The Tor Browser: addon-sdk/source/test/test-content-script.js@ac0c01689b40 (annotated)

addon-sdk/source/test/test-content-script.js@ac0c01689b40 (annotated)

addon-sdk/source/test/test-content-script.js

Thu, 15 Jan 2015 15:59:08 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 15 Jan 2015 15:59:08 +0100
branch: TOR_BUG_9701
changeset 10: ac0c01689b40
permissions: -rw-r--r--

Implement a real Private Browsing Mode condition by changing the API/ABI;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

 /* 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/. */
 const hiddenFrames = require("sdk/frame/hidden-frame");
 const { create: makeFrame } = require("sdk/frame/utils");
 const { window } = require("sdk/addon/window");
 const { Loader } = require('sdk/test/loader');
 const { URL } = require("sdk/url");
 const testURI = require("./fixtures").url("test.html");
 const testHost = URL(testURI).scheme + '://' + URL(testURI).host;
 /*
  * Utility function that allow to easily run a proxy test with a clean
  * new HTML document. See first unit test for usage.
  */
 function createProxyTest(html, callback) {
   return function (assert, done) {
     let url = 'data:text/html;charset=utf-8,' + encodeURIComponent(html);
     let principalLoaded = false;
     let element = makeFrame(window.document, {
       nodeName: "iframe",
       type: "content",
       allowJavascript: true,
       allowPlugins: true,
       allowAuth: true,
       uri: testURI
     });
     element.addEventListener("DOMContentLoaded", onDOMReady, false);
     function onDOMReady() {
       // Reload frame after getting principal from `testURI`
       if (!principalLoaded) {
         element.setAttribute("src", url);
         principalLoaded = true;
         return;
       }
       assert.equal(element.getAttribute("src"), url, "correct URL loaded");
       element.removeEventListener("DOMContentLoaded", onDOMReady,
                                                   false);
       let xrayWindow = element.contentWindow;
       let rawWindow = xrayWindow.wrappedJSObject;
       let isDone = false;
       let helper = {
         xrayWindow: xrayWindow,
         rawWindow: rawWindow,
         createWorker: function (contentScript) {
           return createWorker(assert, xrayWindow, contentScript, helper.done);
         },
         done: function () {
           if (isDone)
             return;
           isDone = true;
           element.parentNode.removeChild(element);
           done();
         }
       };
       callback(helper, assert);
     }
   };
 }
 function createWorker(assert, xrayWindow, contentScript, done) {
   let loader = Loader(module);
   let Worker = loader.require("sdk/content/worker").Worker;
   let worker = Worker({
     window: xrayWindow,
     contentScript: [
       'new ' + function () {
         assert = function assert(v, msg) {
           self.port.emit("assert", {assertion:v, msg:msg});
         }
         done = function done() {
           self.port.emit("done");
         }
       },
       contentScript
     ]
   });
   worker.port.on("done", done);
   worker.port.on("assert", function (data) {
     assert.ok(data.assertion, data.msg);
   });
   return worker;
 }
 /* Examples for the `createProxyTest` uses */
 let html = "<script>var documentGlobal = true</script>";
 exports["test Create Proxy Test"] = createProxyTest(html, function (helper, assert) {
   // You can get access to regular `test` object in second argument of
   // `createProxyTest` method:
   assert.ok(helper.rawWindow.documentGlobal,
               "You have access to a raw window reference via `helper.rawWindow`");
   assert.ok(!("documentGlobal" in helper.xrayWindow),
               "You have access to an XrayWrapper reference via `helper.xrayWindow`");
   // If you do not create a Worker, you have to call helper.done(),
   // in order to say when your test is finished
   helper.done();
 });
 exports["test Create Proxy Test With Worker"] = createProxyTest("", function (helper) {
   helper.createWorker(
     "new " + function WorkerScope() {
       assert(true, "You can do assertions in your content script");
       // And if you create a worker, you either have to call `done`
       // from content script or helper.done()
       done();
     }
   );
 });
 exports["test Create Proxy Test With Events"] = createProxyTest("", function (helper, assert) {
   let worker = helper.createWorker(
     "new " + function WorkerScope() {
       self.port.emit("foo");
     }
   );
   worker.port.on("foo", function () {
     assert.pass("You can use events");
     // And terminate your test with helper.done:
     helper.done();
   });
 });
 // Bug 714778: There was some issue around `toString` functions
 //             that ended up being shared between content scripts
 exports["test Shared To String Proxies"] = createProxyTest("", function(helper) {
   let worker = helper.createWorker(
     'new ' + function ContentScriptScope() {
       // We ensure that `toString` can't be modified so that nothing could
       // leak to/from the document and between content scripts
       // It only applies to JS proxies, there isn't any such issue with xrays.
