Return storage promise from settings.set().

lib/lists.js

@@ -68,6 +68,7 @@
 			value = settings[type + "List"];
 		}
 		lists[type] = getDomainRegExpList(value);
+		return lists[type];
 	}
 	Object.keys(lists).forEach(function(type){
 		settings.on(type + "List", function({newValue}){
@@ -107,8 +108,10 @@
 		return lists[type];
 	};
 	scope.appendTo = function appendToList(type, entry){
-		settings[type + "List"] += (settings[type + "List"]? ",": "") + entry;
-		updateList(type);
+		var oldValue = settings[type + "List"];
+		return settings.set(type + "List", oldValue + (oldValue? ",": "") + entry).then(function(){
+			return updateList(type);
+		});
 	};
 	scope.update = updateList;
 	scope.updateAll = function updateAllLists(){

lib/settings.js

@@ -144,11 +144,13 @@
 				if (!settingDefinition.transient){
 					var storeObject = {};
 					storeObject[name] = newValue;
-					browser.storage.local.set(storeObject).then(function(){
+					var promise = browser.storage.local.set(storeObject);
+					promise.then(function(){
 						logging.verbose("New value stored for %s:", name, newValue);
 					}, function(err){
 						logging.warning("Unable to store new value for %s:", name, newValue, err);
 					});
+					return promise;
 				}
 				else {
 					logging.warning("Transient setting %s cannot be stored.", name);
@@ -171,10 +173,10 @@
 								matching = [newEntry];
 							}
 							matching[0][settingDefinition.name] = newValue;
-							urlContainer.set(urlContainerValue);
+							return urlContainer.set(urlContainerValue);
 						}
 						else {
-							storeValue(newValue);
+							return storeValue(newValue);
 						}
 					}
 					else{
@@ -186,7 +188,7 @@
 				return function setValue(newValue){
 					logging.verbose("New value for %s:", name, newValue);
 					if (isValid(newValue)){
-						storeValue(newValue);
+						return storeValue(newValue);
 					}
 					else{
 						logging.warning("Invalid value for %s:", name, newValue);