feat(max): Add max function (#114) (#115)

the max function could find the maximum value of the list

Closes #114

Author: mis101bird

src/index.js

@@ -38,6 +38,7 @@ import checkPalindrome from './checkPalindrome'
 import isFunction from './is-function'
 import isOdd from './is-odd'
 import isNumeric from './is-numeric'
+import max from './max'
 
 export {
   isOdd,
@@ -80,5 +81,5 @@ export {
   isFunction,
   subtraction,
   isNumeric,
+  max,
 }
-

src/max.js

@@ -0,0 +1,18 @@
+export default max
+/**
+ * This method return the maximum value of the list that user gave
+ *
+ * @param {Array} list - get the maximum value of the list
+ * @returns {Number} - the maximum value of the list
+ */
+
+function __getMax(maxValue, value) {
+  if (value > maxValue) {
+    maxValue = value
+  }
+  return maxValue
+}
+
+function max(list) {
+  return list.reduce(__getMax, Number.NEGATIVE_INFINITY)
+}

test/max.test.js

@@ -0,0 +1,8 @@
+import test from 'ava'
+import {max} from '../src'
+
+test('find the maximum value of list', t => {
+  const list = [ 22, 1, 99, 45 ]
+  const result = max(list)
+  t.deepEqual(99, result)
+})