Bug 1329017 - Enable the no-useless-return rule for eslint and use es…

…lint --fix to autofix the errors. r=standard8

MozReview-Commit-ID: 2MhpvzUDgtK

browser/base/content/abouthome/aboutHome.js

@@ -292,7 +292,6 @@ function loadSnippets() {
     } catch (ex) {
       showSnippets();
       loadCompleted();
-      return;
     }
   } else {
     showSnippets();

browser/base/content/browser-data-submission-info-bar.js

@@ -104,7 +104,6 @@ var gDataNotificationInfoBar = {
           this._displayDataPolicyInfoBar(request);
         } catch (ex) {
           request.onUserNotifyFailed(ex);
-          return;
         }
         break;
 

browser/base/content/test/general/browser_bookmark_popup.js

@@ -96,7 +96,6 @@ add_task(function* panel_shown_for_once_for_doubleclick_on_new_bookmark_star_and
 add_task(function* panel_shown_once_for_slow_doubleclick_on_new_bookmark_star_and_autocloses() {
   todo(false, "bug 1250267, may need to add some tracking state to " +
               "browser-places.js for this.");
-  return;
 
   /*
   yield test_bookmarks_popup({

browser/base/content/test/general/browser_bug356571.js

@@ -62,7 +62,7 @@ var gProgressListener = {
 
 function test() {
   todo(false, "temp. disabled");
-  return; /* FIXME */
+  /* FIXME */
   /*
   waitForExplicitFinish();
   // Wait for all tabs to finish loading

browser/base/content/test/general/browser_contextmenu.js

@@ -374,7 +374,6 @@ add_task(function* test_textarea() {
   // Disabled since this is seeing spell-check-enabled
   // instead of spell-add-dictionaries-main
   todo(false, "spell checker tests are failing, bug 1246296");
-  return;
 
   /*
   yield test_contextmenu("#test-textarea",
@@ -398,7 +397,6 @@ add_task(function* test_textarea() {
 
 add_task(function* test_textarea_spellcheck() {
   todo(false, "spell checker tests are failing, bug 1246296");
-  return;
 
   /*
   yield test_contextmenu("#test-textarea",
@@ -438,7 +436,6 @@ add_task(function* test_plaintext2() {
 
 add_task(function* test_undo_add_to_dictionary() {
   todo(false, "spell checker tests are failing, bug 1246296");
-  return;
 
   /*
   yield test_contextmenu("#test-textarea",
@@ -472,7 +469,6 @@ add_task(function* test_undo_add_to_dictionary() {
 
 add_task(function* test_contenteditable() {
   todo(false, "spell checker tests are failing, bug 1246296");
-  return;
 
   /*
   yield test_contextmenu("#test-contenteditable",
@@ -726,7 +722,6 @@ add_task(function* test_imagelink() {
 
 add_task(function* test_select_input_text() {
   todo(false, "spell checker tests are failing, bug 1246296");
-  return;
 
   /*
   yield test_contextmenu("#test-select-input-text",
@@ -759,7 +754,6 @@ add_task(function* test_select_input_text() {
 
 add_task(function* test_select_input_text_password() {
   todo(false, "spell checker tests are failing, bug 1246296");
-  return;
 
   /*
   yield test_contextmenu("#test-select-input-text-type-password",
@@ -878,7 +872,6 @@ add_task(function* test_srcdoc() {
 
 add_task(function* test_input_spell_false() {
   todo(false, "spell checker tests are failing, bug 1246296");
-  return;
 
   /*
   yield test_contextmenu("#test-contenteditable-spellcheck-false",

browser/base/content/test/newtab/head.js

@@ -491,7 +491,6 @@ function whenSearchInitDone() {
             // Wait for the search controller to receive the event, then resolve.
             if (content.gSearch._contentSearchController.defaultEngine) {
               resolve();
-              return;
             }
           }
           content.setTimeout(resolver, 0);

browser/components/customizableui/CustomizableWidgets.jsm

@@ -917,7 +917,6 @@ const CustomizableWidgets = [
       if (!gotView) {
         aEvent.preventDefault();
         aEvent.stopPropagation();
-        return;
       }
     },
     onCreated(node) {

browser/components/extensions/test/browser/browser_ext_tabs_onUpdated.js

@@ -122,7 +122,6 @@ add_task(function* test_pinned() {
           // Remove created tab.
           browser.tabs.remove(tabId);
           browser.test.notifyPass("finish");
-          return;
         }
       });
       browser.tabs.update(tab.id, {pinned: true});
@@ -144,7 +143,6 @@ add_task(function* test_unpinned() {
           // Remove created tab.
           browser.tabs.remove(tabId);
           browser.test.notifyPass("finish");
-          return;
         }
       });
       browser.tabs.update(tab.id, {pinned: false});
@@ -167,7 +165,6 @@ add_task(function* test_url() {
           // Remove created tab.
           browser.tabs.remove(tabId);
           browser.test.notifyPass("finish");
-          return;
         }
       });
       browser.tabs.update(tab.id, {url: "about:blank"});

