testing-library / jest-dom

@testing-library/jest-dom version: 6.1.5
node version: N/A - using Bun 1.0.15
jest (or vitest) version: N/A - using bun test
npm (or yarn) version: N/A - using Bun 1.0.15
@testing-library/react version: 14.1.2

Relevant code or config:

This code works in practice, it's just the types that are causing a problem:

import * as matchers from "@testing-library/jest-dom/matchers";
import { expect, mock, test } from "bun:test";

expect.extend(matchers);
//            ^ Argument of type 'TestingLibraryMatchers<any, void> & Record<string, any>' is not assignable to parameter of type 'ExpectExtendMatchers...

What you did:

Tried to extend expect from bun:test with matchers from @testing-library/jest-dom/matchers.

I don't think this is specific to Bun, but they just added support for expect.extend so I thought I'd give it go.

What happened:

The TypeScript definitions for the "./matchers" export don't seem to match the implementations of the actual matchers.

Take toBeChecked, for example. The implementation is here:

jest-dom/src/to-be-checked.js

Line 4 in b7b7c6a

export function toBeChecked(element) {

But the type definition doesn't include the element parameter:

jest-dom/types/matchers.d.ts

Line 433 in b7b7c6a

toBeChecked(): R

Also, the R generic is specified as void in the export statement, so the return type is effectively missing as well. (Should be something like { pass: boolean; message: () => string; }.)

jest-dom/types/matchers.d.ts

Lines 667 to 669 in b7b7c6a

    
           declare const matchers: matchers.TestingLibraryMatchers<any, void> & 
        
             Record<string, any> 
        
           export = matchers

Reproduction:

See "Relevant code" section above.

Problem description:

Types should match the implementation.

Suggested solution:

https://github.com/testing-library/jest-dom/blob/main/types/matchers.d.ts should be updated to match the implementation of the matcher functions. If those types are correct in some other context (since they do seem to match the implementation when called as a property of an expect() result), then a separate definition file should be created for the "./matchers" export.

I tried the same thing and got the similar problem.

Here is the related test:

import {
  expect,
  test,
} from 'bun:test'
import {
  render,
  screen,
} from '@testing-library/react'
import * as extensions from '@testing-library/jest-dom/matchers'
import App from './App'

expect.extend(extensions)

test('renders', async () => {
  render(<App  />);

  expect(screen.getByText('Click on the Vite and React logos to learn more')).toBeInTheDocument();
})

Running bun tsc --noEmit gave me:

src/App.test.tsx:12:15 - error TS2345: Argument of type 'TestingLibraryMatchers<any, void> & Record<string, any>' is not assignable to parameter of type 'ExpectExtendMatchers<{ [x: string]: ...; toBeInTheDOM: unknown; toBeInTheDocument: unknown; toBeVisible: unknown; toBeEmpty: unknown; toBeEmptyDOMElement: unknown; toBeDisabled: unknown; toBeEnabled: unknown; toBeInvalid: unknown; toBeRequired: unknown; toBeValid: unknown; toContainElement: unknown; ... 15 more ...;...'.
  Types of property 'toBeInTheDOM' are incompatible.
    Type '(container?: HTMLElement | SVGElement | undefined) => void' is not assignable to type 'CustomMatcher<unknown, any[]>'.
      Types of parameters 'container' and 'expected' are incompatible.
        Type 'unknown' is not assignable to type 'HTMLElement | SVGElement | undefined'.

12 expect.extend(extensions)
                 ~~~~~~~~~~

src/App.test.tsx:17:79 - error TS2339: Property 'toBeInTheDocument' does not exist on type 'Matchers<HTMLElement>'.

17   expect(screen.getByText('Click on the Vite and React logos to learn more')).toBeInTheDocument();
                                                                                 ~~~~~~~~~~~~~~~~~

However, the test is running as expected. Only the typing is the issue here.

@soullivaneuh I just submitted #566 to address this issue.

🎉 This issue has been resolved in version 6.2.1 🎉

The release is available on:

Your semantic-release bot 📦🚀

	declare const matchers: matchers.TestingLibraryMatchers<any, void> &
	Record<string, any>
	export = matchers