jest-dom VS user-event

//config/jest/setupTests.ts // jest-dom adds custom jest matchers for asserting on DOM nodes. // allows you to do things like: // expect(element).toHaveTextContent(/react/i) // learn more: https://github.com/testing-library/jest-dom import '@testing-library/jest-dom';

Update: Just got it working. Following the instructions on this github issue and using `shamefully-hoist=true` with pnpm I got it working. The issue I was facing was with pnpm.

React Testing Library uses jest-dom which has a .getByText() matcher.

vitest-dom extends the standard Jest matchers with convenient methods like .toBeDisabled. Now you can write tests that assert on the state of the DOM. The package is a fork of @testing-library/jest-dom.

jest-dom matchers

At the time of writing this article, it still seems to be an open issue. However, a workaround I found is to add "skipLibCheck": true, to your tsconfig.json file.

// jest-dom adds custom jest matchers for asserting on DOM nodes. // allows you to do things like: // expect(element).toHaveTextContent(/react/i) // learn more: https://github.com/testing-library/jest-dom import '@testing-library/jest-dom'; import { server } from './mocks/server'; beforeAll( () => server.listen( { onUnhandledRequest: 'error' } ) ); afterEach( () => server.resetHandlers() ); afterAll( () => server.close() );

Everything you want to do to your test environment such as extends the jest matchers with @testing-library/jest-dom, mock some APIs that’s not implemented in jdom, you can put to config/jest/setupTests.js:

This will register the additional assertions from @testing-library/jest-dom.

You probably want to be using user-event instead of fireEvent.

With userEvent it is different. Since version 14.0.0 the APIs always return a Promise. Because of that we need to make the whole test async and await on clicking with userEvent.

I just learned to do TDD by react testing library + jest + user event https://github.com/testing-library/user-event

I just tried running WinDirStat on the `node_modules` folder in a Create-React-App project I had lying around. Total size was 234 MB. Of that, 129MB was JS files. By far the biggest piece was TypeScript, which has 45MB of .js in 6 files making up its parsing and IDE language service implementation.

Beyond that, the breakdown is:

- .ts source files: 25MB

- Sourcemaps: 23MB

- Markdown: 15MB

- JSON: 10MB

It also looks like there's a 12MB Linux binary that was only in there as a publishing accident for the `user-event` library that has since been resolved ( https://github.com/testing-library/user-event/issues/266 ).

Or, take Redux Toolkit, which I maintain. If you look at https://unpkg.com/browse/@reduxjs/[email protected]/ , the published package for our current version, it adds up to about 10MB on disk. But, that's because we ship three separate entry points (RTK core, RTK Query UI-agnostic core, RTK Query with React-specific additions), and for each entry point we compile the code to multiple file formats (CommonJS, ESM legacy, ESM modern, ESM with "dev" and "prod" already built in, UMD dev, UMD production), and each of those has sourcemaps. The actual amount of code that ends up in your bundle is about 20KB min+gz.

So, it's a combination of many things: TS itself is big, libraries typically publish packages containing both the original source code plus multiple build artifacts to run in different environments, and packages also include various metadata and other files as well.

To get away from testing our code implementation and get closer to testing how the application is actually used, we turn once again to React Testing Library. Instead of creating fake DOM event objects and simulating various change events, we have the ability to mimic how users would actually interact with the application using userEvent's, which are provided by the user-event library.