[nose] Improved test case

[nose] Improved test case

bob/pipelines/tests/test_wrappers.py

@@ -13,6 +13,7 @@ from sklearn.utils.validation import check_array
 from sklearn.utils.validation import check_is_fitted
 from bob.pipelines.utils import hash_string
 import bob.pipelines as mario
+import tempfile
 
 
 def _offset_add_func(X, offset=1):
@@ -176,14 +177,19 @@ def test_checkpoint_function_sample_transfomer():
     _assert_all_close_numpy_array(oracle, [s.data for s in features])
 
     # test when both model_path and features_dir is None
+    with tempfile.TemporaryDirectory() as dir_name:
         transformer = mario.wrap(
             [FunctionTransformer, "sample", "checkpoint"],
             func=_offset_add_func,
             kw_args=dict(offset=offset),
             validate=True,
+            features_dir=dir_name,
             hash_fn=hash_string,
         )
+
         features = transformer.transform(samples)
+        # Checking if we have 8 chars in the second level
+        assert len(features[0].load.args[0].split("/")[-2]) == 8
         _assert_all_close_numpy_array(oracle, [s.data for s in features])