public queue()

in src/async.ts [42:77]
29 lines of code
3 McCabe index (conditional complexity)

	public queue(promiseFactory: ITask<Promise<T>>): Promise<T> {
		if (this.activePromise) {
			this.queuedPromiseFactory = promiseFactory;

			if (!this.queuedPromise) {
				var onComplete = () => {
					this.queuedPromise = null;

					var result = this.queue(this.queuedPromiseFactory);
					this.queuedPromiseFactory = null;

					return result;
				};

				this.queuedPromise = new Promise<T>((resolve, _reject) => {
					this.activePromise.then(onComplete, onComplete).then(resolve);
				});
			}

			return new Promise<T>((resolve, reject) => {
				this.queuedPromise.then(resolve, reject);
			});
		}

		this.activePromise = promiseFactory();

		return new Promise<T>((resolve, reject) => {
			this.activePromise.then((result: T) => {
				this.activePromise = null;
				resolve(result);
			}, (err: any) => {
				this.activePromise = null;
				reject(err);
			});
		});
	}