Bug 1687235 - Enable ESLint rule no-setter-return for toolkit and services. r=mossop

Differential Revision: https://phabricator.services.mozilla.com/D102153

.eslintrc.js

@@ -669,27 +669,6 @@ module.exports = {
         "dom/media/PeerConnection.jsm",
         "mobile/android/chrome/geckoview/SessionStateAggregator.js",
         "mobile/android/modules/geckoview/DelayedInit.jsm",
-        "services/sync/modules/record.js",
-        "toolkit/actors/AutoCompleteChild.jsm",
-        "toolkit/components/autocomplete/tests/unit/test_stopSearch.js",
-        "toolkit/components/enterprisepolicies/EnterprisePoliciesParent.jsm",
-        "toolkit/components/extensions/ExtensionParent.jsm",
-        "toolkit/components/osfile/modules/osfile_async_front.jsm",
-        "toolkit/components/osfile/modules/osfile_shared_allthreads.jsm",
-        "toolkit/content/aboutSupport.js",
-        "toolkit/content/customElements.js",
-        "toolkit/content/preferencesBindings.js",
-        "toolkit/content/tests/chrome/test_custom_element_base.xhtml",
-        "toolkit/content/viewZoomOverlay.js",
-        "toolkit/content/widgets/*.js",
-        "toolkit/modules/NewTabUtils.jsm",
-        "toolkit/modules/tests/modules/Task.jsm",
-        "toolkit/mozapps/extensions/AddonManager.jsm",
-        "toolkit/mozapps/extensions/internal/PluginProvider.jsm",
-        "toolkit/mozapps/extensions/internal/XPIDatabase.jsm",
-        "toolkit/mozapps/extensions/test/browser/head.js",
-        "toolkit/mozapps/extensions/test/xpcshell/head_addons.js",
-        "toolkit/mozapps/handling/content/dialog.js",
       ],
       rules: {
         "no-setter-return": "off",

services/sync/modules/record.js

@@ -350,7 +350,7 @@ CryptoWrapper.prototype = {
   // Keep both plaintext and encrypted versions of the id to verify integrity
   set id(val) {
     super.id = val;
-    return (this.cleartext.id = val);
+    this.cleartext.id = val;
   },
 };
 

toolkit/components/autocomplete/tests/unit/test_stopSearch.js

@@ -25,9 +25,7 @@ AutoCompleteInput.prototype = {
   textValue: "hello",
   disableAutoComplete: false,
   completeDefaultIndex: false,
-  set popupOpen(val) {
-    return val;
-  }, // ignore
+  set popupOpen(val) {}, // ignore
   get popupOpen() {
     return false;
   },
@@ -44,9 +42,7 @@ AutoCompleteInput.prototype = {
   popup: {
     selectBy() {},
     invalidate() {},
-    set selectedIndex(val) {
-      return val;
-    }, // ignore
+    set selectedIndex(val) {}, // ignore
     get selectedIndex() {
       return -1;
     },

toolkit/components/enterprisepolicies/EnterprisePoliciesParent.jsm

@@ -339,7 +339,6 @@ EnterprisePoliciesManager.prototype = {
     if (val != Ci.nsIEnterprisePolicies.INACTIVE) {
       Services.ppmm.sharedData.set("EnterprisePolicies:Status", val);
     }
-    return val;
   },
 
   get status() {

toolkit/components/extensions/ExtensionParent.jsm

@@ -640,8 +640,6 @@ class DevToolsExtensionPageContextParent extends ExtensionPageContextParent {
     }
 
     this._devToolsToolbox = toolbox;
-
-    return toolbox;
   }
 
   get devToolsToolbox() {

toolkit/components/osfile/modules/osfile_async_front.jsm

@@ -1584,7 +1584,7 @@ OS.Shared = {
     return SharedAll.Config.DEBUG;
   },
   set DEBUG(x) {
-    return (SharedAll.Config.DEBUG = x);
+    SharedAll.Config.DEBUG = x;
   },
 };
 Object.freeze(OS.Shared);

