Multi storage with a bit of refactoring

src/common/multi-storage.js

@@ -1,68 +1,136 @@
 const genericStorage = {};
 
-export function get (key) {
-    return new Promise((resolve, reject) => {
+
+var Storage = function () {
+    this.browser = null;
+};
+
+Storage.prototype = {
+    setBrowser: function (browser) {
+        this.browser = browser;
+    },
+    get: function (key) {
+        this.browser.get(key);
+    },
+    set: function (key, value) {
+        this.browser.set(key, value);
+    },
+    del: function (key) {
+        this.browser.del(key);
+    }
+};
+
+
+var Chrome = function (resolve) {
+    this.get = function (key) {
+        chrome.storage.local.get(key, data => resolve(data[key]));
+    };
+    this.set = function (key, value) {
+        const data = {
+            [key]: value
+        };
+        chrome.storage.local.set(data, resolve());
+    };
+    this.del = function (key) {
+        chrome.storage.local.remove(key, resolve());
+    };
+};
+
+var Local = function (resolve) {
+    this.get = function (key) {
+        resolve(localStorage[key]);
+    };
+    this.set = function (key, value) {
+        localStorage[key] = value;
+        resolve();
+    };
+    this.del = function (key) {
+        delete localStorage[key];
+        resolve();
+    };
+};
+
+var Async = function (resolve, reject) {
+    this.get = function (key) {
+        AsyncStorage.getItem(key, (error, data) => {
+            if (error) {
+                reject(error);
+            } else {
+                resolve(data);
+            }
+        });
+    };
+    this.set = function (key, value) {
+        AsyncStorage.setItem(key, value, error => {
+            if (error) {
+                reject(error);
+            } else {
+                resolve();
+            }
+        });
+    };
+    this.del = function (key) {
+        AsyncStorage.removeItem(key, error => {
+            if (error) {
+                reject(error);
+            } else {
+                resolve();
+            }
+        });
+    };
+};
+
+var Generic = function (resolve) {
+    this.get = function (key) {
+        resolve(genericStorage[key]);
+    };
+    this.set = function (key, value) {
+        genericStorage[key] = value;
+        resolve();
+    };
+    this.del = function (key) {
+        delete genericStorage[key];
+        resolve();
+    };
+};
+
+function BrowserFactory () {
+    this.create = function (resolve, reject) {
+        var browser;
         if (typeof chrome !== "undefined" && chrome.storage) {
-            chrome.storage.local.get(key, data => resolve(data[key]));
+            browser = new Chrome(resolve);
         } else if (typeof localStorage !== "undefined") {
-            resolve(localStorage[key]);
+            browser = new Local(resolve);
         } else if (typeof AsyncStorage !== "undefined") {
-            AsyncStorage.getItem(key, (error, data) => {
-                if (error) {
-                    reject(error);
-                } else {
-                    resolve(data);
-                }
-            });
+            browser = new Async(resolve, reject);
         } else {
-            resolve(genericStorage[key]);
+            browser = new Generic(resolve);
         }
+        return browser;
+    };
+}
+
+
+export function get (key) {
+    return new Promise((resolve, reject) => {
+        var storage = new Storage();
+        storage.setBrowser(new BrowserFactory().create(resolve, reject));
+        storage.get(key);
     });
 }
 
 export function set (key, value) {
     return new Promise((resolve, reject) => {
-        if (typeof chrome !== "undefined" && chrome.storage) {
-            const data = {
-                [key]: value
-            };
-            chrome.storage.local.set(data, resolve);
-        } else if (typeof localStorage !== "undefined") {
-            localStorage[key] = value;
-            resolve();
-        } else if (typeof AsyncStorage !== "undefined") {
-            AsyncStorage.setItem(key, value, error => {
-                if (error) {
-                    reject(error);
-                } else {
-                    resolve();
-                }
-            });
-        } else {
-            genericStorage[key] = value;
-            resolve();
-        }
+        var storage = new Storage();
+        storage.setBrowser(new BrowserFactory().create(resolve, reject));
+        storage.set(key, value);
     });
 }
 
 export function del (key) {
     return new Promise((resolve, reject) => {
-        if (typeof chrome !== "undefined" && chrome.storage) {
-            chrome.storage.local.remove(key, resolve);
-        } else if (typeof localStorage !== "undefined") {
-            delete localStorage[key];
-            resolve();
-        } else if (typeof AsyncStorage !== "undefined") {
-            AsyncStorage.removeItem(key, error => {
-                if (error) {
-                    reject(error);
-                } else {
-                    resolve();
-                }
-            });
-        } else {
-            delete genericStorage[key];
-            resolve();
-        }
+        var storage = new Storage();
+        storage.setBrowser(new BrowserFactory().create(resolve, reject));
+        storage.del(key);
     });
-}
+}