A robust jest setup used in a large project

.babelrc

{
  "presets": [ "react", ["es2015", {"modules": false}], "stage-1" ],
  "plugins": ["react-hot-loader/babel", "transform-runtime", "lodash"],
  "env": {
    "test": {
      "plugins": ["babel-plugin-dynamic-import-node"],
      "presets": ["react", "es2015", "stage-1"],
    }
  }
}

fileMock.js

// config/__mocks__/fileMock.js

module.exports = 'test-file-stub'

jest.js

// config/jest.js

import { shallow, render, mount } from 'enzyme'

// Helper for setting location in tests requiring access to window.location
export const setPathname = pathname => {
  Object.defineProperty(window.location, 'pathname', {
    writable: true,
    value: pathname,
  })
}

// Skip createElement warnings but fail tests on any other warning
console.error = message => {
  if (!/(React.createElement: type should not be null)/.test(message)) {
    throw new Error(message)
  }
}

// Make Enzyme functions available in all test files without importing
global.shallow = shallow
global.render = render
global.mount = mount

const localStorageMock = (function () {
  let store = {}
  return {
    getItem(key) {
      return store[key]
    },
    setItem(key, value) {
      store[key] = value.toString()
    },
    clear() {
      store = {}
    },
  }
}())
Object.defineProperty(window, 'localStorage', { value: localStorageMock })

package.json

{
  ...
  },
  "scripts": {
    "test": "better-npm-run test",
    "test:verbose": "yarn test -- --verbose",
    "test:watch": "yarn test -- --watch",
    "test:coverage": "yarn test -- --maxWorkers 4 --coverage && codecov",
  },
  "betterScripts": {
    "test": {
      "command": "jest",
      "env": {
        "NODE_ENV": "test"
      }
    },
  },
  "jest": {
    "setupFiles": [
      "<rootDir>/config/jest.js"
    ],
    "modulePaths": [
      "src"
    ],
    "moduleNameMapper": {
      "\\.(jpg|jpeg|png|gif|eot|otf|webp|svg|ttf|woff|woff2|mp4|webm|wav|mp3|m4a|aac|oga)$": "<rootDir>/config/__mocks__/fileMock.js",
      "\\.scss$": "identity-obj-proxy"
    },
    "snapshotSerializers": [
      "enzyme-to-json/serializer"
    ],
    "collectCoverageFrom": [
      "src/**/*.{js,jsx}",
      "!**/index.{js,jsx}",
      "!**/*.factory.{js,jsx}",
      "!**/factories/**",
      "!**/*.story.{js,jsx}",
      "!**/stories/**",
      "!**/node_modules/**",
      "!**/vendor/**",
      "!/src/routes/groups/**"
    ],
    "globals": {
      "__DEV__": false,
      "__PROD__": false,
      "__TEST__": true,
      "__DEBUG__": false,
      "__API_ROOT__": "/",
      "__GA_TRACKING_ID__": ""
    }
  },
    "devDependencies": {
    "babel-jest": "^18.0.0",
    "babel-loader": "^6.2.10",
    "babel-plugin-dynamic-import-node": "^1.0.0",
    "babel-plugin-syntax-dynamic-import": "^6.18.0",
    "babel-plugin-transform-runtime": "^6.15.0",
    "babel-preset-es2015": "^6.5.0",
    "babel-preset-react": "^6.5.0",
    "babel-preset-react-optimize": "^1.0.1",
    "babel-preset-stage-1": "^6.16.0",
    "babel-register": "^6.7.2",
    "babel-resolver": "0.0.18",
    "better-npm-run": "0.0.13",
    "codecov": "^1.0.1",
    "enzyme": "^2.7.0",
    "enzyme-to-json": "^1.4.5",
    "identity-obj-proxy": "^3.0.0",
    "jest": "^18.1.0",
    "react-addons-test-utils": "^15.4.2",
  },

  ...
}