[feat] Deprecate RegressionMixin in favor of RegressionTestPlugin

reframe/core/builtins.py

@@ -109,7 +109,7 @@ def sanity_function(fn):
     '''Decorate a test member function to mark it as a sanity check.
 
     This decorator will convert the given function into a
-    :func:`~RegressionMixin.deferrable` and mark it to be executed during the
+    :func:`~RegressionTestPlugin.deferrable` and mark it to be executed during the
     test's sanity stage. When this decorator is used, manually assigning a
     value to :attr:`~RegressionTest.sanity_patterns` in the test is not
     allowed.
@@ -118,7 +118,7 @@ def sanity_function(fn):
     classes may also decorate a different method as the test's sanity
     function. Decorating multiple member functions in the same class is not
     allowed. However, a :class:`RegressionTest` may inherit from multiple
-    :class:`RegressionMixin` classes with their own sanity functions. In this
+    :class:`RegressionTestPlugin` classes with their own sanity functions. In this
     case, the derived class will follow Python's `MRO
     <https://docs.python.org/3/library/stdtypes.html#class.__mro__>`_ to find
     a suitable sanity function.

reframe/core/fixtures.py

@@ -496,7 +496,7 @@ def access_fixture_resources(self):
     that these classes can use the same built-in functionalities as in regular
     tests decorated with
     :func:`@rfm.simple_test<reframe.core.decorators.simple_test>`. This
-    includes the :func:`~reframe.core.pipeline.RegressionMixin.parameter`
+    includes the :func:`~reframe.core.pipeline.RegressionTestPlugin.parameter`
     built-in, where fixtures may have more than one
     :ref:`variant<test-variants>`. When this occurs, a parent test may select
     to either treat a parameterized fixture as a test parameter, or instead,
@@ -595,7 +595,7 @@ class TestE(rfm.RegressionTest):
     A parent test may also specify the value of different variables in the
     fixture class to be set before its instantiation. Each variable must have
     been declared in the fixture class with the
-    :func:`~reframe.core.pipeline.RegressionMixin.variable` built-in,
+    :func:`~reframe.core.pipeline.RegressionTestPlugin.variable` built-in,
     otherwise it is silently ignored. This variable specification is
     equivalent to deriving a new class from the fixture class, and setting
     these variable values in the class body of a newly derived class.

reframe/core/pipeline.py

@@ -8,8 +8,8 @@
 #
 
 __all__ = [
-    'CompileOnlyRegressionTest', 'RegressionTest', 'RunOnlyRegressionTest',
-    'RegressionMixin'
+    'CompileOnlyRegressionTest', 'RegressionMixin',
+    'RegressionTest', 'RunOnlyRegressionTest', 'RegressionTestPlugin'
 ]
 
 
@@ -47,6 +47,7 @@
                                      ReframeError)
 from reframe.core.meta import RegressionTestMeta
 from reframe.core.schedulers import Job
+from reframe.core.warnings import user_deprecation_warning
 
 
 class _NoRuntime(ContainerPlatform):
@@ -103,23 +104,67 @@ def launch_command(self, stagedir):
 _RFM_TEST_KIND_RUN = 2
 
 
-class RegressionMixin(metaclass=RegressionTestMeta):
+class RegressionTestPlugin(metaclass=RegressionTestMeta):
+    '''A reusable test plugin.
+
+    This is a non-test base class that other tests can inherit from in order
+    to augment their behaviour. A plugin can define variables, parameters,
+    hooks etc. The following example shows a plugin that defines a variable
+    and adds a specific job option for every test that uses it.
+
+    .. code-block:: python
+
+        class MyPlugin(RegressionTestPlugin):
+            foo = variable(int, value=0)
+
+            @run_before('run', always_last=True)
+            def add_foo_opt(self):
+                if self.foo:
+                    self.job.options = [f'--foo={self.foo}']
+
+
+        @simple_test
+        class MyTestA(RegressionTest, MyPlugin):
+            """A test using the plugin"""
+
+        @simple_test
+        class MyTestB(RegressionTest, MyPlugin):
+            """Another test using the plugin"""
+
+
+    This class is equivalent to the deprecated :class:`RegressionMixin`.
+
+    .. versionadded:: 4.9
+    '''
+    _rfm_regression_class_kind = _RFM_TEST_KIND_MIXIN
+
+
+class RegressionMixin(RegressionTestPlugin):
     '''Base mixin class for regression tests.
 
-    Multiple inheritance from more than one
-    :class:`RegressionTest` class is not allowed in ReFrame. Hence, mixin
-    classes provide the flexibility to bundle reusable test add-ons, leveraging
-    the metaclass magic implemented in
+    Multiple inheritance from more than one :class:`RegressionTest` class is
+    not allowed. Hence, mixin classes provide the flexibility to bundle
+    reusable test add-ons, leveraging the metaclass magic implemented in
     :class:`RegressionTestMeta`. Using this metaclass allows mixin classes to
     use powerful ReFrame features, such as hooks, parameters or variables.
 