browser/components/extensions/test/browser/browser_ext_tabs_sendMessage.js

@@ -82,7 +82,7 @@ add_task(function* tabsSendMessageReply() {
           } else if (msg == "respond-promise") {
             return Promise.resolve(msg);
           } else if (msg == "respond-never") {
-            return;
+            return undefined;
           } else if (msg == "respond-error") {
             return Promise.reject(new Error(msg));
           } else if (msg == "throw-error") {

browser/components/places/content/sidebarUtils.js

@@ -42,7 +42,6 @@ var SidebarUtils = {
 
     if (aEvent.button == 0 && isContainer && !openInTabs) {
       tbo.view.toggleOpenState(cell.row);
-      return;
     } else if (!mouseInGutter && openInTabs &&
             aEvent.originalTarget.localName == "treechildren") {
       tbo.view.selection.select(cell.row);

browser/components/places/tests/browser/browser_bookmarksProperties.js

@@ -121,7 +121,6 @@ gTests.push({
             break;
           default:
             ok(false, "unknown event: " + aEvent.type);
-            return;
         }
       }
     };
@@ -223,7 +222,6 @@ gTests.push({
             break;
           default:
             ok(false, "unknown event: " + aEvent.type);
-            return;
         }
       }
     };

browser/components/preferences/blocklists.js

@@ -87,13 +87,6 @@ var gBlocklistManager = {
 
     document.title = params.windowTitle;
 
-    let treecols = document.getElementsByTagName("treecols")[0];
-    treecols.addEventListener("click", event => {
-      if (event.target.nodeName != "treecol" || event.button != 0) {
-        return;
-      }
-    });
-
     this._loadBlockLists();
   },
 

browser/components/preferences/in-content/main.js

@@ -197,7 +197,6 @@ var gMainPane = {
           return;
         case CONFIRM_RESTART_PROMPT_RESTART_LATER:
           createOrRemoveSpecialDevEditionFile();
-          return;
       }
     }
   },

browser/components/search/test/browser_426329.js

@@ -155,7 +155,6 @@ add_task(function* testAltReturn() {
 
 // Shift key has no effect for now, so skip it
 add_task(function* testShiftAltReturn() {
-  return;
   /*
   yield* prepareTest();
 

browser/components/uitour/UITour.jsm

@@ -1951,7 +1951,6 @@ this.UITour = {
       ReaderParent.showReaderModeInfoPanel(browser);
     } else {
       log.error("startSubTour: Unknown feature option specified");
-      return;
     }
   },
 
@@ -2031,7 +2030,6 @@ this.UITour = {
           }
         }
         reject("selectSearchEngine could not find engine with given ID");
-        return;
       });
     });
   },

browser/extensions/pocket/content/pocket-content-process.js

@@ -45,8 +45,6 @@ AboutPocketChildListener.prototype = {
       default:
         break;
     }
-
-    return;
   }
 };
 

browser/modules/ContentSearch.jsm

@@ -256,7 +256,6 @@ this.ContentSearch = {
     }
     win.BrowserSearch.recordSearchInTelemetry(engine, data.healthReportKey,
                                               { selection: data.selection });
-    return;
   },
 
   getSuggestions: Task.async(function* (engineName, searchString, browser) {

browser/modules/LaterRun.jsm

@@ -64,7 +64,6 @@ let LaterRun = {
     if (this.hoursSinceInstall > kSelfDestructHoursLimit ||
         this.sessionCount > kSelfDestructSessionLimit) {
       this.selfDestruct();
-      return;
     }
   },
 

toolkit/.eslintrc.js

@@ -202,6 +202,9 @@ module.exports = {
     // Disallow unnecessary .call() and .apply()
     "no-useless-call": "error",
 
+    // Disallow redundant return statements
+    "no-useless-return": "error",
+
     // No using with
     "no-with": "error",
 

toolkit/components/contextualidentity/ContextualIdentityService.jsm

@@ -241,7 +241,6 @@ _ContextualIdentityService.prototype = {
       }
     } catch (error) {
       this.loadError(error);
-      return;
     }
   },
 

toolkit/components/extensions/test/xpcshell/test_ext_runtime_sendMessage.js

@@ -13,7 +13,7 @@ add_task(function* tabsSendMessageReply() {
       } else if (msg == "respond-promise") {
         return Promise.resolve(msg);
       } else if (msg == "respond-never") {
-        return;
+        return undefined;
       } else if (msg == "respond-error") {
         return Promise.reject(new Error(msg));
       } else if (msg == "throw-error") {

