Guide to React Integration Testing

Integrity testing of software is integral to ensuring a successful React project, particularly if the project integrates with multiple external services and APIs. It is critical to verify that the upgrading process goes smoothly and that no features are lost when updating to the most recent version. Without this testing, the project is at risk of not performing as expected.

Setting up the appropriate tests for React components can be a demanding task, as errors in this process may result in both false positive and false negative results. Furthermore, running integration tests for a React project can pose a significant challenge.

Detailed instructions on project setup, test writing, and execution throughout the development process are provided here.

First, we need to discuss what an integration test is and how it differs from unit testing and functional testing.

Integrity testing is what?

Integration testing is the subsequent stage in the software development life cycle following unit testing. Its purpose is to ensure that all of the individual components of the software interact together seamlessly. The objective of integration testing is to detect any issues caused by the integration of multiple modules.

Unit tests are performed on all modules before they are combined for integration testing. Individual programmers or coders are responsible for developing distinct sections of a larger software application. The integrity of the communication between modules is verified during the integration process.

Integration testing is an essential part of software testing, ensuring that all components interact as desired within the larger system. To validate the data flow, it is necessary to verify that all parts or modules can operate independently. Integration testing is employed for this purpose, guaranteeing that all software elements interact harmoniously together.

Integrity tests are designed specifically for websites that utilise React technology. These tests provide a comprehensive analysis of the user experience without needing extensive time and effort devoted to end-to-end testing. Therefore, they are an effective way to evaluate the performance of your application.

Here are three typical kinds of tests:

  • Assembly Line checks the validity of one line of code at a time. But that’s missing the bigger picture.
  • Despite the fact that end-to-end (E2E) testing requires a more substantial investment in terms of time to create and execute, the use of automation technologies, such as Selenium and Cypress, is essential in simulating actual user actions on a website. Through this process, a user experience that is nearly indistinguishable from the genuine article is achieved.
  • Between the two extremes of end-to-end testing and unit testing lies the realm of integration testing. Integration testing helps to ensure that all components of a given application are functioning correctly when they are used in concert with one another. To facilitate this process, there are a number of tools available such as jsDOM, which is designed to simulate browser APIs with minimal overhead, and mocking tools, which simulate external APIs. Both of these tools are included with the Jest testing framework to make integration testing as efficient as possible.

The value of React’s integration testing

Unit testing, integration testing, and end-to-end testing are the three most prevalent varieties of testing.

Integration testing involves several approaches that are not overly time-consuming to implement due to features such as testing component interoperability and simulating real-world scenarios (such as HTTP requests). Not only is this an efficient way to test, but it also serves to build confidence in the development team’s abilities. By incorporating integration testing from the outset, the need for unit tests can be significantly reduced.

Because of this, you need to put in the effort to create integration tests. However, it is possible to create useful unit tests and full-stack tests.

Investing the majority of your resources into creating integration tests can prove to be a wise decision, as they offer the most efficient way to optimise your time and energy expenditure.

Common methods for testing React applications

Integration testing is a critical part of the software development cycle, and there are four main types of integration testing that can be utilised: big-bang testing, top-down testing, bottom-up testing, and sandwich/hybrid testing. In this article, we will discuss the benefits and drawbacks of each approach, so that you can decide which one is best for your development project.

Explosive experiments

The Big Bang Integration Testing approach necessitates a comprehensive integration and testing of all components as one unit. This method involves the simultaneous connection of all components, resulting in a system that is fully functional. The Big Bang approach is distinguished by its holistic approach to integration and testing.

Despite the efficiency of this approach, it is possible that any issues that arise will be difficult to identify due to the lack of monitoring of the interfaces between the various components of the system. Therefore, it is important to take the necessary steps to ensure that the interfaces are being checked, in order to simplify the process of locating the source of any faults.


  • This method is well suited for testing low-scale systems.
  • Finding bugs in these systems will allow you to get your application releases done faster and with less effort.


