Refactor and optimise some tests (#245)

* Rename to follow actual directory name

* Remove unnecessary Reddit call from test

* Refactor test to reduce duplication

* Parameterise some tests

* Standardise formatting

bulkredditdownloader/tests/site_downloaders/test_youtube.py

@@ -0,0 +1,26 @@
+#!/usr/bin/env python3
+# coding=utf-8
+
+from unittest.mock import MagicMock
+
+import pytest
+
+from bulkredditdownloader.resource import Resource
+from bulkredditdownloader.site_downloaders.youtube import Youtube
+
+
+@pytest.mark.online
+@pytest.mark.slow
+@pytest.mark.parametrize(('test_url', 'expected_hash'), (
+    ('https://www.youtube.com/watch?v=uSm2VDgRIUs', '3c79a62898028987f94161e0abccbddf'),
+    ('https://www.youtube.com/watch?v=m-tKnjFwleU', '61651cc6f53782af50030c0a7dd0b6f6'),
+))
+def test_find_resources(test_url: str, expected_hash: str):
+    test_submission = MagicMock()
+    test_submission.url = test_url
+    downloader = Youtube(test_submission)
+    resources = downloader.find_resources()
+    assert len(resources) == 1
+    assert isinstance(resources[0], Resource)
+    resources[0].download()
+    assert resources[0].hash.hexdigest() == expected_hash