toolkit/components/osfile/modules/osfile_shared_allthreads.jsm

@@ -1346,7 +1346,7 @@ Object.defineProperty(exports.OS.Shared, "DEBUG", {
     return Config.DEBUG;
   },
   set(x) {
-    return (Config.DEBUG = x);
+    Config.DEBUG = x;
   },
 });
 Object.defineProperty(exports.OS.Shared, "TEST", {
@@ -1354,7 +1354,7 @@ Object.defineProperty(exports.OS.Shared, "TEST", {
     return Config.TEST;
   },
   set(x) {
-    return (Config.TEST = x);
+    Config.TEST = x;
   },
 });
 

toolkit/content/aboutSupport.js

@@ -1558,7 +1558,7 @@ Serializer.prototype = {
   },
 
   set _currentLine(val) {
-    return (this._lines[this._lines.length - 1] = val);
+    this._lines[this._lines.length - 1] = val;
   },
 
   _serializeElement(elem) {

toolkit/content/customElements.js

@@ -742,7 +742,6 @@
     class BaseText extends MozElements.BaseControlMixin(Base) {
       set label(val) {
         this.setAttribute("label", val);
-        return val;
       }
 
       get label() {
@@ -751,7 +750,6 @@
 
       set crop(val) {
         this.setAttribute("crop", val);
-        return val;
       }
 
       get crop() {
@@ -760,7 +758,6 @@
 
       set image(val) {
         this.setAttribute("image", val);
-        return val;
       }
 
       get image() {
@@ -769,7 +766,6 @@
 
       set command(val) {
         this.setAttribute("command", val);
-        return val;
       }
 
       get command() {
@@ -784,7 +780,6 @@
         if (this.labelElement) {
           this.labelElement.accessKey = val;
         }
-        return val;
       }
 
       get accessKey() {

toolkit/content/preferencesBindings.js

@@ -522,7 +522,6 @@ const Preferences = (window.Preferences = (function() {
         }
         this.emit("change");
       }
-      return val;
     }
 
     get locked() {
@@ -603,13 +602,13 @@ const Preferences = (window.Preferences = (function() {
     set valueFromPreferences(val) {
       // Exit early if nothing to do.
       if (this.readonly || this.valueFromPreferences == val) {
-        return val;
+        return;
       }
 
       // The special value undefined means 'reset preference to default'.
       if (val === undefined) {
         Services.prefs.clearUserPref(this.id);
-        return val;
+        return;
       }
 
       // Force a resync of preferences with value.
@@ -657,7 +656,6 @@ const Preferences = (window.Preferences = (function() {
       if (!this.batching) {
         Services.prefs.savePrefFile(null);
       }
-      return val;
     }
   }
 

toolkit/content/tests/chrome/test_custom_element_base.xhtml

@@ -288,7 +288,6 @@
       set disabled(val) {
         if (val) this.setAttribute("disabled", "true");
         else this.removeAttribute("disabled");
-        return val;
       }
 
       get tabIndex() {
@@ -298,7 +297,6 @@
       set tabIndex(val) {
         if (val) this.setAttribute("tabIndex", val);
         else this.removeAttribute("tabIndex");
-        return val;
       }
     }
 
@@ -363,4 +361,3 @@
   ]]>
   </script>
 </window>
-

toolkit/content/viewZoomOverlay.js

@@ -29,7 +29,6 @@ var ZoomManager = {
 
   set useFullZoom(aVal) {
     Services.prefs.setBoolPref("browser.zoom.full", aVal);
-    return aVal;
   },
 
   get zoom() {
@@ -57,7 +56,6 @@ var ZoomManager = {
 
   set zoom(aVal) {
     this.setZoomForBrowser(gBrowser, aVal);
-    return aVal;
   },
 
   setZoomForBrowser: function ZoomManager_setZoomForBrowser(aBrowser, aVal) {

toolkit/content/widgets/arrowscrollbox.js

@@ -188,7 +188,6 @@
 
     set smoothScroll(val) {
       this.setAttribute("smoothscroll", !!val);
-      return val;
     }
 
     get smoothScroll() {

toolkit/content/widgets/autocomplete-input.js

@@ -178,7 +178,6 @@
 
     set disableAutoComplete(val) {
       this.setAttribute("disableautocomplete", val);
-      return val;
     }
 
     get disableAutoComplete() {
@@ -187,7 +186,6 @@
 
     set completeDefaultIndex(val) {
       this.setAttribute("completedefaultindex", val);
-      return val;
     }
 
