Rev 2924: * New helper method ``bzrlib.tests.randomise_suite`` which returns a in http://people.ubuntu.com/~robertc/baz2.0/in-module-parameterisation

[Robert Collins]

At http://people.ubuntu.com/~robertc/baz2.0/in-module-parameterisation

------------------------------------------------------------
revno: 2924
revision-id: robertc at robertcollins.net-20071020230154-r22h8rsgpbhnw163
parent: robertc at robertcollins.net-20071020224938-bh7rlcyv10oyztxc
committer: Robert Collins <robertc at robertcollins.net>
branch nick: in-module-parameterisation
timestamp: Sun 2007-10-21 09:01:54 +1000
message:
  * New helper method ``bzrlib.tests.randomise_suite`` which returns a
    randomised copy of the input suite. (Robert Collins)
modified:
  NEWS                           NEWS-20050323055033-4e00b5db738777ff
  bzrlib/tests/__init__.py       selftest.py-20050531073622-8d0e3c8845c97a64
  bzrlib/tests/test_selftest.py  test_selftest.py-20051202044319-c110a115d8c0456a
=== modified file 'NEWS'
--- a/NEWS	2007-10-20 22:49:38 +0000
+++ b/NEWS	2007-10-20 23:01:54 +0000
@@ -267,6 +267,9 @@
      TestSuite that does not contain tests from the input that matched a
      regular expression. (Robert Collins)
 
+   * New helper method ``bzrlib.tests.randomise_suite`` which returns a
+     randomised copy of the input suite. (Robert Collins)
+
    * New helper method ``bzrlib.tests.split_suite_by_re`` which splits a test
      suite into two according to a regular expression. (Robert Collins)
 

=== modified file 'bzrlib/tests/__init__.py'
--- a/bzrlib/tests/__init__.py	2007-10-20 22:49:38 +0000
+++ b/bzrlib/tests/__init__.py	2007-10-20 23:01:54 +0000
@@ -2228,6 +2228,13 @@
     return TestUtil.TestSuite(result)
 
 
+def randomise_suite(suite):
+    """Return a new TestSuite with suite's tests in random order."""
+    tests = list(iter_suite_tests(suite))
+    random.shuffle(tests)
+    return TestUtil.TestSuite(tests)
+
+
 def sort_suite_by_re(suite, pattern, exclude_pattern=None,
                      random_order=False, append_rest=True):
     """Create a test suite by sorting another one.
@@ -2258,9 +2265,10 @@
                 result.append(test)
             elif filter_re.search(test_id):
                 result.append(test)
+        result_suite = TestUtil.TestSuite(result)
         if random_order:
-            random.shuffle(result)
-        out_tests.extend(result)
+            result_suite = randomise_suite(result_suite)
+        out_tests.append(result_suite)
     return TestUtil.TestSuite(out_tests)
 
 

=== modified file 'bzrlib/tests/test_selftest.py'
--- a/bzrlib/tests/test_selftest.py	2007-10-20 22:49:38 +0000
+++ b/bzrlib/tests/test_selftest.py	2007-10-20 23:01:54 +0000
@@ -57,6 +57,7 @@
                           exclude_tests_by_re,
                           filter_suite_by_re,
                           iter_suite_tests,
+                          randomise_suite,
                           sort_suite_by_re,
                           split_suite_by_re,
                           test_lsprof,
@@ -1670,6 +1671,22 @@
         self.assertEqual(filtered_names, ['bzrlib.tests.test_selftest.'
             'TestSelftestFiltering.test_filter_suite_by_re'])
 
+    def test_randomise_suite(self):
+        randomised_suite = randomise_suite(self.suite)
+        # randomising should not add or remove test names.
+        self.assertEqual(set(self._test_ids(self.suite)),
+            set(self._test_ids(randomised_suite)))
+        # Technically, this *can* fail, because random.shuffle(list) can be
+        # equal to list. Trying multiple times just pushes the frequency back.
+        # As its len(self.all_names)!:1, the failure frequency should be low
+        # enough to ignore. RBC 20071021.
+        # It should change the order.
+        self.assertNotEqual(self.all_names, self._test_ids(randomised_suite))
+        # But not the length. (Possibly redundant with the set test, but not
+        # necessarily.)
+        self.assertEqual(len(self.all_names),
+            len(self._test_ids(randomised_suite)))
+
     def test_sort_suite_by_re(self):
         sorted_suite = sort_suite_by_re(self.suite, 'test_filter')
         sorted_names = self._test_ids(sorted_suite)