[Solved]-react-testing-library why is toBeInTheDocument() not a function-Reactjs

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.

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.

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 :)

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.

Some of the accepted answers were basically right but some may be slightly outdated: Some references that are good for now: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

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 :)

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';

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"
  ]