title: Error with Inheritance and TypeScript: X is not a constructor function type
body: <p>I have this super class that I want two other classes to inherit from. The classes are listed below. When I compile, the two classes trying to inherit complain about the superclass (the give the same error):
  &quot;[class file path (in this case A)] is not a constructor function type&quot;</p>
  <p>A.ts</p>
  <pre><code>export class A
  {
      //private fields...
  
      constructor(username: string, password: string, firstName: string,
          lastName: string, accountType: string) 
      {
          // initialisation
      }
  }
  </code></pre>
  <p>B.ts</p>
  <pre><code>import A = require('./A);
  export class B extends A
  {
      constructor(username: string, password: string, firstName: string,
          lastName: string, accountType: string) 
      {
          super(username, password, firstName, lastName, accountType);
      }
  }
  </code></pre>
  <p>C.ts</p>
  <pre><code>import A = require('./A );
  export class C extends A
  {
      constructor(username: string, password: string, firstName: string,
          lastName: string, accountType: string) 
      {
          super(username, password, firstName, lastName, accountType);
      }
  }
  </code></pre>
  <p>This is pretty simple, and yet Class C and B cannot compile. All the examples I have seen online do not have any other syntax for writing these classes/ constructor. I am trying to follow convention, but can't seem to get it to work.</p>