     get completeDefaultIndex() {
@@ -196,7 +194,6 @@
 
     set completeSelectedIndex(val) {
       this.setAttribute("completeselectedindex", val);
-      return val;
     }
 
     get completeSelectedIndex() {
@@ -205,7 +202,6 @@
 
     set forceComplete(val) {
       this.setAttribute("forcecomplete", val);
-      return val;
     }
 
     get forceComplete() {
@@ -214,7 +210,6 @@
 
     set minResultsForPopup(val) {
       this.setAttribute("minresultsforpopup", val);
-      return val;
     }
 
     get minResultsForPopup() {
@@ -224,7 +219,6 @@
 
     set timeout(val) {
       this.setAttribute("timeout", val);
-      return val;
     }
 
     get timeout() {
@@ -234,7 +228,6 @@
 
     set searchParam(val) {
       this.setAttribute("autocompletesearchparam", val);
-      return val;
     }
 
     get searchParam() {
@@ -258,8 +251,6 @@
       // "input" event is automatically dispatched by the editor if
       // necessary.
       this._setValueInternal(val, true);
-
-      return this.value;
     }
 
     get textValue() {
@@ -272,9 +263,7 @@
       return true;
     }
 
-    set crop(val) {
-      return false;
-    }
+    set crop(val) {}
 
     get crop() {
       return false;
@@ -293,7 +282,7 @@
     }
 
     set value(val) {
-      return this._setValueInternal(val, false);
+      this._setValueInternal(val, false);
     }
 
     get value() {
@@ -309,7 +298,6 @@
      */
     set maxRows(val) {
       this.setAttribute("maxrows", val);
-      return val;
     }
 
     get maxRows() {
@@ -321,7 +309,6 @@
      */
     set maxdropmarkerrows(val) {
       this.setAttribute("maxdropmarkerrows", val);
-      return val;
     }
 
     get maxdropmarkerrows() {
@@ -333,7 +320,6 @@
      */
     set tabScrolling(val) {
       this.setAttribute("tabscrolling", val);
-      return val;
     }
 
     get tabScrolling() {
@@ -345,7 +331,6 @@
      */
     set ignoreBlurWhileSearching(val) {
       this.setAttribute("ignoreblurwhilesearching", val);
-      return val;
     }
 
     get ignoreBlurWhileSearching() {
@@ -356,7 +341,6 @@
      */
     set highlightNonMatches(val) {
       this.setAttribute("highlightnonmatches", val);
-      return val;
     }
 
     get highlightNonMatches() {

toolkit/content/widgets/autocomplete-popup.js

@@ -159,7 +159,6 @@
           this.richlistbox.selectedItem || this.richlistbox.firstElementChild
         );
       }
-      return val;
     }
 
     get selectedIndex() {
@@ -185,9 +184,7 @@
       return Number(this.getAttribute("overflowpadding"));
     }
 
-    set view(val) {
-      return val;
-    }
+    set view(val) {}
 
     get view() {
       return this.mInput.controller;

toolkit/content/widgets/button.js

@@ -115,7 +115,6 @@
 
     set type(val) {
       this.setAttribute("type", val);
-      return val;
     }
 
     get type() {
@@ -128,7 +127,6 @@
       } else {
         this.removeAttribute("disabled");
       }
-      return val;
     }
 
     get disabled() {
@@ -137,7 +135,6 @@
 
     set group(val) {
       this.setAttribute("group", val);
-      return val;
     }
 
     get group() {
@@ -153,7 +150,6 @@
       } else {
         this.removeAttribute("open");
       }
-      return val;
     }
 
     get open() {
@@ -173,8 +169,6 @@
       } else {
         this.removeAttribute("checked");
       }
-
-      return val;
     }
 
     get checked() {

toolkit/content/widgets/checkbox.js

@@ -70,7 +70,6 @@
         event.initEvent("CheckboxStateChange", true, true);
         this.dispatchEvent(event);
       }
-      return val;
     }
 
     get checked() {

toolkit/content/widgets/dialog.js

@@ -168,7 +168,6 @@
 
     set buttons(val) {
       this._configureButtons(val);
-      return val;
     }
 
     get buttons() {
@@ -177,7 +176,6 @@
 
     set defaultButton(val) {
       this._setDefaultButton(val);
-      return val;
     }
 
