TypeScript reports FirebasePlugin object isn't defined

[peitschie]

Moving conversation from #529 (comment) into it's own bug.

Type regression introduced by the tweak in 5e349af.

Putting the export on the interfaces makes TypeScript decide this is a Module now rather than a Namespace: https://www.typescriptlang.org/docs/handbook/modules.html

In TypeScript, just as in ECMAScript 2015, any file containing a top-level import or export is considered a module. Conversely, a file without any top-level import or export declarations is treated as a script whose contents are available in the global scope (and therefore to modules as well).

[adipascu]

I'm adding this to get typescript running in my project:

import { FirebasePlugin } from "cordova-plugin-firebasex";

declare global {
  interface Window {
    FirebasePlugin: FirebasePlugin;
  }
}

Just noticed your PR #716 that is doing the same thing inside the project, I'd love to see it merged.