Commit 0adcd1d3 authored by Florian Quèze's avatar Florian Quèze
Browse files

Bug 1358798 - add a test preventing us from loading scripts unintentionally...

Bug 1358798 - add a test preventing us from loading scripts unintentionally during startup, r=mconley,mccr8.
parent 07c2f2dc
support-files =
/* Any copyright is dedicated to the Public Domain. */
/* This test records at which phase of startup the JS components and modules
* are first loaded.
* If you made changes that cause this test to fail, it's likely because you
* are loading more JS code during startup.
* Most code has no reason to run off of the app-startup notification
* (this is very early, before we have selected the user profile, so
* preferences aren't accessible yet).
* If your code isn't strictly required to show the first browser window,
* it shouldn't be loaded before we are done with first paint.
* Finally, if your code isn't really needed during startup, it should not be
* loaded before we have started handling user events.
"use strict";
const startupPhases = {
// For app-startup, we have a whitelist of acceptable JS files.
// Anything loaded during app-startup must have a compelling reason
// to run before we have even selected the user profile.
// Consider loading your code after first paint instead,
// eg. from nsBrowserGlue.js' _onFirstWindowLoaded method).
"before profile selection": {whitelist: {
components: new Set([
// Bugs to fix: The following components shouldn't be initialized that early.
modules: new Set([
// Bugs to fix: Probably loaded too early, needs investigation.
// For the following phases of startup we have only a black list for now
// We are at this phase after creating the first browser window (ie. after final-ui-startup).
"before opening first browser window": {blacklist: {
components: new Set([
// We reach this phase right after showing the first browser window.
// This means that anything already loaded at this point has been loaded
// before first paint and delayed it.
"before first paint": {},
// We are at this phase once we are ready to handle user events.
// Anything loaded at this phase or before gets in the way of the user
// interacting with the first browser window.
"before handling user events": {},
function test() {
if (!AppConstants.NIGHTLY_BUILD && !AppConstants.DEBUG) {
ok(!(";1" in Cc),
"the startup recorder component shouldn't exist in this non-nightly non-debug build.");
let data = Cc[";1"].getService();
// Keep only the file name for components, as the path is an absolute file
// URL rather than a resource:// URL like for modules.
for (let phase in data) {
data[phase].components =
data[phase] => f.replace(/.*\//, ""))
.filter(c => c != "startupRecorder.js");
// This block only adds debug output to help find the next bugs to file,
// it doesn't contribute to the actual test.
let previous;
for (let phase in data) {
for (let scriptType in data[phase]) {
for (let f of data[phase][scriptType]) {
// phases are ordered, so if a script wasn't loaded yet at the immediate
// previous phase, it wasn't loaded during any of the previous phases
// either, and is new in the current phase.
if (!previous || !data[previous][scriptType].includes(f))
info(`${scriptType} loaded ${phase}: ${f}`);
previous = phase;
for (let phase in startupPhases) {
let loadedList = data[phase];
let whitelist = startupPhases[phase].whitelist || null;
if (whitelist) {
for (let scriptType in loadedList) {
loadedList[scriptType] = loadedList[scriptType].filter(c => {
if (!whitelist[scriptType].has(c))
return true;
return false;
is(loadedList[scriptType].length, 0,
`should have no unexpected ${scriptType} loaded ${phase}`);
for (let script of loadedList[scriptType]) {
ok(false, `unexpected ${scriptType}: ${script}`);
is(whitelist[scriptType].size, 0,
`all ${scriptType} whitelist entries should have been used`);
for (let script of whitelist[scriptType]) {
ok(false, `unused ${scriptType} whitelist entry: ${script}`);
let blacklist = startupPhases[phase].blacklist || null;
if (blacklist) {
for (let scriptType in blacklist) {
for (let file of blacklist[scriptType]) {
ok(!loadedList[scriptType].includes(file), `${file} is not allowed ${phase}`);
......@@ -66,6 +66,8 @@ EXTRA_PP_COMPONENTS += [
/* 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 */
const {classes: Cc, utils: Cu, interfaces: Ci} = Components;
* The startupRecorder component observes notifications at various stages of
* startup and records the set of JS components and modules that were already
* loaded at each of these points.
