react-testing-library why is toBeInTheDocument() not a 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.

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

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 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Some of the accepted answers were basically right but some may be slightly outdated: Some references that are good for now: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 that file: add import '@testing-library/jest-dom';.

5. You may also want to make sure its captured so put a console.log('hello, world!');.

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

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.