feat: new function (#155)

Author: tyler-vs

src/index.js

@@ -54,6 +54,7 @@ import median from './array-median'
 import timeDifference from './timeDifference'
 import isPrime from './is-prime'
 import swapElements from './swapElements'
+import reverse from './reverse'
 
 export {
   isOdd,
@@ -112,4 +113,5 @@ export {
   timeDifference,
   isPrime,
   swapElements,
+  reverse,
 }

src/reverse.js

@@ -0,0 +1,17 @@
+export default reverse
+
+/**
+ * Original Source: https://stackoverflow.com/a/4859258/7221168
+ *
+ * Function that recursively reverses a string
+ *
+ * @param  {string} str - A string
+ * @return {string}     - A reversed string
+ */
+function reverse(str) {
+  if (str === '') {
+    return str
+  } else {
+    return reverse(str.substr(1)) + str.charAt(0)
+  }
+}

test/reverse.test.js

@@ -0,0 +1,30 @@
+import test from 'ava'
+import {reverse} from '../src'
+
+test('string with only letters', t => {
+  const str = 'abcdefG'
+  const expected = 'Gfedcba'
+  const result = reverse(str)
+  t.is(expected, result)
+})
+
+test('string with only numbers', t => {
+  const str = '1234567890'
+  const expected = '0987654321'
+  const result = reverse(str)
+  t.is(expected, result)
+})
+
+test('string with letters and special characters', t => {
+  const str = 'abc!"§…'
+  const expected = '…§"!cba'
+  const result = reverse(str)
+  t.is(expected, result)
+})
+
+test('string with only special characters', t => {
+  const str = 'œ∑´®†'
+  const expected = '†®´∑œ'
+  const result = reverse(str)
+  t.is(expected, result)
+})