This is how you mock components when testing react with jest:

// in your test file
jest.mock('../path/to/component/to/Component.js');

Create a __mocks__ folder in the same directory of the component you want to test and a file with the same name of the component inside it:

// __mocks__/Component.js
import React from 'react';
export default function mock() {
  return (<span>Component mock</span>);
}