Add GV2 copy for the unknown editor.

app/src/main/java/org/thoughtcrime/securesms/database/model/GroupsV2UpdateMessageProducer.java

@@ -78,20 +78,39 @@ final class GroupsV2UpdateMessageProducer {
   List<String> describeChange(@NonNull DecryptedGroupChange change) {
     List<String> updates = new LinkedList<>();
 
-    describeMemberAdditions(change, updates);
+    if (change.getEditor().isEmpty() || UuidUtil.UNKNOWN_UUID.equals(UuidUtil.fromByteString(change.getEditor()))) {
-    describeMemberRemovals(change, updates);
+      describeUnknownEditorMemberAdditions(change, updates);
-    describeModifyMemberRoles(change, updates);
+      describeUnknownEditorMemberRemovals(change, updates);
-    describeInvitations(change, updates);
+      describeUnknownEditorModifyMemberRoles(change, updates);
-    describeRevokedInvitations(change, updates);
+      describeUnknownEditorInvitations(change, updates);
-    describePromotePending(change, updates);
+      describeUnknownEditorRevokedInvitations(change, updates);
-    describeNewTitle(change, updates);
+      describeUnknownEditorPromotePending(change, updates);
-    describeNewAvatar(change, updates);
+      describeUnknownEditorNewTitle(change, updates);
-    describeNewTimer(change, updates);
+      describeUnknownEditorNewAvatar(change, updates);
-    describeNewAttributeAccess(change, updates);
+      describeUnknownEditorNewTimer(change, updates);
-    describeNewMembershipAccess(change, updates);
+      describeUnknownEditorNewAttributeAccess(change, updates);
+      describeUnknownEditorNewMembershipAccess(change, updates);
 
-    if (updates.isEmpty()) {
+      if (updates.isEmpty()) {
-      describeUnknownChange(change, updates);
+        describeUnknownEditorUnknownChange(updates);
+      }
+
+    } else {
+      describeMemberAdditions(change, updates);
+      describeMemberRemovals(change, updates);
+      describeModifyMemberRoles(change, updates);
+      describeInvitations(change, updates);
+      describeRevokedInvitations(change, updates);
+      describePromotePending(change, updates);
+      describeNewTitle(change, updates);
+      describeNewAvatar(change, updates);
+      describeNewTimer(change, updates);
+      describeNewAttributeAccess(change, updates);
+      describeNewMembershipAccess(change, updates);
+
+      if (updates.isEmpty()) {
+        describeUnknownChange(change, updates);
+      }
     }
 
     return updates;
@@ -110,6 +129,10 @@ final class GroupsV2UpdateMessageProducer {
     }
   }
 
+  private void describeUnknownEditorUnknownChange(@NonNull List<String> updates) {
+    updates.add(context.getString(R.string.MessageRecord_the_group_was_updated));
+  }
+
   private void describeMemberAdditions(@NonNull DecryptedGroupChange change, @NonNull List<String> updates) {
     boolean editorIsYou = change.getEditor().equals(selfUuidBytes);
 
@@ -136,6 +159,18 @@ final class GroupsV2UpdateMessageProducer {
     }
   }
 
+  private void describeUnknownEditorMemberAdditions(@NonNull DecryptedGroupChange change, @NonNull List<String> updates) {
+    for (DecryptedMember member : change.getNewMembersList()) {
+      boolean newMemberIsYou = member.getUuid().equals(selfUuidBytes);
+
+      if (newMemberIsYou) {
+        updates.add(context.getString(R.string.MessageRecord_you_joined_the_group));
+      } else {
+        updates.add(context.getString(R.string.MessageRecord_s_joined_the_group, describe(member.getUuid())));
+      }
+    }
+  }
+
   private void describeMemberRemovals(@NonNull DecryptedGroupChange change, @NonNull List<String> updates) {
     boolean editorIsYou = change.getEditor().equals(selfUuidBytes);
 