       //document.location.toString = function foo() {};
       document.location.toString.foo = "bar";
       assert("foo" in document.location.toString, "document.location.toString can be modified");
       assert(document.location.toString() == "data:text/html;charset=utf-8,",
              "First document.location.toString()");
       self.postMessage("next");
     }
   );
   worker.on("message", function () {
     helper.createWorker(
       'new ' + function ContentScriptScope2() {
         assert(!("foo" in document.location.toString),
                "document.location.toString is different for each content script");
         assert(document.location.toString() == "data:text/html;charset=utf-8,",
                "Second document.location.toString()");
         done();
       }
     );
   });
 });
 // Ensure that postMessage is working correctly across documents with an iframe
 let html = '<iframe id="iframe" name="test" src="data:text/html;charset=utf-8," />';
 exports["test postMessage"] = createProxyTest(html, function (helper, assert) {
   let ifWindow = helper.xrayWindow.document.getElementById("iframe").contentWindow;
   // Listen without proxies, to check that it will work in regular case
   // simulate listening from a web document.
   ifWindow.addEventListener("message", function listener(event) {
     ifWindow.removeEventListener("message", listener, false);
     // As we are in system principal, event is an XrayWrapper
     // xrays use current compartments when calling postMessage method.
     // Whereas js proxies was using postMessage method compartment,
     // not the caller one.
     assert.strictEqual(event.source, helper.xrayWindow,
                       "event.source is the top window");
     assert.equal(event.origin, testHost, "origin matches testHost");
     assert.equal(event.data, "{\"foo\":\"bar\\n \\\"escaped\\\".\"}",
                      "message data is correct");
     helper.done();
   }, false);
   helper.createWorker(
     'new ' + function ContentScriptScope() {
       var json = JSON.stringify({foo : "bar\n \"escaped\"."});
       document.getElementById("iframe").contentWindow.postMessage(json, "*");
     }
   );
 });
 let html = '<input id="input2" type="checkbox" />';
 exports["test Object Listener"] = createProxyTest(html, function (helper) {
   helper.createWorker(
     'new ' + function ContentScriptScope() {
       // Test objects being given as event listener
       let input = document.getElementById("input2");
       let myClickListener = {
         called: false,
         handleEvent: function(event) {
           assert(this === myClickListener, "`this` is the original object");
           assert(!this.called, "called only once");
           this.called = true;
           assert(event.target, input, "event.target is the wrapped window");
           done();
         }
       };
       window.addEventListener("click", myClickListener, true);
       input.click();
       window.removeEventListener("click", myClickListener, true);
     }
   );
 });
 exports["test Object Listener 2"] = createProxyTest("", function (helper) {
   helper.createWorker(
     ('new ' + function ContentScriptScope() {
       // variable replaced with `testHost`
       let testHost = "TOKEN";
       // Verify object as DOM event listener
       let myMessageListener = {
         called: false,
         handleEvent: function(event) {
           window.removeEventListener("message", myMessageListener, true);
           assert(this == myMessageListener, "`this` is the original object");
           assert(!this.called, "called only once");
           this.called = true;
           assert(event.target == document.defaultView, "event.target is the wrapped window");
           assert(event.source == document.defaultView, "event.source is the wrapped window");
           assert(event.origin == testHost, "origin matches testHost");
           assert(event.data == "ok", "message data is correct");
           done();
         }
       };
       window.addEventListener("message", myMessageListener, true);
       document.defaultView.postMessage("ok", '*');
     }
   ).replace("TOKEN", testHost));
 });
 let html = '<input id="input" type="text" /><input id="input3" type="checkbox" />' +
              '<input id="input2" type="checkbox" />';
 exports.testStringOverload = createProxyTest(html, function (helper, assert) {
   // Proxy - toString error
   let originalString = "string";
   let p = Proxy.create({
     get: function(receiver, name) {
       if (name == "binded")
         return originalString.toString.bind(originalString);
       return originalString[name];
     }
   });
   assert.throws(function () {
     p.toString();
   },
   /toString method called on incompatible Proxy/,
   "toString can't be called with this being the proxy");
   assert.equal(p.binded(), "string", "but it works if we bind this to the original string");
   helper.createWorker(
     'new ' + function ContentScriptScope() {
       // RightJS is hacking around String.prototype, and do similar thing:
       // Pass `this` from a String prototype method.
