Shows message status timestamps if available

stylesheets/components/MessageDetail.scss

@@ -198,3 +198,7 @@
   color: $color-white;
   background-color: $color-accent-red;
 }
+
+.module-message-detail__status-timestamp {
+  margin-left: 6px;
+}

ts/components/conversation/MessageDetail.tsx

@@ -19,6 +19,7 @@ import { groupBy } from '../../util/mapUtil';
 import { ContactNameColorType } from '../../types/Colors';
 import { SendStatus } from '../../messages/MessageSendState';
 import * as log from '../../logging/log';
+import { Timestamp } from './Timestamp';
 
 export type Contact = Pick<
   ConversationType,
@@ -35,6 +36,7 @@ export type Contact = Pick<
   | 'unblurredAvatarPath'
 > & {
   status?: SendStatus;
+  statusTimestamp?: number;
 
   isOutgoingKeyError: boolean;
   isUnidentifiedDelivery: boolean;
@@ -182,6 +184,13 @@ export class MessageDetail extends React.Component<Props> {
         </div>
         {errorComponent}
         {unidentifiedDeliveryComponent}
+        {contact.statusTimestamp && (
+          <Timestamp
+            i18n={i18n}
+            module="module-message-detail__status-timestamp"
+            timestamp={contact.statusTimestamp}
+          />
+        )}
       </div>
     );
   }

ts/models/messages.ts

@@ -351,7 +351,9 @@ export class MessageModel extends window.Backbone.Model<MessageAttributesType> {
           window.storage.get('unidentifiedDeliveryIndicators', false) &&
           this.isUnidentifiedDelivery(id, unidentifiedDeliveriesSet);
 
-        let status = getOwn(sendStateByConversationId, id)?.status;
+        const sendState = getOwn(sendStateByConversationId, id);
+
+        let status = sendState?.status;
 
         // If a message was only sent to yourself (Note to Self or a lonely group), it
         //   is shown read.
@@ -362,6 +364,7 @@ export class MessageModel extends window.Backbone.Model<MessageAttributesType> {
         return {
           ...findAndFormatContact(id),
           status,
+          statusTimestamp: sendState?.updatedAt,
           errors: errorsForContact,
           isOutgoingKeyError,
           isUnidentifiedDelivery,