feat(descendingOrder): add descendingOrder function (#209)

Author: RickBr0wn

src/descending-order.js

@@ -0,0 +1,13 @@
+export default descendingOrder
+
+/**
+ * This method will return a number which is the
+ * supplied number re-arranged in descending order
+ * eg: descendingOrder(231) returns 321
+ * @param {Number} - the Number to be sorted
+ * @returns {Number} - number sorted in decending order
+ */
+
+function descendingOrder(num) {
+  return Number(String(num).split('').sort().reverse().join(''))
+}

src/index.js

@@ -76,6 +76,7 @@ import textJustification from './textJustification'
 import removeProperty from './removeProperty'
 import temperatureConverter from './temperatureConverter'
 import last from './last'
+import descendingOrder from './descending-order'
 
 export {
   reverseArrayInPlace,
@@ -156,4 +157,5 @@ export {
   dec2hex,
   temperatureConverter,
   last,
+  descendingOrder,
 }

test/array-average.test.js

@@ -1,5 +1,7 @@
 import test from 'ava'
-import {arrayAverage} from '../src'
+import {
+  arrayAverage
+} from '../src'
 
 test('Calculates the average of an array', t => {
   const array = [1, 2, 3, 4]

test/descending-order.test.js

@@ -0,0 +1,11 @@
+import test from 'ava'
+import {
+  descendingOrder,
+} from '../src'
+
+test('Return a number which is the param re-arranged in descending order ', t => {
+  const num = 213
+  const expected = 321
+  const actual = descendingOrder(num)
+  t.deepEqual(actual, expected)
+})