Write generate_scenarios.

5 files changed, 161 insertions, 7 deletions

diff --git a/lib/testscenarios/__init__.py b/lib/testscenarios/__init__.py
index 57b49b4..4e0bf5d 100644
--- a/lib/testscenarios/__init__.py
+++ b/lib/testscenarios/__init__.py
@@ -29,9 +29,15 @@ See the README for a manual, and the docstrings on individual functions and
 methods for details.
 """
 
+__all__ = [
+    'TestWithScenarios',
+    'generate_scenarios',
+    ]
+
 
 import unittest
 
+from testscenarios.scenarios import generate_scenarios
 from testscenarios.testcase import TestWithScenarios
 
 
diff --git a/lib/testscenarios/scenarios.py b/lib/testscenarios/scenarios.py
new file mode 100644
index 0000000..bbc73ad
--- /dev/null
+++ b/lib/testscenarios/scenarios.py
@@ -0,0 +1,50 @@
+#  testscenarios: extensions to python unittest to allow declarative
+#  dependency injection ('scenarios') by tests.
+#  Copyright (C) 2009  Robert Collins <robertc@robertcollins.net>
+#
+#  This program is free software; you can redistribute it and/or modify
+#  it under the terms of the GNU General Public License as published by
+#  the Free Software Foundation; either version 2 of the License, or
+#  (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program; if not, write to the Free Software
+#  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+#
+
+__all__ = [
+    'generate_scenarios',
+    ]
+
+import unittest
+
+from testtools.testcase import clone_test_with_new_id
+from testtools import iterate_tests
+
+def generate_scenarios(test_or_suite):
+    """Yield the tests in test_or_suite with scenario multiplication done.
+
+    TestCase objects with no scenarios specified are yielded unaltered. Tests
+    with scenarios are not yielded at all, instead the results of multiplying
+    them by the scenarios they specified gets yielded.
+
+    :param test_or_suite: A TestCase or TestSuite.
+    :return: A generator of tests - objects satisfying the TestCase protocol.
+    """
+    for test in iterate_tests(test_or_suite):
+        scenarios = getattr(test, 'scenarios', None)
+        if scenarios:
+            for name, parameters in scenarios:
+                newtest = clone_test_with_new_id(test,
+                    test.id() + '(' + name + ')')
+                newtest.scenarios = None
+                for key, value in parameters.iteritems():
+                    setattr(newtest, key, value)
+                yield newtest
+        else:
+            yield test
diff --git a/lib/testscenarios/testcase.py b/lib/testscenarios/testcase.py
index ec27e39..712d543 100644
--- a/lib/testscenarios/testcase.py
+++ b/lib/testscenarios/testcase.py
@@ -25,6 +25,8 @@ import unittest
 
 from testtools.testcase import clone_test_with_new_id
 
+from testscenarios.scenarios import generate_scenarios
+
 class TestWithScenarios(unittest.TestCase):
     """A TestCase with support for scenarios via a scenarios attribute.
     