     get defaultButton() {

toolkit/content/widgets/findbar.js

@@ -278,7 +278,6 @@
     set findMode(val) {
       this._findMode = val;
       this._updateBrowserWithState();
-      return val;
     }
 
     get findMode() {
@@ -287,7 +286,6 @@
 
     set prefillWithSelection(val) {
       this.setAttribute("prefillwithselection", val);
-      return val;
     }
 
     get prefillWithSelection() {
@@ -340,7 +338,6 @@
 
         this._browser.finder.addResultListener(this);
       }
-      return val;
     }
 
     get browser() {

toolkit/content/widgets/general.js

@@ -10,13 +10,12 @@
   class MozDeck extends MozXULElement {
     set selectedIndex(val) {
       if (this.selectedIndex == val) {
-        return val;
+        return;
       }
       this.setAttribute("selectedIndex", val);
       var event = document.createEvent("Events");
       event.initEvent("select", true, true);
       this.dispatchEvent(event);
-      return val;
     }
 
     get selectedIndex() {
@@ -33,7 +32,6 @@
         ++selectedIndex;
       }
       this.selectedIndex = selectedIndex;
-      return val;
     }
 
     get selectedPanel() {

toolkit/content/widgets/menu.js

@@ -60,7 +60,6 @@
     class MozMenuBase extends MozMenuItemBaseMixin(Base) {
       set open(val) {
         this.openMenu(val);
-        return val;
       }
 
       get open() {

toolkit/content/widgets/menulist.js

@@ -115,7 +115,8 @@
     set value(val) {
       // if the new value is null, we still need to remove the old value
       if (val == null) {
-        return (this.selectedItem = val);
+        this.selectedItem = val;
+        return;
       }
 
       var arr = null;
@@ -130,8 +131,6 @@
         this.selectedItem = null;
         this.setAttribute("value", val);
       }
-
-      return val;
     }
 
     // nsIDOMXULSelectControlElement
@@ -152,7 +151,6 @@
     // nsIDOMXULMenuListElement
     set image(val) {
       this.setAttribute("image", val);
-      return val;
     }
 
     // nsIDOMXULMenuListElement
@@ -167,7 +165,6 @@
 
     set description(val) {
       this.setAttribute("description", val);
-      return val;
     }
 
     get description() {
@@ -177,7 +174,6 @@
     // nsIDOMXULMenuListElement
     set open(val) {
       this.openMenu(val);
-      return val;
     }
 
     // nsIDOMXULMenuListElement
@@ -208,7 +204,6 @@
       } else {
         this.selectedItem = null;
       }
-      return val;
     }
 
     // nsIDOMXULSelectControlElement
@@ -237,11 +232,11 @@
     set selectedItem(val) {
       var oldval = this.mSelectedInternal;
       if (oldval == val) {
-        return val;
+        return;
       }
 
       if (val && !this.contains(val)) {
-        return val;
+        return;
       }
 
       if (oldval) {
@@ -278,8 +273,6 @@
       event = document.createEvent("Events");
       event.initEvent("ValueChange", true, true);
       this.dispatchEvent(event);
-
-      return val;
     }
 
     // nsIDOMXULSelectControlElement

toolkit/content/widgets/panel.js

@@ -81,7 +81,7 @@
       if (!v) {
         this.initialize();
       }
-      return (super.hidden = v);
+      super.hidden = v;
     }
 
     removeAttribute(name) {

toolkit/content/widgets/radio.js

@@ -211,7 +211,6 @@
           break;
         }
       }
-      return val;
     }
 
     get value() {
@@ -228,7 +227,6 @@
       for (var i = 0; i < children.length; ++i) {
         children[i].disabled = val;
       }
-      return val;
     }
 
     get disabled() {
@@ -254,7 +252,6 @@
 
     set selectedIndex(val) {
       this.selectedItem = this._getRadioChildren()[val];
-      return val;
     }
 
     get selectedIndex() {
@@ -320,8 +317,6 @@
           }
         }
       }
-
-      return val;
     }
 
     get selectedItem() {
@@ -350,7 +345,6 @@
           children[i].removeAttribute("focused");
         }
       }
-      return val;
     }
 
