Simplified Sliding Sync (#28515)

* Experimental SSS

Working branch to get SSS functional on element-web.

Requires https://github.com/matrix-org/matrix-js-sdk/pull/4400

* Adjust tests to use new behaviour

* Remove well-known proxy URL lookup; always use native

This is actually required for SSS because otherwise it would use
the proxy over native support.

* Linting

* Debug logging

* Control the race condition when swapping between rooms

* Dont' filter by space as synapse doesn't support it

* Remove SS code related to registering lists and managing ranges

- Update the spidering code to spider all the relevant lists.
- Add canonical alias to the required_state to allow room name calcs to work.

Room sort order is busted because we don't yet look at `bump_stamp`.

* User bumpStamp if it is present

* Drop initial room load from 20 per list to 10

* Half the batch size to trickle more quickly

* Prettier

* prettier on tests too

* Remove proxy URL & unused import

* Hopefully fix tests to assert what the behaviour is supposed to be

* Move the singleton to the manager tyo fix import loop

* Very well, code, I will remove you

Why were you there in the first place?

* Strip out more unused stuff

* Fix playwright test

Seems like this lack of order updating unless a room is selected
was just always a bug with both regular and non-sliding sync. I
have no idea how the test passed on develop because it won't run.

* Fix test to do maybe what it was supposed to do... possibly?

* Remove test for old pre-simplified sliding sync behaviour

* Unused import

* Remove sliding sync proxy & test

I was wrong about what this test was asserting, it was suposed
to assert that notification dots aren't shown (because SS didn't
support them somehow I guess) but they are fine in SSS so the test
is just no longer relevant.

* Remove now pointless credentials

* Remove subscription removal as SSS doesn't do that

* Update tests

* add test

* Switch to new labs flag & break if old labs flag is enabled

* Remove unused import & fix test

* Fix other test

* Remove name & description from old labs flag

as they're not displayed anywhere so not useful

* Remove old sliding sync option

by making it not a feature

* Add back unread nindicator test but inverted

and minus the bit about disabling notification which surely would have
defeated the original point anyway?

* Reinstate test for room_subscriptions

...and also make tests actually use sliding sync

* Use UserFriendlyError

* Remove empty constructor

* Remove unrelated changes

* Unused import

* Fix import

* Avoid moving import

---------

Co-authored-by: Kegan Dougal <7190048+kegsay@users.noreply.github.com>

src/components/views/rooms/RoomSublist.tsx

@@ -42,8 +42,6 @@ import ContextMenu, {
 } from "../../structures/ContextMenu";
 import AccessibleButton, { type ButtonEvent } from "../../views/elements/AccessibleButton";
 import type ExtraTile from "./ExtraTile";
-import SettingsStore from "../../../settings/SettingsStore";
-import { SlidingSyncManager } from "../../../SlidingSyncManager";
 import NotificationBadge from "./NotificationBadge";
 import RoomTile from "./RoomTile";
 
@@ -106,12 +104,8 @@ export default class RoomSublist extends React.Component<IProps, IState> {
     private heightAtStart: number;
     private notificationState: ListNotificationState;
 
-    private slidingSyncMode: boolean;
-
     public constructor(props: IProps) {
         super(props);
-        // when this setting is toggled it restarts the app so it's safe to not watch this.
-        this.slidingSyncMode = SettingsStore.getValue("feature_sliding_sync");
 
         this.layout = RoomListLayoutStore.instance.getLayoutFor(this.props.tagId);
         this.heightAtStart = 0;
@@ -165,9 +159,6 @@ export default class RoomSublist extends React.Component<IProps, IState> {
     }
 
     private get numVisibleTiles(): number {
-        if (this.slidingSyncMode) {
-            return this.state.rooms.length;
-        }
         const nVisible = Math.ceil(this.layout.visibleTiles);
         return Math.min(nVisible, this.numTiles);
     }
@@ -329,12 +320,6 @@ export default class RoomSublist extends React.Component<IProps, IState> {
     };
 
     private onShowAllClick = async (): Promise<void> => {
-        if (this.slidingSyncMode) {
-            const count = RoomListStore.instance.getCount(this.props.tagId);
-            await SlidingSyncManager.instance.ensureListRegistered(this.props.tagId, {
-                ranges: [[0, count]],
-            });
-        }
         // read number of visible tiles before we mutate it
         const numVisibleTiles = this.numVisibleTiles;
         const newHeight = this.layout.tilesToPixelsWithPadding(this.numTiles, this.padding);
@@ -554,13 +539,8 @@ export default class RoomSublist extends React.Component<IProps, IState> {
 
         let contextMenu: JSX.Element | undefined;
         if (this.state.contextMenuPosition) {
-            let isAlphabetical = RoomListStore.instance.getTagSorting(this.props.tagId) === SortAlgorithm.Alphabetic;
-            let isUnreadFirst = RoomListStore.instance.getListOrder(this.props.tagId) === ListAlgorithm.Importance;
-            if (this.slidingSyncMode) {
-                const slidingList = SlidingSyncManager.instance.slidingSync?.getListParams(this.props.tagId);
-                isAlphabetical = (slidingList?.sort || [])[0] === "by_name";
-                isUnreadFirst = (slidingList?.sort || [])[0] === "by_notification_level";
-            }
+            const isAlphabetical = RoomListStore.instance.getTagSorting(this.props.tagId) === SortAlgorithm.Alphabetic;
+            const isUnreadFirst = RoomListStore.instance.getListOrder(this.props.tagId) === ListAlgorithm.Importance;
 
             // Invites don't get some nonsense options, so only add them if we have to.
             let otherSections: JSX.Element | undefined;
@@ -763,17 +743,12 @@ export default class RoomSublist extends React.Component<IProps, IState> {
             // floats above the resize handle, if we have one present. If the user has all
             // tiles visible, it becomes 'show less'.
             let showNButton: JSX.Element | undefined;
-            const hasMoreSlidingSync =
-                this.slidingSyncMode && RoomListStore.instance.getCount(this.props.tagId) > this.state.rooms.length;
 
-            if (maxTilesPx > this.state.height || hasMoreSlidingSync) {
+            if (maxTilesPx > this.state.height) {
                 // the height of all the tiles is greater than the section height: we need a 'show more' button
                 const nonPaddedHeight = this.state.height - RESIZE_HANDLE_HEIGHT - SHOW_N_BUTTON_HEIGHT;
                 const amountFullyShown = Math.floor(nonPaddedHeight / this.layout.tileHeight);
-                let numMissing = this.numTiles - amountFullyShown;
-                if (this.slidingSyncMode) {
-                    numMissing = RoomListStore.instance.getCount(this.props.tagId) - amountFullyShown;
-                }
+                const numMissing = this.numTiles - amountFullyShown;
                 const label = _t("room_list|show_n_more", { count: numMissing });
                 let showMoreText: ReactNode = <span className="mx_RoomSublist_showNButtonText">{label}</span>;
                 if (this.props.isMinimized) showMoreText = null;