[PATCH v3 2/3] Include the responsible actor in applicable events

[Johan Herland]

We want to use the events as an audit log. An important part of this is
recording _who_ made the changes that the events represent.

To accomplish this, we need to know the current user (aka. request.user)
at the point where we create the Event instance. Event creation is
currently triggered by signals, but neither the signal handlers, nor the
model classes themselves have easy access to request.user.

For Patch-based events (patch-created, patch-state-changed,
patch-delegated, patch-completed), we can do the following hack:
The relevant events are created in signal handlers that are all hooked
up to either the pre_save or post_save signals sent by Patch.save().
But before calling Patch.save(), Patchwork must naturally query
Patch.is_editable() to ascertain whether the patch can in fact be
changed by the current user. Thus, we only need a way to communicate
the current user from Patch.is_editable() to the signal handlers that
create the resulting Events. The Patch object itself is available in
both places, so we simply add an ._edited_by attribute to the instance
(which fortunately is not detected as a persistent db field by Django).

The series-completed event is also triggered by Patch.save(), so uses
the same trick as above.

For the check-created event the current user always happens to be the
same as the .user field recorded in the Check object itself.

The remaining events (cover-created, series-created) are both triggered
by incoming emails, hence have no real actor as such, so we simply leave
the actor as None/NULL.

Closes: #73
Cc: Mauro Carvalho Chehab <mchehab+samsung at kernel.org>
Signed-off-by: Johan Herland <johan at herland.net>
---
 patchwork/models.py            |  6 +++++-
 patchwork/signals.py           | 10 ++++++++--
 patchwork/tests/test_events.py |  7 +++++++
 3 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/patchwork/models.py b/patchwork/models.py
index b43c15a..f37572e 100644
--- a/patchwork/models.py
+++ b/patchwork/models.py
@@ -498,9 +498,13 @@ class Patch(Submission):
             return False
 
         if user in [self.submitter.user, self.delegate]:
+            self._edited_by = user
             return True
 
-        return self.project.is_editable(user)
+        if self.project.is_editable(user):
+            self._edited_by = user
+            return True
+        return False
 
     @property
     def combined_check_state(self):
diff --git a/patchwork/signals.py b/patchwork/signals.py
index 666199b..987cc5a 100644
--- a/patchwork/signals.py
+++ b/patchwork/signals.py
@@ -77,6 +77,7 @@ def create_patch_created_event(sender, instance, created, raw, **kwargs):
         return Event.objects.create(
             category=Event.CATEGORY_PATCH_CREATED,
             project=patch.project,
+            actor=getattr(patch, '_edited_by', None),
             patch=patch)
 
     # don't trigger for items loaded from fixtures or new items
@@ -93,6 +94,7 @@ def create_patch_state_changed_event(sender, instance, raw, **kwargs):
         return Event.objects.create(
             category=Event.CATEGORY_PATCH_STATE_CHANGED,
             project=patch.project,
+            actor=getattr(patch, '_edited_by', None),
             patch=patch,
             previous_state=before,
             current_state=after)
@@ -116,6 +118,7 @@ def create_patch_delegated_event(sender, instance, raw, **kwargs):
         return Event.objects.create(
             category=Event.CATEGORY_PATCH_DELEGATED,
             project=patch.project,
+            actor=getattr(patch, '_edited_by', None),
             patch=patch,
             previous_delegate=before,
             current_delegate=after)
@@ -139,6 +142,7 @@ def create_patch_completed_event(sender, instance, raw, **kwargs):
         return Event.objects.create(
             category=Event.CATEGORY_PATCH_COMPLETED,
             project=patch.project,
+            actor=getattr(patch, '_edited_by', None),
             patch=patch,
             series=patch.series)
 
@@ -184,6 +188,7 @@ def create_check_created_event(sender, instance, created, raw, **kwargs):
         return Event.objects.create(
             category=Event.CATEGORY_CHECK_CREATED,
             project=check.patch.project,
+            actor=check.user,
             patch=check.patch,
             created_check=check)
 
@@ -219,10 +224,11 @@ def create_series_completed_event(sender, instance, raw, **kwargs):
     # exists in the wild ('PATCH 5/n'), so we probably want to retest a series
     # in that case.
 
-    def create_event(series):
+    def create_event(series, actor):
         return Event.objects.create(
             category=Event.CATEGORY_SERIES_COMPLETED,
             project=series.project,
+            actor=actor,
             series=series)
 
     # don't trigger for items loaded from fixtures, new items or items that
@@ -241,4 +247,4 @@ def create_series_completed_event(sender, instance, raw, **kwargs):
     # we can't use "series.received_all" here since we haven't actually saved
     # the instance yet so we duplicate that logic here but with an offset
     if (instance.series.received_total + 1) >= instance.series.total:
-        create_event(instance.series)
+        create_event(instance.series, getattr(instance, '_edited_by', None))
diff --git a/patchwork/tests/test_events.py b/patchwork/tests/test_events.py
index e5c40b5..415237f 100644
--- a/patchwork/tests/test_events.py
+++ b/patchwork/tests/test_events.py
@@ -110,8 +110,10 @@ class PatchChangedTest(_BaseTestCase):
         patch = utils.create_patch(series=None)
         old_state = patch.state
         new_state = utils.create_state()
+        actor = utils.create_maintainer(project=patch.project)
 
         patch.state = new_state
+        self.assertTrue(patch.is_editable(actor))
         patch.save()
 
         events = _get_events(patch=patch)
@@ -120,6 +122,7 @@ class PatchChangedTest(_BaseTestCase):
         self.assertEqual(events[1].category,
                          Event.CATEGORY_PATCH_STATE_CHANGED)
         self.assertEqual(events[1].project, patch.project)
+        self.assertEqual(events[1].actor, actor)
         self.assertEventFields(events[1], previous_state=old_state,
                                current_state=new_state)
 
@@ -127,10 +130,12 @@ class PatchChangedTest(_BaseTestCase):
         # purposefully setting series to None to minimize additional events
         patch = utils.create_patch(series=None)
         delegate_a = utils.create_user()
+        actor = utils.create_maintainer(project=patch.project)
 
         # None -> Delegate A
 
         patch.delegate = delegate_a
+        self.assertTrue(patch.is_editable(actor))
         patch.save()
 
         events = _get_events(patch=patch)
@@ -139,6 +144,7 @@ class PatchChangedTest(_BaseTestCase):
         self.assertEqual(events[1].category,
                          Event.CATEGORY_PATCH_DELEGATED)
         self.assertEqual(events[1].project, patch.project)
+        self.assertEqual(events[1].actor, actor)
         self.assertEventFields(events[1], current_delegate=delegate_a)
 
         delegate_b = utils.create_user()
@@ -175,6 +181,7 @@ class CheckCreatedTest(_BaseTestCase):
         self.assertEqual(events.count(), 1)
         self.assertEqual(events[0].category, Event.CATEGORY_CHECK_CREATED)
         self.assertEqual(events[0].project, check.patch.project)
+        self.assertEqual(events[0].actor, check.user)
         self.assertEventFields(events[0])
 
 
-- 
2.19.2