title: Typescript test with Jest with Enzyme does not recognise components
body: <p>I have a test for Typescript using Jest with Enzyme. Tests work perfect but when i add a component, it gives me a <code>Unterminated regular expression</code> error </p>
  
  <pre><code>import {} from 'jasmine';
  import {shallow} from 'enzyme';
  import {Show, Hide} from '../components/show_hide';
  
  describe('&lt;Show /&gt; Tests', () =&gt; {
      it('Show should render once', () =&gt; {
          const component = shallow(&lt;Show /&gt;);
          expect(component).toHaveLength(1);
      })
  })
  </code></pre>
  
  <p>When I run <code>yarn test</code> the result on the console is</p>
  
  <pre><code> FAIL  __tests__/show_hide.ts
    ● Test suite failed to run
  
      /path/to/repo/__tests__/show_hide.ts: Unterminated regular expression (4:35)
          2 | describe('&lt;Show /&gt; Tests', () =&gt; {
          3 |     it('Show should render once', () =&gt; {
        &gt; 4 |         const component = shallow(/&gt;);, expect(component).toHaveLength(1));
            |                                    ^
          5 |     });
          6 | });
          7 | //# sourceMappingURL=data:application/json;base64,eyJ2ZXJzaW9uIjozLCJmaWxlIjoic2hvd19oaWRlLmpzIiwic291cmNlUm9vdCI6IiIsInNvdXJjZXMiOlsiLi4vX190ZXN0c19fL3Nob3dfaGlkZS50cyJdLCJuYW1lcyI6W10sIm1hcHBpbmdzIjoiQUFDQSxPQUFPLEVBQUMsT0FBTyxFQUFDLE1BQU0sUUFBUSxDQUFDO0FBRy9CLFFBQVEsQ0FBQyxnQkFBZ0IsRUFBRTtJQUMxQixFQUFFLENBQUMsbUJBQW1CLEVBQUU7UUFDdkIsTUFBTSxTQUFTLEdBQUcsT0FBTyxDQUFPLElBQUksRUFDcEMsTUFBTSxDQUFDLFNBQVMsQ0FBQyxDQUFDLFlBQVksQ0FBQyxDQUFDLENBQUMsQ0FBQSxDQUFDO0lBQ25DLENBQUMsQ0FBQyxDQUFBO0FBQ0gsQ0FBQyxDQUFDLENBQUEifQ==
  </code></pre>
  
  <p>The jest configuration inside <code>package.json</code> is</p>
  
  <pre><code>  "jest": {
      "transform": {
        "^.+\\.tsx?$": "&lt;rootDir&gt;/node_modules/ts-jest/preprocessor.js"
      },
      "testRegex": "(/__tests__/.*|\\.(test|spec))\\.(ts|tsx|js)$",
      "moduleFileExtensions": [
        "ts",
        "tsx",
        "js",
        "json"
      ],
    },
  </code></pre>
  
  <p>Any thoughts on that?</p>