toolkit/components/passwordmgr/test/test_prompt_async.html

@@ -51,11 +51,8 @@
                 if (topic === "domwindowopened") {
                     this.windowsOpen++;
                     this.windowsRegistered++;
-                    return;
-                }
-                if (topic === "domwindowclosed") {
+                } else if (topic === "domwindowclosed") {
                     this.windowsOpen--;
-                    return;
                 }
             },
 

toolkit/components/perfmonitoring/tests/browser/head.js

@@ -130,7 +130,6 @@ function AlertListener(accept, {register, unregister}) {
     }
     this.result = result;
     this.triggered = true;
-    return;
   };
   this.triggered = false;
   this.result = null;

toolkit/components/places/tests/history/test_remove.js

@@ -133,7 +133,6 @@ add_task(function* test_remove_single() {
   } finally {
     yield PlacesTestUtils.clearHistory();
   }
-  return;
 });
 
 // Test removing a list of pages

toolkit/components/satchel/test/test_form_autocomplete.html

@@ -1023,7 +1023,6 @@
     default:
         ok(false, "Unexpected invocation of test #" + testNum);
         SimpleTest.finish();
-        return;
   }
 }
 

toolkit/components/satchel/test/test_form_autocomplete_with_list.html

@@ -479,7 +479,6 @@
     default:
       ok(false, "Unexpected invocation of test #" + testNum);
       SimpleTest.finish();
-      return;
     }
 }
 

toolkit/components/viewsource/content/viewSourceUtils.js

@@ -335,7 +335,6 @@ var gViewSourceUtils = {
       // we failed loading it with the external editor.
       Components.utils.reportError(ex);
       this.handleCallBack(aCallBack, false, data);
-      return;
     }
   },
 

toolkit/components/workerloader/tests/utils_mainthread.js

@@ -28,7 +28,6 @@ function worker_handler(worker) {
       return;
     default:
       SimpleTest.ok(false, "test_osfile.xul: wrong message " + JSON.stringify(msg.data));
-      return;
     }
   };
 }

toolkit/components/workerloader/tests/worker_handler.js

@@ -28,7 +28,6 @@ function worker_handler(worker) {
       return;
     default:
       SimpleTest.ok(false, "test_osfile.xul: wrong message " + JSON.stringify(msg.data));
-      return;
     }
   };
 }

toolkit/content/tests/widgets/popup_shared.js

@@ -63,7 +63,6 @@ function finish() {
     return;
   }
   SimpleTest.finish();
-  return;
 }
 
 function ok(condition, message) {

toolkit/identity/Identity.jsm

@@ -199,7 +199,6 @@ IDService.prototype = {
             }
             self.RP._doLogin(rp, rpLoginOptions, assertion);
             self.RP._cleanUpProvisionFlow(aRPId, aProvId);
-            return;
           });
         });
       });

toolkit/mozapps/extensions/LightweightThemeManager.jsm

@@ -885,7 +885,6 @@ function _persistProgressListener(successCallback) {
         if (aRequest.QueryInterface(Ci.nsIHttpChannel).requestSucceeded) {
           // success
           successCallback();
-          return;
         }
       } catch (e) { }
       // failure

toolkit/mozapps/extensions/content/extensions.js

@@ -2061,7 +2061,6 @@ var gHeader = {
   onKeyPress(aEvent) {
     if (String.fromCharCode(aEvent.charCode) == "/") {
       this.focusSearchBox();
-      return;
     }
   },
 

toolkit/mozapps/extensions/internal/XPIProvider.jsm

@@ -1941,7 +1941,6 @@ function removeAsync(aFile) {
       if (!(e instanceof OS.File.Error) || !e.becauseNoSuchFile)
         throw e;
       // The file has already gone away
-      return;
     }
   });
 }

toolkit/mozapps/extensions/nsBlocklistService.js

@@ -936,7 +936,6 @@ Blocklist.prototype = {
       }
     } catch (e) {
       LOG("Blocklist::_loadBlocklistFromFile: Error constructing blocklist " + e);
-      return;
     }
   },
 

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

@@ -354,7 +354,7 @@ add_task(function* canUndoUninstallDisabled() {
 // Tests that uninstalling an enabled lightweight theme offers the option to undo
 add_task(function* uninstallLWTOffersUndo() {
   // skipped since lightweight themes don't support undoable uninstall yet
-  return;
+
   /*
   LightweightThemeManager.currentTheme = dummyLWTheme("theme1");
 

toolkit/mozapps/preferences/changemp.js

@@ -196,8 +196,6 @@ function setPasswordStrength() {
 
   var mymeter = document.getElementById('pwmeter');
   mymeter.value = pwstrength;
-
-  return;
 }
 
 function checkPasswords() {