Couple of fixes

.gitignore

@@ -1,3 +1,5 @@
 __pycache__
 *.pyc
 django_byostorage.egg-info
+.coverage
+htmlcov

byostorage/models.py

@@ -1,6 +1,6 @@
 from django.conf import settings
 from django.db import models
-from django.core.files.storage import get_storage_class
+from django.core.files.storage import get_storage_class, FileSystemStorage
 from django.core.exceptions import ValidationError
 import json
 
@@ -52,14 +52,19 @@ class UserStorage(models.Model):
         except Exception as e:
             raise ValueError("Error in settings for storage '{0}' [{1}]".format(self.name, e))
 
-    def test_connection(self):
+    def test_storage(self):
         # just do something that requires connection
-        self.instance().exists('ping.txt')
+        try:
+            self.instance().listdir('')
+        except FileNotFoundError:
+            # FileSystemStorage doesn't create the base_dir until write
+            pass
+        return True
 
     def save(self, *args, **kwargs):
-        # check the settings are valid
+        # ensure the settings JSON isvalid
-        validate_json(self.settings_data)
+        if self.settings_data:
-        self.test_connection()
+            validate_json(self.settings_data)
 
         super(UserStorage, self).save(*args, **kwargs)
 

byostorage/tests.py

@@ -7,6 +7,9 @@ from .models import UserStorage
 from .user import BYOStorage
 from .http import HTTPStorage
 
+#import logging
+#logging.basicConfig(level=logging.DEBUG)
+
 class MultiStorageTestCase(TestCase):
 
     def test_storage_selection(self):
@@ -56,8 +59,8 @@ class UserStorageTestCase(TestCase):
             UserStorage.objects.create(name='one', storage='django.core.files.storage.FileSystemStorage',
             settings_data='{"location": "foo}')
 
-    def test_bad_settings(self):
+    def test_connection(self):
-        UserStorage.objects.create(name='one', storage='storages.backends.s3boto3.S3Boto3Storage',
+        instance = UserStorage.objects.create(name='one', storage='storages.backends.s3boto3.S3Boto3Storage',
                 settings_data='''
 {
   "access_key": "polyphonic_test_key",
@@ -67,6 +70,23 @@ class UserStorageTestCase(TestCase):
 }
 ''')
 
+    
+    def test_bad_connection(self):
+        try:
+            UserStorage.objects.create(name='one', storage='storages.backends.s3boto3.S3Boto3Storage',
+                   settings_data='''
+{
+  "access_key": "polyphonic_test_key",
+  "secret_key": "the_wrong_secret",
+  "endpoint_url": "http://localhost:9000",
+  "bucket_name": "missing"
+}
+''')
+            self.fail("Should have raised an exception")
+        except Exception as e:
+            pass
+
+
 class BYOStorageTestCase(TestCase):
 
     def setUp(self):