Un used variable is emmitted while transpiling enums.

TypeScript code

module Workspace {
  export enum State {
    IN_PROGRESS,
    BUFFER_RENDERED,
    SKIPPED,
    TIME_OUT
  }
}

Compled JavaScript Code.

 
var Workspace;
(function (Workspace) {
    (function (State) {
        State[State["IN_PROGRESS"] = 0] = "IN_PROGRESS";
        State[State["BUFFER_RENDERED"] = 1] = "BUFFER_RENDERED";
        State[State["SKIPPED"] = 2] = "SKIPPED";
        State[State["TIME_OUT"] = 3] = "TIME_OUT";
    })(Workspace.State || (Workspace.State = {}));
    var State = Workspace.State; // this code is use no where.
})(Workspace || (Workspace = {}));

I am using TypeScript version 1.5.3

TypeScript 1.5.3 で enum の例を再現し、出力された JavaScript を報告内容と比較します。未使用の State 変数を出力する enum のトランスパイル経路を追跡します。enum の動作を変更せずに、同等の未使用変数が出力されなくなれば完了です。