как добавить jest в проект

{
  "name": "my-project",
  "version": "1.0.0",
  "description": "",
  "private": true,
  "scripts": {
    "dev": "cross-env NODE_ENV=development webpack --mode development",
    "build": "cross-env NODE_ENV=production webpack --mode production",
    "start": "cross-env NODE_ENV=development webpack-dev-server --mode development --open",
    "stats": "webpack --json > stats.json && webpack-bundle-analyzer stats.json",
    "storybook": "start-storybook -p 6006",
    "build-storybook": "build-storybook",
    "test": "jest"
  },
  "jest": {
    "moduleNameMapper": {
      "moduleFileExtensions": ["js", "jsx"],
      "moduleDirectories": ["node_modules", "src"],
      "\\.(jpg|jpeg|png|gif|eot|otf|webp|svg|ttf|woff|woff2|mp4|webm|wav|mp3|m4a|aac|oga)$": "<rootDir>/__mocks__/fileMock.js",
      "\\.(css|less)$": "<rootDir>/__mocks__/styleMock.js"
    }
  },
  "dependencies": {
    "@babel/polyfill": "^7.8.7",
    "animate.css": "^3.7.2",
    "babel-preset-react": "^6.24.1",
    "dotenv-webpack": "^1.7.0",
    "firebase": "^7.13.1",
    "i18next": "^19.3.2",
    "i18next-browser-languagedetector": "^4.0.2",
    "i18next-xhr-backend": "^3.2.2",
    "react": "latest",
    "react-animate-on-scroll": "^2.1.5",
    "react-dom": "latest",
    "react-google-maps": "^9.4.5",
    "react-id-swiper": "^3.0.0",
    "react-redux": "^7.2.0",
    "react-router-dom": "^5.1.2",
    "react-stripe-checkout": "^2.6.3",
    "redux": "^4.0.5",
    "redux-logger": "^3.0.6",
    "redux-persist": "^6.0.0",
    "redux-saga": "^1.1.3",
    "redux-thunk": "^2.3.0",
    "reselect": "^4.0.0",
    "swiper": "^5.3.6",
    "uuid": "^7.0.3"
  },
  "browserslist": "> 0.25%, not dead",
  "author": "Surovets Viacheslav",
  "license": "ISC",
  "devDependencies": {
    "@babel/core": "^7.8.7",
    "@babel/plugin-proposal-class-properties": "^7.8.3",
    "@babel/preset-env": "^7.8.7",
    "@babel/preset-react": "^7.8.3",
    "@storybook/addon-actions": "^5.3.14",
    "@storybook/addon-links": "^5.3.14",
    "@storybook/addons": "^5.3.14",
    "@storybook/react": "^5.3.14",
    "babel-eslint": "^10.1.0",
    "babel-loader": "^8.0.6",
    "clean-webpack-plugin": "^3.0.0",
    "copy-webpack-plugin": "^5.1.1",
    "cross-env": "^7.0.2",
    "css-loader": "^3.4.2",
    "enzyme": "^3.11.0",
    "enzyme-adapter-react-16": "^1.15.2",
    "eslint": "^6.8.0",
    "eslint-plugin-react": "^7.19.0",
    "eslint-plugin-react-hooks": "0.0.0-235a6c4af",
    "file-loader": "^5.1.0",
    "html-webpack-plugin": "^3.2.0",
    "i": "^0.3.6",
    "jest": "^25.2.7",
    "mini-css-extract-plugin": "^0.9.0",
    "npm": "^6.14.2",
    "optimize-css-assets-webpack-plugin": "^5.0.3",
    "ramda": "^0.27.0",
    "react-i18next": "^11.3.3",
    "style-loader": "^1.1.3",
    "styled-components": "^5.0.1",
    "svg-inline-loader": "^0.8.2",
    "terser-webpack-plugin": "^2.3.5",
    "url-loader": "^3.0.0",
    "webpack": "^4.42.0",
    "webpack-bundle-analyzer": "^3.6.0",
    "webpack-cli": "^3.3.11",
    "webpack-dev-server": "^3.10.3"
  }
}

import React from 'react';
import { shallow } from 'enzyme';
import Root from './Root';

it ( 'should ', () => {
  expect(shallow(<Root />)).toMatchSnapshot();
});