Created an in memory store for use in tests.

test/in-memory-store.ts

@@ -0,0 +1,29 @@
+export default class InMemoryStore {
+  private store: {[key: string]: string}
+  private secureStore: {[key: string]: string}
+
+  public constructor() {
+    this.store = {}
+    this.secureStore = {}
+  }
+
+  private secureKey(key: string, login: string): string {
+    return `__key/${key}/${login}`
+  }
+
+  public setItem(key: string, loginOrValue: string, secureValue?: string) {
+    if (secureValue) {
+      this.secureStore[this.secureKey(key, loginOrValue)] = secureValue
+    } else {
+      this.store[key] = loginOrValue
+    }
+  }
+
+  public getItem(key: string, login?: string): string {
+    if (login) {
+      return this.secureStore[this.secureKey(key, login)]
+    } else {
+      return this.store[key]
+    }
+  }
+}