Improve test coverage a little bit

src/skhep_testdata/__init__.py

@@ -6,5 +6,5 @@
 __all__ = ("data_path", "download_all", "known_files", "__version__")
 
 
-def __dir__() -> tuple[str, ...]:
+def __dir__() -> tuple[str, ...]:  # pragma: no cover
     return __all__

src/skhep_testdata/local_files.py

@@ -10,7 +10,7 @@
 from . import data, remote_files
 
 if sys.version_info < (3, 9):
-    import importlib_resources as resources
+    import importlib_resources as resources  # pragma: no cover
 else:
     from importlib import resources
 

src/skhep_testdata/remote_files.py

@@ -11,7 +11,7 @@
 import yaml
 
 if sys.version_info < (3, 9):
-    import importlib_resources as resources
+    import importlib_resources as resources  # pragma: no cover
 else:
     from importlib import resources
 

tests/test_local_files.py

@@ -1,8 +1,8 @@
 from __future__ import annotations
 
 import os
-
 import pytest
+import requests
 
 import skhep_testdata as skhtd
 
@@ -25,6 +25,12 @@ def test_data_path_missing():
         skhtd.data_path("doesnt-exist.root", raise_missing=True)
 
 
+def test_data_path_cached():
+    skhtd.known_files.add("dummy-cached.root")
+    with pytest.raises(requests.exceptions.HTTPError):
+        skhtd.data_path("dummy-cached.root", raise_missing=False, cache_dir="tmp")
+
+
 def test_delegate_to_remote(monkeypatch, tmpdir):
     def dummy_remote_file(filename, data_dir=None, raise_missing=False):
         if not data_dir: