feat(storage): add localstorage

src/client/storage/LocalStorage.ts

@@ -2,7 +2,7 @@ import { Storage } from './Storage'
 
 export class LocalStorage implements Storage {
   public async isSupported(): Promise<boolean> {
-    return Promise.resolve(window && !!window.localStorage)
+    return Promise.resolve(typeof window !== 'undefined' && !!window.localStorage)
   }
 
   public async get(key: string): Promise<any> {

src/client/storage/StorageProvider.ts

@@ -0,0 +1,15 @@
+import { FileStorage } from "./FileStorage"
+import { LocalStorage } from "./LocalStorage"
+import { Storage } from "./Storage"
+
+export async function getStorage(): Promise<Storage> {
+    const local: LocalStorage = new LocalStorage()
+    const file: FileStorage = new FileStorage()
+    if (await local.isSupported()) {
+        return local
+    } else if (await file.isSupported()) {
+        return file
+    } else {
+        throw new Error('no storage type supported')
+    }
+}