       // It is funny because typeof this == "object"!
       // So that when we pass `this` to a native method,
       // our proxy code can fail on another even more crazy thing.
       // See following test to see what fails around proxies.
       String.prototype.update = function () {
         assert(typeof this == "object", "in update, `this` is an object");
         assert(this.toString() == "input", "in update, `this.toString works");
         return document.querySelectorAll(this);
       };
       assert("input".update().length == 3, "String.prototype overload works");
       done();
     }
   );
 });
 exports["test MozMatchedSelector"] = createProxyTest("", function (helper) {
   helper.createWorker(
     'new ' + function ContentScriptScope() {
       // Check mozMatchesSelector XrayWrappers bug:
       // mozMatchesSelector returns bad results when we are not calling it from the node itself
       // SEE BUG 658909: mozMatchesSelector returns incorrect results with XrayWrappers
       assert(document.createElement( "div" ).mozMatchesSelector("div"),
              "mozMatchesSelector works while being called from the node");
       assert(document.documentElement.mozMatchesSelector.call(
                document.createElement( "div" ),
                "div"
              ),
              "mozMatchesSelector works while being called from a " +
              "function reference to " +
              "document.documentElement.mozMatchesSelector.call");
       done();
     }
   );
 });
 exports["test Events Overload"] = createProxyTest("", function (helper) {
   helper.createWorker(
     'new ' + function ContentScriptScope() {
       // If we add a "____proxy" attribute on XrayWrappers in order to store
       // the related proxy to create an unique proxy for each wrapper;
       // we end up setting this attribute to prototype objects :x
       // And so, instances created with such prototype will be considered
       // as equal to the prototype ...
       //   // Internal method that return the proxy for a given XrayWrapper
       //   function proxify(obj) {
       //     if (obj._proxy) return obj._proxy;
       //     return obj._proxy = Proxy.create(...);
       //   }
       //
       //   // Get a proxy of an XrayWrapper prototype object
       //   let proto = proxify(xpcProto);
       //
       //   // Use this proxy as a prototype
       //   function Constr() {}
       //   Constr.proto = proto;
       //
       //   // Try to create an instance using this prototype
       //   let xpcInstance = new Constr();
       //   let wrapper = proxify(xpcInstance)
       //
       //   xpcProto._proxy = proto and as xpcInstance.__proto__ = xpcProto,
       //   xpcInstance._proxy = proto ... and profixy(xpcInstance) = proto :(
       //
       let proto = window.document.createEvent('HTMLEvents').__proto__;
       window.Event.prototype = proto;
       let event = document.createEvent('HTMLEvents');
       assert(event !== proto, "Event should not be equal to its prototype");
       event.initEvent('dataavailable', true, true);
       assert(event.type === 'dataavailable', "Events are working fine");
       done();
     }
   );
 });
 exports["test Nested Attributes"] = createProxyTest("", function (helper) {
   helper.createWorker(
     'new ' + function ContentScriptScope() {
       // XrayWrappers has a bug when you set an attribute on it,
       // in some cases, it creates an unnecessary wrapper that introduces
       // a different object that refers to the same original object
       // Check that our wrappers don't reproduce this bug
       // SEE BUG 658560: Fix identity problem with CrossOriginWrappers
       let o = {sandboxObject:true};
       window.nested = o;
       o.foo = true;
       assert(o === window.nested, "Nested attribute to sandbox object should not be proxified");
       window.nested = document;
       assert(window.nested === document, "Nested attribute to proxy should not be double proxified");
       done();
     }
   );
 });
 exports["test Form nodeName"] = createProxyTest("", function (helper) {
   helper.createWorker(
     'new ' + function ContentScriptScope() {
       let body = document.body;
       // Check form[nodeName]
       let form = document.createElement("form");
       let input = document.createElement("input");
       input.setAttribute("name", "test");
       form.appendChild(input);
       body.appendChild(form);
