title: Imported symbol from typescript library is undefined
body: <p>I am developing a React/Redux application using Typescript. In order to simplify development, I want to create libraries for each "domain" or "feature" that will encapsulate specifics of the domain and expose an API to the top-level application. </p>
  
  <p>So far I have created a library (in Typescript) named <code>@foo/foo</code> and a main application that depends on this library. The library has a toplevel <code>index.ts</code> file that looks like:</p>
  
  <pre><code>export * from "./services/Executor";
  export * from "./services/Foo";
  export * from "./services/Result";
  export * from "./services/listFoo";
  </code></pre>
  
  <p>The file <code>./services/Executor.ts</code> exports a bunch of functions like:</p>
  
  <pre><code>export const fetchFoo = ...
  </code></pre>
  
  <p>Then I created an application using <code>create-react-app --script react-ts</code> and in one of the actions file I do:</p>
  
  <pre><code>import { fetchFoo } from '@foo/foo';
  ...
  </code></pre>
  
  <p>But when I run the React application using <code>npm run start</code>, I got:</p>
  
  <blockquote>
    <p>TypeError: fetchFoo is not a function</p>
  </blockquote>
  
  <p>From my research on the web I assume I am messing up with modules import semantics: Both packages are configured (in <code>tsconfig.json</code>) to be compiled to <code>es6</code> with <code>esModuleInterop: true</code>. I tried changing <code>modules</code> field but to no avail.</p>
  
  <p>What am I doing wrong?</p>
  
  <p><strong>Update</strong>: Here is some code demonstrating the problem: <a href="https://github.com/abailly/react-ts-import-module" rel="nofollow noreferrer">https://github.com/abailly/react-ts-import-module</a></p>