feat(Array/oddItem): Returns an array which contains every odd (secon…

…d) item of the original array.

src/array/index.js

@@ -11,4 +11,5 @@ export { default as splitInHalf } from './split-half.js';
 export { default as longestString } from './longest-string.js';
 export { default as shortestString } from './shortest-string.js';
 export { default as shortestStringLength } from './shortest-string-length.js';
-export { default as longestStringLength } from './longest-string-length.js';
+export { default as longestStringLength } from './longest-string-length.js';
+export { default as oddItem } from './odd-item.js';

src/array/odd-item.js

@@ -0,0 +1,8 @@
+/**
+ * Returns an array which contains every odd (second) item of the original array.
+ * @param {Array} arr 
+ * @returns {Array}
+ */
+const fn = (arr) => arr.filter((arr, index) => index % 2 === 2 - 1);
+
+export default fn;

test/array/index.spec.js

@@ -54,3 +54,7 @@ test('exports a function "(Array.)shortestStringLength"', t => {
 test('exports a function "(Array.)longestStringLength"', t => {
     t.true(typeof (Array.longestStringLength) === 'function')
 });
+
+test('exports a function "(Array.)oddItem"', t => {
+    t.true(typeof (Array.oddItem) === 'function')
+});

test/array/odd-item.spec.js

@@ -0,0 +1,22 @@
+import { oddItem } from '../../src/array';
+const test = require('ava');
+
+
+test('returns en empty array it the array has only one item', t => {
+    let input = ['foo'];
+    let expectation = [];
+    t.is(oddItem(input), expectation);
+});
+
+test('returns every second item of a string with an even number of items', t => {
+    let input = ['foo', 'bar', 'baz', 'foobar'];
+    let expectation = ['bar', 'foobar'];
+    t.deepEqual(oddItem(input), expectation);
+});
+
+
+test('returns every second item of a string with an uneven number of items', t => {
+    let input = ['foo', 'bar', 'baz', 'foobar', 'barbaz'];
+    let expectation = ['bar', 'foobar'];
+    t.deepEqual(oddItem(input), expectation);
+});

test/index.spec.js

@@ -55,3 +55,7 @@ test('exports a function "(arr.)shortestStringLength"', t => {
 test('exports a function "(arr.)longestStringLength"', t => {
     t.true(typeof (arr.longestStringLength) === 'function')
 });
+
+test('exports a function "(arr.)oddItem"', t => {
+    t.true(typeof (arr.oddItem) === 'function')
+});