       assert(form.test == input, "form[nodeName] is valid");
       body.removeChild(form);
       done();
     }
   );
 });
 exports["test localStorage"] = createProxyTest("", function (helper, assert) {
   let worker = helper.createWorker(
     'new ' + function ContentScriptScope() {
       // Check localStorage:
       assert(window.localStorage, "has access to localStorage");
       window.localStorage.name = 1;
       assert(window.localStorage.name == 1, "localStorage appears to work");
       self.port.on("step2", function () {
         window.localStorage.clear();
         assert(window.localStorage.name == undefined, "localStorage really, really works");
         done();
       });
       self.port.emit("step1");
     }
   );
   worker.port.on("step1", function () {
     assert.equal(helper.rawWindow.localStorage.name, 1, "localStorage really works");
     worker.port.emit("step2");
   });
 });
 exports["test Auto Unwrap Custom Attributes"] = createProxyTest("", function (helper) {
   helper.createWorker(
     'new ' + function ContentScriptScope() {
       let body = document.body;
       // Setting a custom object to a proxy attribute is not wrapped when we get it afterward
       let object = {custom: true, enumerable: false};
       body.customAttribute = object;
       assert(object === body.customAttribute, "custom JS attributes are not wrapped");
       done();
     }
   );
 });
 exports["test Object Tag"] = createProxyTest("", function (helper) {
   helper.createWorker(
     'new ' + function ContentScriptScope() {
       // <object>, <embed> and other tags return typeof 'function'
       let flash = document.createElement("object");
       assert(typeof flash == "function", "<object> is typeof 'function'");
       assert(flash.toString().match(/\[object HTMLObjectElement.*\]/), "<object> is HTMLObjectElement");
       assert("setAttribute" in flash, "<object> has a setAttribute method");
       done();
     }
   );
 });
 exports["test Highlight toString Behavior"] = createProxyTest("", function (helper, assert) {
   // We do not have any workaround this particular use of toString
   // applied on <object> elements. So disable this test until we found one!
   //assert.equal(helper.rawWindow.Object.prototype.toString.call(flash), "[object HTMLObjectElement]", "<object> is HTMLObjectElement");
   function f() {};
   let funToString = Object.prototype.toString.call(f);
   assert.ok(/\[object Function.*\]/.test(funToString), "functions are functions 1");
   // This is how jquery call toString:
   let strToString = helper.rawWindow.Object.prototype.toString.call("");
   assert.ok(/\[object String.*\]/.test(strToString), "strings are strings");
   let o = {__exposedProps__:{}};
   let objToString = helper.rawWindow.Object.prototype.toString.call(o);
   assert.ok(/\[object Object.*\]/.test(objToString), "objects are objects");
   // Make sure to pass a function from the same compartments
   // or toString will return [object Object] on FF8+
   let f2 = helper.rawWindow.eval("(function () {})");
   let funToString2 = helper.rawWindow.Object.prototype.toString.call(f2);
   assert.ok(/\[object Function.*\]/.test(funToString2), "functions are functions 2");
   helper.done();
 });
 exports["test Document TagName"] = createProxyTest("", function (helper) {
   helper.createWorker(
     'new ' + function ContentScriptScope() {
       let body = document.body;
       // Check document[tagName]
       let div = document.createElement("div");
       div.setAttribute("name", "test");
       body.appendChild(div);
       assert(!document.test, "document[divName] is undefined");
       body.removeChild(div);
       let form = document.createElement("form");
       form.setAttribute("name", "test");
       body.appendChild(form);
       assert(document.test == form, "document[formName] is valid");
       body.removeChild(form);
       let img = document.createElement("img");
       img.setAttribute("name", "test");
       body.appendChild(img);
       assert(document.test == img, "document[imgName] is valid");
       body.removeChild(img);
       done();
     }
   );
 });
 let html = '<iframe id="iframe" name="test" src="data:text/html;charset=utf-8," />';
 exports["test Window Frames"] = createProxyTest(html, function (helper) {
   helper.createWorker(
     'let glob = this; new ' + function ContentScriptScope() {
       // Check window[frameName] and window.frames[i]