@@ -162,16 +197,28 @@ final class GroupsV2UpdateMessageProducer {
     }
   }
 
+  private void describeUnknownEditorMemberRemovals(@NonNull DecryptedGroupChange change, @NonNull List<String> updates) {
+    for (ByteString member : change.getDeleteMembersList()) {
+      boolean removedMemberIsYou = member.equals(selfUuidBytes);
+
+      if (removedMemberIsYou) {
+        updates.add(context.getString(R.string.MessageRecord_you_are_no_longer_in_the_group));
+      } else {
+        updates.add(context.getString(R.string.MessageRecord_s_is_no_longer_in_the_group, describe(member)));
+      }
+    }
+  }
+
   private void describeModifyMemberRoles(@NonNull DecryptedGroupChange change, @NonNull List<String> updates) {
     boolean editorIsYou = change.getEditor().equals(selfUuidBytes);
 
     for (DecryptedModifyMemberRole roleChange : change.getModifyMemberRolesList()) {
+      boolean changedMemberIsYou = roleChange.getUuid().equals(selfUuidBytes);
       if (roleChange.getRole() == Member.Role.ADMINISTRATOR) {
-        boolean newMemberIsYou = roleChange.getUuid().equals(selfUuidBytes);
         if (editorIsYou) {
           updates.add(context.getString(R.string.MessageRecord_you_made_s_an_admin, describe(roleChange.getUuid())));
         } else {
-          if (newMemberIsYou) {
+          if (changedMemberIsYou) {
             updates.add(context.getString(R.string.MessageRecord_s_made_you_an_admin, describe(change.getEditor())));
           } else {
             updates.add(context.getString(R.string.MessageRecord_s_made_s_an_admin, describe(change.getEditor()), describe(roleChange.getUuid())));
@@ -179,11 +226,10 @@ final class GroupsV2UpdateMessageProducer {
           }
         }
       } else {
-        boolean newMemberIsYou = roleChange.getUuid().equals(selfUuidBytes);
         if (editorIsYou) {
           updates.add(context.getString(R.string.MessageRecord_you_revoked_admin_privileges_from_s, describe(roleChange.getUuid())));
         } else {
-          if (newMemberIsYou) {
+          if (changedMemberIsYou) {
             updates.add(context.getString(R.string.MessageRecord_s_revoked_your_admin_privileges, describe(change.getEditor())));
           } else {
             updates.add(context.getString(R.string.MessageRecord_s_revoked_admin_privileges_from_s, describe(change.getEditor()), describe(roleChange.getUuid())));
@@ -193,6 +239,26 @@ final class GroupsV2UpdateMessageProducer {
     }
   }
 
+  private void describeUnknownEditorModifyMemberRoles(@NonNull DecryptedGroupChange change, @NonNull List<String> updates) {
+    for (DecryptedModifyMemberRole roleChange : change.getModifyMemberRolesList()) {
+      boolean changedMemberIsYou = roleChange.getUuid().equals(selfUuidBytes);
+
+      if (roleChange.getRole() == Member.Role.ADMINISTRATOR) {
+        if (changedMemberIsYou) {
+          updates.add(context.getString(R.string.MessageRecord_you_are_now_an_admin));
+        } else {
+          updates.add(context.getString(R.string.MessageRecord_s_is_now_an_admin, describe(roleChange.getUuid())));
+        }
+      } else {
+        if (changedMemberIsYou) {
+          updates.add(context.getString(R.string.MessageRecord_you_are_no_longer_an_admin));
+        } else {
+          updates.add(context.getString(R.string.MessageRecord_s_is_no_longer_an_admin, describe(roleChange.getUuid())));
+        }
+      }
+    }
+  }
+
   private void describeInvitations(@NonNull DecryptedGroupChange change, @NonNull List<String> updates) {
     boolean editorIsYou       = change.getEditor().equals(selfUuidBytes);
     int     notYouInviteCount = 0;
@@ -216,6 +282,24 @@ final class GroupsV2UpdateMessageProducer {
     }
   }
 
