[feat] Make the @required_version decorator a class definition parameter

reframe/core/decorators.py

@@ -91,6 +91,17 @@ def _validate_test(cls):
         raise ValueError(f'decorated test ({cls.__qualname__!r}) has one or '
                          f'more undefined parameters')
 
+    conditions = [VersionValidator(v) for v in cls._rfm_required_version]
+    if (cls._rfm_required_version and
+        not any(c.validate(osext.reframe_version()) for c in conditions)):
+
+        getlogger().warning(f"skipping incompatible test "
+                            f"'{cls.__qualname__}': not valid for ReFrame "
+                            f"version {osext.reframe_version().split('-')[0]}")
+        return False
+
+    return True
+
 
 def simple_test(cls):
     '''Class decorator for registering tests with ReFrame.
@@ -101,10 +112,9 @@ def simple_test(cls):
 
     .. versionadded:: 2.13
     '''
-    _validate_test(cls)
-
-    for _ in cls.param_space:
-        _register_test(cls)
+    if _validate_test(cls):
+        for _ in cls.param_space:
+            _register_test(cls)
 
     return cls
 
@@ -139,14 +149,14 @@ def parameterized_test(*inst):
     )
 
     def _do_register(cls):
-        _validate_test(cls)
-        if not cls.param_space.is_empty():
-            raise ValueError(
-                f'{cls.__qualname__!r} is already a parameterized test'
-            )
+        if _validate_test(cls):
+            if not cls.param_space.is_empty():
+                raise ValueError(
+                    f'{cls.__qualname__!r} is already a parameterized test'
+                )
 
-        for args in inst:
-            _register_test(cls, args)
+            for args in inst:
+                _register_test(cls, args)
 
         return cls
 
@@ -187,6 +197,12 @@ def required_version(*versions):
        These should be written as ``3.5.0`` and ``3.5.0-dev.0``.
 
     '''
+    warn.user_deprecation_warning(
+        "the '@required_version' decorator is deprecated; please set "
+        "the 'require_version' parameter in the class definition instead",
+        from_version='3.7.0'
+    )
+
     if not versions:
         raise ValueError('no versions specified')
 
@@ -198,8 +214,10 @@ def _skip_tests(cls):
             mod.__rfm_skip_tests = set()
 
         if not any(c.validate(osext.reframe_version()) for c in conditions):
-            getlogger().info('skipping incompatible test defined'
-                             ' in class: %s' % cls.__name__)
+            getlogger().warning(
+                f"skipping incompatible test '{cls.__qualname__}': not valid "
+                f"for ReFrame version {osext.reframe_version().split('-')[0]}"
+            )
             mod.__rfm_skip_tests.add(cls)
 
         return cls

reframe/core/pipeline.py

@@ -138,14 +138,49 @@ class RegressionTest(RegressionMixin, jsonext.JSONSerializable):
     This class provides the implementation of the pipeline phases that the
     regression test goes through during its lifetime.
 
-    .. warning::
-        .. versionchanged:: 3.4.2
-           Multiple inheritance with a shared common ancestor is not allowed.
+    This class accepts parameters at the *class definition*, i.e., the test
+    class can be defined as follows:
+
+    .. code-block:: python
+
+       class MyTest(RegressionTest, param='foo', ...):
+
+    where ``param`` is one of the following:
+
+    :param pin_prefix: lock the test prefix to the directory where the current
+        class lives.
+
+    :param require_version: a list of ReFrame version specifications that this
+        test is allowed to run. A version specification string can have one of
+        the following formats:
+
+        - ``VERSION``: Specifies a single version.
+        - ``{OP}VERSION``, where ``{OP}`` can be any of ``>``, ``>=``, ``<``,
+          ``<=``, ``==`` and ``!=``. For example, the version specification
+          string ``'>=3.5.0'`` will allow the following test to be loaded
+          only by ReFrame 3.5.0 and higher. The ``==VERSION`` specification
+          is the equivalent of ``VERSION``.
+        - ``V1..V2``: Specifies a range of versions.
+
+        The test will be selected if *any* of the versions is satisfied, even
+        if the versions specifications are conflicting.
+
+    :param special: allow pipeline stage methods to be overriden in this class.
 
     .. note::
         .. versionchanged:: 2.19
            Base constructor takes no arguments.
 
+        .. versionadded:: 3.3
+           The ``pin_prefix`` class definition parameter is added.
+
+        .. versionadded:: 3.7.0
+           The ``require_verion`` class definition parameter is added.
+
+    .. warning::
+        .. versionchanged:: 3.4.2
+           Multiple inheritance with a shared common ancestor is not allowed.
+
     '''
 
     def disable_hook(self, hook_name):
@@ -805,10 +840,16 @@ def __getattribute__(self, name):
         return super().__getattribute__(name)
 
     @classmethod
-    def __init_subclass__(cls, *, special=False, pin_prefix=False, **kwargs):
+    def __init_subclass__(cls, *, special=False, pin_prefix=False,
+                          require_version=None, **kwargs):
         super().__init_subclass__(**kwargs)
         cls._rfm_override_final = special
 
+        if require_version:
+            cls._rfm_required_version = require_version
+        elif not hasattr(cls, '_rfm_required_version'):
+            cls._rfm_required_version = []
+
         # Insert the prefix to pin the test to if the test lives in a test
         # library with resources in it.
         if pin_prefix:

unittests/test_loader.py

@@ -61,9 +61,10 @@ def test_load_error(loader):
 
 
 def test_load_bad_required_version(loader):
-    with pytest.raises(ValueError):
-        loader.load_from_file('unittests/resources/checks_unlisted/'
-                              'no_required_version.py')
+    with pytest.warns(ReframeDeprecationWarning):
+        with pytest.raises(ValueError):
+            loader.load_from_file('unittests/resources/checks_unlisted/'
+                                  'no_required_version.py')
 
 
 def test_load_bad_init(loader):