Merge ~cjwatson/launchpad:fix-bugnotification-script-tests into launchpad:master

[Colin Watson]

Fix get_email_notifications tests to be effective

The tests for get_email_notifications didn't test what they claimed to test, because refactorings of the code under test some years ago meant that getBugNotificationRecipients is no longer called there, and it looks as though the tests were fixed up incorrectly. Fix the tests to actually be effective, and add assertions on the log output to ensure that this can't regress in the same way in future.

[Tom Wardill (twom)]

review: Approve

diff --git a/lib/lp/bugs/scripts/tests/test_bugnotification.py b/lib/lp/bugs/scripts/tests/test_bugnotification.py
index 38d11d9..7454ad4 100644
--- a/lib/lp/bugs/scripts/tests/test_bugnotification.py
+++ b/lib/lp/bugs/scripts/tests/test_bugnotification.py
@@ -1,4 +1,4 @@
-# Copyright 2009-2018 Canonical Ltd.  This software is licensed under the
+# Copyright 2009-2020 Canonical Ltd.  This software is licensed under the
 # GNU Affero General Public License version 3 (see the file LICENSE).
 """Tests for constructing bug notification emails for sending."""
 
@@ -10,13 +10,12 @@ from datetime import (
     datetime,
     timedelta,
     )
-import logging
 import re
 from smtplib import SMTPException
 import unittest
 
+from fixtures import FakeLogger
 import pytz
-import six
 from testtools.matchers import (
     MatchesRegex,
     Not,
@@ -54,6 +53,7 @@ from lp.bugs.interfaces.bugnotification import IBugNotificationSet
 from lp.bugs.interfaces.bugtask import (
     BugTaskImportance,
     BugTaskStatus,
+    IBugTaskSet,
     )
 from lp.bugs.mail.bugnotificationrecipients import BugNotificationRecipients
 from lp.bugs.model.bugnotification import (
@@ -62,7 +62,6 @@ from lp.bugs.model.bugnotification import (
     BugNotificationRecipient,
     )
 from lp.bugs.model.bugsubscriptionfilter import BugSubscriptionFilterMute
-from lp.bugs.model.bugtask import BugTask
 from lp.bugs.scripts.bugnotification import (
     construct_email_notifications,
     get_activity_key,
@@ -120,36 +119,11 @@ class MockBug:
     def title(self):
         return "Mock Bug #%s" % self.id
 
-    def getBugNotificationRecipients(self, level=None):
-        recipients = BugNotificationRecipients()
-        no_priv = getUtility(IPersonSet).getByEmail(
-            '[e-mail]')
-        recipients.addDirectSubscriber(no_priv)
-        return recipients
-
     def __eq__(self, other):
         """Compare by id to make different subclasses of MockBug be equal."""
         return self.id == other.id
 
 
-class ExceptionBug(MockBug):
-    """A bug which causes an exception to be raised."""
-
-    def getBugNotificationRecipients(self, level=None):
-        raise Exception('FUBAR')
-
-
-class DBExceptionBug(MockBug):
-    """A bug which causes a DB constraint to be triggered."""
-
-    def getBugNotificationRecipients(self, level=None):
-        # Trigger a DB constraint, resulting in the transaction being
-        # unusable.
-        firefox = getUtility(IProductSet).getByName('firefox')
-        bug_one = getUtility(IBugSet).get(1)
-        BugTask(bug=bug_one, product=firefox, owner=self.owner)
-
-
 class MockBugNotificationRecipient:
     """A mock BugNotificationRecipient for testing."""
 
@@ -172,9 +146,32 @@ class MockBugNotification:
         self.bug = bug
         self.is_comment = is_comment
         self.date_emailed = date_emailed
-        self.recipients = [MockBugNotificationRecipient()]
         self.activity = None
 
+    @property
+    def recipients(self):
+        return [MockBugNotificationRecipient()]
+
+
+class ExceptionBugNotification(MockBugNotification):
+    """A bug notification which causes an exception to be raised."""
+
+    @property
+    def recipients(self):
+        raise Exception('FUBAR')
+
+
+class DBExceptionBugNotification(MockBugNotification):
+    """A bug notification which causes a DB constraint to be triggered."""
+
+    @property
+    def recipients(self):
+        # Trigger a DB constraint, resulting in the transaction being
+        # unusable.
+        firefox = getUtility(IProductSet).getByName('firefox')
+        bug_one = getUtility(IBugSet).get(1)
+        getUtility(IBugTaskSet).createTask(bug_one, self.bug.owner, firefox)
+
 
 class FakeNotification:
     """An even simpler fake notification.
@@ -277,15 +274,15 @@ class TestGetEmailNotifications(TestCase):
         # A comment notification for bug one which raises an exception.
         msg = getUtility(IMessageSet).fromText(
             'Subject', "Comment on bug 1", owner=sample_person)
-        self.bug_one_exception_notification = MockBugNotification(
-            message=msg, bug=ExceptionBug(1, sample_person),
+        self.bug_one_exception_notification = ExceptionBugNotification(
+            message=msg, bug=MockBug(1, sample_person),
             is_comment=True, date_emailed=None)
 