+  private void describeUnknownEditorInvitations(@NonNull DecryptedGroupChange change, @NonNull List<String> updates) {
+    int notYouInviteCount = 0;
+
+    for (DecryptedPendingMember invitee : change.getNewPendingMembersList()) {
+      boolean newMemberIsYou = invitee.getUuid().equals(selfUuidBytes);
+
+      if (newMemberIsYou) {
+        updates.add(context.getString(R.string.MessageRecord_you_were_invited_to_the_group));
+      } else {
+        notYouInviteCount++;
+      }
+    }
+
+    if (notYouInviteCount > 0) {
+      updates.add(context.getResources().getQuantityString(R.plurals.MessageRecord_d_people_were_invited_to_the_group, notYouInviteCount, notYouInviteCount));
+    }
+  }
+
   private void describeRevokedInvitations(@NonNull DecryptedGroupChange change, @NonNull List<String> updates) {
     boolean editorIsYou     = change.getEditor().equals(selfUuidBytes);
     int     notDeclineCount = 0;
@@ -242,6 +326,24 @@ final class GroupsV2UpdateMessageProducer {
     }
   }
 
+  private void describeUnknownEditorRevokedInvitations(@NonNull DecryptedGroupChange change, @NonNull List<String> updates) {
+    int notDeclineCount = 0;
+
+    for (DecryptedPendingMemberRemoval invitee : change.getDeletePendingMembersList()) {
+      boolean inviteeWasYou = invitee.getUuid().equals(selfUuidBytes);
+
+      if (inviteeWasYou) {
+        updates.add(context.getString(R.string.MessageRecord_your_invitation_to_the_group_was_revoked));
+      } else {
+        notDeclineCount++;
+      }
+    }
+
+    if (notDeclineCount > 0) {
+      updates.add(context.getResources().getQuantityString(R.plurals.MessageRecord_d_invitations_were_revoked, notDeclineCount, notDeclineCount));
+    }
+  }
+
   private void describePromotePending(@NonNull DecryptedGroupChange change, @NonNull List<String> updates) {
     boolean editorIsYou = change.getEditor().equals(selfUuidBytes);
 
@@ -269,6 +371,19 @@ final class GroupsV2UpdateMessageProducer {
     }
   }
 
+  private void describeUnknownEditorPromotePending(@NonNull DecryptedGroupChange change, @NonNull List<String> updates) {
+    for (DecryptedMember newMember : change.getPromotePendingMembersList()) {
+      ByteString uuid           = newMember.getUuid();
+      boolean    newMemberIsYou = uuid.equals(selfUuidBytes);
+
+      if (newMemberIsYou) {
+        updates.add(context.getString(R.string.MessageRecord_you_joined_the_group));
+      } else {
+        updates.add(context.getString(R.string.MessageRecord_s_joined_the_group, describe(uuid)));
+      }
+    }
+  }
+
   private void describeNewTitle(@NonNull DecryptedGroupChange change, @NonNull List<String> updates) {
     boolean editorIsYou = change.getEditor().equals(selfUuidBytes);
 
@@ -281,6 +396,12 @@ final class GroupsV2UpdateMessageProducer {
     }
   }
 
+  private void describeUnknownEditorNewTitle(@NonNull DecryptedGroupChange change, @NonNull List<String> updates) {
+    if (change.hasNewTitle()) {
+      updates.add(context.getString(R.string.MessageRecord_the_group_name_has_changed_to_s, change.getNewTitle().getValue()));
+    }
+  }
+
   private void describeNewAvatar(@NonNull DecryptedGroupChange change, @NonNull List<String> updates) {
     boolean editorIsYou = change.getEditor().equals(selfUuidBytes);
 
@@ -293,6 +414,12 @@ final class GroupsV2UpdateMessageProducer {
     }
   }
 
+  private void describeUnknownEditorNewAvatar(@NonNull DecryptedGroupChange change, @NonNull List<String> updates) {
+    if (change.hasNewAvatar()) {
+      updates.add(context.getString(R.string.MessageRecord_the_group_group_avatar_has_been_changed));
+    }
+  }
+
   private void describeNewTimer(@NonNull DecryptedGroupChange change, @NonNull List<String> updates) {
     boolean editorIsYou = change.getEditor().equals(selfUuidBytes);
 
