Loading threads with server-side assistance (#9356)

* Fix bug with message context menu
* fix bug where ThreadSummary failed if no last reply is available
* Fix relations direction API
* Use same API for threads as for any other timeline
* Determine if event belongs to thread on jumping to event
* properly listen to thread deletion
* Add thread redaction tests
* Add fetchInitialEvent tests
* Paginate using default TimelinePanel behaviour
* Remove unused threads deleted code

Co-authored-by: Germain <germain@souquet.com>
Co-authored-by: Germain <germains@element.io>

src/components/views/context_menus/MessageContextMenu.tsx

@@ -382,7 +382,13 @@ export default class MessageContextMenu extends React.Component<IProps, IState>
     public render(): JSX.Element {
         const cli = MatrixClientPeg.get();
         const me = cli.getUserId();
-        const { mxEvent, rightClick, link, eventTileOps, reactions, collapseReplyChain } = this.props;
+        const {
+            mxEvent, rightClick, link, eventTileOps, reactions, collapseReplyChain,
+            ...other
+        } = this.props;
+        delete other.getRelationsForEvent;
+        delete other.permalinkCreator;
+
         const eventStatus = mxEvent.status;
         const unsentReactionsCount = this.getUnsentReactions().length;
         const contentActionable = isContentActionable(mxEvent);
@@ -747,7 +753,7 @@ export default class MessageContextMenu extends React.Component<IProps, IState>
         return (
             <React.Fragment>
                 <IconizedContextMenu
-                    {...this.props}
+                    {...other}
                     className="mx_MessageContextMenu"
                     compact={true}
                     data-testid="mx_MessageContextMenu"

src/components/views/rooms/EventTile.tsx

@@ -540,7 +540,11 @@ export class UnwrappedEventTile extends React.Component<EventTileProps, IState>
 
     private renderThreadInfo(): React.ReactNode {
         if (this.state.thread?.id === this.props.mxEvent.getId()) {
-            return <ThreadSummary mxEvent={this.props.mxEvent} thread={this.state.thread} />;
+            return <ThreadSummary
+                mxEvent={this.props.mxEvent}
+                thread={this.state.thread}
+                data-testid="thread-summary"
+            />;
         }
 
         if (this.context.timelineRenderingType === TimelineRenderingType.Search && this.props.mxEvent.threadRootId) {
@@ -1528,9 +1532,11 @@ export class UnwrappedEventTile extends React.Component<EventTileProps, IState>
 
 // Wrap all event tiles with the tile error boundary so that any throws even during construction are captured
 const SafeEventTile = forwardRef((props: EventTileProps, ref: RefObject<UnwrappedEventTile>) => {
-    return <TileErrorBoundary mxEvent={props.mxEvent} layout={props.layout}>
-        <UnwrappedEventTile ref={ref} {...props} />
-    </TileErrorBoundary>;
+    return <>
+        <TileErrorBoundary mxEvent={props.mxEvent} layout={props.layout}>
+            <UnwrappedEventTile ref={ref} {...props} />
+        </TileErrorBoundary>
+    </>;
 });
 export default SafeEventTile;
 

src/components/views/rooms/ThreadSummary.tsx

@@ -37,7 +37,7 @@ interface IProps {
     thread: Thread;
 }
 
-const ThreadSummary = ({ mxEvent, thread }: IProps) => {
+const ThreadSummary = ({ mxEvent, thread, ...props }: IProps) => {
     const roomContext = useContext(RoomContext);
     const cardContext = useContext(CardContext);
     const count = useTypedEventEmitterState(thread, ThreadEvent.Update, () => thread.length);
@@ -50,6 +50,7 @@ const ThreadSummary = ({ mxEvent, thread }: IProps) => {
 
     return (
         <AccessibleButton
+            {...props}
             className="mx_ThreadSummary"
             onClick={(ev: ButtonEvent) => {
                 defaultDispatcher.dispatch<ShowThreadPayload>({
@@ -94,7 +95,9 @@ export const ThreadMessagePreview = ({ thread, showDisplayname = false }: IPrevi
         await cli.decryptEventIfNeeded(lastReply);
         return MessagePreviewStore.instance.generatePreviewForEvent(lastReply);
     }, [lastReply, content]);
-    if (!preview) return null;
+    if (!preview || !lastReply) {
+        return null;
+    }
 
     return <>
         <MemberAvatar