From 02fedc832271709169a0f55b25fd576ae0f4d908 Mon Sep 17 00:00:00 2001
From: Johnny Zabala <jzabala.s@gmail.com>
Date: Fri, 22 Jun 2018 17:58:22 -0400
Subject: [PATCH] feat(tail): add tail function (#177)

Add tail function that returns all but the first element of array.
* Return [] for null and undefined

Closes #176
---
 src/index.js      |  2 ++
 src/tail.js       | 13 +++++++++++++
 test/tail.test.js | 27 +++++++++++++++++++++++++++
 3 files changed, 42 insertions(+)
 create mode 100644 src/tail.js
 create mode 100644 test/tail.test.js

diff --git a/src/index.js b/src/index.js
index 4be008fb..079e8d3b 100644
--- a/src/index.js
+++ b/src/index.js
@@ -63,6 +63,7 @@ import getQueryStringValue from './get-query-string-value'
 import isLeapYear from './leap-year'
 import removeElementFromArray from './removeElementFromArray'
 import generatePassword from './generate-password'
+import tail from './tail'
 
 export {
   reverseArrayInPlace,
@@ -130,4 +131,5 @@ export {
   isLeapYear,
   removeElementFromArray,
   generatePassword,
+  tail,
 }
diff --git a/src/tail.js b/src/tail.js
new file mode 100644
index 00000000..d9778e9a
--- /dev/null
+++ b/src/tail.js
@@ -0,0 +1,13 @@
+export default tail
+
+/**
+ * Original Source: https://stackoverflow.com/a/35361274/5801753
+ *
+ * This function gets all but the first element of array
+ *
+ * @param {Array} array - The array to get the tail from
+ * @return {Array} - The array without the first element
+ */
+function tail(array) {
+  return Boolean(array) ? array.slice(1) : []
+}
diff --git a/test/tail.test.js b/test/tail.test.js
new file mode 100644
index 00000000..d9926221
--- /dev/null
+++ b/test/tail.test.js
@@ -0,0 +1,27 @@
+import test from 'ava'
+import {tail} from '../src'
+
+test('returns empty array for null', t => {
+  const expected = []
+  const actual = tail(null)
+  t.deepEqual(actual, expected)
+})
+
+test('returns empty array for undefined', t => {
+  const expected = []
+  const actual = tail(undefined)
+  t.deepEqual(actual, expected)
+})
+
+test('returns empty array for empty array', t => {
+  const expected = []
+  const actual = tail([])
+  t.deepEqual(actual, expected)
+})
+
+test('returns the tail of array', t => {
+  const original = [1, 2, 3, 4, 5]
+  const expected = [2, 3, 4, 5]
+  const actual = tail(original)
+  t.deepEqual(actual, expected)
+})