@@ -306,6 +433,13 @@ final class GroupsV2UpdateMessageProducer {
     }
   }
 
+  private void describeUnknownEditorNewTimer(@NonNull DecryptedGroupChange change, @NonNull List<String> updates) {
+    if (change.hasNewTimer()) {
+      String time = ExpirationUtil.getExpirationDisplayValue(context, change.getNewTimer().getDuration());
+      updates.add(context.getString(R.string.MessageRecord_disappearing_message_time_set_to_s, time));
+    }
+  }
+
   private void describeNewAttributeAccess(@NonNull DecryptedGroupChange change, @NonNull List<String> updates) {
     boolean editorIsYou = change.getEditor().equals(selfUuidBytes);
 
@@ -319,6 +453,13 @@ final class GroupsV2UpdateMessageProducer {
     }
   }
 
+  private void describeUnknownEditorNewAttributeAccess(@NonNull DecryptedGroupChange change, @NonNull List<String> updates) {
+    if (change.getNewAttributeAccess() != AccessControl.AccessRequired.UNKNOWN) {
+      String accessLevel = GV2AccessLevelUtil.toString(context, change.getNewAttributeAccess());
+      updates.add(context.getString(R.string.MessageRecord_who_can_edit_group_info_has_been_changed_to_s, accessLevel));
+    }
+  }
+
   private void describeNewMembershipAccess(@NonNull DecryptedGroupChange change, @NonNull List<String> updates) {
     boolean editorIsYou = change.getEditor().equals(selfUuidBytes);
 
@@ -332,6 +473,13 @@ final class GroupsV2UpdateMessageProducer {
     }
   }
 
+  private void describeUnknownEditorNewMembershipAccess(@NonNull DecryptedGroupChange change, @NonNull List<String> updates) {
+    if (change.getNewMemberAccess() != AccessControl.AccessRequired.UNKNOWN) {
+      String accessLevel = GV2AccessLevelUtil.toString(context, change.getNewMemberAccess());
+      updates.add(context.getString(R.string.MessageRecord_who_can_edit_group_membership_has_been_changed_to_s, accessLevel));
+    }
+  }
+
   private @NonNull String describe(@NonNull ByteString uuid) {
     return descriptionStrategy.describe(UuidUtil.fromByteString(uuid));
   }

app/src/main/res/values/strings.xml

@@ -740,6 +740,7 @@
     <string name="MessageRecord_message_encrypted_with_a_legacy_protocol_version_that_is_no_longer_supported">Received a message encrypted using an old version of Signal that is no longer supported. Please ask the sender to update to the most recent version and resend the message.</string>
     <string name="MessageRecord_left_group">You have left the group.</string>
     <string name="MessageRecord_you_updated_group">You updated the group.</string>
+    <string name="MessageRecord_the_group_was_updated">The group was updated.</string>
     <string name="MessageRecord_you_called">You called</string>
     <string name="MessageRecord_called_you">Contact called</string>
     <string name="MessageRecord_missed_call">Missed call</string>
@@ -752,6 +753,7 @@
     <string name="MessageRecord_s_disabled_disappearing_messages">%1$s disabled disappearing messages.</string>
     <string name="MessageRecord_you_set_disappearing_message_time_to_s">You set the disappearing message timer to %1$s.</string>
     <string name="MessageRecord_s_set_disappearing_message_time_to_s">%1$s set the disappearing message timer to %2$s.</string>
+    <string name="MessageRecord_disappearing_message_time_set_to_s">The disappearing message timer has been set to %1$s.</string>
 
     <!-- GV2 specific -->
     <string name="MessageRecord_you_created_the_group">You created the group.</string>
@@ -770,6 +772,8 @@
     <string name="MessageRecord_s_removed_you_from_the_group">%1$s removed you from the group.</string>
     <string name="MessageRecord_you_left_the_group">You left the group.</string>
     <string name="MessageRecord_s_left_the_group">%1$s left the group.</string>
+    <string name="MessageRecord_you_are_no_longer_in_the_group">You are no longer in the group.</string>
+    <string name="MessageRecord_s_is_no_longer_in_the_group">%1$s is no longer in the group.</string>
 