     get focusedItem() {

toolkit/content/widgets/richlistbox.js

@@ -209,7 +209,6 @@
       if (kids && kids.item(0)) {
         this.selectItem(kids[0]);
       }
-      return val;
     }
     get value() {
       if (this.selectedItems.length) {
@@ -226,7 +225,6 @@
     // nsIDOMXULSelectControlElement
     set selType(val) {
       this.setAttribute("seltype", val);
-      return val;
     }
     get selType() {
       return this.getAttribute("seltype");
@@ -235,7 +233,7 @@
     // nsIDOMXULSelectControlElement
     set currentItem(val) {
       if (this._currentItem == val) {
-        return val;
+        return;
       }
 
       if (this._currentItem) {
@@ -255,8 +253,6 @@
           this._fireEvent(val, "DOMMenuItemActive");
         }
       }
-
-      return val;
     }
     get currentItem() {
       return this._currentItem;
@@ -951,7 +947,6 @@
       else {
         this.removeAttribute("searchlabel");
       }
-      return val;
     }
 
     get searchLabel() {
@@ -964,7 +959,6 @@
      */
     set value(val) {
       this.setAttribute("value", val);
-      return val;
     }
 
     get value() {
@@ -980,8 +974,6 @@
       } else {
         this.removeAttribute("selected");
       }
-
-      return val;
     }
 
     get selected() {
@@ -1007,7 +999,6 @@
       } else {
         this.removeAttribute("current");
       }
-      return val;
     }
 
     get current() {

toolkit/content/widgets/search-textbox.js

@@ -39,7 +39,7 @@
             return this.inputField[property];
           },
           set(val) {
-            return (this.inputField[property] = val);
+            this.inputField[property] = val;
           },
         });
       }
@@ -118,7 +118,6 @@
 
     set timeout(val) {
       this.setAttribute("timeout", val);
-      return val;
     }
 
     get timeout() {
@@ -135,7 +134,6 @@
         this.setAttribute("aria-autocomplete", "list");
         this._searchButtonIcon.setAttribute("role", "none");
       }
-      return val;
     }
 
     get searchButton() {
@@ -154,7 +152,6 @@
       if (this._timer) {
         clearTimeout(this._timer);
       }
-      return val;
     }
 
     get value() {
@@ -172,7 +169,6 @@
       } else {
         this.removeAttribute("disabled");
       }
-      return val;
     }
 
     get disabled() {

toolkit/content/widgets/stringbundle.js

@@ -27,7 +27,6 @@
     set src(val) {
       this._bundle = null;
       this.setAttribute("src", val);
-      return val;
     }
 
     get src() {

toolkit/content/widgets/tabbox.js

@@ -42,7 +42,6 @@
 
     set handleCtrlTab(val) {
       this.setAttribute("handleCtrlTab", val);
-      return val;
     }
 
     get handleCtrlTab() {
@@ -72,7 +71,6 @@
         tabs.selectedIndex = val;
       }
       this.setAttribute("selectedIndex", val);
-      return val;
     }
 
     get selectedIndex() {
@@ -87,7 +85,6 @@
           tabs.selectedItem = val;
         }
       }
-      return val;
     }
 
     get selectedTab() {
@@ -102,7 +99,6 @@
           tabpanels.selectedPanel = val;
         }
       }
-      return val;
     }
 
     get selectedPanel() {
@@ -185,7 +181,7 @@
 
     set selectedIndex(val) {
       if (val < 0 || val >= this.children.length) {
-        return val;
+        return;
       }
 
       let panel = this._selectedPanel;
@@ -200,7 +196,6 @@
         event.initEvent("select", true, true);
         this.dispatchEvent(event);
       }
-      return val;
     }
 
     get selectedIndex() {
@@ -218,7 +213,6 @@
         ++selectedIndex;
       }
       this.selectedIndex = selectedIndex;
-      return val;
     }
 
     get selectedPanel() {
@@ -404,7 +398,6 @@
 
     set value(val) {
       this.setAttribute("value", val);
-      return val;
     }
 
     get value() {
@@ -428,8 +421,6 @@
         this.removeAttribute("selected");
         this.removeAttribute("visuallyselected");
       }
-
-      return val;
     }
 
     set linkedPanel(val) {
@@ -511,7 +502,6 @@
           break;
         }
       }
-      return val;
     }
 
