From 3bec6ecfbed80890e6a46ba4a13af1cb08b6975a Mon Sep 17 00:00:00 2001 From: David Rajchenbach-Teller Date: Mon, 10 Jun 2013 11:01:59 -0400 Subject: [PATCH] Bug 872421 - Simple module loader for workers. r=gozala --- toolkit/components/moz.build | 1 + toolkit/components/workerloader/Makefile.in | 20 ++ toolkit/components/workerloader/moz.build | 10 + toolkit/components/workerloader/require.js | 236 ++++++++++++++++++ .../components/workerloader/tests/Makefile.in | 27 ++ .../workerloader/tests/moduleA-depends.js | 14 ++ .../workerloader/tests/moduleB-dependency.js | 11 + .../workerloader/tests/moduleC-circular.js | 18 ++ .../workerloader/tests/moduleD-circular.js | 11 + .../tests/moduleE-throws-during-require.js | 10 + .../tests/moduleF-syntax-error.js | 6 + .../tests/moduleG-throws-later.js | 12 + .../components/workerloader/tests/moz.build | 8 + .../workerloader/tests/test_loading.xul | 41 +++ .../workerloader/tests/utils_mainthread.js | 34 +++ .../workerloader/tests/utils_worker.js | 32 +++ .../workerloader/tests/worker_handler.js | 34 +++ .../workerloader/tests/worker_test_loading.js | 96 +++++++ 18 files changed, 621 insertions(+) create mode 100644 toolkit/components/workerloader/Makefile.in create mode 100644 toolkit/components/workerloader/moz.build create mode 100644 toolkit/components/workerloader/require.js create mode 100644 toolkit/components/workerloader/tests/Makefile.in create mode 100644 toolkit/components/workerloader/tests/moduleA-depends.js create mode 100644 toolkit/components/workerloader/tests/moduleB-dependency.js create mode 100644 toolkit/components/workerloader/tests/moduleC-circular.js create mode 100644 toolkit/components/workerloader/tests/moduleD-circular.js create mode 100644 toolkit/components/workerloader/tests/moduleE-throws-during-require.js create mode 100644 toolkit/components/workerloader/tests/moduleF-syntax-error.js create mode 100644 toolkit/components/workerloader/tests/moduleG-throws-later.js create mode 100644 toolkit/components/workerloader/tests/moz.build create mode 100644 toolkit/components/workerloader/tests/test_loading.xul create mode 100644 toolkit/components/workerloader/tests/utils_mainthread.js create mode 100644 toolkit/components/workerloader/tests/utils_worker.js create mode 100644 toolkit/components/workerloader/tests/worker_handler.js create mode 100644 toolkit/components/workerloader/tests/worker_test_loading.js diff --git a/toolkit/components/moz.build b/toolkit/components/moz.build index f99b8dff71e..7786bf18d2c 100644 --- a/toolkit/components/moz.build +++ b/toolkit/components/moz.build @@ -41,6 +41,7 @@ PARALLEL_DIRS += [ 'urlformatter', 'viewconfig', 'viewsource', + 'workerloader', ] if CONFIG['MOZ_SOCIAL']: diff --git a/toolkit/components/workerloader/Makefile.in b/toolkit/components/workerloader/Makefile.in new file mode 100644 index 00000000000..41b9e8487e6 --- /dev/null +++ b/toolkit/components/workerloader/Makefile.in @@ -0,0 +1,20 @@ +# 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/. + +DEPTH = @DEPTH@ +topsrcdir = @top_srcdir@ +srcdir = @srcdir@ +VPATH = @srcdir@ + +include $(DEPTH)/config/autoconf.mk + +WORKER_FILES := require.js \ + $(NULL) + +INSTALL_TARGETS += WORKER + +WORKER_DEST = $(FINAL_TARGET)/modules/workers + +include $(topsrcdir)/config/rules.mk + diff --git a/toolkit/components/workerloader/moz.build b/toolkit/components/workerloader/moz.build new file mode 100644 index 00000000000..6f5bd1627b1 --- /dev/null +++ b/toolkit/components/workerloader/moz.build @@ -0,0 +1,10 @@ +# -*- Mode: python; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 40 -*- +# vim: set filetype=python: +# 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/. + +TEST_DIRS += ['tests'] + +MODULE = 'workerloader' + diff --git a/toolkit/components/workerloader/require.js b/toolkit/components/workerloader/require.js new file mode 100644 index 00000000000..f399a09d547 --- /dev/null +++ b/toolkit/components/workerloader/require.js @@ -0,0 +1,236 @@ +/* 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/. */ + + +/** + * Implementation of a CommonJS module