settings: Add `can_move_messages_between_channels_group` realm setting.

Added `can_move_messages_between_channels_group` realm setting to replace
`move_messages_between_streams_policy`.

api_docs/changelog.md

@@ -20,6 +20,14 @@ format used by the Zulip server that they are interacting with.
 
 ## Changes in Zulip 10.0
 
+**Feature level 310**
+
+* `PATCH /realm`, [`GET /events`](/api/get-events),
+  [`POST /register`](/api/register-queue):
+  Added `can_move_messages_between_channels_group` realm setting which is a
+  [group-setting value](/api/group-setting-values) describing the set of users
+  with permission to move messages from one channel to another in the organization.
+
 **Feature level 309**
 
 * [Group-setting values](/api/group-setting-values): Starting with

version.py

@@ -34,7 +34,7 @@ DESKTOP_WARNING_VERSION = "5.9.3"
 # new level means in api_docs/changelog.md, as well as "**Changes**"
 # entries in the endpoint's documentation in `zulip.yaml`.
 
-API_FEATURE_LEVEL = 309  # Last bumped for group values in settings.
+API_FEATURE_LEVEL = 310  # Last bumped for adding `can_move_messages_between_channels_group`.
 
 # Bump the minor PROVISION_VERSION to indicate that folks should provision
 # only when going from an old version of the code to a newer version. Bump

web/src/message_edit.ts

@@ -248,8 +248,8 @@ export function is_stream_editable(message: Message, edit_limit_seconds_buffer =
     }
 
     // Organization admins and moderators can edit stream indefinitely,
-    // irrespective of the stream editing deadline, if
+    // irrespective of the stream editing deadline, if they are in the
-    // move_messages_between_streams_policy allows them to do so.
+    // can_move_messages_between_channels_group.
     if (current_user.is_admin || current_user.is_moderator) {
         return true;
     }

web/src/server_events_dispatch.js

@@ -212,6 +212,7 @@ export function dispatch_normal_event(event) {
                 bot_creation_policy: settings_bots.update_bot_permissions_ui,
                 can_delete_any_message_group: noop,
                 can_delete_own_message_group: noop,
+                can_move_messages_between_channels_group: noop,
                 create_multiuse_invite_group: noop,
                 invite_to_stream_policy: noop,
                 default_code_block_language: noop,
@@ -233,7 +234,6 @@ export function dispatch_normal_event(event) {
                 move_messages_between_streams_limit_seconds: noop,
                 move_messages_within_stream_limit_seconds: message_edit.update_inline_topic_edit_ui,
                 message_retention_days: noop,
-                move_messages_between_streams_policy: noop,
                 name: narrow_title.redraw_title,
                 name_changes_disabled: settings_account.update_name_change_display,
                 new_stream_announcements_stream_id: stream_ui_updates.update_announce_stream_option,

web/src/settings_components.ts

@@ -238,7 +238,6 @@ export const simple_dropdown_realm_settings_schema = realm_schema.pick({
     realm_invite_to_stream_policy: true,
     realm_invite_to_realm_policy: true,
     realm_wildcard_mention_policy: true,
-    realm_move_messages_between_streams_policy: true,
     realm_edit_topic_policy: true,
     realm_org_type: true,
 });
@@ -505,6 +504,7 @@ const dropdown_widget_map = new Map<string, DropdownWidget | null>([
     ["realm_can_delete_any_message_group", null],
     ["realm_can_delete_own_message_group", null],
     ["realm_can_manage_all_groups", null],
+    ["realm_can_move_messages_between_channels_group", null],
     ["realm_direct_message_initiator_group", null],
     ["realm_direct_message_permission_group", null],
 ]);
@@ -827,6 +827,7 @@ export function check_realm_settings_property_changed(elem: HTMLElement): boolea
         case "realm_can_delete_any_message_group":
         case "realm_can_delete_own_message_group":
         case "realm_can_manage_all_groups":
+        case "realm_can_move_messages_between_channels_group":
         case "realm_direct_message_initiator_group":
         case "realm_direct_message_permission_group":
             proposed_val = get_dropdown_list_widget_setting_value($elem);
@@ -1067,6 +1068,7 @@ export function populate_data_for_realm_settings_request(
                     "can_manage_all_groups",
                     "can_delete_any_message_group",
                     "can_delete_own_message_group",
+                    "can_move_messages_between_channels_group",
                     "direct_message_initiator_group",
                     "direct_message_permission_group",
                 ]);

web/src/settings_config.ts

@@ -348,8 +348,6 @@ export const edit_topic_policy_values = {
     },
 };
 
-export const move_messages_between_streams_policy_values = email_invite_to_realm_policy_values;
-
 export const time_limit_dropdown_values = [
     {
         text: $t({defaultMessage: "Any time"}),

web/src/settings_data.ts

@@ -176,7 +176,11 @@ export function user_can_create_web_public_streams(): boolean {
 }
 
 export function user_can_move_messages_between_streams(): boolean {
-    return user_has_permission(realm.realm_move_messages_between_streams_policy);
+    return user_has_permission_for_group_setting(
+        realm.realm_can_move_messages_between_channels_group,
+        "can_move_messages_between_channels_group",
+        "realm",
+    );
 }
 
 export function user_can_manage_all_groups(): boolean {

web/src/settings_org.ts

@@ -111,7 +111,6 @@ type OrganizationSettingsOptions = {
     common_message_policy_values: SettingOptionValueWithKey[];
     invite_to_realm_policy_values: SettingOptionValueWithKey[];
     edit_topic_policy_values: SettingOptionValueWithKey[];
-    move_messages_between_streams_policy_values: SettingOptionValueWithKey[];
 };
 
 export function get_organization_settings_options(): OrganizationSettingsOptions {
@@ -131,9 +130,6 @@ export function get_organization_settings_options(): OrganizationSettingsOptions
         edit_topic_policy_values: settings_components.get_sorted_options_list(
             settings_config.edit_topic_policy_values,
         ),
-        move_messages_between_streams_policy_values: settings_components.get_sorted_options_list(
-            settings_config.move_messages_between_streams_policy_values,
-        ),
     };
 }
 
