react enzyme mount ReferenceError: is not defined code example

Example: react enzyme mount ReferenceError: is not defined

"jest": {
    "preprocessorIgnorePatterns": [
      "node_modules/enzyme"
    ],
    "scriptPreprocessor": "<rootDir>/node_modules/babel-jest",
    "setupEnvScriptFile": "node_modules/react-native/jestSupport/env.js",
    "testPathIgnorePatterns": [
      "/node_modules/",
      "packager/react-packager/src/Activity/"
    ],
    "unmockedModulePathPatterns": [
      "react",
      "react-dom",
      "react-native",
      "react-addons-test-utils",
      "promise",
      "source-map",
      "enzyme"
    ]
  },