  • When many modules are combined into one, tracing the origin of errors might be challenging.
  • Big-bang testing takes a long time to get results when applied to a large system with many components.
  • The length of an integration test can fluctuate significantly. All modules must be functional prior to beginning the testing process, so the developers may take more time to rectify any errors. As a result, the overall testing duration may be extended.

Examination from the top down

By utilising the top-down approach, tests are performed in a systematic order, starting with the most complicated modules and finishing with the most basic ones. Following the testing of each component individually, the whole system is assembled to gauge its effectiveness.


  • It’s considerably less of a hassle to track down problems and figure out what caused them.
  • In testing, prioritising the checking of the most crucial units will provide the best results in locating the most essential design problems.
  • It’s possible to make preliminary prototypes.


  • When just the base modules are checked, the testing may be insufficient or miss important details.
  • When there are too many test forms, it slows down the testing process.

Inverse engineering

Bottom-up integration testing is the opposite of top-down integration testing (also known as bottom-to-top testing). This approach starts by examining the individual modules at the lowest level of the system, and then gradually progresses to the more complex modules. If all the components of a system are available for testing simultaneously, this approach can be used.


  • Fault isolation and diagnosis are simplified.
  • It is quicker to find and fix issues when no modules are pending testing.


  • A delay in the delivery of the final product may occur if sufficient time is not spent testing all modules.
  • Despite the rigorous testing process, it is possible that some bugs may go undetected until the end of the process as testers typically only evaluate mission-critical modules at the conclusion. This leaves developers with limited time to identify and correct any issues that may have been overlooked.
  • It might be more difficult to test a software system that is composed of many small components.
  • A working prototype cannot be made using this technique.

Examination of Sandwich and Hybrid Designs

Integration testing is a process of verifying the correct functioning of individual software components when they are combined together. This process involves two aspects: testing the interfaces between components and testing the communication between them. To ensure comprehensive coverage of the components, integration testing can be conducted using either a top-down or a bottom-up approach.

Sandwich testing is a kind of hybrid integration testing that contains elements of both bottom-up and top-down testing strategies.

Sandwich testing provides testers with a number of advantages, allowing them to perform tests with greater accuracy and efficiency. This type of testing is a hybrid system, wherein both stubs and drivers are employed.


  • The best approach to using software testing for long-term projects like operating systems.


  • It’s a time-consuming and expensive procedure.
  • An elevated level of accuracy and ability is needed for this method.

What are the best practices for doing Integration tests?

The following are the stages of an integration test:

  • Creating a strategy for testing.
  • Planning out how tests will go, along with creating test cases and scripts.
  • Tests are executed after units or modules have been integrated.
  • Correction of mistakes once they have been reported.
  • Verifying restored features after fixing an issue.
  • This procedure will be repeated until all problems are fixed.

Jest and the React Testing Library: An Overview

Simply put, what does “Jest” mean?

Jest is a testing framework made specifically for JavaScript and TypeScript. Framework works nicely with React integration.

This testing framework employs a rigorous methodology to ensure the accuracy of any JavaScript library. Writing tests with its intuitive and familiar API is quick and simple, while its comprehensive documentation and ease of setup make it easily customizable to suit your needs.

This framework was designed with simplicity in mind, offering a straightforward, minimalistic layout as well as a strong and reliable Application Programming Interface (API) for individual testing, comparing, mocking, test coverage, and a wide range of other features.

The React Testing Library: A Brief Overview

React Testing Library is a JavaScript testing utility designed to help test React components. Through simulating user interactions with individual components, it is able to verify that the User Interface (UI) is functioning as expected. This allows developers to be confident that their application is behaving as intended.

React Testing Library, created by Kent C. Dodds, is a lightweight testing framework that serves as an alternative to the Enzyme component. This library provides a few additional utilities to the react-dom and react-dom/test-utils packages, allowing for a more comprehensive testing experience.

Due to its design as a DOM testing library, the React Testing Library employs actual DOM elements as part of its testing processes, as opposed to simply relying on the displayed React components.

