Added test headers extractor

tests/test_extractors.py

@@ -68,4 +68,11 @@ def test_use_node_false_disables_readability_and_singlefile(tmp_path, process, d
                                   capture_output=True, env=disable_extractors_dict)
     output_str = add_process.stdout.decode("utf-8")
     assert "> singlefile" not in output_str
-    assert "> readability" not in output_str
+    assert "> readability" not in output_str
+
+def test_headers(tmp_path, process, disable_extractors_dict):
+    add_process = subprocess.run(['archivebox', 'add', 'http://127.0.0.1:8080/static/example.com.html'],
+                                  capture_output=True, env=disable_extractors_dict)
+    archived_item_path = list(tmp_path.glob("archive/**/*"))[0]
+    output_file = archived_item_path / "headers.json"
+    assert output_file.exists()