react-testing-library 为什么 toBeInTheDocument() 不是 function

Question

Here is my code for a tooltip that toggles the CSS property display: block on MouseOver and on Mouse Out display: none .

 it('should show and hide the message using onMouseOver and onMouseOut events respectively', () => {
    const { queryByTestId, queryByText } = render(
      <Tooltip id="test" message="test" />,
    )
    fireEvent.mouseOver(queryByTestId('tooltip'))
    expect(queryByText('test')).toBeInTheDocument()
    fireEvent.mouseOut(queryByTestId('tooltip'))
    expect(queryByText('test')).not.toBeInTheDocument()
    cleanup()
  })

I keep getting the error TypeError: expect(...).toBeInTheDocument is not a function

Has anyone got any ideas why this is happening? My other tests to render and snapshot the component all work as expected. As do the queryByText and queryByTestId.

Answer 1

toBeInTheDocument is not part of RTL. You need to install jest-dom to enable it.

And then import it in your test files by: import '@testing-library/jest-dom'

Answer 2

As mentioned by Giorgio, you need to install jest-dom. Here is what worked for me:

(I was using typescript)

npm i --save-dev @testing-library/jest-dom

Then add an import to your setupTests.ts

import '@testing-library/jest-dom/extend-expect';

Then in your jest.config.js you can load it via:

"setupFilesAfterEnv": [
    "<rootDir>/src/setupTests.ts"
  ]

Answer 3

When you do npm i @testing-library/react make sure there is a setupTests.js file with the following statement in it

import '@testing-library/jest-dom/extend-expect';

Answer 4

Having tried all of the advice in this post and it still not working for me, I'd like to offer an alternative solution:

Install jest-dom:

npm i --save-dev @testing-library/jest-dom

Then create a setupTests.js file in the src directory (this bit is important! I had it in the root dir and this did not work...). In here, put:

import '@testing-library/jest-dom'

(or require(...) if that's your preference).

This worked for me :)

Answer 5

Some of the accepted answers were basically right but some may be slightly outdated: Some references that are good for now:

• https://github.com/testing-library/jest-dom
• https://jestjs.io/docs/configuration

Here are the full things you need:

1. in the project's <rootDir> (aka where package.json and jest.config.js are), make sure you have a file called jest.config.js so that Jest can automatically pick it up for configuration. The file is in JS but is structured similarly to a package.json.
2. Make sure you input the following:

  module.exports = {
    testPathIgnorePatterns: ['<rootDir>/node_modules', '<rootDir>/dist'], // might want?
    moduleNameMapper: {
      '@components(.*)': '<rootDir>/src/components$1' // might want?
    },
    moduleDirectories: ['<rootDir>/node_modules', '<rootDir>/src'],
    setupFilesAfterEnv: ['<rootDir>/src/jest-setup.ts'] // this is the KEY
    // note it should be in the top level of the exported object.
  };

3. Also, note that if you're using typescript you will need to make sure your jest-setup.ts file is compiled (so add it to src or to the list of items to compile in your tsconfig.json .

4. At the top of jest-setup.ts/js (or whatever you want to name this entrypoint) file: add import '@testing-library/jest-dom'; .

5. You may also want to make sure it actually runs so put a console.log('hello, world!'); . You also have the opportunity to add any global functions you'd like to have available in jest such as ( global.fetch = jest.fn() ).

6. Now you actually have to install @testing-library/jest-dom : npm i -D @testing-library/jest-dom in the console.

With those steps you should be ready to use jest-dom:

Without TS: you still need:

1. npm i -D @testing-library/jest-dom
2. Creating a jest.config.js and adding to it a minimum of: module.exports = { setupFilesAfterEnv: ['<rootDir>/[path-to-file]/jest-setup.js'] } .
3. Creating a [path-to-file]/jest-setup.js and adding to it: import '@testing-library/jest-dom'; .

The jest-setup file is also a great place to configure tests like creating a special renderWithProvider( function or setting up global window functions.

Answer 6

If you don't already have jest-dom installed, you need to install it using the command below.

npm i --save-dev @testing-library/jest-dom

create a file in the root of your project folder and name it jest-setup.js. Your file should have the following content.

import "@testing-library/jest-dom/extend-expect";

In your package.json, add the code below to your jest config;

"jest": {
    "setupFilesAfterEnv": ["<rootDir>/jest-setup.js"]
}

Answer 7

I had a hard time solving that problem so I believe it's important to note the followings if you're using CREATE REACT APP for your project:

1. You DO NOT need a jest.config.js file to solve this, so if you have that you can delete it.
2. You DO NOT need to change anything in package.json .
3. You HAVE TO name your jest setup file setupTests.js and have it under the src folder. It WILL NOT work if your setup file is called jest.setup.js or jest-setup.js .

Answer 8

None of the answers worked for me because I made the silly mistake of typing toBeInDocument() instead of toBeInTheDocument() . Maybe someone else did the same mistake :)

Answer 9

1. install required packages

   npm install --save-dev @testing-library/jest-dom eslint-plugin-jest-dom

2. create jest-setup.js in the root folder of your project and add

   import '@testing-library/jest-dom'

3. in jest.config.js

   setupFilesAfterEnv: ['/jest-setup.js']

4. TypeScript only, add the following to the tsconfig.json file. Also, change .js extension to .ts .

   "include": ["./jest-setup.ts"]

toBeInTheDocument() and many similar functions are not part of the React-testing-library . It requires installing an additional package.

Answer 10

For anyone out there that like is trying to run tests in Typescript with jest and is still getting the same error even after installing @testing-library/jest-dom and following all the other answers: you probably need to install the type definitions for jest-dom ( here ) with:

npm i @types/testing-library__jest-dom

or

yarn add @types/testing-library__jest-dom

You need to install them as real dependencies and not as devDependency .

Answer 11

I was having this issue but for @testing-library/jasmine-dom rather than @testing-library/jest-dom .

The process of setup is just a tiny bit different with jasmine. You need to set up the environment in a before function in order for the matchers to be added. I think jest-dom will go ahead and add the matchers when you first import but Jasmine does not.

import { render, screen } from '@testing-library/react';
import MyComponent from './myComponent';
import JasmineDOM from '@testing-library/jasmine-dom';

describe("My Suite", function () {

  beforeAll(() => {
    jasmine.getEnv().addMatchers(JasmineDOM);
  })


  it('render my stuff', () => {
    const { getByText } = render(<MyComponent />);
    const ele = screen.getByText(/something/i);
    expect(ele).toBeInTheDocument();
  });
});

Answer 12

If you're using TS You could also add a test.d.ts file to your test directory and use a triple slash directive: ///<reference types='@testing-library/jest-dom'>

Answer 13

If you are using react-script then follow the below steps

1. Install @testing-library/jest-dom library if not done already using npm i @testing-library/jest-dom .
2. Put import "@testing-library/jest-dom/extend-expect" in setUpTest.js

If you are using jest then import the library in jest.setup.js file.

Answer 14

Instead of doing:

    expect(queryByText('test')).toBeInTheDocument()

you can find and test that it is in the document with just one line by using

    let element = getByText('test');

The test will fail if the element isn't found with the getBy call.