title: ResponsiveMode is undefined in Jest test using lib-common-js
body: <p>I'm trying to write tests for my Office Fabric React, initially started using <a href="https://github.com/wmonk/create-react-app-typescript" rel="nofollow noreferrer">react-scripts-ts</a>, now ejected since I ran into this issue, and I'm running into the following error when using the withResponsiveMode library:</p>
  
  <pre><code>TypeError: Cannot read property 'large' of undefined
  
    13 | const initialState: IAppState = {
    14 |   isMenuVisible: true,
  &gt; 15 |   responsiveMode: ResponsiveMode.large
       |                                  ^
    16 | };
    17 |
    18 | // Actions
  </code></pre>
  
  <p>I'm using the moduleNameMapper setting listed here: <a href="https://github.com/OfficeDev/office-ui-fabric-react/wiki/Fabric-6-Release-Notes" rel="nofollow noreferrer">https://github.com/OfficeDev/office-ui-fabric-react/wiki/Fabric-6-Release-Notes</a>.</p>
  
  <p>My jest config is below:</p>
  
  <pre><code>module.exports = {
    collectCoverageFrom: ["src/**/*.{js,jsx,ts,tsx}"],
    globals: {
      "ts-jest": {
        tsConfigFile: "C:\\repos\\provider-portal-ui\\tsconfig.test.json"
      }
    },
    moduleFileExtensions: [
      "web.ts",
      "ts",
      "web.tsx",
      "tsx",
      "web.js",
      "js",
      "web.jsx",
      "jsx",
      "json",
      "node",
      "mjs"
    ],
    moduleNameMapper: {
      "^react-native$": "react-native-web",
      "office-ui-fabric-react/lib/": "office-ui-fabric-react/lib-commonjs/"
    },
    setupFiles: ["&lt;rootDir&gt;/config/polyfills.js"],
    testEnvironment: "node",
    testMatch: [
      "&lt;rootDir&gt;/src/**/__tests__/**/*.(j|t)s?(x)",
      "&lt;rootDir&gt;/src/**/?(*.)(spec|test).(j|t)s?(x)"
    ],
    testURL: "http://localhost",
    transform: {
      "^.+\\.css$": "jest-css-modules",
      "^.+\\.tsx?$": "ts-jest"
    },
    transformIgnorePatterns: [
      "[/\\\\]node_modules[/\\\\].+\\.(js|jsx|mjs|ts|tsx)$"
    ]
  };
  </code></pre>
  
  <p>tsconfig.json:</p>
  
  <pre><code>{
    "compilerOptions": {
      "baseUrl": ".",
      "outDir": "build/dist",
      "module": "esnext",
      "target": "es5",
      "lib": ["es6", "dom"],
      "sourceMap": true,
      "allowJs": true,
      "jsx": "react",
      "moduleResolution": "node",
      "rootDir": "src",
      "forceConsistentCasingInFileNames": true,
      "noImplicitReturns": true,
      "noImplicitThis": true,
      "noImplicitAny": true,
      "strictNullChecks": true,
      "suppressImplicitAnyIndexErrors": true,
      "noUnusedLocals": true,
      "experimentalDecorators": true
    },
    "exclude": [
      "node_modules",
      "build",
      "scripts",
      "acceptance-tests",
      "webpack",
      "jest",
      "src/setupTests.ts"
    ]
  }
  </code></pre>
  
  <p>tsconfig.test.json:</p>
  
  <pre><code>{
    "extends": "./tsconfig.json",
    "compilerOptions": {
      "module": "commonjs"
    }
  }
  </code></pre>
  
  <p>I'm guessing this is some sort of configuration issue, as this code works fine when not being tested.</p>