       let iframe = document.getElementById("iframe");
       //assert(window.frames.length == 1, "The iframe is reported in window.frames check1");
       //assert(window.frames[0] == iframe.contentWindow, "The iframe is reported in window.frames check2");
       assert(window.test == iframe.contentWindow, "window[frameName] is valid");
       done();
     }
   );
 });
 exports["test Collections"] = createProxyTest("", function (helper) {
   helper.createWorker(
     'new ' + function ContentScriptScope() {
       // Highlight XPCNativeWrapper bug with HTMLCollection
       // tds[0] is only defined on first access :o
       let body = document.body;
       let div = document.createElement("div");
       body.appendChild(div);
       div.innerHTML = "<table><tr><td style='padding:0;border:0;display:none'></td><td>t</td></tr></table>";
       let tds = div.getElementsByTagName("td");
       assert(tds[0] == tds[0], "We can get array element multiple times");
       body.removeChild(div);
       done();
     }
   );
 });
 let html = '<input id="input" type="text" /><input id="input3" type="checkbox" />' +
              '<input id="input2" type="checkbox" />';
 exports["test Collections 2"] = createProxyTest(html, function (helper) {
   helper.createWorker(
     'new ' + function ContentScriptScope() {
       // Verify that NodeList/HTMLCollection are working fine
       let body = document.body;
       let inputs = body.getElementsByTagName("input");
       assert(body.childNodes.length == 3, "body.childNodes length is correct");
       assert(inputs.length == 3, "inputs.length is correct");
       assert(body.childNodes[0] == inputs[0], "body.childNodes[0] is correct");
       assert(body.childNodes[1] == inputs[1], "body.childNodes[1] is correct");
       assert(body.childNodes[2] == inputs[2], "body.childNodes[2] is correct");
       let count = 0;
       for(let i in body.childNodes) {
         count++;
       }
       assert(count == 6, "body.childNodes is iterable");
       done();
     }
   );
 });
 exports["test valueOf"] = createProxyTest("", function (helper) {
     helper.createWorker(
       'new ' + function ContentScriptScope() {
         // Bug 787013: Until this bug is fixed, we are missing some methods
         // on JS objects that comes from global `Object` object
         assert(!('valueOf' in window), "valueOf is missing");
         assert(!('toLocateString' in window), "toLocaleString is missing");
         done();
       }
     );
 });
 exports["test XMLHttpRequest"] = createProxyTest("", function (helper) {
   helper.createWorker(
     'new ' + function ContentScriptScope() {
       // XMLHttpRequest doesn't support XMLHttpRequest.apply,
       // that may break our proxy code
       assert(new window.XMLHttpRequest(), "we are able to instantiate XMLHttpRequest object");
       done();
     }
   );
 });
 exports["test XPathResult"] = createProxyTest("", function (helper, assert) {
   const XPathResultTypes = ["ANY_TYPE",
                             "NUMBER_TYPE", "STRING_TYPE", "BOOLEAN_TYPE",
                             "UNORDERED_NODE_ITERATOR_TYPE",
                             "ORDERED_NODE_ITERATOR_TYPE",
                             "UNORDERED_NODE_SNAPSHOT_TYPE",
                             "ORDERED_NODE_SNAPSHOT_TYPE",
                             "ANY_UNORDERED_NODE_TYPE",
                             "FIRST_ORDERED_NODE_TYPE"];
   // Check XPathResult bug with constants being undefined on XPCNativeWrapper
   let xpcXPathResult = helper.xrayWindow.XPathResult;
   XPathResultTypes.forEach(function(type, i) {
     assert.equal(xpcXPathResult.wrappedJSObject[type],
                      helper.rawWindow.XPathResult[type],
                      "XPathResult's constants are valid on unwrapped node");
     assert.equal(xpcXPathResult[type], i,
                      "XPathResult's constants are defined on " +
                      "XPCNativeWrapper (platform bug #)");
   });
   let value = helper.rawWindow.XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE;
   let worker = helper.createWorker(
     'new ' + function ContentScriptScope() {
       self.port.on("value", function (value) {
         // Check that our work around is working:
         assert(window.XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE === value,
                "XPathResult works correctly on Proxies");
         done();
       });
     }
   );
   worker.port.emit("value", value);
