Room list: assign room to custom section

apps/web/playwright/e2e/left-panel/room-list-panel/room-list-custom-sections.spec.ts

@@ -175,4 +175,93 @@
             await expect(getSectionHeader(page, "Low Priority")).toBeVisible();
         });
     });
+
+    test.describe("Adding a room to a custom section", () => {
+        /**
+         * Asserts a room is nested under a specific section using the treegrid aria-level hierarchy.
+         * Section header rows sit at aria-level=1; room rows nested within a section sit at aria-level=2.
+         * Verifies that the closest preceding aria-level=1 row is the expected section header.
+         */
+        async function assertRoomInSection(page: Page, sectionName: string, roomName: string): Promise<void> {
+            const roomList = getRoomList(page);
+            const roomRow = roomList.getByRole("row", { name: `Open room ${roomName}` });
+            // Room row must be at aria-level=2 (i.e. inside a section)
+            await expect(roomRow).toHaveAttribute("aria-level", "2");
+            // The closest preceding aria-level=1 row must be the expected section header.
+            // XPath preceding:: axis returns nodes before the context in document order; [1] picks the nearest one.
+            const closestSectionHeader = roomRow.locator(`xpath=preceding::*[@role="row" and @aria-level="1"][1]`);
+            await expect(closestSectionHeader).toContainText(sectionName);
+        }
+
+        test("should add a room to a custom section via the More Options menu", async ({ page, app }) => {
+            await app.client.createRoom({ name: "my room" });
+            await createCustomSection(page, "Work");
+
+            const roomList = getRoomList(page);
+
+            // Room starts in Chats section (aria-level=2)
+            const roomItem = roomList.getByRole("row", { name: "Open room my room" });
+            await expect(roomItem).toBeVisible();
+
+            // Open More Options and move to the Work section
+            await roomItem.hover();
+            await roomItem.getByRole("button", { name: "More Options" }).click();
+            await page.getByRole("menuitem", { name: "Move to" }).hover();
+            await page.getByRole("menuitem", { name: "Work" }).click();
+
+            // Room should now be nested under the Work section header (aria-level=1 → aria-level=2)
+            await assertRoomInSection(page, "Work", "my room");
+        });
+
+        test(
+            "should show 'Chat moved' toast when adding a room to a custom section",
+            { tag: "@screenshot" },
+            async ({ page, app }) => {
+                await app.client.createRoom({ name: "my room" });
+                await createCustomSection(page, "Work");
+
+                const roomList = getRoomList(page);
+                const roomItem = roomList.getByRole("row", { name: "Open room my room" });
+
+                await roomItem.hover();
+                await roomItem.getByRole("button", { name: "More Options" }).click();
+                await page.getByRole("menuitem", { name: "Move to" }).hover();
+                await page.getByRole("menuitem", { name: "Work" }).click();
+
+                // The "Chat moved" toast should appear
+                await expect(page.getByText("Chat moved")).toBeVisible();
+
+                // Remove focus outline from the room item before taking the screenshot
+                await page.getByRole("button", { name: "User menu" }).focus();
+
+                await expect(roomList).toMatchScreenshot("room-list-sections-chat-moved-toast.png");
+            },
+        );
+
+        test("should remove a room from a custom section when toggling the same section", async ({ page, app }) => {
+            await app.client.createRoom({ name: "my room" });
+            await createCustomSection(page, "Work");
+
+            const roomList = getRoomList(page);
+
+            // Move to Work section and verify placement via aria-level
+            let roomItem = roomList.getByRole("row", { name: "Open room my room" });
+            await roomItem.hover();
+            await roomItem.getByRole("button", { name: "More Options" }).click();
+            await page.getByRole("menuitem", { name: "Move to" }).hover();
+            await page.getByRole("menuitem", { name: "Work" }).click();
+
+            await assertRoomInSection(page, "Work", "my room");
+
+            // Toggle off by selecting the same section again
+            roomItem = roomList.getByRole("row", { name: "Open room my room" });
+            await roomItem.hover();
+            await roomItem.getByRole("button", { name: "More Options" }).click();
+            await page.getByRole("menuitem", { name: "Move to" }).hover();
+            await page.getByRole("menuitem", { name: "Work" }).click();
+
+            // Room is back in the Chats section
+            await assertRoomInSection(page, "Chats", "my room");
+        });
+    });
 });

