In today’s digital economy, software developers cannot afford to rely on anything less than the latest software development practices to deliver efficient products and services. As per the data reported by Statista, the number of mobile app downloads globally has been increasing from 2016 onward, surpassing 200 billion in 2019. In 2021, consumers downloaded 230 billion mobile apps to their connected devices, an increase of more than 63% from 140.7 billion app downloads in 2016.
Given the increasing number of app downloads, testing apps has become more critical than ever, as it helps you rectify mistakes and verify that your code is working. Perhaps even more importantly, testing ensures that your code continues to work in the future as you add new features, refactor the existing ones, or upgrade significant dependencies of your project. According to the World Quality Report, automating the testing process is helping organizations speed up their decision-making to provide better outcomes in a shorter period. Automating the testing process has many benefits, but the most crucial advantage is that app developers can use automated tests to detect problems quickly before sending them to QA. Moreover, tests can run automatically whenever source code changes are checked in and notify the team or the developer if they fail. Features like these save app developers time and increase their confidence.
Nowadays, most applications running on different platforms, such as iOS, Android, and the web, are developed with the help of React Native. React Native is an open framework for cross-platform mobile app development for iOS and Android. So, React Native automation testing plays a crucial role in the app testing process. Given that React Native generates cross-platform apps, manual testing will quickly become a highly time-consuming task. In this regard, React Native automation testing will save both time and money in the longer run.
Now, let's take a look at various testing processes available for React Native apps and five popular React Native testing tools for automated testing.
Various Types of React Native App Testing
React Native has been enjoying great popularity for its features over the years, and it is one of the best programming languages. So, let’s check out various types of testing used for React Native apps.
1. Writing Tests
The first step in testing is to write code that is testable. Writing your entire program in a single file with many lines of code will lead to numerous confusions while testing. So, you can write your code in multiple small modules that you can test more thoroughly than if you tested the assembled whole. In this way, writing testable code is intertwined with writing clean, modular code.
2. Unit Tests
When we test objects with external dependencies, you will need to mock them out. Mocking is when you change some dependency of your code with your own implementation. Usually, working with real objects in tests is better than using mocks, but there are situations where this is not possible. So, mocking will help complete the unit testing of React Native apps without any hurdles.
3. Component Tests
React components are the building blocks of apps, and users can directly interact with their output. Even though your app's business logic has high testing coverage, without component testing, you may deliver a broken user interface to your users. Each component is tested functionally and visually with component testing.
For testing React Native components, there are two essential things you may have to test:
Interaction: This testing ensures that the component is in the operating condition when interacting with a user.
Rendering: This testing ensures that the component rendering output used by React is accurate.
4. Integration Tests
When developers are writing codes for complex software systems, individual components of the app need to interact with each other. All individual units are combined and tested in integration testing to ensure that their cooperation works per the app’s requirement.
An app only needs integration testing if it:
- Combines several modules of the app
- Uses an external system
- Makes a network call to other applications
- Operates any file or database I/O
5. End-to-End Tests
With the end-to-end (E2E) testing, you can check your app's operation on a device (or a simulator/emulator) from the user's perspective. This testing is done by creating your app in the release configuration and running the tests against it. In E2E testing, React Native components, React Native APIs, Redux stores, or any business logic are not tested. E2E testing can give you the highest possible confidence that your app is working correctly.
There are various end-to-end testing tools available for React Native apps. Detox is a popular framework because it is customized for React Native apps. Another popular automation tool in the space of iOS and Android apps is Appium.
5 Popular Test Automation Tools for React Native Apps
Test automation tools help ensure that your app is in perfect condition by performing various tests, ranging from static analysis to end-to-end tests. In the coming section, let's discuss five popular React Native testing tools for automated testing.
Appium is an open-source tool that allows automating native, mobile web, and hybrid applications on iOS mobile, Android mobile, and Windows desktop platforms. Appium’s WebDriver protocol drives iOS, Android, and Windows apps. It is a server that gets commands from an automated script and translates them into a language understandable by mobile devices. At the same time, it receives responses from mobile devices and translates those responses into automated scripts. Since Appium is cross-platform, it lets you write tests against multiple platforms (iOS, Android, and Windows) using the same API. Every platform that Appium supports is powered by one (or more) Appium “drivers,” which are essentially bits of software that implement the Appium protocol for a particular platform.
The main features of Appium are:
- It does not require application source code or library in React applications.
- It has multi-platform support, i.e., it can run the same test cases on multiple platforms.
- It allows the parallel execution of test scripts.
Detox is an end-to-end framework for applications on mobile devices, and Wix developed it. The significant problems in UI testing of mobile devices are slowness and flakiness. Detox solves the problem of slowness and flakiness for UI testing of mobile devices. It provides excellent abstractions to select and trigger actions on elements during the testing.
Some of the significant features of Detox are:
- It monitors asynchronous operations in the app to reduce the flakiness of finding the async elements in the app UI.
- It is a grey-box testing tool that can access the code and data from mobile apps.
- It easily connects to any CI systems and prominent cloud testing services.
- It provides fast feedback on your end-to-end testing.
Notable features of Jest include:
- Speed and performance
- Pre-commit hooks
- Easy to migrate
- Additional features and configurations
Karma is a node-based test tool. Karma’s ability to run tests against real browsers and real devices makes the testing more robust and reliable. As different browsers have different DOM implementations, testing against them is essential if you want to ensure your application will behave appropriately for most of its users. Karma is a tool that makes test-driven development faster and easy. The main focus of Karma is to develop a productive testing environment for the developers, where they get instant feedback about the test.
Notable features of Karma include:
- Remote control
- Easy debugging via WebStorm, IDE, or Google Chrome
- Continuous integration
Significant features of Jasmine are:
- It does not need any DOM.
- It uses clean and obvious syntax.
According to Statista, in 2021, 38% of software developers used React Native to build apps. As people are using more apps based on this framework, React Native test on devices is of utmost importance. Automating the testing with the help of the tools mentioned above will save developers a lot of time and effort.
If your team has existing test automation tools, they can be integrated with the HeadSpin Platform and operated on any device to which you have access. On the HeadSpin Platform, the test automation tool powers the functional aspects of the test, while HeadSpin data and insights enable the non-functional aspects of the test.
1. What is black-box testing?
Ans: Black-box testing is a software testing method that examines the software's functionality without peering into its internal structure or coding. The primary source of black-box testing is a specification of the requirement that the customer states.
2. What is a prop in the React Native framework?
Ans: Prop is a parameter to customize a component during creation and re-render. It is like an argument passed to a React component. A prop is set by the parent component and remains fixed for an entire lifecycle of a component.
3. What is a node-based tool?
Ans: A node-based tool is a tool that needs the Nodejs engine installed for it to run and can be accessed through the node package manager.
4. What makes React Native unique?
Ans: The main difference between React Native framework and other cross-platform development solutions is that it does not render WebViews in its code. It runs on its actual native views and components.