@@ -38,13 +40,8 @@ class TestWithScenarios(unittest.TestCase):
     def run(self, result=None):
         scenarios = getattr(self, 'scenarios', None)
         if scenarios:
-            for name, parameters in scenarios:
-                newtest = clone_test_with_new_id(self,
-                    self.id() + '(' + name + ')')
-                newtest.scenarios = None
-                for key, value in parameters.iteritems():
-                    setattr(newtest, key, value)
-                newtest.run(result)
+            for test in generate_scenarios(self):
+                test.run(result)
             return
         else:
             return super(TestWithScenarios, self).run(result)
diff --git a/lib/testscenarios/tests/__init__.py b/lib/testscenarios/tests/__init__.py
index 1777e74..9bce8a3 100644
--- a/lib/testscenarios/tests/__init__.py
+++ b/lib/testscenarios/tests/__init__.py
@@ -34,6 +34,7 @@ def test_suite():
 def load_tests(standard_tests, module, loader):
     test_modules = [
         'testcase',
+        'scenarios',
         ]
     prefix = "testscenarios.tests.test_"
     test_mod_names = [prefix + test_module for test_module in test_modules]
diff --git a/lib/testscenarios/tests/test_scenarios.py b/lib/testscenarios/tests/test_scenarios.py
new file mode 100644
index 0000000..b019d97
--- /dev/null
+++ b/lib/testscenarios/tests/test_scenarios.py
@@ -0,0 +1,100 @@
+#  testscenarios: extensions to python unittest to allow declarative
+#  dependency injection ('scenarios') by tests.
+#  Copyright (C) 2009  Robert Collins <robertc@robertcollins.net>
+#
+#  This program is free software; you can redistribute it and/or modify
+#  it under the terms of the GNU General Public License as published by
+#  the Free Software Foundation; either version 2 of the License, or
+#  (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program; if not, write to the Free Software
+#  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+#
+
+import unittest
+
+import testscenarios
+from testscenarios.scenarios import generate_scenarios
+from testtools.tests.helpers import LoggingResult
+
+
+class TestGenerateScenarios(unittest.TestCase):
+
+    def test_generate_scenarios_preserves_normal_test(self):
+        class ReferenceTest(unittest.TestCase):
+            def test_pass(self):
+                pass
+        test = ReferenceTest("test_pass")
+        self.assertEqual([test], list(generate_scenarios(test)))
+
+    def test_normal_test_with_one_scenario(self):
+        class ReferenceTest(unittest.TestCase):
+            scenarios = [('demo', {})]
+            def test_pass(self):
+                pass
+        test = ReferenceTest("test_pass")
+        tests = list(generate_scenarios(test))
+        self.assertEqual(
+            'testscenarios.tests.test_scenarios.ReferenceTest.test_pass(demo)',
+            tests[0].id())
+
+    def test_normal_test_two_scenarios(self):
+        class ReferenceTest(unittest.TestCase):
+            scenarios = [('1', {}), ('2', {})]
+            def test_pass(self):
+                pass
+        test = ReferenceTest("test_pass")
+        tests = list(generate_scenarios(test))
+        self.assertEqual(
+            'testscenarios.tests.test_scenarios.ReferenceTest.test_pass(1)',
+            tests[0].id())
+        self.assertEqual(
+            'testscenarios.tests.test_scenarios.ReferenceTest.test_pass(2)',
+            tests[1].id())
+
+    def test_attributes_set(self):
+        class ReferenceTest(unittest.TestCase):
+            scenarios = [
+                ('1', {'foo': 1, 'bar': 2}),
+                ('2', {'foo': 2, 'bar': 4})]
+            def test_check_foo(self):
+                pass
+        test = ReferenceTest("test_check_foo")
+        tests = list(generate_scenarios(test))
+        self.assertEqual(1, tests[0].foo)
+        self.assertEqual(2, tests[0].bar)
+        self.assertEqual(2, tests[1].foo)
+        self.assertEqual(4, tests[1].bar)
+
+    def test_scenarios_attribute_cleared(self):
+        class ReferenceTest(unittest.TestCase):
+            scenarios = [
+                ('1', {'foo': 1, 'bar': 2}),
+                ('2', {'foo': 2, 'bar': 4})]
+            def test_check_foo(self):
+                pass
+        test = ReferenceTest("test_check_foo")
+        tests = list(generate_scenarios(test))
+        for adapted in tests:
+            self.assertEqual(None, adapted.scenarios)
+
+    def test_multiple_tests(self):
+        class Reference1(unittest.TestCase):
+            scenarios = [('1', {}), ('2', {})]
+            def test_something(self):
+                pass
+        class Reference2(unittest.TestCase):
+            scenarios = [('3', {}), ('4', {})]
+            def test_something(self):
+                pass
+        suite = unittest.TestSuite()
+        suite.addTest(Reference1("test_something"))
+        suite.addTest(Reference2("test_something"))
+        tests = list(generate_scenarios(suite))
+        self.assertEqual(4, len(tests))