__extends and static methods / accessors

• skatejs reported issue

• Previously reported issues:

  • Why are TS get/set definedProperties in a class transpiled as enumerable/writable?

• PR from @vvakame to change __extends impementation

• the for loop is there to support browsers pre __proto__, e.g. IE8, IE9, and IE10

  • if we remove it IE10 and below will be broken

• Condition it:

  • seems like a good solution
  • proposal:

var __extendStatics = (this && this.__extendStatics) ||
    Object.setPrototypeOf || 
   ({ __proto__: [] } instanceof Array && function (d, b) { d.__proto__ = b; }) || 
   function (d, b) { for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p]; };

var __extends = (this && this.__extends) || function (d, b) {
   __extendStatics(d, b);
   function __() { this.constructor = d; }
   d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
};

• What about the other side of the issue, emitting methods and accessors as enumrable: false?
  • we have to do it for --target ES5 and not --target ES3
  • if we do this we break the static inheritance for IE10,
  • concolusion:
    • wait on more feedback for this

Promise in lib.d.ts

• Issues:

  • [lib.d.ts BUG] navigator.mediaDevices.getUserMedia returns PromiseLike (actually returns a Promise)
  • Vague error message with async functions

• DOM keeps moving forward, but the lib.d.ts does not

• Resolution:

  • split the DOM into multiple definitions as well, and have the parts depend on what version they need of the library
  • this is a large effort, not clear when or how it can be done
  • No conclusion here, leave it open

Extensibility (@RyanCavanaugh)

• PR: Language service proxy
• Follow up with the experement and see what APIs are needed to be exposed