module.exports not caching when using coffeescript to run my node.js application

Lets say that I have an application:

./app.coffee:

express = require "express"
module.exports = app = express()
require "./models"

./models/index.coffee

app = require "../app"

Then I run the command: coffee app.coffee

The problem is that the code does not run the same way as when it is precompiled.

When I run my app with node (compiled):

  • The app.coffee requires models
  • models requires app and returns the module.exports (app)

When I run my app with coffee:

  • The app.coffee requires models
  • models requires app but app run again and requires models again

It seems that module.exports is not working properly when running my app with coffee. Or maybe I'm doing something wrong?

Node has an altered behavior for managing module cycles which doesn't appear to be supported when using the coffee executable:

When there are circular require() calls, a module might not be done being executed when it is returned.

[...]

When main.js loads a.js, then a.js in turn loads b.js. At that point, b.js tries to load a.js. In order to prevent an infinite loop an unfinished copy of the a.js exports object is returned to the b.js module. b.js then finishes loading, and its exports object is provided to the a.js module.

If you can, try to avoid cycles. One possible alternative is:

express = require "express"
module.exports = app = express()
models = require "./models"
models app

module.exports = (app) ->
  # ...