diff -r 000000000000 -r 6474c204b198 addon-sdk/source/lib/sdk/test/loader.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/addon-sdk/source/lib/sdk/test/loader.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,122 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+const { resolveURI, Require,
+        unload, override, descriptor } = require('../../toolkit/loader');
+const { ensure } = require('../system/unload');
+const addonWindow = require('../addon/window');
+const { PlainTextConsole } = require('sdk/console/plain-text');
+
+let defaultGlobals = override(require('../system/globals'), {
+  console: console
+});
+
+function CustomLoader(module, globals, packaging, overrides={}) {
+  let options = packaging || require("@loader/options");
+  options = override(options, {
+    id: overrides.id || options.id,
+    globals: override(defaultGlobals, globals || {}),
+    modules: override(options.modules || {}, {
+      'sdk/addon/window': addonWindow
+    })
+  });
+
+  let loaderModule = options.isNative ? '../../toolkit/loader' : '../loader/cuddlefish';
+  let { Loader } = require(loaderModule);
+  let loader = Loader(options);
+  let wrapper = Object.create(loader, descriptor({
+    require: Require(loader, module),
+    sandbox: function(id) {
+      let requirement = loader.resolve(id, module.id);
+      let uri = resolveURI(requirement, loader.mapping);
+      return loader.sandboxes[uri];
+    },
+    unload: function(reason) {
+      unload(loader, reason);
+    }
+  }));
+  ensure(wrapper);
+  return wrapper;
+};
+exports.Loader = CustomLoader;
+
+function HookedPlainTextConsole(hook, print, innerID) {
+  this.log = hook.bind(null, "log", innerID);
+  this.info = hook.bind(null, "info", innerID);
+  this.warn = hook.bind(null, "warn", innerID);
+  this.error = hook.bind(null, "error", innerID);
+  this.debug = hook.bind(null, "debug", innerID);
+  this.exception = hook.bind(null, "exception", innerID);
+  this.time = hook.bind(null, "time", innerID);
+  this.timeEnd = hook.bind(null, "timeEnd", innerID);
+
+  this.__exposedProps__ = {
+    log: "rw", info: "rw", warn: "rw", error: "rw", debug: "rw",
+    exception: "rw", time: "rw", timeEnd: "rw"
+  };
+}
+
+// Creates a custom loader instance whose console module is hooked in order
+// to avoid printing messages to the console, and instead, expose them in the
+// returned `messages` array attribute
+exports.LoaderWithHookedConsole = function (module, callback) {
+  let messages = [];
+  function hook(type, innerID, msg) {
+    messages.push({ type: type, msg: msg, innerID: innerID });
+    if (callback)
+      callback(type, msg, innerID);
+  }
+
+  return {
+    loader: CustomLoader(module, {
+      console: new HookedPlainTextConsole(hook, null, null)
+    }, override(require("@loader/options"), {
+      modules: {
+        'sdk/console/plain-text': {
+          PlainTextConsole: HookedPlainTextConsole.bind(null, hook)
+        }
+      }
+    })),
+    messages: messages
+  };
+}
+
+// Same than LoaderWithHookedConsole with lower level, instead we get what is
+// actually printed to the command line console
+exports.LoaderWithHookedConsole2 = function (module, callback) {
+  let messages = [];
+  return {
+    loader: CustomLoader(module, {
+      console: new PlainTextConsole(function (msg) {
+        messages.push(msg);
+        if (callback)
+          callback(msg);
+      })
+    }),
+    messages: messages
+  };
+}
+
+// Creates a custom loader with a filtered console. The callback is passed every
+// console message type and message and if it returns false the message will
+// not be logged normally
+exports.LoaderWithFilteredConsole = function (module, callback) {
+  function hook(type, innerID, msg) {
+    if (callback && callback(type, msg, innerID) == false)
+      return;
+    console[type](msg);
+  }
+
+  return CustomLoader(module, {
+    console: new HookedPlainTextConsole(hook, null, null)
+  }, override(require("@loader/options"), {
+    modules: {
+      'sdk/console/plain-text': {
+        PlainTextConsole: HookedPlainTextConsole.bind(null, hook)
+      }
+    }
+  }));
+}