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

test('union is a Function', () => {
  expect(union).toBeInstanceOf(Function);
});
test('union([1, 2, 3], [4, 3, 2]) returns [1, 2, 3, 4]', () => {
  expect(union([1, 2, 3], [4, 3, 2])).toEqual([1, 2, 3, 4]);
});
test('union(\'str\', \'asd\') returns [ \'s\', \'t\', \'r\', \'a\', \'d\' ]', () => {
  expect(union('str', 'asd')).toEqual([ 's', 't', 'r', 'a', 'd' ]);
});
test('union([[], {}], [1, 2, 3]) returns [[], {}, 1, 2, 3]', () => {
  expect(union([[], {}], [1, 2, 3])).toEqual([[], {}, 1, 2, 3]);
});
test('union([], []) returns []', () => {
  expect(union([], [])).toEqual([]);
});
test('union() throws an error', () => {
  expect(() => {union(); }).toThrow();
});
test('union(true, \'str\') throws an error', () => {
  expect(() => {union(true, 'str'); }).toThrow();
});
test('union(\'false\', true) throws an error', () => {
  expect(() => {union('false', true); }).toThrow();
});
test('union((123, {}) throws an error', () => {
  expect(() => {union(123, {}); }).toThrow();
});
test('union([], {}) throws an error', () => {
  expect(() => {union([], {}); }).toThrow();
});
test('union(undefined, null) throws an error', () => {
  expect(() => {union(undefined, null); }).toThrow();
});
let start = new Date().getTime();
union([1, 2, 3], [4, 3, 2]);
let end = new Date().getTime();
test('union([1, 2, 3], [4, 3, 2]) takes less than 2s to run', () => {
  expect((end - start) < 2000).toBeTruthy();
});