@@ -231,30 +227,38 @@ function set_msg_edit_limit_dropdown(): void {
 }
 
 function message_move_limit_setting_enabled(
-    related_setting_name: "realm_edit_topic_policy" | "realm_move_messages_between_streams_policy",
+    related_setting_name:
+        | "realm_edit_topic_policy"
+        | "realm_can_move_messages_between_channels_group",
 ): boolean {
-    const setting_value_string = $<HTMLSelectOneElement>(
-        `select:not(multiple)#id_${CSS.escape(related_setting_name)}`,
-    ).val();
-    assert(setting_value_string !== undefined);
-    const setting_value = Number.parseInt(setting_value_string, 10);
-
-    let settings_options;
     if (related_setting_name === "realm_edit_topic_policy") {
-        settings_options = settings_config.edit_topic_policy_values;
+        const setting_value_string = $<HTMLSelectOneElement>(
-    } else {
+            `select:not(multiple)#id_${CSS.escape(related_setting_name)}`,
-        settings_options = settings_config.move_messages_between_streams_policy_values;
+        ).val();
-    }
+        assert(setting_value_string !== undefined);
+        const setting_value = Number.parseInt(setting_value_string, 10);
+        const settings_options = settings_config.edit_topic_policy_values;
 
-    if (setting_value === settings_options.by_admins_only.code) {
+        if (
-        return false;
+            setting_value === settings_options.by_admins_only.code ||
-    }
+            setting_value === settings_options.by_moderators_only.code ||
+            setting_value === settings_options.nobody.code
+        ) {
+            return false;
+        }
 
-    if (setting_value === settings_options.by_moderators_only.code) {
+        return true;
-        return false;
     }
-
+    const user_group_id = settings_components.get_dropdown_list_widget_setting_value(
-    if (setting_value === settings_options.nobody.code) {
+        $(`#id_${related_setting_name}`),
+    );
+    assert(typeof user_group_id === "number");
+    const user_group_name = user_groups.get_user_group_from_id(user_group_id).name;
+    if (
+        user_group_name === "role:administrators" ||
+        user_group_name === "role:moderators" ||
+        user_group_name === "role:nobody"
+    ) {
         return false;
     }
 
@@ -280,7 +284,7 @@ function set_msg_move_limit_setting(property_name: MessageMoveTimeLimitSetting):
         disable_setting = message_move_limit_setting_enabled("realm_edit_topic_policy");
     } else {
         disable_setting = message_move_limit_setting_enabled(
-            "realm_move_messages_between_streams_policy",
+            "realm_can_move_messages_between_channels_group",
         );
     }
     enable_or_disable_related_message_move_time_limit_setting(property_name, disable_setting);
@@ -499,6 +503,9 @@ function update_dependent_subsettings(property_name: string): void {
         case "realm_can_delete_own_message_group":
             check_disable_message_delete_limit_setting_dropdown();
             break;
+        case "realm_can_move_messages_between_channels_group":
+            set_msg_move_limit_setting("realm_move_messages_between_streams_limit_seconds");
+            break;
         case "realm_org_join_restrictions":
             set_org_join_restrictions_dropdown();
             break;
@@ -556,6 +563,7 @@ export function discard_realm_property_element_changes(elem: HTMLElement): void
         case "realm_can_delete_any_message_group":
         case "realm_can_delete_own_message_group":
         case "realm_can_manage_all_groups":
+        case "realm_can_move_messages_between_channels_group":
             assert(typeof property_value === "string" || typeof property_value === "number");
             settings_components.set_dropdown_list_widget_setting_value(
                 property_name,
@@ -914,18 +922,32 @@ export function set_up_dropdown_widget_for_realm_group_settings(): void {
         let dropdown_list_item_click_callback:
             | ((current_value: string | number | undefined) => void)
             | undefined;
-        if (setting_name === "direct_message_permission_group") {
+        switch (setting_name) {
-            dropdown_list_item_click_callback = (
+            case "direct_message_permission_group": {
-                current_value: string | number | undefined,
+                dropdown_list_item_click_callback = (
-            ): void => {
+                    current_value: string | number | undefined,
-                assert(typeof current_value === "number");
+                ): void => {
-                check_disable_direct_message_initiator_group_dropdown(current_value);
+                    assert(typeof current_value === "number");
-            };
+                    check_disable_direct_message_initiator_group_dropdown(current_value);
-        } else if (
+                };
-            setting_name === "can_delete_any_message_group" ||
+
-            setting_name === "can_delete_own_message_group"
+                break;
-        ) {
+            }
-            dropdown_list_item_click_callback = check_disable_message_delete_limit_setting_dropdown;
+            case "can_delete_any_message_group":
+            case "can_delete_own_message_group": {
+                dropdown_list_item_click_callback =
+                    check_disable_message_delete_limit_setting_dropdown;
+
+                break;
+            }
+            case "can_move_messages_between_channels_group": {
+                dropdown_list_item_click_callback = () => {
+                    set_msg_move_limit_setting("realm_move_messages_between_streams_limit_seconds");
+                };
+
+                break;
+            }
+            // No default
         }
 
         set_up_dropdown_widget(
@@ -1224,7 +1246,7 @@ export function build_page(): void {
         function (this: HTMLElement) {
             const $policy_dropdown_elem = $(this);
             const property_name = z
-                .enum(["realm_edit_topic_policy", "realm_move_messages_between_streams_policy"])
+                .enum(["realm_edit_topic_policy", "realm_can_move_messages_between_channels_group"])
                 .parse(settings_components.extract_property_name($policy_dropdown_elem));
             const disable_time_limit_setting = message_move_limit_setting_enabled(property_name);
 

web/src/state_data.ts

@@ -295,6 +295,7 @@ export const realm_schema = z.object({
     realm_can_delete_any_message_group: z.number(),
     realm_can_delete_own_message_group: z.number(),
     realm_can_manage_all_groups: z.number(),
+    realm_can_move_messages_between_channels_group: z.number(),
     realm_create_multiuse_invite_group: z.number(),
     realm_date_created: z.number(),
     realm_default_code_block_language: z.string(),
@@ -366,7 +367,6 @@ export const realm_schema = z.object({
     realm_message_content_delete_limit_seconds: z.number().nullable(),
     realm_message_retention_days: z.number(),
     realm_move_messages_between_streams_limit_seconds: z.number().nullable(),
-    realm_move_messages_between_streams_policy: z.number(),
     realm_move_messages_within_stream_limit_seconds: z.number().nullable(),
     realm_name_changes_disabled: z.boolean(),
     realm_name: z.string(),

