Test cleanup and fixes [g-h]

test/head/head.test.js

@@ -1,30 +1,33 @@
 const expect = require('expect');
 const head = require('./head.js');
 
-
-  test('head is a Function', () => {
+test('head is a Function', () => {
   expect(head).toBeInstanceOf(Function);
 });
-  test('head({ a: 1234}) returns undefined', () => {
+test('head({ a: 1234}) returns undefined', () => {
   expect(head({ a: 1234}) === undefined).toBeTruthy();
 });
-  test('head([1, 2, 3]) returns 1', () => {
-  expect(head([1, 2, 3])).toBe(1)
+test('head([1, 2, 3]) returns 1', () => {
+  expect(head([1, 2, 3])).toBe(1);
 });
-  test('head({ 0: false}) returns false', () => {
-  expect(head({ 0: false}), false).toBe()
+test('head({ 0: false}) returns false', () => {
+  expect(head({ 0: false})).toBeFalsy();
 });
-  test('head(String) returns S', () => {
-  expect(head('String'), 'S').toBe()
+test('head(String) returns S', () => {
+  expect(head('String')).toBe('S');
 });
-  t.throws(() => head(null), 'head(null) throws an Error');
-  t.throws(() => head(undefined), 'head(undefined) throws an Error');
-  t.throws(() => head(), 'head() throws an Error');
-
-  let start = new Date().getTime();
-  head([1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 1122, 32124, 23232]);
-  let end = new Date().getTime();
-  test('head([1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 1122, 32124, 23232]) takes less than 2s to run', () => {
+test('head(null) throws an Error', () => {
+  expect(head(null)).toThrow();
+});
+test('head(undefined) throws an Error', () => {
+  expect(head(undefined)).toThrow();
+});
+test('head() throws an Error', () => {
+  expect(head()).toThrow();
+});
+let start = new Date().getTime();
+head([1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 1122, 32124, 23232]);
+let end = new Date().getTime();
+test('head([1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 1122, 32124, 23232]) takes less than 2s to run', () => {
   expect((end - start) < 2000).toBeTruthy();
 });
-