loader for workers. + * + * Use: + * // in the .js file loaded by the constructor of the worker + * importScripts("resource://gre/modules/workers/require.js"); + * let module = require("resource://gre/modules/worker/myModule.js"); + * + * // in myModule.js + * // Load dependencies + * let SimpleTest = require("resource://gre/modules/workers/SimpleTest.js"); + * let Logger = require("resource://gre/modules/workers/Logger.js"); + * + * // Define things that will not be exported + * let someValue = // ... + * + * // Export symbols + * exports.foo = // ... + * exports.bar = // ... + * + * + * Note #1: + * Properties |fileName| and |stack| of errors triggered from a module + * contain file names that do not correspond to human-readable module paths. + * Human readers should rather use properties |moduleName| and |moduleStack|. + * + * Note #2: + * The current version of |require()| only accepts absolute URIs. + * + * Note #3: + * By opposition to some other module loader implementations, this module + * loader does not enforce separation of global objects. Consequently, if + * a module modifies a global object (e.g. |String.prototype|), all other + * modules in the same worker may be affected. + */ + + +(function(exports) { + "use strict"; + + if (exports.require) { + // Avoid double-imports + return; + } + + // Simple implementation of |require| + let require = (function() { + + /** + * Mapping from module paths to module exports. + * + * @keys {string} The absolute path to a module. + * @values {object} The |exports| objects for that module. + */ + let modules = new Map(); + + /** + * Mapping from object urls to module paths. + */ + let paths = { + /** + * @keys {string} The object url holding a module. + * @values {string} The absolute path to that module. + */ + _map: new Map(), + /** + * A regexp that may be used to search for all mapped paths. + */ + get regexp() { + if (this._regexp) { + return this._regexp; + } + let objectURLs = []; + for (let [objectURL, _] of this._map) { + objectURLs.push(objectURL); + } + return this._regexp = new RegExp(objectURLs.join("|"), "g"); + }, + _regexp: null, + /** + * Add a mapping from an object url to a path. + */ + set: function(url, path) { + this._regexp = null; // invalidate regexp + this._map.set(url, path); + }, + /** + * Get a mapping from an object url to a path. + */ + get: function(url) { + return this._map.get(url); + }, + /** + * Transform a string by replacing all the instances of objectURLs + * appearing in that string with the corresponding module path. + * + * This is used typically to translate exception stacks. + * + * @param {string} source A source string. + * @return {string} The same string as |source|, in which every occurrence + * of an objectURL registered in this object has been replaced with the + * corresponding module path. + */ + substitute: function(source) { + let map = this._map; + return source.replace(this.regexp, function(url) { + return map.get(url); + }, "g"); + } + }; + + /** + * A human-readable version of |stack|. + * + * @type {string} + */ + Object.defineProperty(Error.prototype, "moduleStack", + { + get: function() { + return paths.substitute(this.stack); + } + }); + /** + * A human-readable version of |fileName|. + * + * @type {string} + */ + Object.defineProperty(Error.prototype, "moduleName", + { + get: function() { + return paths.substitute(this.fileName); + } + }); + + /** + * Import a module + * + * @param {string} path The path to the module. + * @return {*} An object containing the properties exported by the module. + */ + return function require(path) { + if (typeof path != "string" || path.indexOf("://") == -1) { + throw new TypeError("The argument to require() must be a string uri, got " + path); + } + // Determine uri for the module + let uri = path; + if (!