tests: Add basic singlefile test

tests/test_extractors.py

@@ -10,4 +10,12 @@ def test_ignore_methods():
     Takes the passed method out of the default methods list and returns that value
     """
     ignored = ignore_methods(['title'])
-    assert should_save_title not in ignored
+    assert should_save_title not in ignored
+
+
+
+def test_singlefile_works(tmp_path, process):
+    add_process = subprocess.run(['archivebox', 'add', 'http://127.0.0.1:8080/static/example.com.html'], capture_output=True) 
+    archived_item_path = list(tmp_path.glob('archive/**/*'))[0]
+    output_file = archived_item_path / "single-file.html" 
+    assert output_file.exists()