Merge lp:~cjwatson/lazr.lifecycle/zope.lifecycleevent-4.2.0-compat into lp:lazr.lifecycle

[Colin Watson]

Add ObjectModifiedEvent.descriptions property.

This fixes tests with zope.lifecycleevent >= 4.2.0.

[Ioana Lasc (ilasc)]

review: Approve

=== modified file 'src/lazr/lifecycle/NEWS.txt'
--- src/lazr/lifecycle/NEWS.txt	2019-08-21 12:10:12 +0000
+++ src/lazr/lifecycle/NEWS.txt	2019-10-07 09:12:42 +0000
@@ -6,6 +6,8 @@
 ===
 
 - Import IObjectEvent from zope.interface rather than zope.component.
+- Add ObjectModifiedEvent.descriptions property, for compatibility with
+  zope.lifecycleevent >= 4.2.0.
 
 1.1 (2009-12-03)
 ================

=== modified file 'src/lazr/lifecycle/event.py'
--- src/lazr/lifecycle/event.py	2009-03-24 16:17:11 +0000
+++ src/lazr/lifecycle/event.py	2019-10-07 09:12:42 +0000
@@ -85,3 +85,10 @@
         super(ObjectModifiedEvent, self).__init__(object, user=user)
         self.object_before_modification = object_before_modification
         self.edited_fields = edited_fields
+
+    # Compatibility with zope.lifecycleevent.  (Note that the returned
+    # modification descriptions only implement `IModificationDescription` if
+    # suitable objects were passed when constructing this event.)
+    @property
+    def descriptions(self):
+        return self.edited_fields