     get value() {
@@ -549,7 +539,6 @@
           this.tabbox.tabpanels.selectedPanel = linkedPanel;
         }
       }
-      return val;
     }
 
     get selectedIndex() {
@@ -568,7 +557,6 @@
         // such as -1 if |val| isn't one of our child nodes.
         this.selectedIndex = this.getIndexOfItem(val);
       }
-      return val;
     }
 
     get selectedItem() {
@@ -614,8 +602,6 @@
         let evt = new CustomEvent("AriaFocus");
         val.dispatchEvent(evt);
       }
-
-      return val;
     }
 
     get ariaFocusedItem() {

toolkit/content/widgets/text.js

@@ -300,7 +300,6 @@
 
     set href(val) {
       this.setAttribute("href", val);
-      return val;
     }
 
     get href() {

toolkit/content/widgets/tree.js

@@ -385,7 +385,6 @@
     set ordinal(val) {
       this.style.MozBoxOrdinalGroup = val;
       this.setAttribute("ordinal", val);
-      return val;
     }
 
     get ordinal() {
@@ -1040,7 +1039,6 @@
       } else {
         this.removeAttribute("editable");
       }
-      return val;
     }
 
     get editable() {
@@ -1051,7 +1049,6 @@
      */
     set selType(val) {
       this.setAttribute("seltype", val);
-      return val;
     }
 
     get selType() {
@@ -1060,9 +1057,8 @@
 
     set currentIndex(val) {
       if (this.view) {
-        return (this.view.selection.currentIndex = val);
+        this.view.selection.currentIndex = val;
       }
-      return val;
     }
 
     get currentIndex() {
@@ -1078,7 +1074,6 @@
       } else {
         this.removeAttribute("keepcurrentinview");
       }
-      return val;
     }
 
     get keepCurrentInView() {
@@ -1091,7 +1086,6 @@
       } else {
         this.removeAttribute("enableColumnDrag");
       }
-      return val;
     }
 
     get enableColumnDrag() {
@@ -1112,7 +1106,6 @@
       } else {
         this.removeAttribute("disableKeyNavigation");
       }
-      return val;
     }
 
     get disableKeyNavigation() {

toolkit/content/widgets/wizard.js

@@ -145,7 +145,7 @@
     }
 
     set title(val) {
-      return (document.title = val);
+      document.title = val;
     }
 
     get title() {
@@ -154,7 +154,7 @@
 
     set canAdvance(val) {
       this.getButton("next").disabled = !val;
-      return (this._canAdvance = val);
+      this._canAdvance = val;
     }
 
     get canAdvance() {
@@ -163,7 +163,7 @@
 
     set canRewind(val) {
       this.getButton("back").disabled = !val;
-      return (this._canRewind = val);
+      this._canRewind = val;
     }
 
     get canRewind() {
@@ -180,7 +180,7 @@
 
     set currentPage(val) {
       if (!val) {
-        return val;
+        return;
       }
 
       this._currentPage = val;
@@ -195,8 +195,6 @@
       this._advanceFocusToPage(val);
 
       this._fireEvent(val, "pageshow");
-
-      return val;
     }
 
     get currentPage() {
@@ -205,14 +203,12 @@
 
     set pageIndex(val) {
       if (val < 0 || val >= this.pageCount) {
-        return val;
+        return;
       }
 
       var page = this.wizardPages[val];
       this._pageStack[this._pageStack.length - 1] = page;
       this.currentPage = page;
-
-      return val;
     }
 
     get pageIndex() {
@@ -512,7 +508,6 @@
     set next(val) {
       this.setAttribute("next", val);
       this.parentNode._accessMethod = "random";
-      return val;
     }
   }
 

toolkit/modules/NewTabUtils.jsm

@@ -193,7 +193,6 @@ LinksStorage.prototype = {
   set _storedVersion(aValue) {
     Services.prefs.setIntPref("browser.newtabpage.storageVersion", aValue);
     this.__storedVersion = aValue;
-    return aValue;
   },
 
   /**

toolkit/modules/tests/modules/Task.jsm

@@ -491,7 +491,7 @@ Task.Debugging = {
     if (!x) {
       gCurrentTask = null;
     }
-    return (gMaintainStack = x);
+    gMaintainStack = x;
   },
 