web/src/stream_popover.js

@@ -354,7 +354,7 @@ export async function build_move_topic_to_stream_popover(
 
     // When the modal is opened for moving the whole topic from left sidebar,
     // we do not have any message object and so we disable the stream input
-    // based on the move_messages_between_streams_policy setting and topic
+    // based on the can_move_messages_between_channels_group setting and topic
     // input based on edit_topic_policy. In other cases, message object is
     // available and thus we check the time-based permissions as well in the
     // below if block to enable or disable the stream and topic input.

web/templates/settings/organization_permissions_admin.hbs

@@ -201,13 +201,10 @@
                 </div>
             </div>
 
-            <div class="input-group">
+            {{> ../dropdown_widget_with_label
-                <label for="realm_move_messages_between_streams_policy" class="settings-field-label">{{t "Who can move messages to another channel" }}
+              widget_name="realm_can_move_messages_between_channels_group"
-                </label>
+              label=(t 'Who can move messages to another channel')
-                <select name="realm_move_messages_between_streams_policy" class="setting-widget prop-element bootstrap-focus-style move-message-policy-setting settings_select" id="id_realm_move_messages_between_streams_policy" data-setting-widget-type="number">
+              value_type="number" }}
-                    {{> dropdown_options_widget option_values=move_messages_between_streams_policy_values}}
-                </select>
-            </div>
 
             <div class="input-group time-limit-setting">
                 <label for="realm_move_messages_between_streams_limit_seconds" class="settings-field-label">{{t "Time limit for moving messages between channels" }} <i>({{t "does not apply to moderators and administrators" }})</i></label>

web/tests/settings_data.test.js

@@ -162,11 +162,6 @@ test_policy(
     "realm_invite_to_realm_policy",
     settings_data.user_can_invite_users_by_email,
 );
-test_policy(
-    "user_can_move_messages_between_streams",
-    "realm_move_messages_between_streams_policy",
-    settings_data.user_can_move_messages_between_streams,
-);
 
 function test_message_policy(label, policy, validation_func) {
     run_test(label, ({override}) => {
@@ -228,17 +223,6 @@ run_test("user_can_move_messages_to_another_topic_nobody_case", ({override}) =>
     assert.equal(settings_data.user_can_move_messages_to_another_topic(), false);
 });
 
-run_test("user_can_move_messages_between_streams_nobody_case", ({override}) => {
-    override(current_user, "is_admin", true);
-    override(current_user, "is_guest", false);
-    override(
-        realm,
-        "realm_move_messages_between_streams_policy",
-        settings_config.move_messages_between_streams_policy_values.nobody.code,
-    );
-    assert.equal(settings_data.user_can_move_messages_between_streams(), false);
-});
-
 test_realm_group_settings(
     "realm_can_add_custom_emoji_group",
     settings_data.user_can_add_custom_emoji,
@@ -254,6 +238,11 @@ test_realm_group_settings(
     settings_data.user_can_delete_own_message,
 );
 
+test_realm_group_settings(
+    "realm_can_move_messages_between_channels_group",
+    settings_data.user_can_move_messages_between_streams,
+);
+
 run_test("using_dark_theme", ({override}) => {
     override(user_settings, "color_scheme", settings_config.color_scheme_values.dark.code);
     assert.equal(settings_data.using_dark_theme(), true);

web/tests/settings_org.test.js

@@ -506,6 +506,7 @@ function test_discard_changes_button({override}, discard_changes) {
 
 test("set_up", ({override, override_rewire}) => {
     override_rewire(settings_org, "check_disable_message_delete_limit_setting_dropdown", noop);
+    override_rewire(settings_org, "message_move_limit_setting_enabled", noop);
     override(realm, "realm_available_video_chat_providers", {
         jitsi_meet: {
             id: 1,

zerver/actions/create_realm.py

@@ -41,7 +41,6 @@ from zerver.models.realm_audit_logs import AuditLogEventType
 from zerver.models.realms import (
     CommonPolicyEnum,
     InviteToRealmPolicyEnum,
-    MoveMessagesBetweenStreamsPolicyEnum,
     get_org_type_display_name,
     get_realm,
 )
@@ -125,10 +124,6 @@ def set_realm_permissions_based_on_org_type(realm: Realm) -> None:
         # Don't allow members (students) to manage user groups or
         # stream subscriptions.
         realm.invite_to_stream_policy = CommonPolicyEnum.MODERATORS_ONLY
-        # Allow moderators (TAs?) to move topics between streams.
-        realm.move_messages_between_streams_policy = (
-            MoveMessagesBetweenStreamsPolicyEnum.MODERATORS_ONLY
-        )
 
 
 @transaction.atomic(savepoint=False)
@@ -299,6 +294,10 @@ def do_create_realm(
                 Realm.ORG_TYPES["education_nonprofit"]["id"]: SystemGroups.MODERATORS,
                 Realm.ORG_TYPES["education"]["id"]: SystemGroups.MODERATORS,
             },
+            "can_move_messages_between_channels_group": {
+                Realm.ORG_TYPES["education_nonprofit"]["id"]: SystemGroups.MODERATORS,
+                Realm.ORG_TYPES["education"]["id"]: SystemGroups.MODERATORS,
+            },
         }
         set_default_for_realm_permission_group_settings(
             realm, group_settings_defaults_for_org_types

zerver/lib/event_schema.py

@@ -1067,6 +1067,7 @@ group_setting_update_data_type = DictType(
         ("can_delete_any_message_group", group_setting_type),
         ("can_delete_own_message_group", group_setting_type),
         ("can_manage_all_groups", group_setting_type),
+        ("can_move_messages_between_channels_group", group_setting_type),
         ("direct_message_initiator_group", group_setting_type),
         ("direct_message_permission_group", group_setting_type),
     ],

zerver/migrations/0611_realm_can_move_messages_between_channels_group.py

@@ -0,0 +1,23 @@
+# Generated by Django 5.0.9 on 2024-10-12 13:48
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("zerver", "0610_mark_introduce_resolve_topic_modal_as_read"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="realm",
+            name="can_move_messages_between_channels_group",
+            field=models.ForeignKey(
+                null=True,
+                on_delete=django.db.models.deletion.RESTRICT,
+                related_name="+",
+                to="zerver.usergroup",
+            ),
+        ),
+    ]

zerver/migrations/0612_set_default_value_for_can_move_messages_between_channels_group.py

