2 files changed, 90 insertions, 9 deletions

diff --git a/src/mailman/utilities/tests/test_uid.py b/src/mailman/utilities/tests/test_uid.py
new file mode 100644
index 000000000..28df1c4b4
--- /dev/null
+++ b/src/mailman/utilities/tests/test_uid.py
@@ -0,0 +1,84 @@
+# Copyright (C) 2015 by the Free Software Foundation, Inc.
+#
+# This file is part of GNU Mailman.
+#
+# GNU Mailman 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 3 of the License, or (at your option)
+# any later version.
+#
+# GNU Mailman 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
+# GNU Mailman.  If not, see <http://www.gnu.org/licenses/>.
+
+"""Test the uid module."""
+
+__all__ = [
+    'TestUID',
+    ]
+
+
+import os
+import uuid
+import unittest
+
+from contextlib import ExitStack
+from mailman.config import config
+from mailman.testing.layers import ConfigLayer
+from mailman.utilities import uid
+from unittest.mock import patch
+
+
+
+class TestUID(unittest.TestCase):
+    layer = ConfigLayer
+
+    def _uid_files(self):
+        return [filename
+                for filename in os.listdir(os.path.join(config.VAR_DIR))
+                if filename.startswith('.uid')
+                ]
+
+    def test_context(self):
+        self.assertNotIn('.uid.foo', self._uid_files())
+        uid.UIDFactory('foo').new()
+        self.assertIn('.uid.foo', self._uid_files())
+
+    def test_no_context(self):
+        self.assertNotIn('.uid', self._uid_files())
+        uid.UIDFactory().new()
+        self.assertIn('.uid', self._uid_files())
+
+    def test_unpredictable_id(self):
+        with patch('mailman.utilities.uid.layers.is_testing',
+                   return_value=False):
+            self.assertNotEqual(uid.UIDFactory().new().int, 1)
+
+    def test_uid_record_try_again(self):
+        called = False
+        def record_second(ignore):
+            nonlocal called
+            if not called:
+                called = True
+                raise ValueError
+        with ExitStack() as resources:
+            resources.enter_context(
+                patch('mailman.utilities.uid.layers.is_testing',
+                      return_value=False))
+            resources.enter_context(
+                patch('mailman.utilities.uid.UID.record', record_second))
+            mock = resources.enter_context(
+                patch('mailman.utilities.uid.uuid.uuid4',
+                      return_value=uuid.UUID(int=1)))
+            uid.UIDFactory().new()
+            self.assertEqual(mock.call_count, 2)
+
+    def test_unpredictable_token_factory(self):
+        with patch('mailman.utilities.uid.layers.is_testing',
+                   return_value=False):
+            self.assertNotEqual(uid.TokenFactory().new(),
+                                '0000000000000000000000000000000000000001')
diff --git a/src/mailman/utilities/uid.py b/src/mailman/utilities/uid.py
index 9f24cef68..007f7e8f5 100644
--- a/src/mailman/utilities/uid.py
+++ b/src/mailman/utilities/uid.py
@@ -30,7 +30,6 @@ __all__ = [
 import os
 import time
 import uuid
-import errno
 import random
 import hashlib
 
@@ -64,7 +63,7 @@ class _PredictableIDGenerator:
             # These will get automatically cleaned up by the test
             # infrastructure.
             self._uid_file = os.path.join(config.VAR_DIR, '.uid')
-            if self._context:
+            if self._context is not None:
                 self._uid_file += '.' + self._context
             self._lock_file = self._uid_file + '.lock'
             self._lockobj = Lock(self._lock_file)
@@ -90,7 +89,7 @@ class _PredictableIDGenerator:
         The type of the returned id is intended to be the type that
         makes sense for the subclass overriding this method.
         """
-        raise NotImplementedError
+        raise NotImplementedError                   # pragma: no cover
 
     def _next_predictable_id(self):
         """Generate a predictable id for when Mailman being tested.
@@ -98,20 +97,18 @@ class _PredictableIDGenerator:
         The type of the returned id is intended to be the type that
         makes sense for the subclass overriding this method.
         """
-        raise NotImplementedError
+        raise NotImplementedError                   # pragma: no cover
 
     def _next_id(self):
         with self._lock:
             try:
                 with open(self._uid_file) as fp:
                     uid = int(fp.read().strip())
-                    next_uid = uid + 1
+                    next_uid = uid + 1              # pragma: no branch
                 with open(self._uid_file, 'w') as fp:
-                    fp.write(str(next_uid))
+                    fp.write(str(next_uid))         # pragma: no branch
                 return uid
-            except IOError as error:
-                if error.errno != errno.ENOENT:
-                    raise
+            except FileNotFoundError:
                 with open(self._uid_file, 'w') as fp:
                     fp.write('2')
                 return 1