(uri.endsWith(".js"))) { + uri += ".js"; + } + + // Exports provided by the module + let exports = Object.create(null); + + // Identification of the module + let module = { + id: path, + uri: uri, + exports: exports + }; + + // Make module available immediately + // (necessary in case of circular dependencies) + if (modules.has(path)) { + return modules.get(path); + } + modules.set(path, exports); + + + // Load source of module, synchronously + let xhr = new XMLHttpRequest(); + xhr.open("GET", uri, false); + xhr.responseType = "text"; + xhr.send(); + + + let source = xhr.responseText; + let name = ":" + path; + let objectURL; + try { + if (source == "") { + // There doesn't seem to be a better way to detect that the file couldn't be found + throw new Error("Could not find module " + path); + } + // From the source, build a function and an object URL. We + // avoid any newline at the start of the file to ensure that + // we do not mess up with line numbers. However, using object URLs + // messes up with stack traces in instances of Error(). + source = "require._tmpModules[\"" + name + "\"] = " + + "function(exports, require, modules) {" + + source + + "\n}\n"; + let blob = new Blob([(new TextEncoder()).encode(source)]); + objectURL = URL.createObjectURL(blob); + paths.set(objectURL, path); + importScripts(objectURL); + require._tmpModules[name](exports, require, modules); + + } catch (ex) { + // Module loading has failed, exports should not be made available + // after all. + modules.delete(path); + throw ex; + } finally { + if (objectURL) { + // Clean up the object url as soon as possible. It will not be needed. + URL.revokeObjectURL(objectURL); + } + delete require._tmpModules[name]; + } + + Object.freeze(module.exports); + return module.exports; + }; + })(); + + /** + * An object used to hold temporarily the module constructors + * while they are being loaded. + * + * @keys {string} The path to the module, prefixed with ":". + * @values {function} A function wrapping the module. + */ + require._tmpModules = Object.create(null); + Object.freeze(require); + + Object.defineProperty(exports, "require", { + value: require, + enumerable: true, + configurable: false + }); +})(this); \ No newline at end of file diff --git a/toolkit/components/workerloader/tests/Makefile.in b/toolkit/components/workerloader/tests/Makefile.in new file mode 100644 index 00000000000..cc086d48369 --- /dev/null +++ b/toolkit/components/workerloader/tests/Makefile.in @@ -0,0 +1,27 @@ +# 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/. + +DEPTH = @DEPTH@ +topsrcdir = @top_srcdir@ +srcdir = @srcdir@ +VPATH = @srcdir@ +relativesrcdir = @relativesrcdir@ + +include $(DEPTH)/config/autoconf.mk + +MOCHITEST_CHROME_FILES := \ + test_loading.xul \ + worker_test_loading.js \ + utils_worker.js \ + utils_mainthread.js \ + moduleA-depends.js \ + moduleB-dependency.js \ + moduleC-circular.js \ + moduleD-circular.js \ + moduleE-throws-during-require.js \ + moduleF-syntax-error.js \ + moduleG-throws-later.js \ + $(NULL) + +include $(topsrcdir)/config/rules.mk diff --git a/toolkit/components/workerloader/tests/moduleA-depends.js b/toolkit/components/workerloader/tests/moduleA-depends.js new file mode 100644 index 00000000000..e775ad611d0 --- /dev/null +++ b/toolkit/components/workerloader/tests/moduleA-depends.js @@ -0,0 +1,14 @@ +/* Any copyright is dedicated to the Public Domain. + http://creativecommons.org/publicdomain/zero/1.0/ */ + +// A trivial module that depends on an equally trivial module +let B = require("chrome://mochitests/content/chrome/toolkit/components/workerloader/tests/moduleB-dependency.js"); + +// Ensure that the initial set of exports is empty +if (Object.keys(exports).length) { + throw new Error("exports should be empty, initially"); +} + +// Export some values +exports.A = true; +exports.importedFoo = B.foo; diff --git a/toolkit/components/workerloader/tests/moduleB-dependency.js b/toolkit/components/workerloader/tests/moduleB-dependency.js new file mode 100644 index 00000000000..eaa97fd5b16 --- /dev/null +++ b/toolkit/components/workerloader/tests/moduleB-dependency.js @@ -0,0 +1,11 @@ +/* Any copyright is dedicated to the Public Domain. + * http://creativecommons.org/publicdomain/zero/1.0/ */ + +exports.B = true; +exports.foo = "foo"; + +// Side-effect to detect if we attempt to re-execute this module. +if ("loadedB" in self) { + throw new Error("B has been evaluted twice"); +} +self.loadedB = true; \ No newline at end of file diff --git a/toolkit/components/workerloader/tests/moduleC-circular.js b/toolkit/components/workerloader/tests/moduleC-circular.js new file mode 100644 index 00000000000..0d6450b0927 --- /dev/null +++ b/toolkit/components/workerloader/tests/moduleC-circular.js @@ -0,0 +1,18 @@ +/* Any copyright is dedicated to the Public Domain. + * http://creativecommons.org/publicdomain/zero/1.0/ */ + +// Module C and module D have circular dependencies. +// This should not prevent from loading them. + +// This value is set before any circular dependency, it should be visible +// in D. +exports.enteredC = true; + +let D = require("chrome://mochitests/content/chrome/toolkit/components/workerloader/tests/moduleD-circular.js"); + +// The following values are set after importing D. +// copiedFromD.copiedFromC should have only one field |enteredC| +exports.copiedFromD = JSON.parse(JSON.stringify(D)); +// exportedFromD.copiedFromC should have all the fields defined in |exports| +exports.exportedFromD = D; +exports.finishedC = true; \ No newline at end of file diff --git a/toolkit/components/workerloader/tests/moduleD-circular.js b/toolkit/components/workerloader/tests/moduleD-circular.js new file mode 100644 index 00000000000..ed1439f432c --- /dev/null +++ b/toolkit/components/workerloader/tests/moduleD-circular.js @@ -0,0 +1,11 @@ +/* Any copyright is dedicated to the Public Domain. + * http://creativecommons.org/publicdomain/zero/1.0/ */ + +// Module C and module D have circular dependencies. +// This should not prevent from loading them. + +exports.enteredD = true; +let C = require("chrome://mochitests/content/chrome/toolkit/components/workerloader/tests/moduleC-circular.js"); +exports.copiedFromC = JSON.parse(JSON.stringify(C)); +exports.exportedFromC = C; +exports.finishedD = true; \ No newline at end of file diff --git a/toolkit/components/workerloader/tests/moduleE-throws-during-require.js b/toolkit/components/workerloader/tests/moduleE-throws-during-require.js new file mode 100644 index 00000000000..38f9a31584f --- /dev/null +++ b/toolkit/components/workerloader/tests/moduleE-throws-during-require.js @@ -0,0 +1,10 @@ +/* Any copyright is dedicated to the Public Domain. + * http://creativecommons.org/publicdomain/zero/1.0/ */ + +// Skip a few lines +// 5 +// 6 +// 7 +// 8 +// 9 +throw new Error("Let's see if this error is obtained with the right origin"); \ No newline at end of file diff --git a/toolkit/components/workerloader/tests/moduleF-syntax-error.js b/toolkit/components/workerloader/tests/moduleF-syntax-error.js new file mode 100644 index 00000000000..c03fa32f8ac --- /dev/null +++ b/toolkit/components/workerloader/tests/moduleF-syntax-error.js @@ -0,0 +1,6 @@ + + +Anything that doesn't parse as JavaScript diff --git a/toolkit/components/workerloader/tests/moduleG-throws-later.js b/toolkit/components/workerloader/tests/moduleG-throws-later.js new file mode 100644 index 00000000000..92fc010d224 --- /dev/null +++ b/toolkit/components/workerloader/tests/moduleG-throws-later.js @@ -0,0 +1,12 @@ +/* Any copyright is dedicated to the Public Domain. + * http://creativecommons.org/publicdomain/zero/1.0/ */ + +// Skip a few lines +// 5 +// 6 +// 7 +// 8 +// 9 +exports.doThrow = function doThrow() { + Array.prototype.sort.apply("foo"); // This will raise a native TypeError +}; \ No newline at end of file diff --git a/toolkit/components/workerloader/tests/moz.build b/toolkit/components/workerloader/tests/moz.build new file mode 100644 index 00000000000..5ba645202a6 --- /dev/null +++ b/toolkit/components/workerloader/tests/moz.build @@ -0,0 +1,8 @@ +# -*- Mode: python; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 40 -*- +# vim: set filetype=python: +# 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/. + +MODULE = 'workerloader' + diff --git a/toolkit/components/workerloader/tests/test_loading.xul b/toolkit/components/workerloader/tests/test_loading.xul new file mode 100644 index 00000000000..2744270e14d --- /dev/null +++ b/toolkit/components/workerloader/tests/test_loading.xul @@ -0,0 +1,41 @@ + + + + + + + +

