Today businesses are more inclined towards building cross-platform mobile apps using React Native. Such apps are readily available across all the major mobile app platforms with ease. This saves them a lot of time and money that they would have otherwise spent on developing individual apps for different platforms. When it comes to building business apps, quality always remains as the top priority. Today user expectations are getting higher every year and they are very clear about the app reviews. This means it will not take much time to know whether they like or hate an app available on the app store.
With mobile usage increasing than ever it becomes important for app developers and businesses to build the app the right way and ensure it works across different devices smoothly. Compatibility with different OS versions, chipsets, resolutions and hardware requirements are some of the areas to cover for sure. Keeping everything in mind offering unmatched user experience becomes a challenging task.
This is where you need the right testing tools for the React Native project. In order to find bugs and issues faster and resolve them at the lighting speed automation testing is said to be better.
One of the issues you will come across during testing is handling app permissions. You need to be sure that each test is launched individually and the execution will not be messed up with the permission pop up. There are a lot of plugins available to take care of this issue for native scripts. There are some hybrid frameworks too which can take care of this issue.
In some situations, the local databases and app states are shared between some separate tests. So for the people who are working on UI testing automation, it can create issues. So to take care of the app states shared between tests you can choose to go for platform-specific approaches or go ahead to implement custom methods which can clear memory files or cache or any other data. The frameworks dedicated to React Native also cover this issue.
The composition is the base of mobile software development. This means a number of smaller components of software come together to form a bigger one. The bigger one possesses greater functionality in order to achieve the goal of the app. The right practice to run tests for a mobile application is to cover functionality at every level.
The different types of testing followed for React Native apps are:
It is possible to test each of the components functionally or visually. In order to test React components, ReactTestUtils offers a simple framework.
The next comes is integration testing. In this phase, a bunch of different units are tested together as one component or entity.
This is a kind of black-box testing which is focused on user interactions and requirements. It covers all the user interactions, underlying software the application as a single entity.
The developers of Facebook have developed this and it works with React Native on a default basis. One of the attractive features of Jest is Snapshot testing. Jest comes with great official docs and by following the guide, you will be able to run it fast. It enjoys 24953 stars on GitHub.
Jest can run tests in parallel reliably all the while ensuring a single global state for tests. In order to make things move faster, Jest runs the failed tests first and based on how long test files take, and it re-organized runs.
By adding the flag coverage generate code coverage. There is no need for any additional setup. Jest can collect code coverage information including the untested files from the entire projects.
Jest can mock any object outside the scope of the test in a simple manner. For the same, it uses custom resolver for imports within the test. In order to spy on function calls which come with readable test syntax, you can make use of imports that are mocked with rich Mock Functions API.
Detox is an end-to-end testing library which is used for apps build on React Native. By using it, you can emulate the behavior of the users and test your apps automatically to know how the users react to it. It also supports permissions different device configurations, notifications and everything which the user may wish to do with the app.
Detox was developed from scratch to support the projects of React Native as well as the other pure native ones. It tests mobile apps while it is running on the simulator or real mobile device and interacts with it just like any user. When it comes to automated testing E2E remains as the core problem due to its flakiness. This is where Detox comes into the picture. It enjoys 4455 stars on GitHub.
· Works in complete sync with the app
· Developed by Wix for React Native
· For Gray box testing
· Not as capable as Appium
· Has a smaller community
Cypress is a testing tool which lets you write test faster and use it with no or less setup efforts. It is a secure and reliable way of testing applications which run on a browser. Cypress enjoys 11,453 stars on GitHub.
Cypress is developed by keeping developers and QA engineers in mind. This helps them to work better.
Being an open source, it gets to enjoy the benefits coming from the community and this way the tools of Cypress is getting evolved faster and better.
Cypress is developed on a new architecture completely, and it enjoys a lot more power. There is no Selenium.
Whenever changes are made in the tests, Cypress automatically reloads. You can see in your app in real time the commands getting executed.
While running tests Cypress takes snapshots. So to know what happened at every step you can simply visit the Command Log and hover over the commands.
If your tests are failing continuously they debug from the familiar tools like Chrome Dev Tools directly. Debugging will take place at lightning speed by using stack traces and readable errors.
Now you will not have to add sleep or waits into your tests. This task will be taken care of by Cypress as it automatically waits for assertions and commands before moving ahead. There will be no more async issues.
It simulates React Components like jQuery and ReactDOM finding DOM. It can be used to check if components have certain props or have children and are also used to shallow render React components.
It enjoys 16,967 stars on GitHub.
React Native Tools are nothing but an extension which offers a development environment for the projects builds on React Native. When you use this extension, you will be able to quickly run the react-native commands from the command palette after debugging the code. You can see details at
Karma aims at developing a productive testing environment for the developers. Such a situation will be focused on saving the developers from a large number of configurations and just letting them write the code for the tests and get instant feedback. Getting such instantaneous feedback will make the developers more creative and productive.
A few reasons to choose Karma for your project are:
You can test the codes on real devices like phones or tablets or on real browsers.
You can either write a simple adapter for any of the frameworks you choose or describe the tests using QUnit, Mocha and Jasmine.
Now you can control the complete workflow from your IDE or command line. All you need to do is just save the file, and Karma will run the tests.
Carrying out easy debugging via WebStorm or your IDE or Google Chrome.
This testing tool is developed and maintained by the open source community which is present in GitHub.
It allows having simple integration with Travis, Jenkins or Semaphore.
It is released under the MIT license and it enjoys 10,629 stars on GitHub.
Some of the top features of Mocha are:
· Browser support
· Test coverage reporting
· Test retry support
· Extensible reporting
· Node debugger support
You can have Jasmine implemented in any development methodology. Here all you need to do is to visit the website https://jasmine.github.io/and then download the standalone library files for it from there. Once done that you can implement it in your application.
· It does not need to have DOM
· Unit testing frameworks highly influence it
You can use Calabash to write and execute acceptance tests. It is used for mobile apps, and it is cross-platform supporting which means that you can use it for iOS and Android native apps. This testing tool is developed and maintained by Xamarin and is open source and free. Calabash comes with libraries which lets the test code to interact with native and hybrid apps programmatically. The interactions are about a number of different end-user actions. These end-user actions can be of:
· Assertions: This can be something like there should be a “Login” button
· Gestures:Gestures or touches for instance swipe, tap or rotate
· Screenshots:Take screendump of the current view you have on the screen of the current device.
You will find different automation libraries for Android and iOS on GitHub. The iOS version enjoys more than 18,000 stars while the Android version enjoys more than 16,000 stars on GitHub.
Appium is an open source tool which is used for automating mobile web, native and hybrid applications on Android mobile, iOS mobile and Windows desktop platforms. Appium support cross-platform testing and so you can write tests using a single API and then run them against multiple platforms. In short, Appium makes the code reuse among different test suites possible.
Appium mobile automation has been set around a philosophy which consists of four points and they are:
· In order to automate your app, you should not have to recompile or modify it.
· In order to write and run tests, you should not be limited to a specific framework or language.
· When it comes to automation APIs, the mobile automation framework should not repeat things from scratch.
· The mobile automation framework should be open source in all terms.
Here in this post, we have faced the different challenges which we face when carrying out React Native app testing. You can follow our blog article Top 10 React Native Developer Tools to Develop Powerful Mobile App in 2019. We have also discussed about the different types of testing for better clarity. The test automation framework used here are the most popular ones which are used to take care of native apps, the mobile web, hybrid apps and React Native apps. So whether you are a React Native developer or an app owner having an idea about such tools can be good.