Use DOM Testing Library to test any JS framework

Intro to Use DOM Testing Library to test any JS framework

Instructor: [0:00] Hey, folks. This module is a little bit unique because I don't necessarily recommend that you do all of the things specifically that I'm going to show you. I mostly just want to show you that it is totally possible to use DOM testing library with anything that renders to the DOM. Let's take a look at this project really quick.

[0:18] Here we've got a bunch of different files. We have this from HTML. I bet you didn't even know that this was a library, but it does exist and it's just a thing that takes HTML, turned it into DOM. It has a component kind of API, which is interesting. We've got Mithril and Knockout and jQuery, Hyperapp, a whole bunch.

[0:35] We also have a Svelte counter, which is an interesting and unique one. We're going back to Angular JS here. Of course, we do have React and so we can take a look at how you do React without React testing library and Jest with DOM testing library.

[0:49] We also have Vue in here, but there's already actually a Vue testing library. There's an Angular testing library, there's a Svelte testing library, a Preact testing library.

[0:58] They're already implementations of testing libraries specific to each one these frameworks, but it's a good idea for you to understand how these things work under the hood. That's why we're going to show you this directly without using those abstractions.

[1:12] Each one of these is slightly unique, but the thing that I like most about this is that most of the test after you get pass that first render right here are going to be the exact same. They all just get the counter, they click on the counter, they verify that the counter is incremented, they click on it again and verifies it increments again.

[1:30] That's one of the things that I love so much about the testing library family of tools. You can learn React testing library and then jump into a Vue project and you can start testing with the Vue testing library there.

[1:41] That's just one of the things that falls out of the beautiful pattern of separating ourselves from implementation details. We don't have to worry about what the implementation for getting stuff onto the page is. Our testing library can handle all of that.

[1:55] I'm really excited for you to check some of this out. It's quite fascinating. Let's go ahead and jump in.

The person using your application components shouldn’t have to know or care what framework(s) you used to write your application. Guess what: Neither should your tests. 

This course explores the 

. You’ll get hands-on experience writing tests for any JavaScript framework, giving you the confidence you need to ship your JavaScript application with your framework of choice.

To use DOM Testing Library with [React](https://reactjs.org/), we’ll write a custom render function that utilizes the getQueriesForElement function. Because React binds all event handlers to the body we’ll have to append our container to the body and we’ll add a cleanup method to unmount the component and cleanup the DOM. If you like this, checkout [react-testing-library](https://github.com/kentcdodds/react-testing-library).

If you like this, checkout [React Testing Library](https://testing-library.com/react).

Use DOM Testing Library with React

To use DOM Testing Library with [Preact](https://preactjs.com/), we’ll write a custom render function that utilizes the getQueriesForElement function. Because preact re-renders asynchronously, we’ll use a custom fireEventAsync function to ensure that the app has re-rendered after every event we fire. If you like this, checkout [preact-testing-library](https://github.com/antsmartian/preact-testing-library).

If you like this, checkout [Preact Testing Library](https://testing-library.com/preact).

Use DOM Testing Library with Preact

To use DOM Testing Library with [jQuery](https://jquery.com/), we’ll create a DOM node and apply our jQuery plugin to that DOM node, then we can use getQueriesForElement on that DOM node to get the queries we need to start writing out our tests.

Use DOM Testing Library with jQuery

To use DOM Testing Library with [Dojo](https://dojotoolkit.org/), we’ll write a custom render function that utilizes the getQueriesForElement function and dojo’s widge-core utilities.

Use DOM Testing Library with Dojo

To use DOM Testing Library with [HyperApp](https://github.com/jorgebucaran/hyperapp), we’ll write a custom render function that utilizes the getQueriesForElement function. HyperApp renders and re-renders asynchronously, so we’ll use a custom `fireEventAsync` utility function to ensure that the app has re-rendered after every event we fire.

Use DOM Testing Library with HyperApp

To use DOM Testing Library with [AngularJS](https://angularjs.org/), we’ll write a custom render function. We’ll pass our template and angular module we’d like to use for bootstrapping a mini-app inside a div we create, then use getQueriesForElement for that mini-app container. From there we can use all the regular utilities we enjoy from dom-testing-library.

Use DOM Testing Library with AngularJS

To use DOM Testing Library with [Angular](https://angular.io/), we’ll write a custom render function that utilizes the getQueriesForElement function. Here we need to create a test bed testing module which we’ll use to get a native element for our container.

If you like this, checkout [Angular Testing Library](https://testing-library.com/angular).

Use DOM Testing Library with Angular

To use DOM Testing Library with [VueJS](https://vuejs.org/), we’ll write a custom render function that utilizes the getQueriesForElement function. Vue is another library that re-renders asynchronously, so we’ll use that custom fireEventAsync to ensure that we wait until the next tick of the event loop before making further queries. If you enjoy this, checkout [vue-testing-library](https://github.com/dfcook/vue-testing-library).

Use DOM Testing Library with VueJS

To use DOM Testing Library with [Mithril](https://mithril.js.org/), we’ll write a custom render function which mounts a mithril component and then utilize the getQueriesForElement function on the container where it’s been mounted. Mithril is unique in how it re-renders so we’ll use dom-testing-library’s `wait` function for our assertions.

Use DOM Testing Library with Mithril

To use DOM Testing Library with [Svelte](https://svelte.technology/), we’ll write a custom render function that utilizes the getQueriesForElement function. We’ll take the svelte template and create a constructor for that as well as the data to interpolate. Then we can use dom-testing-library queries as normal.

If you like this, checkout [Svelte Testing Library](https://github.com/testing-library/svelte-testing-library).

Use DOM Testing Library with Svelte

To use DOM Testing Library with [from-html](https://github.com/m3g4p0p/from-html), we’ll write a custom render function that utilizes the getQueriesForElement function. In our situation we’ve made a custom “component” class for from-html, we mount that manually and then we can use DOM Testing Library's queries on the container we create.

Intro to Use DOM Testing Library to test any JS framework

Transcript

Intro to Use DOM Testing Library to test any JS framework