1var assert = require('assert');
2
3function decimalToBinary(num) {
4  if (num >= 1) {
5    if (num % 2) {
6      return decimalToBinary((num - 1) / 2) + 1;
7    } else {
8      return decimalToBinary(num / 2) + 0;
9    }
10  } else {
11    return '';
12  }
13}
14
15try {
16  assert.equal(decimalToBinary(3), 11);
17
18  console.log('PASSED: ' + 'decimalToBinary(3) should return 11');
19} catch (err) {
20  console.log(err);
21}
22
23try {
24  assert.equal(decimalToBinary(8), 1000);
25
26  console.log('PASSED: ' + 'decimalToBinary(8) should return 1000');
27} catch (err) {
28  console.log(err);
29}
30
31try {
32  assert.equal(decimalToBinary(1000), 1111101000);
33
34  console.log('PASSED: ' + 'decimalToBinary(1000) should return 1111101000');
35} catch (err) {
36  console.log(err);
37}
38
39try {
40  assertIsFunction(decimalToBinary, '`decimalToBinary` is a function');
41
42  console.log('PASSED: ' + '`decimalToBinary` is a function');
43} catch (err) {
44  console.log(err);
45}
46
47function assertIsFunction(f) {
48  return typeof f === 'function';
49}