Cannot call method 'on' of undefined, in other library when using Docpad

[dhbaird]

./node_modules/.bin/docpad --version
6.21.10

node --version
v0.8.18

npm --version
1.2.2

pkgcloud version: 0.6.7-1

uname -a
Linux ubuntu-lxc 3.8.0 #6 SMP Sat Feb 23 19:11:54 MST 2013 x86_64 x86_64 x86_64 GNU/Linux

I've been having some trouble using docpad in conjunction with another library, pkgcloud. Here's what I do:

//var docpad = require('docpad'); // <--- uncomment this line to cause error in pkgcloud
var pkgcloud = require('pkgcloud');
console.log('createClient()');
var rackspace = pkgcloud.storage.createClient({
  provider: 'rackspace',
  username: 'nodejitsu',
  apiKey: 'foobar'
});
console.log('getContainers()');
rackspace.getContainers(function(err, containers) {
    console.log('Great!')
});

Actual output (when docpad is included):

createClient()
getContainers()
Great!

/home/me/node_modules/pkgcloud/lib/pkgcloud/core/base/client.js:229
      response.on('end', function () {
               ^
TypeError: Cannot call method 'on' of undefined
    at Client.request (/home/me/node_modules/pkgcloud/lib/pkgcloud/core/base/client.js:229:16)
    at Request.Client.auth [as _callback] (/home/me/node_modules/pkgcloud/lib/pkgcloud/rackspace/client.js:80:5)
    at Request.init.self.callback (/home/me/node_modules/pkgcloud/node_modules/request/main.js:127:22)
    at Request.EventEmitter.emit (events.js:99:17)
    at Request.<anonymous> (/home/me/node_modules/pkgcloud/node_modules/request/main.js:767:16)
    at Request.EventEmitter.emit (events.js:126:20)
    at IncomingMessage.Request.start.self.req.self.httpModule.request.buffer (/home/me/node_modules/pkgcloud/node_modules/request/main.js:729:14)
    at IncomingMessage.EventEmitter.emit (events.js:126:20)
    at IncomingMessage._emitEnd (http.js:366:10)
    at HTTPParser.parserOnMessageComplete [as onMessageComplete] (http.js:149:23)

Expected output (when docpad is disabled):

createClient()
getContainers()
Great!

[dhbaird]

Here's a slight variation, that shows another problem as well,

var docpad = require('docpad'); // <--- uncomment this line to cause error in pkgcloud
var pkgcloud = require('pkgcloud');
console.log('createClient()');
var rackspace = pkgcloud.storage.createClient({
  provider: 'rackspace',
  username: 'nodejitsu',
  apiKey: 'foobar'
});
console.log('getContainers()');
rackspace.getContainers(function(err, containers) {
    console.log('here1')
    console.log(err); // <--- err won't print if docpad is enabled :(
    console.log('here2')
    console.log(containers);
    console.log('Great!')
});

Here's what actually gets printed:

createClient()
getContainers()
here1
[TypeError: Object [object Object] has no method 'slice']     <---- Problem right here!
here2
undefined
Great! 

/home/dbaird/local/src/yourpost/node_modules/pkgcloud/lib/pkgcloud/core/base/client.js:229
      response.on('end', function () {
               ^
TypeError: Cannot call method 'on' of undefined
    at Client.request (/home/dbaird/local/src/yourpost/node_modules/pkgcloud/lib/pkgcloud/core/base/client.js:229:16)
    at Request.Client.auth [as _callback] (/home/dbaird/local/src/yourpost/node_modules/pkgcloud/lib/pkgcloud/rackspace/client.js:80:5)
    at Request.init.self.callback (/home/dbaird/local/src/yourpost/node_modules/pkgcloud/node_modules/request/main.js:127:22)
    at Request.EventEmitter.emit (events.js:99:17)
    at Request.<anonymous> (/home/dbaird/local/src/yourpost/node_modules/pkgcloud/node_modules/request/main.js:767:16)
    at Request.EventEmitter.emit (events.js:126:20)
    at IncomingMessage.Request.start.self.req.self.httpModule.request.buffer (/home/dbaird/local/src/yourpost/node_modules/pkgcloud/node_modules/request/main.js:729:14)
    at IncomingMessage.EventEmitter.emit (events.js:126:20)
    at IncomingMessage._emitEnd (http.js:366:10)
    at HTTPParser.parserOnMessageComplete [as onMessageComplete] (http.js:149:23)

Here's what is expected:

createClient()
getContainers()
here1
[Error: Invalid URI "?format=json"]        <----- Expected this
here2
undefined
Great!

[dhbaird]

I've narrowed down the source that causes the trouble:

diff --git a/src/lib/prototypes.coffee b/src/lib/prototypes.coffee
index 9654b77..34e8ab2 100755
--- a/src/lib/prototypes.coffee
+++ b/src/lib/prototypes.coffee
@@ -1,12 +1,12 @@
 String::explode or= ->
        @.split(/[,\s]+/g)

-Array::remove or= (from, to) ->
-       rest = @slice((to or from) + 1 or @length)
-       @length = (if from < 0 then @length + from else from)
-       @push.apply(this,rest)
+#Array::remove or= (from, to) ->
+#      rest = @slice((to or from) + 1 or @length)
+#      @length = (if from < 0 then @length + from else from)
+#      @push.apply(this,rest)

 Date::toShortDateString or= ->
        return @toDateString().replace(/^[^\s]+\s/,'')

[dhbaird]

Okay, here is the culprit in the snippit below, where the Array::remove prototype is clogging things up in Pkgcloud. The "for (var i in self.before)" loop triggers an exception because it hits the Array::remove method. I found this by using the node-inspector debugger. I'm kind of stumped what the best way is to resolve this issue... Maybe to insert a type check into sendRequest to make sure the type is not an array, prior to scanning through the keys?

pkgcloud/lib/pkgcloud/core/base/client.js

  function sendRequest () {
    //
    // Setup any specific request options before 
    // making the request
    //
    if (self.before) {
      var errors = false;
      for (var i in self.before) {
        var fn = self.before[i];
        try {
          options = fn.call(self, options) || options;  // <----- fn somehow ends up being Array::remove, causes exception
        // on errors do error handling, break.
        } catch (exc) { errs.handle(exc, errback); errors = true; break; }
      }
      if (errors) { return; }
    }

    //
    // Set the url for the request based
    // on the `path` supplied.
    //
    if (typeof options.path === 'string') {
      options.path = [options.path];
    }

    //
    // Allow override of URL on parameters, otherwise use the function
    //
    if (!options.url) {
      options.url = self.url.apply(self, options.path);
    }

    // dont delete the delete. this options path thing was messing
    // request up.
    delete options.path;

    if (!errback || !callback) {
      try {
        return request(options);
      } // if request throws still return an EE
      catch (exc1) { return errs.handle(exc1); }
    } else {
      try {
        return request(options, handleRequest);
      } catch (exc2) { return errs.handle(exc2, errback); }
    }
  }

[balupton]

Cool, do we ever use those prototypes anymore? Happy to kill them.

[dhbaird]

Awesome, we may fix this problem in two projects at once! It's a pincer attack :) If it helps, I am working on a little patch that catches a few instances of "remove()" specifically, but I dunno about the other prototypes.

[balupton]

Fixed in the just released v6.28.0 :) Great work.