apps/web/src/stores/room-list-v3/RoomListStoreV3.ts

@@ -62,6 +62,8 @@ export enum RoomListStoreV3Event {
     ListsLoaded = "lists_loaded",
     /** Fired when a new section is created in the room list. */
     SectionCreated = "section_created",
+    /** Fired when a room's tags change. */
+    RoomTagged = "room_tagged",
 }
 
 // The result object for returning rooms from the store
@@ -93,6 +95,7 @@ export const CHATS_TAG = "chats";
 export const LISTS_UPDATE_EVENT = RoomListStoreV3Event.ListsUpdate;
 export const LISTS_LOADED_EVENT = RoomListStoreV3Event.ListsLoaded;
 export const SECTION_CREATED_EVENT = RoomListStoreV3Event.SectionCreated;
+export const ROOM_TAGGED_EVENT = RoomListStoreV3Event.RoomTagged;
 
 /**
  * This store allows for fast retrieval of the room list in a sorted and filtered manner.
@@ -243,6 +246,7 @@ export class RoomListStoreV3Class extends AsyncStoreWithClient<EmptyObject> {
             case "MatrixActions.Room.tags": {
                 const room = payload.room;
                 this.addRoomAndEmit(room);
+                this.emit(ROOM_TAGGED_EVENT);
                 break;
             }
 
@@ -493,6 +497,13 @@ export class RoomListStoreV3Class extends AsyncStoreWithClient<EmptyObject> {
         this.emit(SECTION_CREATED_EVENT, tag);
     }
 
+    /**
+     * Returns the ordered section tags.
+     */
+    public get orderedSectionTags(): string[] {
+        return this.sortedTags;
+    }
+
     /**
      * Load the custom sections from the settings store and update the sorted tags.
      */

apps/web/src/stores/room-list-v3/section.ts

@@ -12,6 +12,20 @@
 
 type Tag = string;
 
+/**
+ * Prefix for custom section tags.
+ */
+export const CUSTOM_SECTION_TAG_PREFIX = "element.io.section.";
+
+/**
+ * Checks if a given tag is a custom section tag.
+ * @param tag - The tag to check.
+ * @returns True if the tag is a custom section tag, false otherwise.
+ */
+export function isCustomSectionTag(tag: string): boolean {
+    return tag.startsWith(CUSTOM_SECTION_TAG_PREFIX);
+}
+
 /**
  * Structure of the custom section stored in the settings. The tag is used as a unique identifier for the section, and the name is given by the user.
  */
@@ -41,7 +55,7 @@
     const [shouldCreateSection, sectionName] = await modal.finished;
     if (!shouldCreateSection || !sectionName) return undefined;
 
-    const tag = `element.io.section.${window.crypto.randomUUID()}`;
+    const tag = `${CUSTOM_SECTION_TAG_PREFIX}${window.crypto.randomUUID()}`;
     const newSection: CustomSection = { tag, name: sectionName };
 
     // Save the new section data

apps/web/src/utils/room/tagRoom.ts

@@ -13,20 +13,29 @@ import { DefaultTagID, type TagID } from "../../stores/room-list-v3/skip-list/ta
 import RoomListActions from "../../actions/RoomListActions";
 import dis from "../../dispatcher/dispatcher";
 import { getTagsForRoom } from "./getTagsForRoom";
+import { isCustomSectionTag } from "../../stores/room-list-v3/section";
 
