Handle overlapping black regexes

It's very common for blacklist files and/or a black regex to have
overlapping matches. In this case ostestr was incorrectly trying to
remove tests from the set of test cases more than once. This commit
fixes this case by simply adding a check if the test is in the set
before trying to delete it. If it's not there, then something else
already removed it from the set of tests we'll be running so we can
just move on.

Change-Id: I1dabf9fb9c182af3dd6e124e79e54e1eb99bed82

os_testr/testlist_builder.py

@@ -94,6 +94,9 @@ def construct_list(blacklist_file, whitelist_file, regex, black_regex,
     for (rex, msg, s_list) in black_data:
         for test_case in list_of_test_cases:
             if rex.search(test_case):
+                # NOTE(mtreinish): In the case of overlapping regex the test
+                # case might have already been removed from the set of tests
+                if test_case in set_of_test_cases:
                     set_of_test_cases.remove(test_case)
                     s_list.append(test_case)
 

os_testr/tests/testlist_builder.py

@@ -114,3 +114,25 @@ class TestConstructList(base.TestCase):
                                                          False)
         self.assertEqual(set(result),
                          set(('fake_test1[tg]', 'fake_test3[tg,foo]')))
+
+    def test_overlapping_black_regex(self):
+
+        black_list = [(re.compile('compute.test_keypairs.KeypairsTestV210'),
+                       '', []),
+                      (re.compile('compute.test_keypairs.KeypairsTestV21'),
+                       '', [])]
+        test_lists = [
+            'compute.test_keypairs.KeypairsTestV210.test_create_keypair',
+            'compute.test_keypairs.KeypairsTestV21.test_create_keypair',
+            'compute.test_fake.FakeTest.test_fake_test']
+        with mock.patch('os_testr.regex_builder._get_test_list',
+                        return_value=test_lists):
+            with mock.patch('os_testr.testlist_builder.black_reader',
+                            return_value=black_list):
+                result = list_builder.construct_list('file',
+                                                     None,
+                                                     'fake_test',
+                                                     None,
+                                                     False)
+        self.assertEqual(
+            list(result), ['compute.test_fake.FakeTest.test_fake_test'])