Testing React Applications with Jest: The modem mobile application development process is becoming easier and rich with each passing day. With mobile application development companies adopting the latest technologies and methodologies in each phase of the app development life cycle, the application that is developed is feature-rich and robust indeed.
When it comes to the testing phase, it should be made sure that the applications or technologies used should be on-point to provide clients with a perfect application as requested. Testing front-end applications is becoming easier with time and OpenXcell uses the latest technologies for this. Here, the testing process of ReactJS applications before publishing by the expert team at OpenXcell is discussed.
Whenever our team is testing, specifically front end, there are a number of things that we consider while testing React Applications with Jest.
- We believe in early testing. The sooner we get the bugs, the sooner we can solve it in the iteration and save our development time in the final stages
- Focus is laid on the crucial parts while testing and exhaustive testing is kept secondary to cover more than 90% of scenarios
- We make sure that our testing processes are updated regularly, as running the same tests over the applications will not give us new results
- Each application is unique and so we believe in context testing. Some applications focus only on a few specific features, while others need the overall application to be flawless
- It is made sure that the application has requested features and does not contain any error by providing smooth functionalities after publishing
How OpenXcell Team Tests ReactJS Applications
A major reason to use Jest is that it gives the ‘zero configuration’ testing platform to run tests parallelly but isolated and thus maximizes the performance. Documentation and maintenance of the toolkit are superb as Jest provides everything in one single toolkit.
Highlighting features of Jest:
With this feature, you can use Jest configuration free and thus makes the testing process easier and fast
You can embed snapshots inline or keep them live with your tests to keep a track of large objects
Run tests parallel to each other but in their own individual processes and thus you an give a boost to your performance
Jest runs tests parallel to each other, and so the process of testing becomes faster by maximizing the performance as well. Jest starts by re-running the failed tests and then the new tests
With built-in coverage reports, Jest requires no additional setup. Code coverage information from the entire project and untested files as well.
When the tests fail, Jest provides a rich context stating why the application has failed and thus you can solve it while re-running the test again
Easy to Setup
Jest is the easiest testing framework to set up and it’s very easy to install. You have to just find an empty directory to install it and start using it
When we are doing unit testing, mocking is really very important. Jest provides simple mock functions, timer mocks, manual module mocks, ES6 class mocks, and more
Delta Testing with Watch
You can run Jest in watch-mode and it runs the test automatically whenever there is a change in code
Our testing process is designed to make sure that all these features are leveraged to its fullest to make a robust and error-free ReactJS application. The testing process is categorized into three main types, namely, Unit Testing, Integration Testing, and End to End Testing. The maximum focus of time and effort is laid on End to End testing, then Integration testing, and lastly on Unit testing.
Read This: Preparation for Mobile App Release
When we are testing, we make sure that the tests are written in a way that it tests only the logic that is rendered and the internal implementation is not considered. In short, our tests focus more on what the user sees or interacts with. Using Jest provides another benefit, that is we are independent of testing the lifecycle as React itself tests that.
We make sure that our tests are smaller and thus are easier to read, implement, and interpret. When it comes to comparatively bigger components, our team splits it into smaller pieces and then performs testing for ensuring proper testing.
Testing React applications with Jest has proved to be a boon for the team at OpenXcell as it makes the testing process more efficient and easy. Jest being a node-based runner, it does not run the tests in the real-browser, rather it runs them in the Node environment with fake DOM implementation.
The basic flow of using Jest for testing is,
- Libraries are installed and webpack is run
- React countdown timer is started
- Tests customized to the application are written
- Testing components are run
- Finally, the business logic is tested
Test-driven development is also implemented sometimes by the team at OpenXcell for some of the applications where the code is written only if the automated test fails and thus the duplication of code is eliminated.
The team at OpenXcell makes sure that testing ReactJS apps with Jest is done on-point to provide the clients with an application that is flawless and gives them the desired experience after publishing. You can get benefits of these and more advanced technologies incorporated in the mobile application development process with OpenXcell. Grab your requirements, send in, and get an application tailored to your requirements.