How to Test React/TypeScript Components

TypeScript/React Testing: Components, Hooks, Custom Hooks, Redux and Zustand

By viewer request we are looking at testing React TypeScript components all the way from render components, through components with state, asynchronous components, custom hooks, Redux and Zustand.

00:00 Introduction
00:47 Project Setup
01:55 Basic component testing
05:06 Multiple element testing
08:22 Event handler testing
11:51 Testing state hooks
14:07 Testing async hooks
17:56 Testing simple custom hooks
19:53 Testing async custom hooks
22:18 Testing Redux components
26:19 Testing Zustand components
29:03 Outroduction

Code: https://github.com/jherr/ts-react-testing  

React Testing Library: https://testing-library.com/docs/react-testing-library/intro/ 
Mock Service Worker: https://mswjs.io/ 
React Hooks Testing Library: https://github.com/testing-library/react-hooks-testing-library#readme 

#typescript #testing #react

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How native is React Native? | React Native vs Native App Development

If you are undertaking a mobile app development for your start-up or enterprise, you are likely wondering whether to use React Native. As a popular development framework, React Native helps you to develop near-native mobile apps. However, you are probably also wondering how close you can get to a native app by using React Native. How native is React Native?

In the article, we discuss the similarities between native mobile development and development using React Native. We also touch upon where they differ and how to bridge the gaps. Read on.

A brief introduction to React Native

Let’s briefly set the context first. We will briefly touch upon what React Native is and how it differs from earlier hybrid frameworks.

React Native is a popular JavaScript framework that Facebook has created. You can use this open-source framework to code natively rendering Android and iOS mobile apps. You can use it to develop web apps too.

Facebook has developed React Native based on React, its JavaScript library. The first release of React Native came in March 2015. At the time of writing this article, the latest stable release of React Native is 0.62.0, and it was released in March 2020.

Although relatively new, React Native has acquired a high degree of popularity. The “Stack Overflow Developer Survey 2019” report identifies it as the 8th most loved framework. Facebook, Walmart, and Bloomberg are some of the top companies that use React Native.

The popularity of React Native comes from its advantages. Some of its advantages are as follows:

• Performance: It delivers optimal performance.
• Cross-platform development: You can develop both Android and iOS apps with it. The reuse of code expedites development and reduces costs.
• UI design: React Native enables you to design simple and responsive UI for your mobile app.
• 3rd party plugins: This framework supports 3rd party plugins.
• Developer community: A vibrant community of developers support React Native.

Why React Native is fundamentally different from earlier hybrid frameworks

Are you wondering whether React Native is just another of those hybrid frameworks like Ionic or Cordova? It’s not! React Native is fundamentally different from these earlier hybrid frameworks.

React Native is very close to native. Consider the following aspects as described on the React Native website:

• Access to many native platforms features: The primitives of React Native render to native platform UI. This means that your React Native app will use many native platform APIs as native apps would do.
• Near-native user experience: React Native provides several native components, and these are platform agnostic.
• The ease of accessing native APIs: React Native uses a declarative UI paradigm. This enables React Native to interact easily with native platform APIs since React Native wraps existing native code.

Due to these factors, React Native offers many more advantages compared to those earlier hybrid frameworks. We now review them.

#android app #frontend #ios app #mobile app development #benefits of react native #is react native good for mobile app development #native vs #pros and cons of react native #react mobile development #react native development #react native experience #react native framework #react native ios vs android #react native pros and cons #react native vs android #react native vs native #react native vs native performance #react vs native #why react native #why use react native

How to add Cypress for Create React App with TypeScript

In this lesson we look at how to add #cypress with code coverage support for a Create #React App application with #TypeScript.

In the end you will have a developer flow that can save you a bunch of time in testing effort 

#react-native #react #cypress #typescript 

How to Write Tests with React Testing Library and TypeScript

Everyone knows writing tests is super important for software development. It enables us to change codes more speedy with less bugs.

When it comes to frontend, React Testing Library is becoming popular because it’s easier to test React hooks compared with enzyme. However, the way to create tests is completely different. So this article explains how to write the basic AAA pattern tests with React Testing Library and TypeScript.

If you would like to know other topics of React Testing Library, please refer the articles below.

#web-development #typescript #react #react-testing-library #javascript

How to Test React/TypeScript Components

TypeScript/React Testing: Components, Hooks, Custom Hooks, Redux and Zustand

By viewer request we are looking at testing React TypeScript components all the way from render components, through components with state, asynchronous components, custom hooks, Redux and Zustand.

00:00 Introduction
00:47 Project Setup
01:55 Basic component testing
05:06 Multiple element testing
08:22 Event handler testing
11:51 Testing state hooks
14:07 Testing async hooks
17:56 Testing simple custom hooks
19:53 Testing async custom hooks
22:18 Testing Redux components
26:19 Testing Zustand components
29:03 Outroduction

Code: https://github.com/jherr/ts-react-testing  

React Testing Library: https://testing-library.com/docs/react-testing-library/intro/ 
Mock Service Worker: https://mswjs.io/ 
React Hooks Testing Library: https://github.com/testing-library/react-hooks-testing-library#readme 

#typescript #testing #react

Testing Microservices Applications

The shift towards microservices and modular applications makes testing more important and more challenging at the same time. You have to make sure that the microservices running in containers perform well and as intended, but you can no longer rely on conventional testing strategies to get the job done.

This is where new testing approaches are needed. Testing your microservices applications require the right approach, a suitable set of tools, and immense attention to details. This article will guide you through the process of testing your microservices and talk about the challenges you will have to overcome along the way. Let’s get started, shall we?

A Brave New World

Traditionally, testing a monolith application meant configuring a test environment and setting up all of the application components in a way that matched the production environment. It took time to set up the testing environment, and there were a lot of complexities around the process.

Testing also requires the application to run in full. It is not possible to test monolith apps on a per-component basis, mainly because there is usually a base code that ties everything together, and the app is designed to run as a complete app to work properly.

Microservices running in containers offer one particular advantage: universal compatibility. You don’t have to match the testing environment with the deployment architecture exactly, and you can get away with testing individual components rather than the full app in some situations.

Of course, you will have to embrace the new cloud-native approach across the pipeline. Rather than creating critical dependencies between microservices, you need to treat each one as a semi-independent module.

The only monolith or centralized portion of the application is the database, but this too is an easy challenge to overcome. As long as you have a persistent database running on your test environment, you can perform tests at any time.

Keep in mind that there are additional things to focus on when testing microservices.

• Microservices rely on network communications to talk to each other, so network reliability and requirements must be part of the testing.
• Automation and infrastructure elements are now added as codes, and you have to make sure that they also run properly when microservices are pushed through the pipeline
• While containerization is universal, you still have to pay attention to specific dependencies and create a testing strategy that allows for those dependencies to be included

Test containers are the method of choice for many developers. Unlike monolith apps, which lets you use stubs and mocks for testing, microservices need to be tested in test containers. Many CI/CD pipelines actually integrate production microservices as part of the testing process.

Contract Testing as an Approach

As mentioned before, there are many ways to test microservices effectively, but the one approach that developers now use reliably is contract testing. Loosely coupled microservices can be tested in an effective and efficient way using contract testing, mainly because this testing approach focuses on contracts; in other words, it focuses on how components or microservices communicate with each other.

Syntax and semantics construct how components communicate with each other. By defining syntax and semantics in a standardized way and testing microservices based on their ability to generate the right message formats and meet behavioral expectations, you can rest assured knowing that the microservices will behave as intended when deployed.

#testing #software testing #test automation #microservice architecture #microservice #test #software test automation #microservice best practices #microservice deployment #microservice components