Implement MSC4155: Invite filtering (#29603)

* Add settings for MSC4155

* copyright

* Tweak to not use js-sdk

* Update for latest MSC

* Various tidyups

* Move tab

* i18n

* update .snap

* mvvm

* lint

* add header

* Remove capability check

* fix

* Rewrite to use Settings

* lint

* lint

* fix test

* Tweaks

* lint

* revert copyright

* update screenshot

* cleanup

src/settings/Settings.tsx

@@ -47,6 +47,8 @@ import { type RecentEmojiData } from "../emojipicker/recent.ts";
 import { type Assignable } from "../@types/common.ts";
 import { SortingAlgorithm } from "../stores/room-list-v3/skip-list/sorters/index.ts";
 import MediaPreviewConfigController from "./controllers/MediaPreviewConfigController.ts";
+import InviteRulesConfigController from "./controllers/InviteRulesConfigController.ts";
+import { type ComputedInviteConfig } from "../@types/invite-rules.ts";
 
 export const defaultWatchManager = new WatchManager();
 
@@ -351,6 +353,7 @@ export interface Settings {
     "Electron.enableHardwareAcceleration": IBaseSetting<boolean>;
     "Electron.enableContentProtection": IBaseSetting<boolean>;
     "mediaPreviewConfig": IBaseSetting<MediaPreviewConfig>;
+    "inviteRules": IBaseSetting<ComputedInviteConfig>;
     "Developer.elementCallUrl": IBaseSetting<string>;
 }
 
@@ -434,6 +437,11 @@ export const SETTINGS: Settings = {
         supportedLevels: LEVELS_ROOM_SETTINGS,
         default: MediaPreviewConfigController.default,
     },
+    "inviteRules": {
+        controller: new InviteRulesConfigController(),
+        supportedLevels: [SettingLevel.ACCOUNT],
+        default: InviteRulesConfigController.default,
+    },
     "feature_report_to_moderators": {
         isFeature: true,
         labsGroup: LabGroup.Moderation,

src/settings/controllers/InviteRulesConfigController.ts

@@ -0,0 +1,88 @@
+/*
+Copyright 2025 New Vector Ltd.
+
+SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only OR LicenseRef-Element-Commercial
+Please see LICENSE files in the repository root for full details.
+*/
+
+import { type MatrixClient, type IContent } from "matrix-js-sdk/src/matrix";
+
+import { type SettingLevel } from "../SettingLevel.ts";
+import MatrixClientBackedController from "./MatrixClientBackedController.ts";
+import {
+    type ComputedInviteConfig as ComputedInviteRules,
+    INVITE_RULES_ACCOUNT_DATA_TYPE,
+    type InviteConfigAccountData,
+} from "../../@types/invite-rules.ts";
+import { _t } from "../../languageHandler.tsx";
+
+/**
+ * Handles invite filtering rules provided by MSC4155.
+ * This handler does not make use of the roomId parameter.
+ */
+export default class InviteRulesConfigController extends MatrixClientBackedController {
+    public static readonly default: ComputedInviteRules = {
+        allBlocked: false,
+    };
+
+    private static getValidSettingData(content: IContent): ComputedInviteRules {
+        const expectedConfig = content as InviteConfigAccountData;
+        return {
+            allBlocked: !!expectedConfig.blocked_users?.includes("*"),
+        };
+    }
+
+    public initMatrixClient(newClient: MatrixClient): void {
+        newClient.doesServerSupportUnstableFeature("org.matrix.msc4155").then((result) => {
+            this.featureSupported = result;
+        });
+    }
+
+    public featureSupported?: boolean;
+
+    public constructor() {
+        super();
+        this.featureSupported = false;
+    }
+
+    private getValue = (): ComputedInviteRules => {
+        const accountData =
+            this.client?.getAccountData(INVITE_RULES_ACCOUNT_DATA_TYPE)?.getContent<InviteConfigAccountData>() ?? {};
+        return InviteRulesConfigController.getValidSettingData(accountData);
+    };
+
+    public getValueOverride(_level: SettingLevel): ComputedInviteRules {
+        return this.getValue();
+    }
+
+    public get settingDisabled(): true | string {
+        return this.featureSupported ? true : _t("settings|not_supported");
+    }
+
+    public async beforeChange(
+        _level: SettingLevel,
+        _roomId: string | null,
+        newValue: ComputedInviteRules,
+    ): Promise<boolean> {
+        if (!this.client) {
+            return false;
+        }
+        const existingContent = this.client
+            .getAccountData(INVITE_RULES_ACCOUNT_DATA_TYPE)
+            ?.getContent<InviteConfigAccountData>();
+        const newContent: InviteConfigAccountData = {
+            ...existingContent,
+            blocked_users: [...(existingContent?.blocked_users ?? [])],
+        };
+        if (newValue.allBlocked && !newContent.blocked_users!.includes("*")) {
+            newContent.blocked_users!.push("*");
+        } else if (!newValue.allBlocked && newContent.blocked_users?.includes("*")) {
+            newContent.blocked_users = newContent.blocked_users.filter((u) => u !== "*");
+        } else {
+            // No changes required.
+            return false;
+        }
+        await this.client.setAccountData(INVITE_RULES_ACCOUNT_DATA_TYPE, newContent);
+        return true;
+    }
+}

src/settings/handlers/AccountSettingsHandler.ts

@@ -204,6 +204,9 @@ export default class AccountSettingsHandler extends MatrixClientBackedSettingsHa
             case "mediaPreviewConfig":
                 // Handled in MediaPreviewConfigController.
                 return;
+            case "inviteRules":
+                // Handled in InviteRulesConfigController.
+                return;
             default:
                 return this.setAccountData(DEFAULT_SETTINGS_EVENT_TYPE, settingName, newValue);
         }

src/settings/handlers/RoomAccountSettingsHandler.ts

@@ -122,6 +122,9 @@ export default class RoomAccountSettingsHandler extends MatrixClientBackedSettin
             case "mediaPreviewConfig":
                 // Handled in MediaPreviewConfigController.
                 return;
+            case "inviteRules":
+                // Handled in InviteRulesConfigController.
+                return;
             default:
                 return this.setRoomAccountData(roomId, DEFAULT_SETTINGS_EVENT_TYPE, settingName, newValue);
         }