+ + 

+  
+  
diff --git a/toolkit/components/workerloader/tests/utils_mainthread.js b/toolkit/components/workerloader/tests/utils_mainthread.js
new file mode 100644
index 00000000000..148591c3df8
--- /dev/null
+++ b/toolkit/components/workerloader/tests/utils_mainthread.js
@@ -0,0 +1,34 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+function worker_handler(worker) {
+  worker.onerror = function(error) {
+    error.preventDefault();
+    ok(false, "error "+ error.message);
+  };
+  worker.onmessage = function(msg) {
+//    ok(true, "MAIN: onmessage " + JSON.stringify(msg.data));
+    switch (msg.data.kind) {
+    case "is":
+      SimpleTest.ok(msg.data.outcome, msg.data.description +
+         "( "+ msg.data.a + " ==? " + msg.data.b + ")" );
+      return;
+    case "isnot":
+      SimpleTest.ok(msg.data.outcome, msg.data.description +
+      "( "+ msg.data.a + " !=? " + msg.data.b + ")" );
+         return;
+    case "ok":
+      SimpleTest.ok(msg.data.condition, msg.data.description);
+      return;
+    case "info":
+      SimpleTest.info(msg.data.description);
+      return;
+    case "finish":
+      SimpleTest.finish();
+      return;
+    default:
+      SimpleTest.ok(false, "test_osfile.xul: wrong message " + JSON.stringify(msg.data));
+      return;
+    }
+  };
+}
diff --git a/toolkit/components/workerloader/tests/utils_worker.js b/toolkit/components/workerloader/tests/utils_worker.js
new file mode 100644
index 00000000000..da82d4b0ab9
--- /dev/null
+++ b/toolkit/components/workerloader/tests/utils_worker.js
@@ -0,0 +1,32 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+function log(text) {
+  dump("WORKER " + text + "\n");
+}
+
+function send(message) {
+  self.postMessage(message);
+}
+
+function finish() {
+  send({kind: "finish"});
+}
+
+function ok(condition, description) {
+  send({kind: "ok", condition: !!condition, description: "" + description});
+}
+
+function is(a, b, description) {
+  let outcome = a == b; // Need to decide outcome here, as not everything can be serialized
+  send({kind: "is", outcome: outcome, description: "" + description, a: "" + a, b: "" + b});
+}
+
+function isnot(a, b, description) {
+  let outcome = a != b; // Need to decide outcome here, as not everything can be serialized
+  send({kind: "isnot", outcome: outcome, description: "" + description, a: "" + a, b: "" + b});
+}
+
+function info(description) {
+  send({kind: "info", description: "" + description});
+}
diff --git a/toolkit/components/workerloader/tests/worker_handler.js b/toolkit/components/workerloader/tests/worker_handler.js
new file mode 100644
index 00000000000..b09b8c34ca8
--- /dev/null
+++ b/toolkit/components/workerloader/tests/worker_handler.js
@@ -0,0 +1,34 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+function worker_handler(worker) {
+  worker.onerror = function(error) {
+    error.preventDefault();
+    ok(false, "error "+error);
+  }
+  worker.onmessage = function(msg) {
+    ok(true, "MAIN: onmessage " + JSON.stringify(msg.data));
+    switch (msg.data.kind) {
+    case "is":
+      SimpleTest.ok(msg.data.outcome, msg.data.description +
+         "( "+ msg.data.a + " ==? " + msg.data.b + ")" );
+      return;
+    case "isnot":
+      SimpleTest.ok(msg.data.outcome, msg.data.description +
+      "( "+ msg.data.a + " !=? " + msg.data.b + ")" );
+         return;
+    case "ok":
+      SimpleTest.ok(msg.data.condition, msg.data.description);
+      return;
+    case "info":
+      SimpleTest.info(msg.data.description);
+      return;
+    case "finish":
+      SimpleTest.finish();
+      return;
+    default:
+      SimpleTest.ok(false, "test_osfile.xul: wrong message " + JSON.stringify(msg.data));
+      return;
+    }
+  };
+}
diff --git a/toolkit/components/workerloader/tests/worker_test_loading.js b/toolkit/components/workerloader/tests/worker_test_loading.js
new file mode 100644
index 00000000000..9bf02d9423a
--- /dev/null
+++ b/toolkit/components/workerloader/tests/worker_test_loading.js