 /**
- * Toggle tag for a given room
+ * Toggle tag for a given room.
+ * A room can only be in one section: either a custom section, Favourite, or LowPriority.
+ * Applying any of these will atomically replace the current section tag.
  * @param room The room to tag
  * @param tagId The tag to invert
  */
 export function tagRoom(room: Room, tagId: TagID): void {
-    if (tagId === DefaultTagID.Favourite || tagId === DefaultTagID.LowPriority) {
-        const inverseTag = tagId === DefaultTagID.Favourite ? DefaultTagID.LowPriority : DefaultTagID.Favourite;
-        const isApplied = getTagsForRoom(room).includes(tagId);
-        const removeTag = isApplied ? tagId : inverseTag;
-        const addTag = isApplied ? null : tagId;
-        dis.dispatch(RoomListActions.tagRoom(room.client, room, removeTag, addTag));
-    } else {
+    if (tagId !== DefaultTagID.Favourite && tagId !== DefaultTagID.LowPriority && !isCustomSectionTag(tagId)) {
         logger.warn(`Unexpected tag ${tagId} applied to ${room.roomId}`);
+        return;
     }
+
+    // Find the section tag currently applied (Fav, LowPriority, or custom) — at most one exists
+    const currentSectionTag =
+        getTagsForRoom(room).find(
+            (t) => t === DefaultTagID.Favourite || t === DefaultTagID.LowPriority || isCustomSectionTag(t),
+        ) ?? null;
+
+    const isApplied = currentSectionTag === tagId;
+    const removeTag = currentSectionTag;
+    const addTag = isApplied ? null : tagId;
+    dis.dispatch(RoomListActions.tagRoom(room.client, room, removeTag, addTag));
 }

apps/web/src/viewmodels/room-list/RoomListItemViewModel.ts

@@ -10,6 +10,7 @@
     RoomNotifState,
     type RoomListItemViewSnapshot,
     type RoomListItemViewActions,
+    type Section,
 } from "@element-hq/web-shared-components";
 import { RoomEvent } from "matrix-js-sdk/src/matrix";
 import { CallType } from "matrix-js-sdk/src/webrtc/call";
@@ -37,7 +38,8 @@
 import type { ViewRoomPayload } from "../../dispatcher/payloads/ViewRoomPayload";
 import PosthogTrackers from "../../PosthogTrackers";
 import { type Call, CallEvent } from "../../models/Call";
-import RoomListStoreV3 from "../../stores/room-list-v3/RoomListStoreV3";
+import RoomListStoreV3, { CHATS_TAG } from "../../stores/room-list-v3/RoomListStoreV3";
+import { _t } from "../../languageHandler";
 
 interface RoomItemProps {
     room: Room;
@@ -96,6 +98,13 @@
         this.disposables.trackListener(props.room, RoomEvent.Name, this.onRoomChanged);
         this.disposables.trackListener(props.room, RoomEvent.Tags, this.onRoomChanged);
 
+        const orderSectionsRef = SettingsStore.watchSetting("RoomList.OrderedCustomSections", null, () =>
+            this.onOrderedCustomSectionsChange(),
+        );
+        this.disposables.track(() => {
+            SettingsStore.unwatchSetting(orderSectionsRef);
+        });
+
         // Load message preview asynchronously (sync data is already complete)
         void this.loadAndSetMessagePreview();
     }
@@ -181,6 +190,7 @@
         this.snapshot.merge({
             ...newItem,
             notification: keepIfSame(this.snapshot.current.notification, newItem.notification),
+            sections: keepIfSame(this.snapshot.current.sections, newItem.sections),
             // Preserve message preview - it's managed separately by loadAndSetMessagePreview
             messagePreview: this.snapshot.current.messagePreview,
         });
@@ -279,6 +289,9 @@
 
         const canMoveToSection = SettingsStore.getValue("feature_room_list_sections");
 
