Bug 1386807 - Part 2: Add embedded webextension to enable CSS and JS overrides r=kmag,mconley

MozReview-Commit-ID: JdSUZYHkuiV

--HG--
extra : rebase_source : 66d5d0c6c7b386ca70b6abfeb50090d8cf00f7b6

browser/extensions/webcompat/bootstrap.js

@@ -6,7 +6,14 @@ ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
 ChromeUtils.import("resource://gre/modules/Services.jsm");
 
 const PREF_BRANCH = "extensions.webcompat.";
-const PREF_DEFAULTS = {perform_ua_overrides: true};
+const PREF_DEFAULTS = {
+  perform_injections: true,
+  perform_ua_overrides: true
+};
+
+const INJECTIONS_ENABLE_PREF_NAME = "extensions.webcompat.perform_injections";
+
+const BROWSER_STARTUP_FINISHED_TOPIC = "browser-delayed-startup-finished";
 
 const UA_OVERRIDES_INIT_TOPIC = "useragentoverrides-initialized";
 const UA_ENABLE_PREF_NAME = "extensions.webcompat.perform_ua_overrides";
@@ -15,6 +22,15 @@ ChromeUtils.defineModuleGetter(this, "UAOverrider", "chrome://webcompat/content/
 ChromeUtils.defineModuleGetter(this, "UAOverrides", "chrome://webcompat/content/data/ua_overrides.jsm");
 
 let overrider;
+let webextensionPort;
+
+function InjectionsEnablePrefObserver() {
+  let isEnabled = Services.prefs.getBoolPref(INJECTIONS_ENABLE_PREF_NAME);
+  webextensionPort.postMessage({
+    type: "injection-pref-changed",
+    prefState: isEnabled
+  });
+}
 
 function UAEnablePrefObserver() {
   let isEnabled = Services.prefs.getBoolPref(UA_ENABLE_PREF_NAME);
@@ -57,6 +73,9 @@ this.startup = function({webExtension}) {
   // Intentionally reset the preference on every browser restart to avoid site
   // breakage by accidentally toggled preferences or by leaving it off after
   // debugging a site.
+  Services.prefs.clearUserPref(INJECTIONS_ENABLE_PREF_NAME);
+  Services.prefs.addObserver(INJECTIONS_ENABLE_PREF_NAME, InjectionsEnablePrefObserver);
+
   Services.prefs.clearUserPref(UA_ENABLE_PREF_NAME);
   Services.prefs.addObserver(UA_ENABLE_PREF_NAME, UAEnablePrefObserver);
 
@@ -64,7 +83,7 @@ this.startup = function({webExtension}) {
   // initialize our overrider there. This is done to avoid slowing down the
   // apparent startup proces, since we avoid loading anything before the first
   // window is visible to the user. See bug 1371442 for details.
-  let startupWatcher = {
+  let uaStartupObserver = {
     observe(aSubject, aTopic, aData) {
       if (aTopic !== UA_OVERRIDES_INIT_TOPIC) {
         return;
@@ -75,9 +94,29 @@ this.startup = function({webExtension}) {
       overrider.init();
     }
   };
-  Services.obs.addObserver(startupWatcher, UA_OVERRIDES_INIT_TOPIC);
+  Services.obs.addObserver(uaStartupObserver, UA_OVERRIDES_INIT_TOPIC);
+
+  // Observe browser-delayed-startup-finished and only initialize our embedded
+  // WebExtension after that. Otherwise, we'd try to initialize as soon as the
+  // browser starts up, which adds a heavy startup penalty.
+  let appStartupObserver = {
+    observe(aSubject, aTopic, aData) {
+      webExtension.startup().then((api) => {
+        api.browser.runtime.onConnect.addListener((port) => {
+          webextensionPort = port;
+        });
+
+        return Promise.resolve();
+      }).catch((ex) => {
+        console.error(ex);
+      });
+      Services.obs.removeObserver(this, BROWSER_STARTUP_FINISHED_TOPIC);
+    }
+  };
+  Services.obs.addObserver(appStartupObserver, BROWSER_STARTUP_FINISHED_TOPIC);
 };
 
 this.shutdown = function() {
+  Services.prefs.removeObserver(INJECTIONS_ENABLE_PREF_NAME, InjectionsEnablePrefObserver);
   Services.prefs.removeObserver(UA_ENABLE_PREF_NAME, UAEnablePrefObserver);
 };

browser/extensions/webcompat/content/data/ua_overrides.jsm

@@ -3,48 +3,11 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 /**
- * This is an array of objects that specify user agent overrides. Each object
- * can have three attributes:
+ * For detailed information on our policies, and a documention on this format
+ * and its possibilites, please check the Mozilla-Wiki at
  *
- *   * `baseDomain`, required: The base domain that further checks and user
- *     agents override are applied to. This does not include subdomains.
- *   * `applications`: Array of applications this override is valid in.
- *     Defaults to ["firefox"], can be one or more of:
- *     * `firefox`: Firefox Desktop (regardless of the operating system)
- *     * `fennec`: Firefox for Android
- *   * `uriMatcher`: Function that gets the requested URI passed in the first
- *     argument and needs to return boolean whether or not the override should
- *     be applied. If not provided, the user agent override will be applied
- *     every time.
- *   * `uaTransformer`, required: Function that gets the original Firefox user
- *     agent passed as its first argument and needs to return a string that
- *     will be used as the the user agent for this URI.
- *
- * Examples:
- *
- * Gets applied for all requests to mozilla.org and subdomains made on
- * Firefox Desktop:
- *
- * ```
- *   {
- *     baseDomain: "mozilla.org",
- *     uriMatcher: (uri) => uri.includes("/app/"),
- *     uaTransformer: (originalUA) => `Ohai Mozilla, it's me, ${originalUA}`
- *   }
- * ```
- *
- * Applies to *.example.com/app/* on Firefox for Android:
- *
- * ```
- *   {
- *     baseDomain: "example.com",
- *     applications: ["fennec"],
- *     uriMatcher: (uri) => uri.includes("/app/"),
- *     uaTransformer: (originalUA) => originalUA.replace("Firefox", "Otherfox")
- *   }
- * ```
+ * https://wiki.mozilla.org/Compatibility/Go_Faster_Addon/Override_Policies_and_Workflows#User_Agent_overrides
  */
-
 const UAOverrides = [
 
