Create `UserMessage` type

Describes user visible messages that can have attachments.

ts/components/conversation/media-gallery/AttachmentListSection.tsx

@@ -44,12 +44,16 @@ export class AttachmentListSection extends React.Component<Props, {}> {
       switch (type) {
         case 'media':
           return (
-            <ImageThumbnail key={message.id} i18n={i18n} message={message} />
+            <ImageThumbnail
+              key={message.received_at}
+              i18n={i18n}
+              message={message}
+            />
           );
         case 'documents':
           return (
             <DocumentListEntry
-              key={message.id}
+              key={message.received_at}
               i18n={i18n}
               fileSize={firstAttachment.size}
               fileName={firstAttachment.fileName}

ts/components/conversation/media-gallery/propTypes/Message.tsx

@@ -2,7 +2,6 @@
  * @prettier
  */
 export interface Message {
-  id: string;
   body?: string;
   received_at: number;
   attachments: Array<{

ts/test/components/media-gallery/groupMessagesByDate.ts

@@ -13,7 +13,6 @@ import {
 import { Message } from '../../../components/conversation/media-gallery/propTypes/Message';
 
 const toMessage = (date: Date): Message => ({
-  id: date.toUTCString(),
   received_at: date.getTime(),
   attachments: [],
 });
@@ -44,12 +43,10 @@ describe('groupMessagesByDate', () => {
         type: 'today',
         messages: [
           {
-            id: 'Thu, 12 Apr 2018 12:00:00 GMT',
             received_at: 1523534400000,
             attachments: [],
           },
           {
-            id: 'Thu, 12 Apr 2018 00:01:00 GMT',
             received_at: 1523491260000,
             attachments: [],
           },
@@ -59,7 +56,6 @@ describe('groupMessagesByDate', () => {
         type: 'yesterday',
         messages: [
           {
-            id: 'Wed, 11 Apr 2018 23:59:00 GMT',
             received_at: 1523491140000,
             attachments: [],
           },
@@ -69,7 +65,6 @@ describe('groupMessagesByDate', () => {
         type: 'thisWeek',
         messages: [
           {
-            id: 'Mon, 09 Apr 2018 00:01:00 GMT',
             received_at: 1523232060000,
             attachments: [],
           },
@@ -79,12 +74,10 @@ describe('groupMessagesByDate', () => {
         type: 'thisMonth',
         messages: [
           {
-            id: 'Sun, 08 Apr 2018 23:59:00 GMT',
             received_at: 1523231940000,
             attachments: [],
           },
           {
-            id: 'Sun, 01 Apr 2018 00:01:00 GMT',
             received_at: 1522540860000,
             attachments: [],
           },
@@ -96,12 +89,10 @@ describe('groupMessagesByDate', () => {
         month: 2,
         messages: [
           {
-            id: 'Sat, 31 Mar 2018 23:59:00 GMT',
             received_at: 1522540740000,
             attachments: [],
           },
           {
-            id: 'Thu, 01 Mar 2018 14:00:00 GMT',
             received_at: 1519912800000,
             attachments: [],
           },
@@ -113,12 +104,10 @@ describe('groupMessagesByDate', () => {
         month: 1,
         messages: [
           {
-            id: 'Mon, 28 Feb 2011 23:59:00 GMT',
             received_at: 1298937540000,
             attachments: [],
           },
           {
-            id: 'Tue, 01 Feb 2011 10:00:00 GMT',
             received_at: 1296554400000,
             attachments: [],
           },

ts/types/Message.ts

@@ -4,7 +4,8 @@
 import { Attachment } from './Attachment';
 import { IndexableBoolean } from './IndexedDB';
 
-export type Message = IncomingMessage | OutgoingMessage | VerifiedChangeMessage;
+export type Message = UserMessage | VerifiedChangeMessage;
+export type UserMessage = IncomingMessage | OutgoingMessage;
 
 export type IncomingMessage = Readonly<
   {