     <!-- GV2 role change -->
     <string name="MessageRecord_you_made_s_an_admin">You made %1$s an admin.</string>
@@ -778,6 +782,10 @@
     <string name="MessageRecord_you_revoked_admin_privileges_from_s">You revoked admin privileges from %1$s.</string>
     <string name="MessageRecord_s_revoked_your_admin_privileges">%1$s revoked your admin privileges."</string>
     <string name="MessageRecord_s_revoked_admin_privileges_from_s">%1$s revoked admin privileges from %2$s.</string>
+    <string name="MessageRecord_s_is_now_an_admin">%1$s is now an admin.</string>
+    <string name="MessageRecord_you_are_now_an_admin">You are now an admin.</string>
+    <string name="MessageRecord_s_is_no_longer_an_admin">%1$s is no longer an admin.</string>
+    <string name="MessageRecord_you_are_no_longer_an_admin">You are no longer an admin.</string>
 
     <!-- GV2 invitations -->
     <string name="MessageRecord_you_invited_s_to_the_group">You invited %1$s to the group.</string>
@@ -786,6 +794,11 @@
         <item quantity="one">%1$s invited 1 person to the group.</item>
         <item quantity="other">%1$s invited %2$d people to the group.</item>
     </plurals>
+    <string name="MessageRecord_you_were_invited_to_the_group">You were invited to the group.</string>
+    <plurals name="MessageRecord_d_people_were_invited_to_the_group">
+        <item quantity="one">1 person was invited to the group.</item>
+        <item quantity="other">%1$d people were invited to the group.</item>
+    </plurals>
 
     <!-- GV2 invitation revokes -->
     <plurals name="MessageRecord_you_revoked_invites">
@@ -798,6 +811,11 @@
     </plurals>
     <string name="MessageRecord_someone_declined_an_invitation_to_the_group">Someone declined an invitation to the group.</string>
     <string name="MessageRecord_you_declined_the_invitation_to_the_group">You declined the invitation to the group.</string>
+    <string name="MessageRecord_your_invitation_to_the_group_was_revoked">Your invitation to the group was revoked.</string>
+    <plurals name="MessageRecord_d_invitations_were_revoked">
+      <item quantity="one">An invitation to the group was revoked.</item>
+      <item quantity="other">%1$d invitations to the group were revoked.</item>
+    </plurals>
 
     <!-- GV2 invitation acceptance -->
     <string name="MessageRecord_you_accepted_invite">You accepted the invitation to the group.</string>
@@ -808,18 +826,22 @@
     <!-- GV2 title change -->
     <string name="MessageRecord_you_changed_the_group_name_to_s">You changed the group name to \"%1$s\".</string>
     <string name="MessageRecord_s_changed_the_group_name_to_s">%1$s changed the group name to \"%2$s\".</string>
+    <string name="MessageRecord_the_group_name_has_changed_to_s">The group name has changed to \"%1$s\".</string>
 
     <!-- GV2 avatar change -->
     <string name="MessageRecord_you_changed_the_group_avatar">You changed the group avatar.</string>
     <string name="MessageRecord_s_changed_the_group_avatar">%1$s changed the group avatar.</string>
+    <string name="MessageRecord_the_group_group_avatar_has_been_changed">The group avatar has been changed.</string>
 
     <!-- GV2 attribute access level change -->
     <string name="MessageRecord_you_changed_who_can_edit_group_info_to_s">You changed who can edit group info to \"%1$s\".</string>
     <string name="MessageRecord_s_changed_who_can_edit_group_info_to_s">%1$s changed who can edit group info to \"%2$s\".</string>
+    <string name="MessageRecord_who_can_edit_group_info_has_been_changed_to_s">Who can edit group info has been changed to \"%1$s\".</string>
 
     <!-- GV2 membership access level change -->
     <string name="MessageRecord_you_changed_who_can_edit_group_membership_to_s">You changed who can edit group membership to \"%1$s\".</string>
     <string name="MessageRecord_s_changed_who_can_edit_group_membership_to_s">%1$s changed who can edit group membership to \"%2$s\".</string>
+    <string name="MessageRecord_who_can_edit_group_membership_has_been_changed_to_s">Who can edit group membership has been changed to \"%1$s\".</string>
 