 });
 exports["test Prototype Inheritance"] = createProxyTest("", function (helper) {
   helper.createWorker(
     'new ' + function ContentScriptScope() {
       // Verify that inherited prototype function like initEvent
       // are handled correctly. (e2.type will return an error if it's not the case)
       let event1 = document.createEvent( 'MouseEvents' );
       event1.initEvent( "click", true, true );
       let event2 = document.createEvent( 'MouseEvents' );
       event2.initEvent( "click", true, true );
       assert(event2.type == "click", "We are able to create an event");
       done();
     }
   );
 });
 exports["test Functions"] = createProxyTest("", function (helper) {
   helper.rawWindow.callFunction = function callFunction(f) f();
   helper.rawWindow.isEqual = function isEqual(a, b) a == b;
   // bug 784116: workaround in order to allow proxy code to cache proxies on
   // these functions:
   helper.rawWindow.callFunction.__exposedProps__ = {__proxy: 'rw'};
   helper.rawWindow.isEqual.__exposedProps__ = {__proxy: 'rw'};
   helper.createWorker(
     'new ' + function ContentScriptScope() {
       // Check basic usage of functions
       let closure2 = function () {return "ok";};
       assert(window.wrappedJSObject.callFunction(closure2) == "ok", "Function references work");
       // Ensure that functions are cached when being wrapped to native code
       let closure = function () {};
       assert(window.wrappedJSObject.isEqual(closure, closure), "Function references are cached before being wrapped to native");
       done();
     }
   );
 });
 let html = '<input id="input2" type="checkbox" />';
 exports["test Listeners"] = createProxyTest(html, function (helper) {
   helper.createWorker(
     'new ' + function ContentScriptScope() {
       // Verify listeners:
       let input = document.getElementById("input2");
       assert(input, "proxy.getElementById works");
       function onclick() {};
       input.onclick = onclick;
       assert(input.onclick === onclick, "on* attributes are equal to original function set");
       let addEventListenerCalled = false;
       let expandoCalled = false;
       input.addEventListener("click", function onclick(event) {
         input.removeEventListener("click", onclick, true);
         assert(!addEventListenerCalled, "closure given to addEventListener is called once");
         if (addEventListenerCalled)
           return;
         addEventListenerCalled = true;
         assert(!event.target.ownerDocument.defaultView.documentGlobal, "event object is still wrapped and doesn't expose document globals");
         let input2 = document.getElementById("input2");
         input.onclick = function (event) {
           input.onclick = null;
           assert(!expandoCalled, "closure set to expando is called once");
           if (expandoCalled) return;
           expandoCalled = true;
           assert(!event.target.ownerDocument.defaultView.documentGlobal, "event object is still wrapped and doesn't expose document globals");
           setTimeout(function () {
             input.click();
             done();
           }, 0);
         }
         setTimeout(function () {
           input.click();
         }, 0);
       }, true);
       input.click();
     }
   );
 });
 exports["test MozRequestAnimationFrame"] = createProxyTest("", function (helper) {
   helper.createWorker(
     'new ' + function ContentScriptScope() {
       window.mozRequestAnimationFrame(function callback() {
         assert(callback == this, "callback is equal to `this`");
         done();
       });
     }
   );
 });
 exports["testGlobalScope"] = createProxyTest("", function (helper) {
   helper.createWorker(
     'let toplevelScope = true;' +
     'assert(window.toplevelScope, "variables in toplevel scope are set to `window` object");' +
     'assert(this.toplevelScope, "variables in toplevel scope are set to `this` object");' +
     'done();'
   );
 });
 // Bug 715755: proxy code throw an exception on COW
 // Create an http server in order to simulate real cross domain documents
 exports["test Cross Domain Iframe"] = createProxyTest("", function (helper) {
   let serverPort = 8099;
   let server = require("sdk/test/httpd").startServerAsync(serverPort);
   server.registerPathHandler("/", function handle(request, response) {
     // Returns the webpage that receive a message and forward it back to its
     // parent document by appending ' world'.
