Add a decorator for specifying the RunTest object to use.

testtools/__init__.py

@@ -11,6 +11,7 @@ __all__ = [
     'MultipleExceptions',
     'MultiTestResult',
     'PlaceHolder',
+    'run_tests_with',
     'TestCase',
     'TestResult',
     'TextTestResult',
@@ -33,6 +34,7 @@ from testtools.testcase import (
     PlaceHolder,
     TestCase,
     clone_test_with_new_id,
+    run_tests_with,
     skip,
     skipIf,
     skipUnless,

testtools/testcase.py

@@ -6,10 +6,11 @@ __metaclass__ = type
 __all__ = [
     'clone_test_with_new_id',
     'MultipleExceptions',
-    'TestCase',
+    'run_tests_with',
     'skip',
     'skipIf',
     'skipUnless',
+    'TestCase',
     ]
 
 import copy
@@ -61,6 +62,13 @@ except ImportError:
         """
 
 
+def run_tests_with(test_runner):
+    def decorator(f):
+        f._run_tests_with = test_runner
+        return f
+    return decorator
+
+
 class MultipleExceptions(Exception):
     """Represents many exceptions raised from some operation.
 
@@ -100,7 +108,8 @@ class TestCase(unittest.TestCase):
         # __details is lazy-initialized so that a constructed-but-not-run
         # TestCase is safe to use with clone_test_with_new_id.
         self.__details = None
-        self.__RunTest = runTest
+        test_method = self._get_test_method()
+        self.__RunTest = getattr(test_method, '_run_tests_with', runTest)
         self.__exception_handlers = []
         self.exception_handlers = [
             (self.skipException, self._report_skip),

testtools/tests/test_runtest.py

@@ -4,6 +4,7 @@
 
 from testtools import (
     ExtendedToOriginalDecorator,
+    run_tests_with,
     RunTest,
     TestCase,
     TestResult,
@@ -206,6 +207,16 @@ class TestTestCaseSupportForRunTest(TestCase):
         from_run_test = case.run(result)
         self.assertThat(from_run_test, Is(CustomRunTest.marker))
 
+    def test_decorator_for_run_test(self):
+        class SomeCase(TestCase):
+            @run_tests_with(CustomRunTest)
+            def test_foo(self):
+                pass
+        result = TestResult()
+        case = SomeCase('test_foo')
+        from_run_test = case.run(result)
+        self.assertThat(from_run_test, Is(CustomRunTest.marker))
+
 
 def test_suite():
     from unittest import TestLoader