Test cleanup and fixes [a-b]

test/attempt/attempt.test.js

@@ -1,15 +1,12 @@
 const expect = require('expect');
 const attempt = require('./attempt.js');
 
-
-  test('attempt is a Function', () => {
+test('attempt is a Function', () => {
   expect(attempt).toBeInstanceOf(Function);
 });
-  test('Returns a value', () => {
-  expect(attempt(() => 0), 0).toBe()
+test('Returns a value', () => {
+  expect(attempt(() => 0)).toBe(0);
 });
-  test('Returns an error', () => {
-  expect(attempt(() => {throw new Error();}) instanceof Error).toBeTruthy();
+test('Returns an error', () => {
+  expect(attempt(() => {throw new Error();})).toBeInstanceOf(Error);
 });
-  
-