refactor: remove shared preferences and use memory to save data

flutter/beagle/lib/default/default_storage.dart

@@ -16,31 +16,28 @@
  */
 
 import 'package:beagle/interface/storage.dart';
-import 'package:shared_preferences/shared_preferences.dart';
 
 class DefaultStorage implements Storage {
+  Map<String, String> storage = {};
+
   @override
   Future<void> clear() async {
-    final prefs = await SharedPreferences.getInstance();
-    await prefs.clear();
+    storage.clear();
   }
 
   @override
   Future<String> getItem(String key) async {
-    final prefs = await SharedPreferences.getInstance();
-    final result = prefs.getString(key);
-    return result;
+    return storage[key];
   }
 
   @override
   Future<void> removeItem(String key) async {
-    final prefs = await SharedPreferences.getInstance();
-    await prefs.remove(key);
+    storage.remove(key);
   }
 
   @override
   Future<void> setItem(String key, String value) async {
-    final prefs = await SharedPreferences.getInstance();
-    await prefs.setString(key, value);
+    storage[key] = value;
   }
+
 }

flutter/beagle/pubspec.yaml

@@ -13,7 +13,6 @@ dependencies:
     sdk: flutter
   flutter_js: ^0.5.0+0
   get_it: ^7.1.3
-  shared_preferences: ^2.0.6
   url_launcher: ^6.0.6
 
 dev_dependencies:

flutter/beagle/test/default/default_storage_test.dart

@@ -16,11 +16,9 @@
 
 import 'package:beagle/default/default_storage.dart';
 import 'package:flutter_test/flutter_test.dart';
-import 'package:shared_preferences/shared_preferences.dart';
 
 void main() {
   group('Given a DefaultStorage', () {
-    SharedPreferences.setMockInitialValues({});
     final defaultStorage = DefaultStorage();
     group('When setItem is called', () {
       test('Then it should store the value for the key', () async {