Linked lists in Javascript

LinkedList.js

/**
 * Linked lists in Javascript
 * @see https://dev.to/ryanfarney3/intro-to-linked-lists-in-js-19b4
 */

class Node {

    constructor(data, next = null) {
        this.data = data;
        this.next = next;
    }
}

class LinkedList {

    constructor(data = null) {
        this.head = data;
    }

    first() {
        return this.head;
    }

    last() {
        let node = this.head;
        if (!node) return null;

        while (node) {
            if (node.next === null) return node;
            node = node.next;
        }
    }

    prepend(data) {
        this.head = new Node(data, this.head);
    }

    reset() {
        this.head = null;
    }

    removeFirst() {
        if (!this.head) return;
        this.head = this.head.next;
    }

    removeLast() {
        if (!this.head) return;
        if (!this.head.next) return this.head = null;

        let prev = this.head;
        while (prev) {
            let node = prev.next;
            if (!node.next) return prev.next = null;
            prev = prev.next;
        }
    }

    push(data) {
        const node = new Node(data);
        const last = this.last();

        if (last) {
            last.next = node;
        } else {
            this.head = node;
        }
    }
    
    count() {
       let counter = 0;
       let node = this.head;

       while (node) {
           counter++;
           node = node.next;
       }

       return counter;
    }

    isEmpty() {
        return this.count() === 0;
    }
}