Stock checking with coffeescipt
There are issues with your test function, don't return true, just return the result of the test you're doing or your function won't return anything if the test is false:

stockCheck = (stock, msg) -&gt;
    console.log {msg}
    return !stock or stock is 'in stock'


Also, why {msg}? Shouldn't it be just console.log msg?

Your console.log tests are erronous too, your function is supposed to do the test not you when you call it, remove the ? from these lines:

console.log stockCheck(obj.one.stock) # true
console.log stockCheck(obj.two.stock) # true
console.log stockCheck(obj.three.stock) # false