@@ -0,0 +1,46 @@
+# Generated by Django 4.2.1 on 2023-06-12 10:47
+
+from django.db import migrations
+from django.db.backends.base.schema import BaseDatabaseSchemaEditor
+from django.db.migrations.state import StateApps
+from django.db.models import OuterRef
+
+
+def set_default_value_for_can_move_messages_between_channels_group(
+    apps: StateApps, schema_editor: BaseDatabaseSchemaEditor
+) -> None:
+    Realm = apps.get_model("zerver", "Realm")
+    NamedUserGroup = apps.get_model("zerver", "NamedUserGroup")
+
+    move_messages_between_streams_policy_to_group_name = {
+        1: "role:members",
+        2: "role:administrators",
+        3: "role:fullmembers",
+        4: "role:moderators",
+        6: "role:nobody",
+    }
+
+    for id, group_name in move_messages_between_streams_policy_to_group_name.items():
+        Realm.objects.filter(
+            can_move_messages_between_channels_group=None, move_messages_between_streams_policy=id
+        ).update(
+            can_move_messages_between_channels_group=NamedUserGroup.objects.filter(
+                name=group_name, realm=OuterRef("id"), is_system_group=True
+            ).values("pk")
+        )
+
+
+class Migration(migrations.Migration):
+    atomic = False
+
+    dependencies = [
+        ("zerver", "0611_realm_can_move_messages_between_channels_group"),
+    ]
+
+    operations = [
+        migrations.RunPython(
+            set_default_value_for_can_move_messages_between_channels_group,
+            elidable=True,
+            reverse_code=migrations.RunPython.noop,
+        )
+    ]

zerver/migrations/0613_alter_realm_can_move_messages_between_channels_group.py

@@ -0,0 +1,22 @@
+# Generated by Django 5.0.9 on 2024-10-12 13:54
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("zerver", "0612_set_default_value_for_can_move_messages_between_channels_group"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="realm",
+            name="can_move_messages_between_channels_group",
+            field=models.ForeignKey(
+                on_delete=django.db.models.deletion.RESTRICT,
+                related_name="+",
+                to="zerver.usergroup",
+            ),
+        ),
+    ]

zerver/models/realms.py

@@ -359,6 +359,11 @@ class Realm(models.Model):  # type: ignore[django-manager-missing] # django-stub
         default=POLICY_MEMBERS_ONLY
     )
 
+    # UserGroup which is allowed to move messages between streams.
+    can_move_messages_between_channels_group = models.ForeignKey(
+        "UserGroup", on_delete=models.RESTRICT, related_name="+"
+    )
+
     # Global policy for who is allowed to use wildcard mentions in
     # streams with a large number of subscribers.  Anyone can use
     # wildcard mentions in small streams regardless of this setting.
@@ -781,6 +786,15 @@ class Realm(models.Model):  # type: ignore[django-manager-missing] # django-stub
             default_group_name=SystemGroups.OWNERS,
             id_field_name="can_manage_all_groups_id",
         ),
+        can_move_messages_between_channels_group=GroupPermissionSetting(
+            require_system_group=not settings.ALLOW_GROUP_VALUED_SETTINGS,
+            allow_internet_group=False,
+            allow_owners_group=False,
+            allow_nobody_group=True,
+            allow_everyone_group=False,
+            default_group_name=SystemGroups.MEMBERS,
+            id_field_name="can_move_messages_between_channels_group_id",
+        ),
         direct_message_initiator_group=GroupPermissionSetting(
             require_system_group=not settings.ALLOW_GROUP_VALUED_SETTINGS,
             allow_internet_group=False,
@@ -810,6 +824,7 @@ class Realm(models.Model):  # type: ignore[django-manager-missing] # django-stub
         "can_delete_any_message_group",
         "can_delete_own_message_group",
         "can_manage_all_groups",
+        "can_move_messages_between_channels_group",
         "direct_message_initiator_group",
         "direct_message_permission_group",
     ]
@@ -1206,6 +1221,8 @@ def get_realm_with_settings(realm_id: int) -> Realm:
         "can_delete_own_message_group__named_user_group",
         "can_manage_all_groups",
         "can_manage_all_groups__named_user_group",
+        "can_move_messages_between_channels_group",
+        "can_move_messages_between_channels_group__named_user_group",
         "direct_message_initiator_group",
         "direct_message_initiator_group__named_user_group",
         "direct_message_permission_group",

zerver/models/users.py

@@ -823,6 +823,7 @@ class UserProfile(AbstractBaseUser, PermissionsMixin, UserBaseSettings):
             "can_delete_any_message_group",
             "can_delete_own_message_group",
             "can_manage_all_groups",
+            "can_move_messages_between_channels_group",
             "create_multiuse_invite_group",
             "direct_message_initiator_group",
             "direct_message_permission_group",
@@ -898,7 +899,7 @@ class UserProfile(AbstractBaseUser, PermissionsMixin, UserBaseSettings):
         return self.has_permission("create_multiuse_invite_group")
 
     def can_move_messages_between_streams(self) -> bool:
-        return self.has_permission("move_messages_between_streams_policy")
+        return self.has_permission("can_move_messages_between_channels_group")
 
     def can_create_user_groups(self) -> bool:
         return self.has_permission("can_create_groups")