     <!-- End of GV2 specific update messages -->
 

app/src/test/java/org/thoughtcrime/securesms/database/model/GroupsV2UpdateMessageProducerTest.java

@@ -68,6 +68,14 @@ public final class GroupsV2UpdateMessageProducerTest {
     assertThat(producer.describeChange(change), is(singletonList("You updated the group.")));
   }
 
+  @Test
+  public void empty_change_by_unknown() {
+    DecryptedGroupChange change = changeByUnknown()
+                                    .build();
+
+    assertThat(producer.describeChange(change), is(singletonList("The group was updated.")));
+  }
+
   // Member additions
 
   @Test
@@ -115,6 +123,24 @@ public final class GroupsV2UpdateMessageProducerTest {
     assertThat(producer.describeChange(change), is(singletonList("Bob joined the group.")));
   }
 
+  @Test
+  public void unknown_added_you() {
+    DecryptedGroupChange change = changeByUnknown()
+                                    .addMember(you)
+                                    .build();
+
+    assertThat(producer.describeChange(change), is(singletonList("You joined the group.")));
+  }
+
+  @Test
+  public void unknown_added_member() {
+    DecryptedGroupChange change = changeByUnknown()
+                                    .addMember(bob)
+                                    .build();
+
+    assertThat(producer.describeChange(change), is(singletonList("Bob joined the group.")));
+  }
+
   // Member removals
 
   @Test
@@ -162,6 +188,24 @@ public final class GroupsV2UpdateMessageProducerTest {
     assertThat(producer.describeChange(change), is(singletonList("Bob left the group.")));
   }
 
+  @Test
+  public void unknown_removed_member() {
+    DecryptedGroupChange change = changeByUnknown()
+                                    .deleteMember(alice)
+                                    .build();
+
+    assertThat(producer.describeChange(change), is(singletonList("Alice is no longer in the group.")));
+  }
+
+  @Test
+  public void unknown_removed_you() {
+    DecryptedGroupChange change = changeByUnknown()
+                                    .deleteMember(you)
+                                    .build();
+
+    assertThat(producer.describeChange(change), is(singletonList("You are no longer in the group.")));
+  }
+
   // Member role modifications
 
   @Test
@@ -218,6 +262,42 @@ public final class GroupsV2UpdateMessageProducerTest {
     assertThat(producer.describeChange(change), is(singletonList("Alice revoked your admin privileges.")));
   }
 
+  @Test
+  public void unknown_makes_member_admin() {
+    DecryptedGroupChange change = changeByUnknown()
+                                    .promoteToAdmin(alice)
+                                    .build();
+
+    assertThat(producer.describeChange(change), is(singletonList("Alice is now an admin.")));
+  }
+
+  @Test
+  public void unknown_makes_you_admin() {
+    DecryptedGroupChange change = changeByUnknown()
+                                    .promoteToAdmin(you)
+                                    .build();
+
+    assertThat(producer.describeChange(change), is(singletonList("You are now an admin.")));
+  }
+
+  @Test
+  public void unknown_revokes_member_admin() {
+    DecryptedGroupChange change = changeByUnknown()
+                                    .demoteToMember(alice)
+                                    .build();
+
+    assertThat(producer.describeChange(change), is(singletonList("Alice is no longer an admin.")));
+  }
+
+  @Test
+  public void unknown_revokes_your_admin() {
+    DecryptedGroupChange change = changeByUnknown()
+                                    .demoteToMember(you)
+                                    .build();
+
+    assertThat(producer.describeChange(change), is(singletonList("You are no longer an admin.")));
+  }
+
   // Member invitation
 
   @Test
@@ -269,6 +349,46 @@ public final class GroupsV2UpdateMessageProducerTest {
     assertThat(producer.describeChange(change), is(Arrays.asList("Bob invited you to the group.", "Bob invited 3 people to the group.")));
   }
 
