adding a little tests for provider

tests/test_providers.py

@@ -1,3 +1,43 @@
-"""
+"""Objects providers unittests."""
 
-"""
+import unittest2 as unittest
+
+from objects.providers import Provider
+from objects.providers import ProviderDelegate
+from objects.providers import NewInstance
+from objects.providers import Singleton
+from objects.providers import Scoped
+from objects.providers import ExternalDependency
+from objects.providers import Class
+from objects.providers import Object
+from objects.providers import Function
+from objects.providers import Value
+from objects.providers import Callable
+from objects.providers import Config
+
+from objects.utils import is_provider
+
+
+class ProviderTest(unittest.TestCase):
+
+    """Provider test cases."""
+
+    def test_init(self):
+        """Test creating and initialization."""
+        self.assertIsInstance(Provider(), Provider)
+
+    def test_is_provider(self):
+        """Test `is_provider` check."""
+        self.assertTrue(is_provider(Provider()))
+
+    def test_call(self):
+        """Test call."""
+        self.assertRaises(NotImplementedError, Provider().__call__)
+
+    def test_delegate(self):
+        """Test creating of provider delegation."""
+        provider = Provider()
+        delegate = provider.delegate()
+
+        self.assertIsInstance(delegate, ProviderDelegate)
+        self.assertIs(delegate.delegated, provider)