     .. versionadded:: 3.4.2
+
+    .. deprecated:: 4.9
+
+        Use :class:`RegressionTestPlugin` instead.
     '''
 
-    _rfm_regression_class_kind = _RFM_TEST_KIND_MIXIN
+    @classmethod
+    def __init_subclass__(cls, **kwargs):
+        super().__init_subclass__(**kwargs)
+        user_deprecation_warning(
+            '`RegressionMixin` is deprecated; '
+            'please inherit from `RegresssionTestPlugin` instead'
+        )
 
 
-class RegressionTest(RegressionMixin, jsonext.JSONSerializable):
+class RegressionTest(RegressionTestPlugin, jsonext.JSONSerializable):
     '''Base class for regression tests.
 
     All regression tests must eventually inherit from this class.

reframe/utility/typecheck.py

@@ -114,8 +114,8 @@ class ConvertibleType(abc.ABCMeta):
     For example, a class whose constructor accepts and :class:`int` may need
     to support a cast-from-string conversion. This is particular useful if you
     want a custom-typed test
-    :attr:`~reframe.core.pipeline.RegressionMixin.variable` to be able to be
-    set from the command line using the :option:`-S` option.
+    :attr:`~reframe.core.pipeline.RegressionTestPlugin.variable` to be able to
+    be set from the command line using the :option:`-S` option.
 
     In order to support such conversions, a class must use this metaclass and
     define a class method, named as :obj:`__rfm_cast_<type>__`, for each of

unittests/test_fixtures.py

@@ -20,48 +20,48 @@ class Foo:
     # Wrong fixture classes
 
     with pytest.raises(ValueError):
-        class MyTest(rfm.RegressionMixin):
+        class MyTest(rfm.RegressionTestPlugin):
             f = fixture(Foo)
 
     with pytest.raises(ValueError):
-        class MyTest(rfm.RegressionMixin):
-            f = fixture(rfm.RegressionMixin)
+        class MyTest(rfm.RegressionTestPlugin):
+            f = fixture(rfm.RegressionTestPlugin)
 
     # Session and partition scopes must be run-only.
 
     with pytest.raises(ValueError):
-        class MyTest(rfm.RegressionMixin):
+        class MyTest(rfm.RegressionTestPlugin):
             f = fixture(rfm.RegressionTest, scope='session')
 
     with pytest.raises(ValueError):
-        class MyTest(rfm.RegressionMixin):
+        class MyTest(rfm.RegressionTestPlugin):
             f = fixture(rfm.RegressionTest, scope='partition')
 
     with pytest.raises(ValueError):
-        class MyTest(rfm.RegressionMixin):
+        class MyTest(rfm.RegressionTestPlugin):
             f = fixture(rfm.CompileOnlyRegressionTest, scope='session')
 
     with pytest.raises(ValueError):
-        class MyTest(rfm.RegressionMixin):
+        class MyTest(rfm.RegressionTestPlugin):
             f = fixture(rfm.CompileOnlyRegressionTest, scope='partition')
 
 
 def test_fixture_args():
     '''Test invalid fixture arguments.'''
     with pytest.raises(ValueError):
-        class MyTest(rfm.RegressionMixin):
+        class MyTest(rfm.RegressionTestPlugin):
             f = fixture(rfm.RegressionTest, scope='other')
 
     with pytest.raises(ValueError):
-        class MyTest(rfm.RegressionMixin):
+        class MyTest(rfm.RegressionTestPlugin):
             f = fixture(rfm.RegressionTest, action='other')
 
     with pytest.raises(ValueError):
-        class MyTest(rfm.RegressionMixin):
+        class MyTest(rfm.RegressionTestPlugin):
             f = fixture(rfm.RegressionTest, variants='other')
 
     with pytest.raises(TypeError):
-        class MyTest(rfm.RegressionMixin):
+        class MyTest(rfm.RegressionTestPlugin):
             f = fixture(rfm.RegressionTest, variables='other')
 
 
@@ -72,7 +72,7 @@ class Foo(rfm.RegressionTest):
         p = parameter()
 
     with pytest.raises(ValueError):
-        class MyTest(rfm.RegressionMixin):
+        class MyTest(rfm.RegressionTestPlugin):
             f = fixture(Foo)
 
 
@@ -83,15 +83,15 @@ class Foo(rfm.RegressionTest):
         p = parameter(range(4))
 
     with pytest.raises(ValueError):
-        class MyTest(rfm.RegressionMixin):
+        class MyTest(rfm.RegressionTestPlugin):
             f = fixture(Foo, variants={'p': lambda x: x > 10})
 
     with pytest.raises(ValueError):
-        class MyTest(rfm.RegressionMixin):
+        class MyTest(rfm.RegressionTestPlugin):
             f = fixture(Foo, variants=())
 
     # Test default variants argument 'all'
-    class MyTest(rfm.RegressionMixin):
+    class MyTest(rfm.RegressionTestPlugin):
         f = fixture(Foo, variants='all')
 
     assert MyTest.fixture_space['f'].variants == (0, 1, 2, 3,)
@@ -103,7 +103,7 @@ def test_fork_join_variants():
     class Foo(rfm.RegressionTest):
         p = parameter(range(4))
 
