fix(queue-28): implement comparator class

Author: Wakidur Rahaman

utils/comparator-original.js

@@ -0,0 +1,102 @@
+export default class Comparator {
+  /**
+   * Constructor.
+   * @param {function(a: *, b: *)} [compareFunction] - It may be custom compare function that, let's
+   * say may compare custom objects together.
+   */
+
+  constructor(compareFunction) {
+    this.compare = compareFunction || Comparator.defaultCompareFunction;
+  }
+
+  /**
+   * Default comparison function. It just assumes that 'a' and 'b' are strings or numbers.
+   * @param {(string|number)} a
+   * @param {(string|number)} b
+   * @returns {number}
+   */
+  static defaultCompareFunction(a, b) {
+    if (a === b) {
+      return 0;
+    }
+
+    return a < b ? -1 : 1;
+  }
+
+  /**
+   * Checks if two variables are equal.
+   * @param {*} a
+   * @param {*} b
+   * @return {boolean}
+   */
+  // Traditional function
+  equal(a, b) {
+    return this.compare(a, b) === 0;
+  }
+  // Arrow function
+  // equal = (a, b) => this.compare(a, b) === 0;
+
+  /**
+   * Checks if variable "a" is less than "b"
+   * @param {*} a
+   * @param {*} b
+   * @returns  {boolean}
+   */
+  // Traditional function
+  lessThan(a, b) {
+    return this.compare(a, b) < 0;
+  }
+  // Arrow function
+  // lessThan = (a, b) => this.compare(a, b) < 0;
+
+  /**
+   * Checks if variable "a" is greater than "b".
+   * @param {*} a
+   * @param {*} b
+   * @returns  {boolean}
+   */
+  // Traditional function
+  greaterThan(a, b) {
+    return this.compare(a, b) > 0;
+  }
+  // Arrow function
+  // greaterThan = (a, b) => this.compare(a, b) > 0;
+
+  /**
+   * Checks if variable "a" is less than or equal to "b".
+   * @param {*} a
+   * @param {*} b
+   * @returns {boolean}
+   */
+  // Traditional function
+  lessThanOrEqual(a, b) {
+    return this.lessThan(a, b) || this.equal(a, b);
+  }
+  // Arrow function
+  // lessThanOrEqual = (a, b) => this.lessThan(a, b) || this.equal(a, b);
+
+  /**
+   * Checks if variable "a" is greater than or equal to "b"l
+   * @param {*} a
+   * @param {*} b
+   * @returns {boolean}
+   */
+  // Traditional function
+  greaterThanOrEqual(a, b) {
+    return this.greaterThan(a, b) || this.equal(a, b);
+  }
+
+  //Arrow Function
+  // greaterThanOrEqual = (a, b) => this.greaterThan(a, b) || this.equal(a, b);
+
+  /**
+   * Reverses the comparison order.
+   */
+
+  reverse() {
+    const compareOriginal = this.compare;
+    this.compare = (a, b) => compareOriginal(b, a);
+  }
+}
+
+const instanceA = new Comparator();

utils/comparator.ts

@@ -23,5 +23,7 @@ export default class Comparator {
 
       return a < b ? -1 : 1;
     }
+
+    
   }