zerver/openapi/zulip.yaml

@@ -4457,6 +4457,20 @@ paths:
                                             setting controlled this permission; `true` corresponded to `Everyone`, and
                                             `false` to `Admins`.
                                         - $ref: "#/components/schemas/GroupSettingValue"
+                                    can_move_messages_between_channels_group:
+                                      allOf:
+                                        - description: |
+                                            A [group-setting value](/api/group-setting-values) defining the set of
+                                            users who have permission to move messages from one channel to another
+                                            in the organization.
+
+                                            **Changes**: New in Zulip 10.0 (feature level 310). Previously, this
+                                            permission was controlled by the enum `move_messages_between_streams_policy`.
+                                            Values were 1=Members, 2=Admins, 3=Full members, 4=Moderators, 6=Nobody.
+
+                                            In Zulip 7.0 (feature level 159), `Nobody` was added as an option to
+                                            `move_messages_between_streams_policy` enum.
+                                        - $ref: "#/components/schemas/GroupSettingValue"
                                     can_manage_all_groups:
                                       allOf:
                                         - $ref: "#/components/schemas/GroupSettingValue"
@@ -8265,8 +8279,8 @@ paths:
         linked documentation on when users are allowed to update messages are:
 
         - `allow_message_editing`
+        - `can_move_messages_between_channels_group`
         - `edit_topic_policy`
-        - `move_messages_between_streams_policy`
         - `message_content_edit_limit_seconds`
         - `move_messages_within_stream_limit_seconds`
         - `move_messages_between_streams_limit_seconds`
@@ -8276,7 +8290,11 @@ paths:
         of the [`realm op: update_dict`](/api/get-events#realm-update_dict)
         event in [`GET /events`](/api/get-events).
 
-        **Changes**: Prior to Zulip 7.0 (feature level 172), anyone could add a
+        **Changes**: In Zulip 10.0 (feature level 310), `move_messages_between_streams_policy`
+        was removed and replaced by `can_move_messages_between_channels_group`
+        realm setting.
+
+        Prior to Zulip 7.0 (feature level 172), anyone could add a
         topic to channel messages without a topic, regardless of the organization's
         [topic editing permissions](/help/restrict-moving-messages). As of this
         feature level, messages without topics have the same restrictions for
@@ -16281,6 +16299,22 @@ paths:
                               setting controlled this permission; `true` corresponded to `Everyone`, and
                               `false` to `Admins`.
                           - $ref: "#/components/schemas/GroupSettingValue"
+                      realm_can_move_messages_between_channels_group:
+                        allOf:
+                          - description: |
+                              Present if `realm` is present in `fetch_event_types`.
+
+                              A [group-setting value](/api/group-setting-values) defining the set of
+                              users who have permission to move messages from one channel to another
+                              in the organization.
+
+                              **Changes**: New in Zulip 10.0 (feature level 310). Previously, this
+                              permission was controlled by the enum `move_messages_between_streams_policy`.
+                              Values were 1=Members, 2=Admins, 3=Full members, 4=Moderators, 6=Nobody.
+
+                              In Zulip 7.0 (feature level 159), `Nobody` was added as an option to
+                              `move_messages_between_streams_policy` enum.
+                          - $ref: "#/components/schemas/GroupSettingValue"
                       realm_bot_creation_policy:
                         type: integer
                         description: |

zerver/tests/test_home.py

@@ -137,6 +137,7 @@ class HomeTest(ZulipTestCase):
         "realm_can_delete_any_message_group",
         "realm_can_delete_own_message_group",
         "realm_can_manage_all_groups",
+        "realm_can_move_messages_between_channels_group",
         "realm_create_multiuse_invite_group",
         "realm_create_private_stream_policy",
         "realm_create_public_stream_policy",

zerver/tests/test_message_move_stream.py

@@ -2,19 +2,21 @@ from datetime import timedelta
 
 import orjson
 
-from zerver.actions.realm_settings import do_set_realm_property
+from zerver.actions.message_delete import do_delete_messages
+from zerver.actions.realm_settings import (
+    do_change_realm_permission_group_setting,
+    do_set_realm_property,
+)
 from zerver.actions.streams import do_change_stream_post_policy
+from zerver.actions.user_groups import check_add_user_group
 from zerver.actions.users import do_change_user_role
 from zerver.lib.message import has_message_access
 from zerver.lib.test_classes import ZulipTestCase, get_topic_messages
 from zerver.lib.test_helpers import queries_captured
 from zerver.lib.url_encoding import near_stream_message_url
-from zerver.models import Message, Stream, UserMessage, UserProfile
+from zerver.models import Message, NamedUserGroup, Stream, UserMessage, UserProfile
-from zerver.models.realms import (
+from zerver.models.groups import SystemGroups
-    EditTopicPolicyEnum,
+from zerver.models.realms import EditTopicPolicyEnum, get_realm
-    MoveMessagesBetweenStreamsPolicyEnum,
-    get_realm,
-)
 from zerver.models.streams import get_stream
 
 
@@ -49,8 +51,18 @@ class MessageMoveStreamTest(ZulipTestCase):
             user_profile.save(update_fields=["default_language"])
 
         self.login(user_email)
-        stream = self.make_stream(old_stream)
+        try:
-        stream_to = self.make_stream(new_stream)
+            stream = get_stream(old_stream, user_profile.realm)
+            messages = get_topic_messages(user_profile, stream, "test")
+            do_delete_messages(user_profile.realm, messages, acting_user=None)
+        except Stream.DoesNotExist:
+            stream = self.make_stream(old_stream)
+        try:
+            stream_to = get_stream(new_stream, user_profile.realm)
+            messages = get_topic_messages(user_profile, stream_to, "test")
+            do_delete_messages(user_profile.realm, messages, acting_user=None)
+        except Stream.DoesNotExist:
+            stream_to = self.make_stream(new_stream)
         self.subscribe(user_profile, stream.name)
         self.subscribe(user_profile, stream_to.name)
         msg_id = self.send_stream_message(
@@ -104,16 +116,21 @@ class MessageMoveStreamTest(ZulipTestCase):
 
     def test_change_all_propagate_mode_for_moving_old_messages(self) -> None:
         user_profile = self.example_user("hamlet")
+        realm = user_profile.realm
         id1 = self.send_stream_message(user_profile, "Denmark", topic_name="topic1")
         id2 = self.send_stream_message(user_profile, "Denmark", topic_name="topic1")
         id3 = self.send_stream_message(user_profile, "Denmark", topic_name="topic1")
         id4 = self.send_stream_message(user_profile, "Denmark", topic_name="topic1")
         self.send_stream_message(user_profile, "Denmark", topic_name="topic1")
 