-    class MyTest(rfm.RegressionMixin):
+    class MyTest(rfm.RegressionTestPlugin):
         f0 = fixture(Foo, action='fork')
         f1 = fixture(Foo, action='join')
 
@@ -119,7 +119,7 @@ class MyTest(rfm.RegressionMixin):
 
 
 def test_default_args():
-    class Foo(rfm.RegressionMixin):
+    class Foo(rfm.RegressionTestPlugin):
         f = fixture(rfm.RegressionTest)
 
     assert Foo.fixture_space['f'].variables == {}
@@ -132,10 +132,10 @@ def test_fixture_inheritance():
     class Fix(rfm.RunOnlyRegressionTest):
         pass
 
-    class Foo(rfm.RegressionMixin):
+    class Foo(rfm.RegressionTestPlugin):
         f0 = fixture(Fix, scope='test')
 
-    class Bar(rfm.RegressionMixin):
+    class Bar(rfm.RegressionTestPlugin):
         f1 = fixture(Fix, scope='environment')
         f2 = fixture(Fix, scope='partition')
 
@@ -151,10 +151,10 @@ class Baz(Foo, Bar):
 def test_fixture_inheritance_clash():
     '''Fixture name clash is not permitted.'''
 
-    class Foo(rfm.RegressionMixin):
+    class Foo(rfm.RegressionTestPlugin):
         f0 = fixture(rfm.RegressionTest)
 
-    class Bar(rfm.RegressionMixin):
+    class Bar(rfm.RegressionTestPlugin):
         f0 = fixture(rfm.RegressionTest)
 
     # Multiple inheritance clash
@@ -166,7 +166,7 @@ class Baz(Foo, Bar):
 def test_fixture_override():
     '''A child class may only redefine a fixture with the fixture builtin.'''
 
-    class Foo(rfm.RegressionMixin):
+    class Foo(rfm.RegressionTestPlugin):
         f0 = fixture(rfm.RegressionTest)
 
     class Bar(Foo):
@@ -180,14 +180,14 @@ class Baz(Foo):
         Bar.f0 = 4
 
     with pytest.raises(ReframeSyntaxError):
-        class Baz(rfm.RegressionMixin):
+        class Baz(rfm.RegressionTestPlugin):
             f0 = fixture(rfm.RegressionTest)
             f0 = 4
 
 
 def test_fixture_access_in_class_body():
     with pytest.raises(ReframeSyntaxError):
-        class Foo(rfm.RegressionMixin):
+        class Foo(rfm.RegressionTestPlugin):
             f0 = fixture(rfm.RegressionTest)
             print(f0)
 
@@ -218,7 +218,7 @@ def test_fixture_space_access():
     class P0(rfm.RunOnlyRegressionTest):
         p0 = parameter(range(2))
 
-    class Foo(rfm.RegressionMixin):
+    class Foo(rfm.RegressionTestPlugin):
         f0 = fixture(P0, scope='test', action='fork')
         f1 = fixture(P0, scope='environment', action='join')
         f2 = fixture(P0, scope='partition', action='fork')

unittests/test_parameters.py

@@ -199,10 +199,10 @@ class MyTest(ExtendParams):
 
 
 def test_param_space_clash():
-    class Spam(rfm.RegressionMixin):
+    class Spam(rfm.RegressionTestPlugin):
         P0 = parameter([1])
 
-    class Ham(rfm.RegressionMixin):
+    class Ham(rfm.RegressionTestPlugin):
         P0 = parameter([2])
 
     with pytest.raises(ReframeSyntaxError):
@@ -211,10 +211,10 @@ class Eggs(Spam, Ham):
 
 
 def test_multiple_inheritance():
-    class Spam(rfm.RegressionMixin):
+    class Spam(rfm.RegressionTestPlugin):
         P0 = parameter()
 
-    class Ham(rfm.RegressionMixin):
+    class Ham(rfm.RegressionTestPlugin):
         P0 = parameter([2])
 
     class Eggs(Spam, Ham):
@@ -276,7 +276,7 @@ class Foo(rfm.RegressionTest):
 
 
 def test_param_space_read_only():
-    class Foo(rfm.RegressionMixin):
+    class Foo(rfm.RegressionTestPlugin):
         pass
 
     with pytest.raises(ValueError):

unittests/test_pipeline.py

@@ -1065,7 +1065,7 @@ class BaseTest(HelloTest):
         def x(self):
             self.var += 1
 
-    class C(rfm.RegressionMixin):
+    class C(rfm.RegressionTestPlugin):
         @run_before('run')
         def y(self):
             self.foo = 1
@@ -1099,7 +1099,7 @@ def weird_mro_test(HelloTest):
     # See example in https://www.python.org/download/releases/2.3/mro/
     #
     # The MRO of A is ABECDFX, which means that E is more specialized than C!
-    class X(rfm.RegressionMixin):
+    class X(rfm.RegressionTestPlugin):
         pass
 
     class D(X):