+  @Test
+  public void unknown_invited_you() {
+    DecryptedGroupChange change = changeByUnknown()
+                                    .invite(you)
+                                    .build();
+
+    assertThat(producer.describeChange(change), is(singletonList("You were invited to the group.")));
+  }
+
+  @Test
+  public void unknown_invited_1_person() {
+    DecryptedGroupChange change = changeByUnknown()
+                                    .invite(alice)
+                                    .build();
+
+    assertThat(producer.describeChange(change), is(singletonList("1 person was invited to the group.")));
+  }
+
+  @Test
+  public void unknown_invited_2_persons() {
+    DecryptedGroupChange change = changeByUnknown()
+                                    .invite(alice)
+                                    .invite(bob)
+                                    .build();
+
+    assertThat(producer.describeChange(change), is(singletonList("2 people were invited to the group.")));
+  }
+
+  @Test
+  public void unknown_invited_3_persons_and_you() {
+    DecryptedGroupChange change = changeByUnknown()
+                                    .invite(alice)
+                                    .invite(you)
+                                    .invite(UUID.randomUUID())
+                                    .invite(UUID.randomUUID())
+                                    .build();
+
+    assertThat(producer.describeChange(change), is(Arrays.asList("You were invited to the group.", "3 people were invited to the group.")));
+  }
+
   // Member invitation revocation
 
   @Test
@@ -327,6 +447,46 @@ public final class GroupsV2UpdateMessageProducerTest {
     assertThat(producer.describeChange(change), is(singletonList("You declined the invitation to the group.")));
   }
 
+  @Test
+  public void unknown_revokes_your_invite() {
+    DecryptedGroupChange change = changeByUnknown()
+                                    .uninvite(you)
+                                    .build();
+
+    assertThat(producer.describeChange(change), is(singletonList("Your invitation to the group was revoked.")));
+  }
+
+  @Test
+  public void unknown_revokes_1_invite() {
+    DecryptedGroupChange change = changeByUnknown()
+                                    .uninvite(bob)
+                                    .build();
+
+    assertThat(producer.describeChange(change), is(singletonList("An invitation to the group was revoked.")));
+  }
+
+  @Test
+  public void unknown_revokes_2_invites() {
+    DecryptedGroupChange change = changeByUnknown()
+                                    .uninvite(bob)
+                                    .uninvite(UUID.randomUUID())
+                                    .build();
+
+    assertThat(producer.describeChange(change), is(singletonList("2 invitations to the group were revoked.")));
+  }
+
+  @Test
+  public void unknown_revokes_yours_and_three_other_invites() {
+    DecryptedGroupChange change = changeByUnknown()
+                                    .uninvite(bob)
+                                    .uninvite(you)
+                                    .uninvite(UUID.randomUUID())
+                                    .uninvite(UUID.randomUUID())
+                                    .build();
+
+    assertThat(producer.describeChange(change), is(Arrays.asList("Your invitation to the group was revoked.", "3 invitations to the group were revoked.")));
+  }
+
   // Promote pending members
 
   @Test
@@ -374,6 +534,24 @@ public final class GroupsV2UpdateMessageProducerTest {
     assertThat(producer.describeChange(change), is(singletonList("Bob added you to the group.")));
   }
 
+  @Test
+  public void unknown_added_by_invite() {
+    DecryptedGroupChange change = changeByUnknown()
+                                    .promote(you)
+                                    .build();
+
+    assertThat(producer.describeChange(change), is(singletonList("You joined the group.")));
+  }
+
+  @Test
+  public void unknown_promotes_pending_member() {
+    DecryptedGroupChange change = changeByUnknown()
+                                    .promote(alice)
+                                    .build();
+
+    assertThat(producer.describeChange(change), is(singletonList("Alice joined the group.")));
+  }
+
   // Title change
 
   @Test
@@ -393,6 +571,15 @@ public final class GroupsV2UpdateMessageProducerTest {
 
     assertThat(producer.describeChange(change), is(singletonList("You changed the group name to \"Title 2\".")));
   }
+
+  @Test
+  public void unknown_changed_title() {
+    DecryptedGroupChange change = changeByUnknown()
+                                    .title("Title 3")
+                                    .build();
+
+    assertThat(producer.describeChange(change), is(singletonList("The group name has changed to \"Title 3\".")));
+  }
   
