Separated settings migration

For #166

lib/settingsMigration.js

@@ -0,0 +1,133 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+(function(){
+	"use strict";
+	
+	var scope;
+	if ((typeof exports) !== "undefined"){
+		scope = exports;
+	}
+	else {
+		window.scope.settingsMigration = {};
+		scope = window.scope.settingsMigration;
+	}
+	scope.validVersions = [undefined, 0.1, 0.2, 0.3, 0.4];
+	scope.transitions = {
+		"": function(oldStorage){
+			return {
+				storageVersion: 0.2
+			};
+		},
+		0.1: function(oldStorage){
+			var newStorage = {
+				storageVersion: 0.2
+			};
+			if (oldStorage.hasOwnProperty("askOnlyOnce")){
+				newStorage.askOnlyOnce = oldStorage.askOnlyOnce? "individual": "no";
+			}
+			return newStorage;
+		},
+		0.2: function(oldStorage){
+			var newStorage = {
+				storageVersion: 0.3,
+				urlSettings: (
+					oldStorage.urlSettings &&
+						Array.isArray(oldStorage.urlSettings)
+				)? oldStorage.urlSettings: []
+			};
+
+			var urlSettings = {};
+
+			(oldStorage.blackList || "").split(",")
+				.map(function(url){return url.trim();})
+				.filter(function(url){return !!url;})
+				.forEach(function(url){
+					var entry = urlSettings[url];
+					if (!entry){
+						entry = {url, blockMode: "block"};
+						urlSettings[url] = entry;
+						newStorage.urlSettings.push(entry);
+					}
+				});
+			(oldStorage.whiteList || "").split(",")
+				.map(function(url){return url.trim();})
+				.filter(function(url){return !!url;})
+				.forEach(function(url){
+					var entry = urlSettings[url];
+					if (!entry){
+						entry = {url, blockMode: "allow"};
+						urlSettings[url] = entry;
+						newStorage.urlSettings.push(entry);
+					}
+				});
+			(oldStorage.ignoreList || "").split(",")
+				.map(function(url){return url.trim();})
+				.filter(function(url){return !!url;})
+				.forEach(function(url){
+					var entry = urlSettings[url];
+					if (!entry){
+						entry = {url, showNotifications: false};
+						urlSettings[url] = entry;
+						newStorage.urlSettings.push(entry);
+					}
+					else {
+						entry.showNotifications = false;
+					}
+				});
+			["whiteList", "blackList", "ignoreList"].forEach(function(list){
+				if (oldStorage.hasOwnProperty(list)){
+					newStorage[list] = "";
+				}
+			});
+
+			return newStorage;
+		},
+		0.3: function(oldStorage){
+			var newStorage = {
+				storageVersion: 0.4
+			};
+			if (oldStorage.hasOwnProperty("apiWhiteList")){
+				const protectedAPIFeatures = {};
+				Object.keys(oldStorage.apiWhiteList).forEach(function(key){
+					protectedAPIFeatures[key] = !oldStorage.apiWhiteList[key];
+				});
+				newStorage.protectedAPIFeatures = protectedAPIFeatures;
+			}
+			return newStorage;
+		},
+	};
+	
+	scope.check = function(storage, {settings, logging, changeValue, urlContainer}){
+		
+		if (!storage.storageVersion){
+			logging.message("No storage version found. Initializing storage.");
+			browser.storage.local.remove(Object.keys(storage));
+			storage = scope.transitions[""]({});
+			browser.storage.local.set(storage);
+		}
+		else if (storage.storageVersion !== settings.storageVersion){
+			var toChange = {};
+			while (storage.storageVersion !== settings.storageVersion){
+				logging.message("Old storage found (",
+					storage.storageVersion, "expected", settings.storageVersion,
+					")");
+				if (scope.transitions[storage.storageVersion]){
+					var changes = scope.transitions[storage.storageVersion](storage);
+					Object.entries(changes).forEach(function(entry){
+						const [name, value] = entry;
+						toChange[name] = value;
+						storage[name] = value;
+					});
+				}
+				else {
+					logging.warning("Unable to migrate storage.");
+					break;
+				}
+			}
+			logging.notice("Changed settings:", toChange);
+			browser.storage.local.set(toChange);
+		}
+	};
+}());