Exporting classes with node.js

mattr- picture mattr- · Aug 2, 2013 · Viewed 65.9k times · Source

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?

Answer

mrvn picture mrvn · Aug 2, 2013

require returns an object, you should store it somewhere

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

and then use this object

var bobInstance = new Bob();