integration testing is crucial for React applications, as it helps catch bugs and utilize the Test Driven Development (TDD) approach without needing regular maintenance when the implementation changes.
React-testing-library is an excellent tool for writing React integration tests. It allows users to interact with the app and validate its state and behavior from a user's perspective.
*This is not the official Fetchly opinion but the opinion of the writer who is employed by Fetchly*