   /*
@@ -57,7 +20,7 @@ const UAOverrides = [
   {
     baseDomain: "schub.io",
     applications: ["firefox", "fennec"],
-    uriMatcher: (uri) => uri.includes("webcompat-ua-dummy.schub.io"),
+    uriMatcher: (uri) => uri.includes("webcompat-addon-testcases.schub.io"),
     uaTransformer: (originalUA) => {
       let prefix = originalUA.substr(0, originalUA.indexOf(")") + 1);
       return `${prefix} AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.98 Safari/537.36`;

browser/extensions/webcompat/install.rdf.in

@@ -10,10 +10,11 @@
 
   <Description about="urn:mozilla:install-manifest">
     <em:id>webcompat@mozilla.org</em:id>
-    <em:version>1.1</em:version>
+    <em:version>2.0</em:version>
     <em:type>2</em:type>
     <em:bootstrap>true</em:bootstrap>
     <em:multiprocessCompatible>true</em:multiprocessCompatible>
+    <em:hasEmbeddedWebExtension>true</em:hasEmbeddedWebExtension>
 
     <!-- Firefox Desktop -->
     <em:targetApplication>

browser/extensions/webcompat/moz.build

@@ -11,6 +11,19 @@ FINAL_TARGET_FILES.features['webcompat@mozilla.org'] += [
   'bootstrap.js'
 ]
 
+FINAL_TARGET_FILES.features['webcompat@mozilla.org']['webextension'] += [
+  'webextension/background.js',
+  'webextension/manifest.json'
+]
+
+FINAL_TARGET_FILES.features['webcompat@mozilla.org']['webextension']['injections']['css'] += [
+  'webextension/injections/css/bug0000000-dummy-css-injection.css'
+]
+
+FINAL_TARGET_FILES.features['webcompat@mozilla.org']['webextension']['injections']['js'] += [
+  'webextension/injections/js/bug0000000-dummy-js-injection.js'
+]
+
 FINAL_TARGET_PP_FILES.features['webcompat@mozilla.org'] += [
   'install.rdf.in'
 ]

browser/extensions/webcompat/webextension/background.js

@@ -0,0 +1,55 @@
+/**
+ * For detailed information on our policies, and a documention on this format
+ * and its possibilites, please check the Mozilla-Wiki at
+ *
+ * https://wiki.mozilla.org/Compatibility/Go_Faster_Addon/Override_Policies_and_Workflows#User_Agent_overrides
+ */
+const contentScripts = [
+  {
+    matches: ["*://webcompat-addon-testcases.schub.io/*"],
+    css: [{file: "injections/css/bug0000000-dummy-css-injection.css"}],
+    js: [{file: "injections/js/bug0000000-dummy-js-injection.js"}],
+    runAt: "document_start"
+  }
+];
+
+/* globals browser */
+
+let port = browser.runtime.connect();
+let registeredContentScripts = [];
+
+function registerContentScripts() {
+  contentScripts.forEach(async (contentScript) => {
+    try {
+      let handle = await browser.contentScripts.register(contentScript);
+      registeredContentScripts.push(handle);
+    } catch (ex) {
+      console.error("Registering WebCompat GoFaster content scripts failed: ", ex);
+    }
+  });
+}
+
+function unregisterContentScripts() {
+  registeredContentScripts.forEach((contentScript) => {
+    contentScript.unregister();
+  });
+}
+
+port.onMessage.addListener((message) => {
+  switch (message.type) {
+    case "injection-pref-changed":
+      if (message.prefState) {
+        registerContentScripts();
+      } else {
+        unregisterContentScripts();
+      }
+      break;
+  }
+});
+
+/**
+ * Note that we reset all preferences on extension startup, so the injections will
+ * never be disabled when this loads up. Because of that, we can simply register
+ * right away.
+ */
+registerContentScripts();

browser/extensions/webcompat/webextension/injections/css/bug0000000-dummy-css-injection.css

@@ -0,0 +1,3 @@
+#css-injection.red {
+  background-color: #0f0;
+}

browser/extensions/webcompat/webextension/injections/js/bug0000000-dummy-js-injection.js

@@ -0,0 +1,11 @@
+"use strict";
+
+/* globals exportFunction */
+
+Object.defineProperty(window.wrappedJSObject, "isTestFeatureSupported", {
+  get: exportFunction(function() {
+    return true;
+  }, window),
+
+  set: exportFunction(function() {}, window)
+});

browser/extensions/webcompat/webextension/manifest.json

@@ -0,0 +1,23 @@
+{
+  "manifest_version": 2,
+  "name": "Web Compat",
+  "description": "Urgent post-release fixes for web compatibility.",
+  "version": "2.0",
+
+  "applications": {
+    "gecko": {
+      "id": "webcompat@mozilla.org",
+      "strict_min_version": "59.0b5"
+    }
+  },
+
+  "permissions": [
+    "<all_urls>"
+  ],
+
+  "background": {
+    "scripts": [
+      "background.js"
+    ]
+  }
+}