Smooth Scroll Utility Helper for ReactJs or JS applications

smoothScroll.js

export const smoothScroll = {
    timer: null,

    stop: function () {
        clearTimeout(this.timer);
    },

    scrollTo: function (id, callback) {
        let settings = {
            duration: 1000,
            easing: {
                outQuint: function (x, t, b, c, d) {
                    return c*((t=t/d-1)*t*t*t*t + 1) + b;
                }
            }
        };
        let percentage;
        let startTime;
        let node = document.getElementById(id);
        console.log(id);
        let nodeTop = node.offsetTop;
        let nodeHeight = node.offsetHeight;
        let body = document.body;
        let html = document.documentElement;
        let height = Math.max(
            body.scrollHeight,
            body.offsetHeight,
            html.clientHeight,
            html.scrollHeight,
            html.offsetHeight
        );
        let windowHeight = window.innerHeight
        let offset = window.pageYOffset;
        let delta = nodeTop - offset;
        let bottomScrollableY = height - windowHeight;
        let targetY = (bottomScrollableY < delta) ?
            bottomScrollableY - (height - nodeTop - nodeHeight + offset):
            delta;

        startTime = Date.now();
        percentage = 0;

        if (this.timer) {
            clearInterval(this.timer);
        }

        let self = this;

        function step () {
            let yScroll;
            let elapsed = Date.now() - startTime;

            if (elapsed > settings.duration) {
                clearTimeout(self.timer);
            }

            percentage = elapsed / settings.duration;

            if (percentage > 1) {
                clearTimeout(self.timer);

                if (callback) {
                    callback();
                }
            } else {
                yScroll = settings.easing.outQuint(0, elapsed, offset, targetY, settings.duration);
                window.scrollTo(0, yScroll);
                self.timer = setTimeout(step, 10);
            }
        }

        this.timer = setTimeout(step, 10);
    }
};