fix #339 by normalizing localStorage and browser.storage.local usage

src/browser.js

@@ -10,10 +10,42 @@ exports.formatArgs = formatArgs;
 exports.save = save;
 exports.load = load;
 exports.useColors = useColors;
-exports.storage = 'undefined' != typeof chrome
-               && 'undefined' != typeof chrome.storage
-                  ? chrome.storage.local
-                  : localstorage();
+exports.storage = (function() {
+  var browser = window.browser || window.chrome;
+
+  if (typeof browser !== 'undefined' &&
+      typeof browser.storage !== 'undefined' &&
+      typeof browser.storage.local !== 'undefined') {
+    if (browser.storage.local.get.length === 2) {
+      // Chrome/Opera/Edge use the callback pattern
+      return browser.storage.local;
+    } else if (browser.storage.local.get.length === 1) {
+      // Firefox uses the Promise pattern
+      return {
+        get: function(key, cb) {
+          browser.storage.local.get(key).then(cb);
+        },
+        set: browser.storage.local.set,
+        remove: browser.storage.local.remove
+      };
+    }
+  }
+
+  if (window.localStorage) {
+    return {
+      get: function(key, cb) {
+        var value = window.localStorage.getItem(key);
+        cb(value);
+      },
+      set: function(key, value) {
+        window.localStorage.setItem(key, value);
+      },
+      remove: function(key) {
+        window.localStorage.removeItem(key);
+      }
+    };
+  }
+})();
 
 /**
  * Colors.
@@ -131,13 +163,11 @@ function log() {
  */
 
 function save(namespaces) {
-  try {
-    if (null == namespaces) {
-      exports.storage.removeItem('debug');
-    } else {
-      exports.storage.debug = namespaces;
-    }
-  } catch(e) {}
+  if (null == namespaces) {
+    exports.storage.remove('debug');
+  } else {
+    exports.storage.set('debug', namespaces);
+  }
 }
 
 /**
@@ -148,38 +178,22 @@ function save(namespaces) {
  */
 
 function load() {
-  try {
-    return exports.storage.debug;
-  } catch(e) {}
-
-  // If debug isn't set in LS, and we're in Electron, try to load $DEBUG
-  if (typeof process !== 'undefined' && 'env' in process) {
-    return process.env.DEBUG;
+  if (exports.storage) {
+    exports.storage.get('debug', exports.enable);
+  } else {
+    if (typeof process !== 'undefined' &&
+        typeof process.env !== 'undefined' &&
+        typeof process.env.DEBUG !== 'undefined') {
+      exports.enable(process.env.DEBUG);
+    }
   }
 }
 
 /**
- * Enable namespaces listed in `localStorage.debug` initially.
+ * Enable namespaces listed in the storage `debug`` initially.
  */
 
-exports.enable(load());
-
-/**
- * Localstorage attempts to return the localstorage.
- *
- * This is necessary because safari throws
- * when a user disables cookies/localstorage
- * and you attempt to access it.
- *
- * @return {LocalStorage}
- * @api private
- */
-
-function localstorage() {
-  try {
-    return window.localStorage;
-  } catch (e) {}
-}
+exports.load();
 
 /** Attach to Window*/
 if (window) {