Add test for save method

AirBnB_clone/tests/test_models/test_engine/test_file_storage.py

@@ -13,6 +13,8 @@
 from models.review import Review
 from models.state import State
 from models.user import User
+import json
+import os
 import pep8
 import unittest
 FileStorage = file_storage.FileStorage
@@ -87,3 +89,21 @@ def test_new(self):
                 test_dict[instance_key] = instance
                 self.assertEqual(test_dict, storage._FileStorage__objects)
         storage._FileStorage__objects = {}
+
+    def test_save(self):
+        """Test that save properly saves objects to file.json"""
+        os.remove("file.json")
+        storage = FileStorage()
+        new_dict = {}
+        for key, value in classes.items():
+            instance = value()
+            instance_key = instance.__class__.__name__ + "." + instance.id
+            new_dict[instance_key] = instance
+        storage._FileStorage__objects = new_dict
+        storage.save()
+        for key, value in new_dict.items():
+            new_dict[key] = value.to_dict()
+        string = json.dumps(new_dict)
+        with open("file.json", "r") as f:
+            js = f.read()
+        self.assertEqual(json.loads(string), json.loads(js))