* The records are meant to be used by startup tests in
* browser/base/content/test/performance
* This component only exists in nightly and debug builds, it doesn't ship in
* our release builds.
function startupRecorder() {
this.wrappedJSObject = this;
this.loader = Cc[";1"].getService(Ci.xpcIJSModuleLoader); = {};
startupRecorder.prototype = {
classID: Components.ID("{11c095b2-e42e-4bdf-9dd0-aed87595f6a4}"),
QueryInterface: XPCOMUtils.generateQI([Ci.nsIObserver]),
record(name) {[name] = {
components: this.loader.loadedComponents(),
modules: this.loader.loadedModules()
observe(subject, topic, data) {
if (topic == "app-startup") {
// We can't ensure our observer will be called first or last, so the list of
// topics we observe here should avoid the topics used to trigger things
// during startup (eg. the topics observed by nsBrowserGlue.js).
let topics = [
"profile-do-change", // This catches stuff loaded during app-startup
"toplevel-window-ready", // Catches stuff from final-ui-startup
for (let t of topics)
Services.obs.addObserver(this, t);
Services.obs.removeObserver(this, topic);
if (topic == "sessionstore-windows-restored") {
// We use idleDispatch here to record the set of loaded scripts after we
// are fully done with startup and ready to react to user events.
this.record.bind(this, "before handling user events"));
} else {
const topicsToNames = {
"profile-do-change": "before profile selection",
"toplevel-window-ready": "before opening first browser window",
"widget-first-paint": "before first paint",
this.NSGetFactory = XPCOMUtils.generateNSGetFactory([startupRecorder]);
# This component restricts its registration for the app-startup category
# to the browser app so it doesn't get loaded in xpcshell.
component {11c095b2-e42e-4bdf-9dd0-aed87595f6a4} startupRecorder.js
contract;1 {11c095b2-e42e-4bdf-9dd0-aed87595f6a4}
category app-startup startupRecorder service,;1 application={ec8030f7-c20a-464f-9b0e-13a3a9e97384}
......@@ -568,6 +568,11 @@
#if defined(MOZ_DEBUG) || defined(NIGHTLY_BUILD)
; [Extensions]
......@@ -79,4 +79,12 @@ interface xpcIJSModuleLoader : nsISupports
* otherwise
boolean isModuleLoaded(in AUTF8String aResourceURI);
// These 2 functions are for startup testing purposes. They are not expected
// to be used for production code.
void loadedModules([optional] out unsigned long length,
[retval, array, size_is(length)] out string aModules);
void loadedComponents([optional] out unsigned long length,
[retval, array, size_is(length)] out string aComponents);
......@@ -924,6 +924,36 @@ mozJSComponentLoader::IsModuleLoaded(const nsACString& aLocation,
return NS_OK;
NS_IMETHODIMP mozJSComponentLoader::LoadedModules(uint32_t* length,
char*** aModules)
char** modules = new char*[mImports.Count()];
*length = mImports.Count();
*aModules = modules;
for (auto iter = mImports.Iter(); !iter.Done(); iter.Next()) {
*modules = NS_strdup(iter.Data()->location);
return NS_OK;
NS_IMETHODIMP mozJSComponentLoader::LoadedComponents(uint32_t* length,
char*** aComponents)
char** comp = new char*[mModules.Count()];
*length = mModules.Count();
*aComponents = comp;
for (auto iter = mModules.Iter(); !iter.Done(); iter.Next()) {
*comp = NS_strdup(iter.Data()->location);
return NS_OK;
static JSObject*
ResolveModuleObjectPropertyById(JSContext* aCx, HandleObject aModObj, HandleId id)
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