use pytest in unit tests

python-threatexchange/threatexchange/content_type/tests/test_file_content_type.py

@@ -0,0 +1,27 @@
+import pytest
+from threatexchange.content_type.photo import PhotoContent
+from threatexchange.content_type.video import VideoContent
+from threatexchange.content_type.file_content import FileContent
+
+@pytest.mark.parametrize("file_name,expected_content_type", [
+    ("file.jpg", PhotoContent),
+    ("file.JPG", PhotoContent),
+    ("file.mp4", VideoContent),
+    ("file.MP4", VideoContent),
+    ("archive.photo.png", PhotoContent),
+    ("movie.backup.mp4", VideoContent),
+])
+def test_file_content_detection(file_name, expected_content_type):
+    """
+    Tests that FileContent correctly identifies the content type
+    as either PhotoContent or VideoContent based on file extension.
+    """
+    content_type = FileContent.get_content_type_from_filename(file_name)
+    assert content_type == expected_content_type, f"Failed for {file_name}"
+
+def test_unknown_file_type():
+    """
+    Tests that an unknown file type returns None.
+    """
+    file_content = FileContent.get_content_type_from_filename("file.txt")
+    assert file_content is None