[feat] Add possibility to inherit the prefix from the parent class

reframe/core/pipeline.py

@@ -727,7 +727,12 @@ def __new__(cls, *args, **kwargs):
             if osext.is_interactive():
                 prefix = os.getcwd()
             else:
-                prefix = os.path.abspath(os.path.dirname(inspect.getfile(cls)))
+                try:
+                    prefix = cls._rfm_pinned_prefix
+                except AttributeError:
+                    prefix = os.path.abspath(
+                        os.path.dirname(inspect.getfile(cls))
+                    )
 
         obj._rfm_init(name, prefix)
         return obj
@@ -736,10 +741,17 @@ def __init__(self):
         pass
 
     @classmethod
-    def __init_subclass__(cls, *, special=False, **kwargs):
+    def __init_subclass__(cls, *, special=False, pin_prefix=False, **kwargs):
         super().__init_subclass__(**kwargs)
         cls._rfm_special_test = special
 
+        # Insert the prefix to pin the test to if the test lives in a test
+        # library with resources in it.
+        if pin_prefix:
+            cls._rfm_pinned_prefix = os.path.abspath(
+                os.path.dirname(inspect.getfile(cls))
+            )
+
     def _rfm_init(self, name=None, prefix=None):
         if name is not None:
             self.name = name

unittests/resources/checks/pinnedcheck.py

@@ -0,0 +1,10 @@
+# Copyright 2016-2020 Swiss National Supercomputing Centre (CSCS/ETH Zurich)
+# ReFrame Project Developers. See the top-level LICENSE file for details.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
+import reframe as rfm
+
+
+class PinnedTest(rfm.RunOnlyRegressionTest, pin_prefix=True):
+    '''A simple base test for verifying that prefix pinning works correctly'''

unittests/test_pipeline.py

@@ -18,6 +18,7 @@
                                      SanityError)
 from reframe.frontend.loader import RegressionCheckLoader
 from unittests.resources.checks.hellocheck import HelloTest
+from unittests.resources.checks.pinnedcheck import PinnedTest
 
 
 def _run(test, partition, prgenv):
@@ -284,6 +285,15 @@ def __init__(self):
     _run(MyTest(), *local_exec_ctx)
 
 
+def test_pinned_test(local_exec_ctx):
+    class MyTest(PinnedTest):
+        pass
+
+    pinned = MyTest()
+    expected_prefix = os.path.join(os.getcwd(), 'unittests/resources/checks')
+    assert pinned._prefix == expected_prefix
+
+
 def test_supports_system(hellotest, testsys_system):
     hellotest.valid_systems = ['*']
     assert hellotest.supports_system('gpu')