export as namespace MyModuleName;

export class Position {
  x: number;
  y: number;

  public clone(): Position;

  constructor(x: number, y: number);
}

export class Size {
  width: number;
  height: number;
}

export interface Drawable {
  draw(context: Context, cursor: Position): void;
}

import * as MyModuleName from 'path/to/mymodulename/main.js'

Module not found: Error: Can't resolve 'path/to/mymodulename' in 'somewhere/in/project'