   /**

toolkit/mozapps/extensions/AddonManager.jsm

@@ -3051,7 +3051,6 @@ var AddonManagerInternal = {
     if (aValue != gAutoUpdateDefault) {
       Services.prefs.setBoolPref(PREF_EM_AUTOUPDATE_DEFAULT, aValue);
     }
-    return aValue;
   },
 
   get checkCompatibility() {
@@ -3067,7 +3066,6 @@ var AddonManagerInternal = {
         Services.prefs.clearUserPref(PREF_EM_CHECK_COMPATIBILITY);
       }
     }
-    return aValue;
   },
 
   get strictCompatibility() {
@@ -3079,7 +3077,6 @@ var AddonManagerInternal = {
     if (aValue != gStrictCompatibility) {
       Services.prefs.setBoolPref(PREF_EM_STRICT_COMPATIBILITY, aValue);
     }
-    return aValue;
   },
 
   get checkUpdateSecurityDefault() {
@@ -3099,7 +3096,6 @@ var AddonManagerInternal = {
         Services.prefs.clearUserPref(PREF_EM_CHECK_UPDATE_SECURITY);
       }
     }
-    return aValue;
   },
 
   get updateEnabled() {
@@ -3111,7 +3107,6 @@ var AddonManagerInternal = {
     if (aValue != gUpdateEnabled) {
       Services.prefs.setBoolPref(PREF_EM_UPDATE_ENABLED, aValue);
     }
-    return aValue;
   },
 
   _verifyThirdPartyInstall(browser, url, install, info, source) {

toolkit/mozapps/extensions/internal/PluginProvider.jsm

@@ -323,7 +323,7 @@ PluginWrapper.prototype = {
     }
 
     if (val === previousVal) {
-      return val;
+      return;
     }
 
     let { tags } = pluginFor(this);
@@ -362,8 +362,6 @@ PluginWrapper.prototype = {
         "userDisabled",
       ]);
     }
-
-    return val;
   },
 
   async enable() {

toolkit/mozapps/extensions/internal/XPIDatabase.jsm

@@ -984,7 +984,7 @@ AddonWrapper = class {
     }
 
     if (val == addon.applyBackgroundUpdates) {
-      return val;
+      return;
     }
 
     XPIDatabase.setAddonProperties(addon, {
@@ -993,14 +993,12 @@ AddonWrapper = class {
     AddonManagerPrivate.callAddonListeners("onPropertyChanged", this, [
       "applyBackgroundUpdates",
     ]);
-
-    return val;
   }
 
   set syncGUID(val) {
     let addon = addonFor(this);
     if (addon.syncGUID == val) {
-      return val;
+      return;
     }
 
     if (addon.inDatabase) {
@@ -1008,8 +1006,6 @@ AddonWrapper = class {
     }
 
     addon.syncGUID = val;
-
-    return val;
   }
 
   get install() {

toolkit/mozapps/extensions/test/browser/head.js

@@ -1131,7 +1131,7 @@ MockAddon.prototype = {
 
   set appDisabled(val) {
     if (val == this._appDisabled) {
-      return val;
+      return;
     }
 
     AddonManagerPrivate.callAddonListeners("onPropertyChanged", this, [
@@ -1142,8 +1142,6 @@ MockAddon.prototype = {
     this._appDisabled = val;
     var newActive = this.shouldBeActive;
     this._updateActiveState(currentActive, newActive);
-
-    return val;
   },
 
   get userDisabled() {
@@ -1188,7 +1186,7 @@ MockAddon.prototype = {
   },
 
   set permissions(val) {
-    return (this._permissions = val);
+    this._permissions = val;
   },
 
   get applyBackgroundUpdates() {

toolkit/mozapps/extensions/test/xpcshell/head_addons.js

@@ -195,7 +195,7 @@ Object.defineProperty(this, "gUseRealCertChecks", {
     return AddonTestUtils.useRealCertChecks;
   },
   set(val) {
-    return (AddonTestUtils.useRealCertChecks = val);
+    AddonTestUtils.useRealCertChecks = val;
   },
 });
 
@@ -204,7 +204,7 @@ Object.defineProperty(this, "TEST_UNPACKED", {
     return AddonTestUtils.testUnpacked;
   },
   set(val) {
-    return (AddonTestUtils.testUnpacked = val);
+    AddonTestUtils.testUnpacked = val;
   },
 });