-        do_set_realm_property(
+        members_system_group = NamedUserGroup.objects.get(
-            user_profile.realm,
+            name=SystemGroups.MEMBERS, realm=realm, is_system_group=True
-            "move_messages_between_streams_policy",
+        )
-            MoveMessagesBetweenStreamsPolicyEnum.MEMBERS_ONLY,
+
+        do_change_realm_permission_group_setting(
+            realm,
+            "can_move_messages_between_channels_group",
+            members_system_group,
             acting_user=None,
         )
 
@@ -784,13 +801,16 @@ class MessageMoveStreamTest(ZulipTestCase):
         )
 
     def test_move_message_between_streams_policy_setting(self) -> None:
-        (user_profile, old_stream, new_stream, msg_id, msg_id_later) = self.prepare_move_topics(
+        othello = self.example_user("othello")
-            "othello", "old_stream_1", "new_stream_1", "test"
+        cordelia = self.example_user("cordelia")
-        )
+        realm = othello.realm
-
-        def check_move_message_according_to_policy(role: int, expect_fail: bool = False) -> None:
-            do_change_user_role(user_profile, role, acting_user=None)
 
+        def check_move_message_according_to_permission(
+            username: str, expect_fail: bool = False
+        ) -> None:
+            (user_profile, old_stream, new_stream, msg_id, msg_id_later) = self.prepare_move_topics(
+                username, "old_stream", "new_stream", "test"
+            )
             result = self.client_patch(
                 "/json/messages/" + str(msg_id),
                 {
@@ -812,77 +832,117 @@ class MessageMoveStreamTest(ZulipTestCase):
                 messages = get_topic_messages(user_profile, new_stream, "test")
                 self.assert_length(messages, 4)
 
-        # Check sending messages when policy is MoveMessagesBetweenStreamsPolicyEnum.NOBODY.
+        administrators_system_group = NamedUserGroup.objects.get(
-        do_set_realm_property(
+            name=SystemGroups.ADMINISTRATORS, realm=realm, is_system_group=True
-            user_profile.realm,
-            "move_messages_between_streams_policy",
-            MoveMessagesBetweenStreamsPolicyEnum.NOBODY,
-            acting_user=None,
         )
-        check_move_message_according_to_policy(UserProfile.ROLE_REALM_OWNER, expect_fail=True)
+        full_members_system_group = NamedUserGroup.objects.get(
-        check_move_message_according_to_policy(
+            name=SystemGroups.FULL_MEMBERS, realm=realm, is_system_group=True
-            UserProfile.ROLE_REALM_ADMINISTRATOR, expect_fail=True
+        )
+        members_system_group = NamedUserGroup.objects.get(
+            name=SystemGroups.MEMBERS, realm=realm, is_system_group=True
+        )
+        moderators_system_group = NamedUserGroup.objects.get(
+            name=SystemGroups.MODERATORS, realm=realm, is_system_group=True
+        )
+        nobody_system_group = NamedUserGroup.objects.get(
+            name=SystemGroups.NOBODY, realm=realm, is_system_group=True
         )
 
-        # Check sending messages when policy is MoveMessagesBetweenStreamsPolicyEnum.ADMINS_ONLY.
+        # Check sending messages when nobody is allowed to move messages.
-        do_set_realm_property(
+        do_change_realm_permission_group_setting(
-            user_profile.realm,
+            realm,
-            "move_messages_between_streams_policy",
+            "can_move_messages_between_channels_group",
-            MoveMessagesBetweenStreamsPolicyEnum.ADMINS_ONLY,
+            nobody_system_group,
             acting_user=None,
         )
-        check_move_message_according_to_policy(UserProfile.ROLE_MODERATOR, expect_fail=True)
+        check_move_message_according_to_permission("desdemona", expect_fail=True)
-        check_move_message_according_to_policy(UserProfile.ROLE_REALM_ADMINISTRATOR)
+        check_move_message_according_to_permission("iago", expect_fail=True)
 
-        (user_profile, old_stream, new_stream, msg_id, msg_id_later) = self.prepare_move_topics(
+        # Check sending messages when only administrators are allowed.
-            "othello", "old_stream_2", "new_stream_2", "test"
+        do_change_realm_permission_group_setting(
-        )
+            realm,
-        # Check sending messages when policy is MoveMessagesBetweenStreamsPolicyEnum.MODERATORS_ONLY.
+            "can_move_messages_between_channels_group",
-        do_set_realm_property(
+            administrators_system_group,
-            user_profile.realm,
-            "move_messages_between_streams_policy",
-            MoveMessagesBetweenStreamsPolicyEnum.MODERATORS_ONLY,
             acting_user=None,
         )
-        check_move_message_according_to_policy(UserProfile.ROLE_MEMBER, expect_fail=True)
+        check_move_message_according_to_permission("shiva", expect_fail=True)
-        check_move_message_according_to_policy(UserProfile.ROLE_MODERATOR)
+        check_move_message_according_to_permission("iago")
 
-        (user_profile, old_stream, new_stream, msg_id, msg_id_later) = self.prepare_move_topics(
+        # Check sending messages when only moderators are allowed.
-            "othello", "old_stream_3", "new_stream_3", "test"
+        do_change_realm_permission_group_setting(
-        )
+            realm,
-        # Check sending messages when policy is MoveMessagesBetweenStreamsPolicyEnum.FULL_MEMBERS_ONLY.
+            "can_move_messages_between_channels_group",
-        do_set_realm_property(
+            moderators_system_group,
-            user_profile.realm,
-            "move_messages_between_streams_policy",
-            MoveMessagesBetweenStreamsPolicyEnum.FULL_MEMBERS_ONLY,
             acting_user=None,
         )
-        do_set_realm_property(
+        check_move_message_according_to_permission("cordelia", expect_fail=True)
-            user_profile.realm, "waiting_period_threshold", 100000, acting_user=None
+        check_move_message_according_to_permission("shiva")
-        )
-        check_move_message_according_to_policy(UserProfile.ROLE_MEMBER, expect_fail=True)
 
