diff --git a/bulkredditdownloader/tests/test_resource.py b/bulkredditdownloader/tests/test_resource.py
new file mode 100644
index 0000000..209f8cb
--- /dev/null
+++ b/bulkredditdownloader/tests/test_resource.py
@@ -0,0 +1,20 @@
+#!/usr/bin/env python3
+# coding=utf-8
+
+import pytest
+
+from bulkredditdownloader.resource import Resource
+
+
+@pytest.mark.parametrize(('test_url', 'expected'), (
+    ('test.png', '.png'),
+    ('another.mp4', '.mp4'),
+    ('test.jpeg', '.jpeg'),
+    ('http://www.random.com/resource.png', '.png'),
+    ('https://www.resource.com/test/example.jpg', '.jpg'),
+    ('hard.png.mp4', '.mp4'),
+))
+def test_resource_get_extension(test_url: str, expected: str):
+    test_resource = Resource(None, test_url)
+    result = test_resource._determine_extension()
+    assert result == expected