Promise Que in JS

promiseque.js

class PromiseQue {
    constructor(concurrentCount = 5) {
        this.todo = [];
        this.running = [];
        this.maxTask = concurrentCount;
    }

    runNext(){
        return ((this.running.length < this.maxTask) && this.todo.length);
    }

    run () {
        if (this.running.length > 0) {
            return;
        }
        while (this.runNext()) {
            const promise = this.todo.shift();
            promise.then(() => {
                this.running = this.running.filter(p => p !== promise);
                this.run();
            });
            this.running.push(promise);
        }
    }

    async push(task) {
        while (this.maxTask <= this.running.length) {
            // wait for empty slot
            await sleep(5);
        }

        this.todo.push(task);
        this.run()
    }

    async waitAllFinished (){
        while (this.running.length > 0) {
            await sleep(5);
        }
        return true;
    }
}