-        do_set_realm_property(user_profile.realm, "waiting_period_threshold", 0, acting_user=None)
+        # Check sending messages when full members are allowed.
-        check_move_message_according_to_policy(UserProfile.ROLE_MEMBER)
+        do_change_realm_permission_group_setting(
-
+            realm,
-        (user_profile, old_stream, new_stream, msg_id, msg_id_later) = self.prepare_move_topics(
+            "can_move_messages_between_channels_group",
-            "othello", "old_stream_4", "new_stream_4", "test"
+            full_members_system_group,
-        )
-        # Check sending messages when policy is MoveMessagesBetweenStreamsPolicyEnum.MEMBERS_ONLY.
-        do_set_realm_property(
-            user_profile.realm,
-            "move_messages_between_streams_policy",
-            MoveMessagesBetweenStreamsPolicyEnum.MEMBERS_ONLY,
             acting_user=None,
         )
-        check_move_message_according_to_policy(UserProfile.ROLE_GUEST, expect_fail=True)
+        do_set_realm_property(othello.realm, "waiting_period_threshold", 100000, acting_user=None)
-        check_move_message_according_to_policy(UserProfile.ROLE_MEMBER)
+        check_move_message_according_to_permission("othello", expect_fail=True)
+
+        do_set_realm_property(realm, "waiting_period_threshold", 0, acting_user=None)
+        check_move_message_according_to_permission("cordelia")
+
+        # Check sending messages when members are allowed.
+        do_change_realm_permission_group_setting(
+            realm,
+            "can_move_messages_between_channels_group",
+            members_system_group,
+            acting_user=None,
+        )
+        check_move_message_according_to_permission("polonius", expect_fail=True)
+        check_move_message_according_to_permission("cordelia")
+
+        # Test for checking setting for non-system user group.
+        user_group = check_add_user_group(
+            realm, "new_group", [othello, cordelia], acting_user=othello
+        )
+        do_change_realm_permission_group_setting(
+            realm, "can_move_messages_between_channels_group", user_group, acting_user=None
+        )
+
+        # Othello and Cordelia are in the allowed user group, so can move messages.
+        check_move_message_according_to_permission("othello")
+        check_move_message_according_to_permission("cordelia")
+
+        # Iago is not in the allowed user group, so cannot move messages.
+        check_move_message_according_to_permission("iago", expect_fail=True)
+
+        # Test for checking the setting for anonymous user group.
+        anonymous_user_group = self.create_or_update_anonymous_group_for_setting(
+            [othello],
+            [administrators_system_group],
+        )
+        do_change_realm_permission_group_setting(
+            realm,
+            "can_move_messages_between_channels_group",
+            anonymous_user_group,
+            acting_user=None,
+        )
+
+        # Othello is the direct member of the anonymous user group, so can move messages.
+        check_move_message_according_to_permission("othello")
+        # Iago is in the `administrators_system_group` subgroup, so can move messages.
+        check_move_message_according_to_permission("iago")
+
+        # Shiva is not in the anonymous user group, so cannot move messages.
+        check_move_message_according_to_permission("shiva", expect_fail=True)
 
     def test_move_message_to_stream_time_limit(self) -> None:
         shiva = self.example_user("shiva")
         iago = self.example_user("iago")
         cordelia = self.example_user("cordelia")
 
+        realm = cordelia.realm
+
         test_stream_1 = self.make_stream("test_stream_1")
         test_stream_2 = self.make_stream("test_stream_2")
 
@@ -900,10 +960,14 @@ class MessageMoveStreamTest(ZulipTestCase):
 
         self.send_stream_message(cordelia, test_stream_1.name, topic_name="test", content="third")
 
-        do_set_realm_property(
+        members_system_group = NamedUserGroup.objects.get(
-            cordelia.realm,
+            name=SystemGroups.MEMBERS, realm=realm, is_system_group=True
-            "move_messages_between_streams_policy",
+        )
-            MoveMessagesBetweenStreamsPolicyEnum.MEMBERS_ONLY,
+
+        do_change_realm_permission_group_setting(
+            realm,
+            "can_move_messages_between_channels_group",
+            members_system_group,
             acting_user=None,
         )
 
@@ -968,10 +1032,16 @@ class MessageMoveStreamTest(ZulipTestCase):
         (user_profile, old_stream, new_stream, msg_id, msg_id_later) = self.prepare_move_topics(
             "othello", "old_stream_1", "new_stream_1", "test"
         )
-        do_set_realm_property(
+        realm = user_profile.realm
-            user_profile.realm,
+
-            "move_messages_between_streams_policy",
+        members_system_group = NamedUserGroup.objects.get(
-            MoveMessagesBetweenStreamsPolicyEnum.MEMBERS_ONLY,
+            name=SystemGroups.MEMBERS, realm=realm, is_system_group=True
+        )
+
+        do_change_realm_permission_group_setting(
+            realm,
+            "can_move_messages_between_channels_group",
+            members_system_group,
             acting_user=None,
         )
 
@@ -1066,10 +1136,14 @@ class MessageMoveStreamTest(ZulipTestCase):
         realm.save()
         self.login("cordelia")
 
-        do_set_realm_property(
+        members_system_group = NamedUserGroup.objects.get(
-            user_profile.realm,
+            name=SystemGroups.MEMBERS, realm=realm, is_system_group=True
-            "move_messages_between_streams_policy",
+        )
-            MoveMessagesBetweenStreamsPolicyEnum.MEMBERS_ONLY,
+
+        do_change_realm_permission_group_setting(
+            realm,
+            "can_move_messages_between_channels_group",
+            members_system_group,
             acting_user=None,
         )
 
@@ -1101,7 +1175,7 @@ class MessageMoveStreamTest(ZulipTestCase):
             "iago", "test move stream", "new stream", "test"
         )
 
