[Feature Contribution]: Changes in Code

index.js

@@ -1,24 +1,47 @@
+/**
+  * Hello Matt!
+  * Just wanted to contribute to you work. Let me know if this is ok with you and you can merge it with you master
+  *
+  * 1. @start: will always have default value of 0
+  * 2. @end: will require validation on program start
+  * 3. changes made to accomodate ES6
+  * 4. returns empty array even if no arguments are fed when the module is invoked
+  *
+  * Cheers and have a nice day.
+  **/
 
-module.exports = function newArray(start, end) {
-    var n0 = typeof start === 'number',
-        n1 = typeof end === 'number'
 
-    if (n0 && !n1) {
-        end = start
-        start = 0
-    } else if (!n0 && !n1) {
-        start = 0
-        end = 0
+module.exports = (start = 0, end) => {
+  let startStatus = (!Number.isNaN(start) && typeof start === "number");
+  let endStatus = (!Number.isNaN(end) && typeof end === "number");
+
+  /* make sure we have the right value for start */
+  start = (!startStatus) ? 0 : start;
+  startStatus = true;
+
+  /* when end is a falsy value type */
+  if (startStatus && !endStatus) {
+    end = start;
+    start = 0;
+  }
+
+  /* we need to make sure that length value for initializing array is always 0 or positive */
+  const length = end - start;
+
+  if (length < 0) {
+    throw new Error("Difference between 'end' and 'start' must always be '0' or greater");
+  }
+  else {
+    /* initialize */
+    let arrayOfNumbers = new Array(length); 
+
+    /* iteration to create array */
+    for (let i = 0, currentValue = start; i < length; ++i, ++currentValue) {
+      arrayOfNumbers[i] = currentValue;
     }
 
-    start = start|0
-    end = end|0
-    var len = end-start
-    if (len<0)
-        throw new Error('array length must be positive')
-
-    var a = new Array(len)
-    for (var i=0, c=start; i<len; i++, c++)
-        a[i] = c
-    return a
-}
+    /* return to caller */
+    return arrayOfNumbers;
+  }
+}
+