PromiseCompletionSource what is like TaskCompletionSource<T> in C#

PromiseCompletionSource.ts

export class PromiseCompletionSource<T> {
    public readonly promise: Promise<T>;

    private resolver: (x?: T) => void;
    private rejector: (reason?: any) => void;

    constructor() {
        this.promise = new Promise<T>((resolve, reject) => {
            this.resolver = resolve;
            this.rejector = reject;
        });
    }

    public resolve(x: T) {
        if (this.resolver) {
            this.resolver(x);
        }
    }

    public reject(reason?: any) {
        if (this.rejector) {
            this.rejector(reason);
        }
    }
}