Exporting classes with node.js

Question

Exporting classes with node.js

I have the following test code that is being ran by jasmine-node in a file called bob_test.spec.js

require('./bob');

describe("Bob", function() {
  var bob = new Bob();

  it("stating something", function() {
    var result = bob.hey('Tom-ay-to, tom-aaaah-to.');
    expect(result).toEqual('Whatever');
  });
});

In order to make the test pass, I've written the following production code in a file called bob.js

"use strict";

var Bob = function() {
}

Bob.prototype.hey = function (text) {
  return "Whatever";
}

module.exports = Bob;

When I run the test - using jasmine-node . - I get the following F

Failures:

1) Bob encountered a declaration exception
Message:
    ReferenceError: Bob is not defined
Stacktrace:
    ReferenceError: Bob is not defined
    at null.<anonymous> (/Users/matt/Code/oss/deliberate-practice/exercism/javascript/bob/bob_test.spec.js:4:17)
    at Object.<anonymous> (/Users/matt/Code/oss/deliberate-practice/exercism/javascript/bob/bob_test.spec.js:3:1)
    at Module._compile (module.js:456:26)
    at Object.Module._extensions..js (module.js:474:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Module.require (module.js:364:17)
    at require (module.js:380:17)

Finished in 0.02 seconds
1 test, 1 assertion, 1 failure, 0 skipped

Based on what I understand about Javascript, I feel like this should work. What does node.js do differently with constructor functions and module exports that prevents this from working I like think it should?

javascript
node.js
jasmine
jasmine-node

Answer 1

require returns an object, you should store it somewhere

var Bob = require('./bob');

and then use this object

var bobInstance = new Bob();

Answer 2

Improving marvin's answer:

"use strict";
var Bob = function() {}

Bob.prototype.hey = function (text) {
  return "Whatever";
}

module.exports = new Bob();

// another file
var Bob = require('./bob');
Bob.hey('text');

So you can create an object passing it to module.exports module.exports = new Bob();

Answer 3

This should fix the error you were having while running your tests via jasmine-node:

// Generated by CoffeeScript 1.6.2
(function() {
  var Bob;

  Bob = (function() {
    function Bob() {}

    Bob.prototype.hey = function(what) {
      return 'Whatever.';
    };

    return Bob;

  })();

  module.exports = Bob;

}).call(this);