         # A comment notification for bug one which raises a DB exception.
         msg = getUtility(IMessageSet).fromText(
             'Subject', "Comment on bug 1", owner=sample_person)
-        self.bug_one_dbexception_notification = MockBugNotification(
-            message=msg, bug=DBExceptionBug(1, sample_person),
+        self.bug_one_dbexception_notification = DBExceptionBugNotification(
+            message=msg, bug=MockBug(1, sample_person),
             is_comment=True, date_emailed=None)
 
         # We need to commit the transaction, since the error handling
@@ -298,6 +295,8 @@ class TestGetEmailNotifications(TestCase):
         self._fake_utility = FakeBugNotificationSetUtility()
         sm.registerUtility(self._fake_utility)
 
+        self.logger = self.useFixture(FakeLogger())
+
     def tearDown(self):
         super(TestGetEmailNotifications, self).tearDown()
         sm = getSiteManager()
@@ -339,7 +338,8 @@ class TestGetEmailNotifications(TestCase):
             ]
         sent_notifications = self._getAndCheckSentNotifications(
             notifications_to_send)
-        self.assertEqual(sent_notifications, notifications_to_send)
+        self.assertEqual(sent_notifications, [self.bug_one_notification])
+        self.assertIn('Exception: FUBAR', self.logger.output)
 
     def test_catch_simple_exception_in_the_middle(self):
         # Make sure that the first and last notifications are sent even
@@ -353,7 +353,8 @@ class TestGetEmailNotifications(TestCase):
             notifications_to_send)
         self.assertEqual(
             sent_notifications,
-            notifications_to_send)
+            [self.bug_one_notification, self.bug_one_another_notification])
+        self.assertIn('Exception: FUBAR', self.logger.output)
 
     def test_catch_db_exception_last(self):
         # Make sure that the first notification is sent even if the
@@ -365,7 +366,11 @@ class TestGetEmailNotifications(TestCase):
             ]
         sent_notifications = self._getAndCheckSentNotifications(
             notifications_to_send)
-        self.assertEqual(sent_notifications, notifications_to_send)
+        self.assertEqual(sent_notifications, [self.bug_one_notification])
+        self.assertIn(
+            'IllegalTarget: A fix for this bug has already been requested for '
+            'Mozilla Firefox',
+            self.logger.output)
 
         # The transaction should have been rolled back and restarted
         # properly, so getting something from the database shouldn't
@@ -385,7 +390,12 @@ class TestGetEmailNotifications(TestCase):
         sent_notifications = self._getAndCheckSentNotifications(
             notifications_to_send)
         self.assertEqual(
-            sent_notifications, notifications_to_send)
+            sent_notifications,
+            [self.bug_one_notification, self.bug_one_another_notification])
+        self.assertIn(
+            'IllegalTarget: A fix for this bug has already been requested for '
+            'Mozilla Firefox',
+            self.logger.output)
 
         # The transaction should have been rolled back and restarted
         # properly, so getting something from the database shouldn't
@@ -401,13 +411,6 @@ class TestGetEmailNotifications(TestCase):
         # verifies that the fix for that bug (re-raising the exception) stays
         # in place.
 
-        # Set up logging so we can later assert that no exceptions are logged.
-        log_output = six.StringIO()
-        logger = logging.getLogger()
-        log_handler = logging.StreamHandler(log_output)
-        logger.addHandler(logging.StreamHandler(log_output))
-        self.addCleanup(logger.removeHandler, log_handler)
-
         # Make some data to feed to get_email_notifications.
         person = getUtility(IPersonSet).getByEmail('[e-mail]')
         msg = getUtility(IMessageSet).fromText('', '', owner=person)
@@ -429,7 +432,7 @@ class TestGetEmailNotifications(TestCase):
         email_notifications.close()
 
         # Verify that no "Error while building email notifications." is logged.
-        self.assertEqual('', log_output.getvalue())
+        self.assertEqual('', self.logger.output)
 
 
 class TestNotificationCommentBatches(unittest.TestCase):