Because it encourages sound testing procedures and is (relatively) simple to implement, you can get started with it right away.

Step one of working with the example application

We’ll be using npm, which requires node.js, to build the react app, so make sure you have it installed (node package manager).

By executing the following command in the terminal, you can create a directory that contains a subdirectory named ‘src’. This subdirectory will store all of the application’s user interface-related files in one convenient location, thus facilitating compilation of the necessary files.

To commence this project, we will be installing and configuring the required libraries. This process is made simpler and more convenient through the effective use of the available command. This command will enable us to smoothly deploy and launch a React application.

Despite the fact that Jest and the React testing framework are powerful tools, they do not provide the capability to perform end-to-end testing. End-to-end testing involves testing the entire application to determine how the components work together. Consequently, this type of testing is not supported by either Jest or the React testing framework.

Attempting to develop an understanding of increasingly complex applications while encountering numerous hurdles can be disheartening. Fortunately, there are a variety of helpful tools available for executing end-to-end testing of React-based applications. Moreover, automated testing might present better and faster results.

At the conclusion of this guide, you should now feel confident in your ability to use React for integrated testing. You should have a better understanding of how to successfully incorporate the tests you have created into the overall React testing environment. With this knowledge and skill set in hand, you can confidently test any and all features.

When performing integration testing, we assess the compatibility and functionality of the individual components when integrated together. To ensure that our modifications have not caused any problems, we may also undertake regression tests for increased confidence.

Integration testing allows developers to evaluate the entire application stack, ensuring that each component functions as intended, and that all components are working together harmoniously. This type of testing is essential for verifying the functionality of the entire application, rather than just individual components.

In order to guarantee that all components of your application are fitting together efficiently and correctly, integration testing is absolutely essential. Integration tests can be created in any framework, and most frameworks provide support for visual testing of React applications.


  1. Is it true that Jest excels in integration testing?

    Integration testing can be accomplished efficiently and effectively using Jest, a free and open-source test framework created by Facebook. This command-line tool, which is similar to Jasmine and Mocha, provides an ideal solution for testing the entire technology stack, not just the user interface.

    No setup is required to take advantage of the fake functions feature. Furthermore, it provides an excellent capability known as snapshot testing, which allows testers to verify the results of rendering components.
  2. What is the best tool for testing React applications?

    There is a plethora of open-source testing tools available for React applications. Each of these tools has its own unique features, which means that software engineers must carefully consider which one they will use. The two most popular tools for testing React components are Jest and Enzyme.

    Unit testing and system testing are both possible with the proper instruments. A few of the most commonly utilised testing tools, selected by both developers and testers, include:
    • Jest
    • Mocha
    • Jasmine
    • Enzyme
    • Chai
    • CypressIO
  3. A better question: Jest or Mocha?

    In order to ensure the success of your React project, it is recommended to use either Mocha or Jest for testing purposes. While Jest’s approach to testing is more minimalistic, Mocha provides some additional features that can come in handy.

    Jest is an excellent choice for those who require an uncomplicated testing experience and are not interested in understanding a new syntax. Alternatively, if you are seeking more advanced features and the most up-to-date extras, Mocha is the optimal solution.
  4. I’m trying to understand the distinction between the Jest and the React testing libraries.

    Given its role as a test runner, Jest is the ideal tool for testers who need to locate, run, and evaluate the success or failure of tests. On the other hand, React Testing Library provides a virtual DOM for testing React components.

    While Jest is a unique tool that is favoured by many developers, React testing makes it possible to interface with any other testing library.
  5. Do we need Enzymes for Jest to work?

    The React application was the preferred choice for testing by both Jest and Enzyme. While Jest can be utilised with any testing framework, Enzyme at present only works with the React testing framework.

    If you have not yet installed Enzyme, Jest will still work effectively for testing purposes. Jest has a wide range of excellent features, but combining it with Enzyme will make it significantly more powerful. While it is possible to use Enzyme without Jest, you must pair it with another test runner in order to make it functional. To put it differently, Enzyme cannot run tests without a test runner.

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