-        with self.assert_database_query_count(51), self.assert_memcached_count(14):
+        with self.assert_database_query_count(53), self.assert_memcached_count(14):
             result = self.client_patch(
                 f"/json/messages/{msg_id}",
                 {
@@ -1579,12 +1653,6 @@ class MessageMoveStreamTest(ZulipTestCase):
             to_invite_only=False,
         )
 
-    def test_can_move_messages_between_streams(self) -> None:
-        def validation_func(user_profile: UserProfile) -> bool:
-            return user_profile.can_move_messages_between_streams()
-
-        self.check_has_permission_policies("move_messages_between_streams_policy", validation_func)
-
     def test_move_message_from_private_to_private_with_old_member(self) -> None:
         admin_user = self.example_user("iago")
         user_losing_access = self.example_user("cordelia")

zerver/tests/test_message_move_topic.py

@@ -363,7 +363,7 @@ class MessageMoveTopicTest(ZulipTestCase):
         set_topic_visibility_policy(desdemona, muted_topics, UserTopic.VisibilityPolicy.MUTED)
         set_topic_visibility_policy(cordelia, muted_topics, UserTopic.VisibilityPolicy.MUTED)
 
-        with self.assert_database_query_count(27):
+        with self.assert_database_query_count(29):
             check_update_message(
                 user_profile=desdemona,
                 message_id=message_id,
@@ -393,7 +393,7 @@ class MessageMoveTopicTest(ZulipTestCase):
         ]
         set_topic_visibility_policy(desdemona, muted_topics, UserTopic.VisibilityPolicy.MUTED)
         set_topic_visibility_policy(cordelia, muted_topics, UserTopic.VisibilityPolicy.MUTED)
-        with self.assert_database_query_count(33):
+        with self.assert_database_query_count(34):
             check_update_message(
                 user_profile=desdemona,
                 message_id=message_id,
@@ -426,7 +426,7 @@ class MessageMoveTopicTest(ZulipTestCase):
         set_topic_visibility_policy(desdemona, muted_topics, UserTopic.VisibilityPolicy.MUTED)
         set_topic_visibility_policy(cordelia, muted_topics, UserTopic.VisibilityPolicy.MUTED)
 
-        with self.assert_database_query_count(27):
+        with self.assert_database_query_count(29):
             check_update_message(
                 user_profile=desdemona,
                 message_id=message_id,
@@ -449,7 +449,7 @@ class MessageMoveTopicTest(ZulipTestCase):
         second_message_id = self.send_stream_message(
             hamlet, stream_name, topic_name="changed topic name", content="Second message"
         )
-        with self.assert_database_query_count(22):
+        with self.assert_database_query_count(23):
             check_update_message(
                 user_profile=desdemona,
                 message_id=second_message_id,

zerver/tests/test_realm.py

@@ -62,12 +62,7 @@ from zerver.models import (
 )
 from zerver.models.groups import SystemGroups
 from zerver.models.realm_audit_logs import AuditLogEventType
-from zerver.models.realms import (
+from zerver.models.realms import CommonPolicyEnum, InviteToRealmPolicyEnum, get_realm
-    CommonPolicyEnum,
-    InviteToRealmPolicyEnum,
-    MoveMessagesBetweenStreamsPolicyEnum,
-    get_realm,
-)
 from zerver.models.streams import get_stream
 from zerver.models.users import get_system_bot, get_user_profile_by_id
 
@@ -119,16 +114,13 @@ class RealmTest(ZulipTestCase):
         self.assertEqual(realm.can_create_public_channel_group_id, admins_group.id)
 
         self.assertEqual(realm.invite_to_realm_policy, InviteToRealmPolicyEnum.ADMINS_ONLY)
-        self.assertEqual(
-            realm.move_messages_between_streams_policy,
-            MoveMessagesBetweenStreamsPolicyEnum.MODERATORS_ONLY,
-        )
         self.assertEqual(realm.invite_to_stream_policy, CommonPolicyEnum.MODERATORS_ONLY)
         realm = get_realm("test_education_non_profit")
         moderators_group = NamedUserGroup.objects.get(
             name=SystemGroups.MODERATORS, realm=realm, is_system_group=True
         )
         self.assertEqual(realm.can_create_groups.id, moderators_group.id)
+        self.assertEqual(realm.can_move_messages_between_channels_group.id, moderators_group.id)
 
     def test_permission_for_education_for_profit_organization(self) -> None:
         realm = do_create_realm(
@@ -143,16 +135,13 @@ class RealmTest(ZulipTestCase):
         self.assertEqual(realm.can_create_public_channel_group_id, admins_group.id)
 
         self.assertEqual(realm.invite_to_realm_policy, InviteToRealmPolicyEnum.ADMINS_ONLY)
-        self.assertEqual(
-            realm.move_messages_between_streams_policy,
-            MoveMessagesBetweenStreamsPolicyEnum.MODERATORS_ONLY,
-        )
         self.assertEqual(realm.invite_to_stream_policy, CommonPolicyEnum.MODERATORS_ONLY)
         realm = get_realm("test_education_for_profit")
         moderators_group = NamedUserGroup.objects.get(
             name=SystemGroups.MODERATORS, realm=realm, is_system_group=True
         )
         self.assertEqual(realm.can_create_groups.id, moderators_group.id)
+        self.assertEqual(realm.can_move_messages_between_channels_group.id, moderators_group.id)
 
     def test_realm_enable_spectator_access(self) -> None:
         realm = do_create_realm(

zerver/views/realm.py

@@ -145,6 +145,7 @@ def update_realm(
     can_create_private_channel_group: Json[GroupSettingChangeRequest] | None = None,
     can_create_web_public_channel_group: Json[GroupSettingChangeRequest] | None = None,
     can_manage_all_groups: Json[GroupSettingChangeRequest] | None = None,
+    can_move_messages_between_channels_group: Json[GroupSettingChangeRequest] | None = None,
     direct_message_initiator_group: Json[GroupSettingChangeRequest] | None = None,
     direct_message_permission_group: Json[GroupSettingChangeRequest] | None = None,
     invite_to_stream_policy: Json[CommonPolicyEnum] | None = None,