const expect = require('expect');
const words = require('./words.js');

test('words is a Function', () => {
  expect(words).toBeInstanceOf(Function);
});
test('words('I love javaScript!!') returns [I, love, javaScript]', () => {
  expect(words('I love javaScript!!')).toEqual(["I", "love", "javaScript"]);
});
test('words('python, javaScript & coffee') returns [python, javaScript, coffee]', () => {
  expect(words('python, javaScript & coffee')).toEqual(["python", "javaScript", "coffee"]);
});
test('words(I love javaScript!!) returns an array', () => {
  expect(Array.isArray(words('I love javaScript!!'))).toBeTruthy();
});
test('words() throws an error', () => {
  expect(words()).toThrow();
});
test('words(null) throws an error', () => {
  expect(words(null)).toThrow();
});
test('words(undefined) throws an error', () => {
  expect(words(undefined)).toThrow();
});
test('words({}) throws an error', () => {
  expect(words({})).toThrow();
});
test('words([]) throws an error', () => {
  expect(words([])).toThrow();
});
test('words(1234) throws an error', () => {
  expect(words(1234)).toThrow();
});