Extend a CoffeeScript class loaded with RequireJS inside a TypeScript code - coffeescript

Question

Currently I have a large codebase developed with CoffeeScript and want to extend it with some TypeScript.
Let's say I have the following code in the CoffeeClass.coffee file:
define 'CoffeeClass', ->
class CoffeeClass
foo: () -> 1
It is meant to be loaded through require in the following manner (let's call this file CoffeeUser.coffee):
require ['CoffeeClass'], (CoffeeClass) ->
class MyClass extends CoffeeClass
foo: () -> super() + 1
console.log (new MyClass().foo()) # => 2
Now it can be loaded in browser with the standard RequireJS markup:
<script data-main="CoffeeUser.js" src="require.js"></script>
I want to extend the CoffeeClass from the TypeScript code. That's what I've tried:
First write a CoffeeClass.d.ts definiton file (I know it is wrong but it's showing what I'm trying to achieve):
export class CoffeeClass {
foo(): number;
}
And then try to use it from TypeScriptUser.ts:
import CoffeeClass = require('CoffeeClass');
class TypeScriptUser extends CoffeeClass {
foo(): number {
return super.foo() + 1;
}
}
But it won't compile partly because I cannot find the right syntax for the d.ts file and partly because I cannot properly tell the compiler how to extend the CoffeeClass (as far as I can tell the compiler cannot understand that CoffeeClass is really a class and not just a module).
So can I tell the TypeScript compiler that the module is a class here? If no, how would you recommend me to change the CoffeeClass design to extend it from TypeScript code and don't lose all the type safety?

Answer 1

Finally I've found the solution. That's the special export = syntax. Here it is. CoffeeClass.d.ts:
declare class CoffeeClass {
foo(): number;
}
export = CoffeeClass;
And TypeUser.ts:
/// <reference path="CoffeeClass.d.ts" />
import CoffeeClass = require('CoffeeClass')
class MyClass extends CoffeeClass {
foo() {
return super.foo() + 1;
}
}
console.log(new MyClass().foo()); // => 2
Note that the compiler will infer the proper require call when compiling the code.