devtools/shared/flags.js

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this
   3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 "use strict";
   6
   7 /**
   8  * This module controls various global flags that can be toggled on and off.
   9  * These flags are generally used to change the behavior of the code during
  10  * testing. They are tracked by preferences so that they are propagated
  11  * between the parent and content processes. The flags are exposed via a module
  12  * as a conveniene and to stop from littering preference names throughout the
  13  * code ase.
  14  *
  15  * Each of the flags is documented where it is defined.
  16  */
  17
  18 /**
  19  * We cannot make a normal property writeable on `exports` because
  20  * the module system freezes it. This function observes a preference
  21  * and provides the latest value through a getter.
  22  */
  23 function makePrefTrackedFlag(exports, name, pref) {
  24   let flag;
  25   // We don't have access to pref in worker, so disable all logs by default
  26   if (isWorker) {
  27     flag = false;
  28   } else {
  29     flag = Services.prefs.getBoolPref(pref, false);
  30     const prefObserver = () => {
  31       flag = Services.prefs.getBoolPref(pref, false);
  32     };
  33     Services.prefs.addObserver(pref, prefObserver);
  34
  35     // Also listen for Loader unload to unregister the pref observer and prevent leaking
  36     const unloadObserver = function (subject) {
  37       if (subject.wrappedJSObject == require("@loader/unload")) {
  38         Services.prefs.removeObserver(pref, prefObserver);
  39         Services.obs.removeObserver(unloadObserver, "devtools:loader:destroy");
  40       }
  41     };
  42     Services.obs.addObserver(unloadObserver, "devtools:loader:destroy");
  43   }
  44   Object.defineProperty(exports, name, {
  45     get() {
  46       return flag;
  47     },
  48   });
  49 }
  50
  51 /**
  52  * Setting the "devtools.debugger.log" preference to true will enable logging of
  53  * the RDP calls to the devtools server.
  54  */
  55 makePrefTrackedFlag(exports, "wantLogging", "devtools.debugger.log");
  56
  57 /**
  58  * Setting the "devtools.debugger.log.verbose" preference to true will enable a
  59  * more verbose logging of the the RDP. The "devtools.debugger.log" preference
  60  * must be set to true as well for this to have any effect.
  61  */
  62 makePrefTrackedFlag(exports, "wantVerbose", "devtools.debugger.log.verbose");
  63
  64 /**
  65  * Setting the "devtools.testing" preference to true will toggle on certain
  66  * behaviors that can differ from the production version of the code. These
  67  * behaviors typically enable easier testing or enhanced debugging features.
  68  */
  69 makePrefTrackedFlag(exports, "testing", "devtools.testing");