Support both python2.7 and bzr load_tests argument lists

2 files changed, 37 insertions, 16 deletions

diff --git a/lib/testscenarios/scenarios.py b/lib/testscenarios/scenarios.py
index f008d50..3cf8091 100644
--- a/lib/testscenarios/scenarios.py
+++ b/lib/testscenarios/scenarios.py
@@ -80,23 +80,27 @@ def generate_scenarios(test_or_suite):
             yield test
 
 
-def load_tests_apply_scenarios(loader, standard_tests, pattern):
+def load_tests_apply_scenarios(*params):
     """Multiply out all tests in a module that have scenarios.
 
     If this is referenced by the `load_tests` attribute of a module, then
-    Python2.7 or other testloaders that implement this protocol will
-    automatically arrange for the scenarios to be expanded.  In this case it
-    is not necessary (or desirable) to subclass TestWithScenarios.
+    testloaders that implement this protocol will automatically arrange for
+    the scenarios to be expanded.  In this case it is not necessary (or
+    desirable) to subclass TestWithScenarios.
 
-    Note that this function implements the protocol used by Python2.7 
-    <http://docs.python.org/library/unittest.html#load-tests-protocol> which
-    is different from the `load_tests` method originally used in bzr 
-    and some other projects <http://pad.lv/607412>.
+    Two different calling conventions for load_tests have been used, and this
+    function should support both.  Python 2.7 passes (loader, standard_tests,
+    pattern), and bzr, nose and others have used (standard_tests,
+    module, loader).  See <http://pad.lv/607412>.
 
     :param loader: A TestLoader.
     :param standard_test: The test objects found in this module before 
         multiplication.
     """
+    if getattr(params[0], 'suiteClass', None) is not None:
+        loader, standard_tests, pattern = params
+    else:
+        standard_tests, module, loader = params
     result = loader.suiteClass()
     result.addTests(generate_scenarios(standard_tests))
     return result
diff --git a/lib/testscenarios/tests/test_scenarios.py b/lib/testscenarios/tests/test_scenarios.py
index 621cfdc..97a2a6b 100644
--- a/lib/testscenarios/tests/test_scenarios.py
+++ b/lib/testscenarios/tests/test_scenarios.py
@@ -177,20 +177,37 @@ class TestApplyScenarios(testtools.TestCase):
 
 class TestLoadTests(testtools.TestCase):
 
+    class SampleTest(unittest.TestCase):
+        def test_nothing(self): 
+            pass
+        scenarios = [
+            ('a', {}),
+            ('b', {}),
+            ]
+
     def test_load_tests_apply_scenarios(self):
-        class SampleTest(unittest.TestCase):
-            def test_nothing(self): 
-                pass
-            scenarios = [
-                ('a', {}),
-                ('b', {}),
-                ]
         suite = load_tests_apply_scenarios(
             unittest.TestLoader(),
-            [SampleTest('test_nothing')],
+            [self.SampleTest('test_nothing')],
             None)
         result_tests = list(testtools.iterate_tests(suite))
         self.assertEquals(
             2,
             len(result_tests),
             result_tests)
+
+    def test_load_tests_apply_scenarios_old_style(self):
+        """Call load_tests in the way used by pre-Python2.7 code.
+
+        See <https://bugs.launchpad.net/bzr/+bug/607412>
+        """
+        suite = load_tests_apply_scenarios(
+            [self.SampleTest('test_nothing')],
+            self.__class__.__module__,
+            unittest.TestLoader(),
+            )
+        result_tests = list(testtools.iterate_tests(suite))
+        self.assertEquals(
+            2,
+            len(result_tests),
+            result_tests)