[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):
@@ -176,15 +177,20 @@ 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
-    transformer = mario.wrap(
-        [FunctionTransformer, "sample", "checkpoint"],
-        func=_offset_add_func,
-        kw_args=dict(offset=offset),
-        validate=True,
-        hash_fn=hash_string,
-    )
-    features = transformer.transform(samples)
-    _assert_all_close_numpy_array(oracle, [s.data for s in features])
+    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])
 
 
 def test_checkpoint_fittable_sample_transformer():