Articles Tagged testing

There’s been news about Chrome freezing their User-Agent string (and all other major browsers are on board). That means they’ll still have a User-Agent (UA) string (that comes across in headers and is available in JavaScript as navigator.userAgent. By freezing it, it will be less useful over time in detecting the browser/platform/version, although the quoted reason for doing it is more about privacy and stopping fingerprinting rather than developer concerns.

In the front-end world, the general advice is: you … Read article “Freezing User-Agent Strings”

As you begin to make use of React hooks in your applications, you’ll want to be certain the code you write is nothing short of solid. There’s nothing like shipping buggy code. One way to be certain your code is bug-free is to write tests. And testing React hooks is not much different from how React applications are tested in general.

In this tutorial, we will look at how to do that by making use of a to-do application built … Read article “Testing React Hooks With Enzyme and React Testing Library”

WebPageTest is an online tool and an Open Source project to help developers audit the performance of their websites. As a Web Performance Evangelist at Theodo, I use it every single day. I am constantly amazed at what it offers to the web development community at large and the web performance folks particularly — for free.

But things can get difficult pretty quickly when dealing with Single Page Applications — usually written with React, Vue, Svelte or any other … Read article “Recipes for Performance Testing Single Page Applications in WebPageTest”

Testing applications is crucially important to ensuring that the code is error-free and the logic requirements are met. However, writing tests manually is tedious and prone to human bias and error. Furthermore, maintenance can be a nightmare, especially when features are added or business logic is changed. We’ll learn how model-based testing can eliminate the need to manually write integration and end-to-end tests, by automatically generating full tests that keep up-to-date with an abstract model for any app.… Read article “Model-Based Testing in React with State Machines”

Every now and then, a debate flares up about the value of typed JavaScript. “Just write more tests!” yell some opponents. “Replace unit tests with types!” scream others. Both are right in some ways, and wrong in others. Twitter affords little room for nuance. But in the space of this article we can try to lay out a reasoned argument for how both can and should coexist.… Read article “Types or Tests: Why Not Both?”

End-to-end tests are written to assert the flow of an application from start to finish. Instead of handling the tests yourself — you know, manually clicking all over the application — you can write a test that runs as you build the application. That’s what we call continuous integration and it’s a beautiful thing. Write some code, save it, and let tooling do the dirty work of making sure it doesn’t break anything.

Cypress is just one end-to-end testing … Read article “Using Cypress to Write Tests for a React Application”