Isomorphic global augmentation

[alfaproject]

Currently, there is the need to add a lot of boilerplate code if we want to target more than one global environment, and I was wondering if TypeScript should sugar this a bit.

TypeScript Version: ^2.0.0

Code

declare global {
  // Augment Node.js `global`
  namespace NodeJS {
    interface Global {
      wtf: WTF;
    }
  }

  // Augment Browser `window`
  interface Window {
    wtf: WTF;
  }

  // Augment Web Worker `self`
  interface WorkerGlobalScope {
    wtf: WTF;
  }
}

// Get the appropriate global object
const root: NodeJS.Global|Window|WorkerGlobalScope =
  (typeof self === 'object' && self.self === self && self) ||
  (typeof global === 'object' && global.global === global && global) ||
  this;

// Get the augmented property
const wtf = root.wtf;

Expected behavior:
TypeScript to detect the appropriate global environment, maybe by giving the compiler some sort of isomorphic flag.

Actual behavior:
A lot of boilerplate code to have an isomorphic framework.

[aluanhaddad]

Why not use this?

declare global {

  // Augment Node.js `global`
  namespace NodeJS {
    interface Global {
      wtf: WTF;
    }
  }
  // Augment Browser `window`
  interface Window extends NodeJS.Global { }
  // Augment Web Worker `self`
  interface WorkerGlobalScope extends NodeJS.Global { }
}

[alfaproject]

My main gripe is actually with what comes after that. ):

[chicoxyzzy]

No reason for TypeScript to handle this. There is proposal to ECMAScript with polyfill

[alfaproject]

Pretty sure TS already polyfills much bigger stuff than this, even things on stage 2. (;
I'd even go as far as having typings for a common shared set of global properties where each environment extends (common Global interface of sorts, even if it's empty)

[mhegazy]

I have filed issue #12902 to track implementing the proposal in https://github.com/tc39/proposal-global

I think this would fall from it.