     let content = "<html><head><meta charset='utf-8'></head>\n";
     content += "<script>\n";
     content += "  window.addEventListener('message', function (event) {\n";
     content += "    parent.postMessage(event.data + ' world', '*');\n";
     content += "  }, true);\n";
     content += "</script>\n";
     content += "<body></body>\n";
     content += "</html>\n";
     response.write(content);
   });
   let worker = helper.createWorker(
     'new ' + function ContentScriptScope() {
       // Waits for the server page url
       self.on("message", function (url) {
         // Creates an iframe with this page
         let iframe = document.createElement("iframe");
         iframe.addEventListener("load", function onload() {
           iframe.removeEventListener("load", onload, true);
           try {
             // Try to communicate with iframe's content
             window.addEventListener("message", function onmessage(event) {
               window.removeEventListener("message", onmessage, true);
               assert(event.data == "hello world", "COW works properly");
               self.port.emit("end");
             }, true);
             iframe.contentWindow.postMessage("hello", "*");
           } catch(e) {
             assert(false, "COW fails : "+e.message);
           }
         }, true);
         iframe.setAttribute("src", url);
         document.body.appendChild(iframe);
       });
     }
   );
   worker.port.on("end", function () {
     server.stop(helper.done);
   });
   worker.postMessage("http://localhost:" + serverPort + "/");
 });
 // Bug 769006: Ensure that MutationObserver works fine with proxies
 let html = '<a href="foo">link</a>';
 exports["test MutationObvserver"] = createProxyTest(html, function (helper) {
   helper.createWorker(
     'new ' + function ContentScriptScope() {
       if (typeof MutationObserver == "undefined") {
         assert(true, "No MutationObserver for this FF version");
         done();
         return;
       }
       let link = document.getElementsByTagName("a")[0];
       // Register a Mutation observer
       let obs = new MutationObserver(function(mutations){
         // Ensure that mutation data are valid
         assert(mutations.length == 1, "only one attribute mutation");
         let mutation = mutations[0];
         assert(mutation.type == "attributes", "check `type`");
         assert(mutation.target == link, "check `target`");
         assert(mutation.attributeName == "href", "check `attributeName`");
         assert(mutation.oldValue == "foo", "check `oldValue`");
         obs.disconnect();
         done();
       });
       obs.observe(document, {
         subtree: true,
         attributes: true,
         attributeOldValue: true,
         attributeFilter: ["href"]
       });
       // Modify the DOM
       link.setAttribute("href", "bar");
     }
   );
 });
 let html = '<script>' +
   'var accessCheck = function() {' +
   '  assert(true, "exporting function works");' +
   '  try{' +
   '    exportedObj.prop;' +
   '    assert(false, "content should not have access to content-script");' +
   '  } catch(e) {' +
   '    assert(e.toString().indexOf("Permission denied") != -1,' +
   '           "content should not have access to content-script");' +
   '  }' +
   '}</script>';
 exports["test nsEp for content-script"] = createProxyTest(html, function (helper) {
   helper.createWorker(
     'let glob = this; new ' + function ContentScriptScope() {
       exportFunction(assert, unsafeWindow, { defineAs: "assert" });
       window.wrappedJSObject.assert(true, "assert exported");
       window.wrappedJSObject.exportedObj = { prop: 42 };
       window.wrappedJSObject.accessCheck();
       done();
     }
   );
 });
 require("test").run(exports);