+        // Build sections list for the "Move to section" submenu
+        const sections: Section[] = canMoveToSection ? RoomListItemViewModel.buildSections(roomTags) : [];
+
         return {
             id: room.roomId,
             room,
@@ -307,6 +320,7 @@
             canMarkAsUnread,
             roomNotifState,
             canMoveToSection,
+            sections,
         };
     }
 
@@ -389,4 +403,42 @@
     public onCreateSection = (): void => {
         RoomListStoreV3.instance.createSection();
     };
+
+    public onToggleSection = (tag: string): void => {
+        tagRoom(this.props.room, tag);
+    };
+
+    private onOrderedCustomSectionsChange = (): void => {
+        // Rebuild sections list to reflect new order
+        const sections = RoomListItemViewModel.buildSections(this.props.room.tags);
+        this.snapshot.merge({ sections: keepIfSame(this.snapshot.current.sections, sections) });
+    };
+
+    /**
+     * Build the list of available sections for the "Move to section" submenu.
+     * Order follows the canonical section order from RoomListStoreV3.
+     */
+    private static buildSections(roomTags: Room["tags"]): Section[] {
+        const customSectionData = SettingsStore.getValue("RoomList.CustomSectionData") || {};
+
+        return (
+            RoomListStoreV3.instance.orderedSectionTags
+                // Exclude the Chats section because the user toggle the other sections to move rooms in and out of the Chats section.
+                .filter((tag) => tag !== CHATS_TAG)
+                .map((tag) => ({
+                    tag,
+                    name: RoomListItemViewModel.getSectionName(tag, customSectionData),
+                    isSelected: Boolean(roomTags[tag]),
+                }))
+        );
+    }
+
+    /**
+     * Get the display name for a section based on its tag.
+     */
+    private static getSectionName(tag: string, customSectionData: Record<string, { name: string }>): string {
+        if (tag === DefaultTagID.Favourite) return _t("room_list|section|favourites");
+        if (tag === DefaultTagID.LowPriority) return _t("room_list|section|low_priority");
+        return customSectionData[tag]?.name || tag;
+    }
 }

apps/web/src/viewmodels/room-list/RoomListViewModel.ts

@@ -13,6 +13,7 @@ import {
     type RoomListViewState,
     type RoomListSection,
     _t,
+    type ToastType,
 } from "@element-hq/web-shared-components";
 import { type MatrixClient, type Room } from "matrix-js-sdk/src/matrix";
 
@@ -156,6 +157,13 @@ export class RoomListViewModel
             this.onSectionCreated as (...args: unknown[]) => void,
         );
 
+        // Subscribe to room tagging
+        this.disposables.trackListener(
+            RoomListStoreV3.instance,
+            RoomListStoreV3Event.RoomTagged as any,
+            this.onRoomTagged,
+        );
+
         // Subscribe to active room changes to update selected room
         const dispatcherRef = dispatcher.register(this.onDispatch);
         this.disposables.track(() => {
@@ -595,15 +603,11 @@ export class RoomListViewModel
 
     public onSectionCreated = (tag: string): void => {
         this.updateRoomListData(false, null, tag);
+        this.showToast("section_created");
+    };
 
-        clearTimeout(this.toastRef);
-        this.snapshot.merge({
-            toast: "section_created",
-        });
-        // Automatically close the toast after 15 seconds
-        this.toastRef = setTimeout(() => {
-            this.closeToast();
-        }, 15 * 1000);
+    public onRoomTagged = (): void => {
+        this.showToast("chat_moved");
     };
 
     public closeToast: () => void = () => {
@@ -612,6 +616,15 @@ export class RoomListViewModel
             toast: undefined,
         });
     };
+
+    private showToast(toast: ToastType): void {
+        clearTimeout(this.toastRef);
+        this.snapshot.merge({ toast });
+        // Automatically close the toast after 15 seconds
+        this.toastRef = setTimeout(() => {
+            this.closeToast();
+        }, 15 * 1000);
+    }
 }
 
 /**