@@ -0,0 +1,96 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+importScripts("utils_worker.js"); // Test suite code
+info("Test suite configured");
+
+importScripts("resource://gre/modules/workers/require.js");
+info("Loader imported");
+
+let tests = [];
+let add_test = function(test) {
+  tests.push(test);
+};
+
+add_test(function test_setup() {
+  ok(typeof require != "undefined", "Function |require| is defined");
+});
+
+// Test simple loading (moduleA-depends.js requires moduleB-dependency.js)
+add_test(function test_load() {
+  let A = require("chrome://mochitests/content/chrome/toolkit/components/workerloader/tests/moduleA-depends.js");
+  ok(true, "Opened module A");
+
+  is(A.A, true, "Module A exported value A");
+  ok(!("B" in A), "Module A did not export value B");
+  is(A.importedFoo, "foo", "Module A re-exported B.foo");
+
+  // re-evaluating moduleB-dependency.js would cause an error, but re-requiring it shouldn't
+  let B = require("chrome://mochitests/content/chrome/toolkit/components/workerloader/tests/moduleB-dependency.js");
+  ok(true, "Managed to re-require module B");
+  is(B.B, true, "Module B exported value B");
+  is(B.foo, "foo", "Module B exported value foo");
+});
+
+// Test simple circular loading (moduleC-circular.js and moduleD-circular.js require each other)
+add_test(function test_circular() {
+  let C = require("chrome://mochitests/content/chrome/toolkit/components/workerloader/tests/moduleC-circular.js");
+  ok(true, "Loaded circular modules C and D");
+  is(C.copiedFromD.copiedFromC.enteredC, true, "Properties exported by C before requiring D can be seen by D immediately");
+
+  let D = require("chrome://mochitests/content/chrome/toolkit/components/workerloader/tests/moduleD-circular.js");
+  is(D.exportedFromC.finishedC, true, "Properties exported by C after requiring D can be seen by D eventually");
+});
+
+// Testing error cases
+add_test(function test_exceptions() {
+  let should_throw = function(f) {
+    try {
+      f();
+      return null;
+    } catch (ex) {
+      return ex;
+    }
+  };
+
+  let exn = should_throw(() => require("chrome://mochitests/content/chrome/toolkit/components/workerloader/tests/this module doesn't exist"));
+  ok(!!exn, "Attempting to load a module that doesn't exist raises an error");
+
+  exn = should_throw(() => require("chrome://mochitests/content/chrome/toolkit/components/workerloader/tests/moduleE-throws-during-require.js"));
+  ok(!!exn, "Attempting to load a module that throws at toplevel raises an error");
+  is(exn.moduleName, "chrome://mochitests/content/chrome/toolkit/components/workerloader/tests/moduleE-throws-during-require.js",
+    "moduleName is correct");
+  isnot(exn.moduleStack.indexOf("moduleE-throws-during-require.js"), -1,
+    "moduleStack contains the name of the module");
+  is(exn.lineNumber, 10, "The error comes with the right line number");
+
+  exn = should_throw(() => require("chrome://mochitests/content/chrome/toolkit/components/workerloader/tests/moduleF-syntaxerror.xml"));
+  ok(!!exn, "Attempting to load a non-well formatted module raises an error");
+
+  exn = should_throw(() => require("chrome://mochitests/content/chrome/toolkit/components/workerloader/tests/moduleG-throws-later.js").doThrow());
+  ok(!!exn, "G.doThrow() has raised an error");
+  info(exn);
+  ok(exn.toString().startsWith("TypeError"), "The exception is a TypeError.");
+  is(exn.moduleName, "chrome://mochitests/content/chrome/toolkit/components/workerloader/tests/moduleG-throws-later.js", "The name of the module is correct");
+  isnot(exn.moduleStack.indexOf("moduleG-throws-later.js"), -1,
+    "The name of the right file appears somewhere in the stack");
+  is(exn.lineNumber, 11, "The error comes with the right line number");
+});
+
+self.onmessage = function(message) {
+  for (let test of tests) {
+    info("Entering " + test.name);
+    try {
+      test();
+    } catch (ex) {
+      ok(false, "Test " + test.name + " failed");
+      info(ex);
+      info(ex.stack);
+    }
+    info("Leaving " + test.name);
+  }
+  finish();
+};
+
+
+