feat: add subtraction (#106)

* WIP: subtract two number

* add test for subtract method

* modify index file

* modify test

Author: jsina

src/index.js

@@ -20,6 +20,7 @@ import startsWith from './startsWith'
 import removeDuplicates from './remove-duplicates'
 import add from './add'
 import subtract from './subtract'
+import subtraction from './subtraction'
 import divide from './divide'
 import multiply from './multiply'
 import square from './square'
@@ -74,4 +75,6 @@ export {
   round,
   checkPalindrome,
   isFunction,
+  subtraction,
 }
+

src/subtraction.js

@@ -0,0 +1,15 @@
+export default subtraction
+
+/**
+ *
+ * This method will return a random integer
+ * between min and max number
+ *
+ * @param {Number} num1 - The first number to be subtracted
+ * @param {Number} max - The second number to subtract from
+ * @return {Number} the subtraction of num1 - num2
+ */
+
+function subtraction(num1, num2) {
+  return num1 - num2
+}

test/subtract.test.js

@@ -0,0 +1,10 @@
+import test from 'ava'
+import subtraction from '../src/subtraction'
+
+test('Subtracts two integers ', t => {
+  const number1 = 23
+  const number2 = 3
+  const expected = 23 - 3
+  const actual = subtraction(number1, number2)
+  t.deepEqual(actual, expected)
+})