   // Avatar change
 
@@ -414,6 +601,15 @@ public final class GroupsV2UpdateMessageProducerTest {
     assertThat(producer.describeChange(change), is(singletonList("You changed the group avatar.")));
   }
 
+  @Test
+  public void unknown_changed_avatar() {
+    DecryptedGroupChange change = changeByUnknown()
+                                    .avatar("Avatar3")
+                                    .build();
+
+    assertThat(producer.describeChange(change), is(singletonList("The group avatar has been changed.")));
+  }
+
   // Timer change
 
   @Test
@@ -434,6 +630,15 @@ public final class GroupsV2UpdateMessageProducerTest {
     assertThat(producer.describeChange(change), is(singletonList("You set the disappearing message timer to 1 minute.")));
   }
 
+  @Test
+  public void unknown_change_timer() {
+    DecryptedGroupChange change = changeByUnknown()
+                                    .timer(120)
+                                    .build();
+
+    assertThat(producer.describeChange(change), is(singletonList("The disappearing message timer has been set to 2 minutes.")));
+  }
+
   // Attribute access change
 
   @Test
@@ -454,6 +659,15 @@ public final class GroupsV2UpdateMessageProducerTest {
     assertThat(producer.describeChange(change), is(singletonList("You changed who can edit group info to \"Only admins\".")));
   }
 
+  @Test
+  public void unknown_changed_attribute_access() {
+    DecryptedGroupChange change = changeByUnknown()
+                                    .attributeAccess(AccessControl.AccessRequired.ADMINISTRATOR)
+                                    .build();
+
+    assertThat(producer.describeChange(change), is(singletonList("Who can edit group info has been changed to \"Only admins\".")));
+  }
+
   // Membership access change
 
   @Test
@@ -474,6 +688,15 @@ public final class GroupsV2UpdateMessageProducerTest {
     assertThat(producer.describeChange(change), is(singletonList("You changed who can edit group membership to \"All members\".")));
   }
 
+  @Test
+  public void unknown_changed_membership_access() {
+    DecryptedGroupChange change = changeByUnknown()
+                                    .membershipAccess(AccessControl.AccessRequired.ADMINISTRATOR)
+                                    .build();
+
+    assertThat(producer.describeChange(change), is(singletonList("Who can edit group membership has been changed to \"Only admins\".")));
+  }
+
   // Multiple changes
 
   @Test
@@ -492,6 +715,24 @@ public final class GroupsV2UpdateMessageProducerTest {
       "Alice changed who can edit group membership to \"All members\".")));
   }
 
+  @Test
+  public void multiple_changes_by_unknown() {
+    DecryptedGroupChange change = changeByUnknown()
+                                    .addMember(bob)
+                                    .membershipAccess(AccessControl.AccessRequired.MEMBER)
+                                    .title("Title 2")
+                                    .avatar("Avatar 1")
+                                    .timer(600)
+                                    .build();
+
+    assertThat(producer.describeChange(change), is(Arrays.asList(
+      "Bob joined the group.",
+      "The group name has changed to \"Title 2\".",
+      "The group avatar has been changed.",
+      "The disappearing message timer has been set to 10 minutes.",
+      "Who can edit group membership has been changed to \"All members\".")));
+  }
+
   // Group state without a change record
 
   @Test
@@ -579,6 +820,10 @@ public final class GroupsV2UpdateMessageProducerTest {
                                     .setEditor(UuidUtil.toByteString(editor));
     }
 
+    ChangeBuilder() {
+      builder = DecryptedGroupChange.newBuilder();
+    }
+
     ChangeBuilder addMember(@NonNull UUID newMember) {
       builder.addNewMembers(DecryptedMember.newBuilder()
                                            .setUuid(UuidUtil.toByteString(newMember)));
@@ -658,6 +903,10 @@ public final class GroupsV2UpdateMessageProducerTest {
     return new ChangeBuilder(groupEditor);
   }
 
+  private static ChangeBuilder changeByUnknown() {
+    return new ChangeBuilder();
+  }
+
   private static @NonNull GroupsV2UpdateMessageProducer.DescribeMemberStrategy createDescriber(@NonNull Map<UUID, String> map) {
     return uuid -> {
       String name = map.get(uuid);