Bug 1432894 - Remove fallback preferences from Marionette. r=whimboo

Marionette has quite a complicated system in
testing/marionette/components/marionette.js for support fallback
preferences for earlier Firefoxen.  Since Firefox 55 shipped
quite some time ago it is time to remove the fallbacks.  This will
significantly simplify the overall complexity of this file.

MozReview-Commit-ID: 5lfstTBVF3N

--HG--
extra : rebase_source : aee88f5741f624355c4c32eecc18940571d1b8cc

testing/marionette/components/marionette.js

@@ -11,6 +11,10 @@ XPCOMUtils.defineLazyServiceGetter(
     this, "env", "@mozilla.org/process/environment;1", "nsIEnvironment");
 ChromeUtils.defineModuleGetter(this, "Log",
     "resource://gre/modules/Log.jsm");
+const {
+  EnvironmentPrefs,
+  MarionettePrefs,
+} = ChromeUtils.import("chrome://marionette/content/prefs.js", {});
 ChromeUtils.defineModuleGetter(this, "Preferences",
     "resource://gre/modules/Preferences.jsm");
 XPCOMUtils.defineLazyGetter(this, "log", () => {
@@ -19,20 +23,13 @@ XPCOMUtils.defineLazyGetter(this, "log", () => {
   return log;
 });
 
-const PREF_ENABLED = "marionette.enabled";
-const PREF_LOG_LEVEL_FALLBACK = "marionette.logging";
-const PREF_LOG_LEVEL = "marionette.log.level";
-const PREF_PORT_FALLBACK = "marionette.defaultPrefs.port";
-const PREF_PORT = "marionette.port";
-const PREF_RECOMMENDED = "marionette.prefs.recommended";
-
-const DEFAULT_LOG_LEVEL = "info";
 const NOTIFY_RUNNING = "remote-active";
 
 // Complements -marionette flag for starting the Marionette server.
 // We also set this if Marionette is running in order to start the server
 // again after a Firefox restart.
 const ENV_ENABLED = "MOZ_MARIONETTE";
+const PREF_ENABLED = "marionette.enabled";
 
 // Besides starting based on existing prefs in a profile and a command
 // line flag, we also support inheriting prefs out of an env var, and to
@@ -274,97 +271,6 @@ const RECOMMENDED_PREFS = new Map([
 const isRemote = Services.appinfo.processType ==
     Services.appinfo.PROCESS_TYPE_CONTENT;
 
-const LogLevel = {
-  get(level) {
-    let levels = new Map([
-      ["fatal", Log.Level.Fatal],
-      ["error", Log.Level.Error],
-      ["warn", Log.Level.Warn],
-      ["info", Log.Level.Info],
-      ["config", Log.Level.Config],
-      ["debug", Log.Level.Debug],
-      ["trace", Log.Level.Trace],
-    ]);
-
-    let s = String(level).toLowerCase();
-    if (!levels.has(s)) {
-      return DEFAULT_LOG_LEVEL;
-    }
-    return levels.get(s);
-  },
-};
-
-function getPrefVal(pref) {
-  const {PREF_STRING, PREF_BOOL, PREF_INT, PREF_INVALID} = Ci.nsIPrefBranch;
-
-  let type = Services.prefs.getPrefType(pref);
-  switch (type) {
-    case PREF_STRING:
-      return Services.prefs.getStringPref(pref);
-
-    case PREF_BOOL:
-      return Services.prefs.getBoolPref(pref);
-
-    case PREF_INT:
-      return Services.prefs.getIntPref(pref);
-
-    case PREF_INVALID:
-      return undefined;
-
-    default:
-      throw new TypeError(`Unexpected preference type (${type}) for ${pref}`);
-  }
-}
-
-// Get preference value of |preferred|, falling back to |fallback|
-// if |preferred| is not user-modified and |fallback| exists.
-function getPref(preferred, fallback) {
-  if (!Services.prefs.prefHasUserValue(preferred) &&
-      Services.prefs.getPrefType(fallback) != Ci.nsIPrefBranch.PREF_INVALID) {
-    return getPrefVal(fallback, getPrefVal(preferred));
-  }
-  return getPrefVal(preferred);
-}
-
-// Marionette preferences recently changed names.  This is an abstraction
-// that first looks for the new name, but falls back to using the old name
-// if the new does not exist.
-//
-// This shim can be removed when Firefox 55 ships.
-const prefs = {
-  get port() {
-    return getPref(PREF_PORT, PREF_PORT_FALLBACK);
-  },
-
-  get logLevel() {
-    let s = getPref(PREF_LOG_LEVEL, PREF_LOG_LEVEL_FALLBACK);
-    return LogLevel.get(s);
-  },
-
-  readFromEnvironment(key) {
-    const env = Cc["@mozilla.org/process/environment;1"]
-        .getService(Ci.nsIEnvironment);
-
-    if (env.exists(key)) {
-      let prefs;
-      try {
-        prefs = JSON.parse(env.get(key));
-      } catch (e) {
-        Cu.reportError(
-            "Invalid Marionette preferences in environment; " +
-            "preferences will not have been applied");
-        Cu.reportError(e);
-      }
-
-      if (prefs) {
-        for (let prefName of Object.keys(prefs)) {
-          Preferences.set(prefName, prefs[prefName]);
-        }
-      }
-    }
-  },
-};
-
 class MarionetteMainProcess {
   constructor() {
     this.server = null;
@@ -377,7 +283,7 @@ class MarionetteMainProcess {
     // and that we are ready to start the Marionette server
     this.finalUIStartup = false;
 
-    log.level = prefs.logLevel;
+    log.level = MarionettePrefs.logLevel;
 
     this.enabled = env.exists(ENV_ENABLED);
     this.alteredPrefs = new Set();
@@ -391,11 +297,11 @@ class MarionetteMainProcess {
   }
 
   set enabled(value) {
-    Services.prefs.setBoolPref(PREF_ENABLED, value);
+    MarionettePrefs.enabled = value;
   }
 
   get enabled() {
-    return Services.prefs.getBoolPref(PREF_ENABLED);
+    return MarionettePrefs.enabled;
   }
 
   receiveMessage({name}) {
@@ -425,7 +331,9 @@ class MarionetteMainProcess {
         Services.obs.addObserver(this, "command-line-startup");
         Services.obs.addObserver(this, "sessionstore-windows-restored");
 
-        prefs.readFromEnvironment(ENV_PRESERVE_PREFS);
+        for (let [pref, value] of EnvironmentPrefs.from(ENV_PRESERVE_PREFS)) {
+          Preferences.set(pref, value);
+        }
         break;
 
       // In safe mode the command line handlers are getting parsed after the
@@ -521,7 +429,7 @@ class MarionetteMainProcess {
       }
       await startupRecorder;
 
-      if (Preferences.get(PREF_RECOMMENDED)) {
+      if (MarionettePrefs.recommendedPrefs) {
         for (let [k, v] of RECOMMENDED_PREFS) {
           if (!Preferences.isSet(k)) {
             log.debug(`Setting recommended pref ${k} to ${v}`);
@@ -533,7 +441,7 @@ class MarionetteMainProcess {
 
       try {
         ChromeUtils.import("chrome://marionette/content/server.js");
-        let listener = new server.TCPListener(prefs.port);
+        let listener = new server.TCPListener(MarionettePrefs.port);
         listener.start();
         this.server = listener;
       } catch (e) {