user_groups: Use can_leave_group setting to check permisison.

This commit adds code to use can_leave_group setting when
checking permission to leave group in webapp.

web/src/settings_data.ts

@@ -231,6 +231,16 @@ export function can_join_user_group(group_id: number): boolean {
     return can_manage_user_group(group_id);
 }
 
+export function can_leave_user_group(group_id: number): boolean {
+    const group = user_groups.get_user_group_from_id(group_id);
+
+    if (user_has_permission_for_group_setting(group.can_leave_group, "can_leave_group", "group")) {
+        return true;
+    }
+
+    return can_manage_user_group(group_id);
+}
+
 export function user_can_create_user_groups(): boolean {
     return user_has_permission_for_group_setting(
         realm.realm_can_create_groups,

web/src/state_data.ts

@@ -147,6 +147,7 @@ export const user_group_schema = z.object({
     direct_subgroup_ids: z.array(z.number()),
     can_add_members_group: group_setting_value_schema,
     can_join_group: group_setting_value_schema,
+    can_leave_group: group_setting_value_schema,
     can_manage_group: group_setting_value_schema,
     can_mention_group: z.number(),
     deactivated: z.boolean(),

web/src/types.ts

@@ -18,6 +18,7 @@ export type UserGroupUpdateEvent = {
         description?: string;
         can_add_members_group?: number;
         can_join_group?: number;
+        can_leave_group?: number;
         can_manage_group?: number;
         can_mention_group?: number;
         deactivated?: boolean;

web/src/user_group_edit.js

@@ -272,7 +272,7 @@ function update_group_membership_button(group_id) {
     }
 
     const can_join_group = settings_data.can_join_user_group(group_id);
-    const can_leave_group = settings_data.can_manage_user_group(group_id);
+    const can_leave_group = settings_data.can_leave_user_group(group_id);
 
     let can_update_membership = true;
     if (!is_member && !can_join_group) {
@@ -339,7 +339,7 @@ export function handle_member_edit_event(group_id, user_ids) {
         const item = group;
         item.is_member = user_groups.is_user_in_group(group_id, people.my_current_user_id());
         item.can_join = settings_data.can_join_user_group(item.id);
-        item.can_leave = settings_data.can_manage_user_group(item.id);
+        item.can_leave = settings_data.can_leave_user_group(item.id);
         const html = render_browse_user_groups_list_item(item);
         const $new_row = $(html);
 
@@ -670,6 +670,10 @@ export function update_group(event) {
             sync_group_permission_setting("can_join_group", group);
             update_group_membership_button(group.id);
         }
+        if (event.data.can_leave_group !== undefined) {
+            sync_group_permission_setting("can_leave_group", group);
+            update_group_membership_button(group.id);
+        }
     }
 }
 
@@ -883,7 +887,7 @@ export function setup_page(callback) {
                     item.id,
                 );
                 item.can_join = settings_data.can_join_user_group(item.id);
-                item.can_leave = settings_data.can_manage_user_group(item.id);
+                item.can_leave = settings_data.can_leave_user_group(item.id);
                 return render_browse_user_groups_list_item(item);
             },
             filter: {

web/src/user_groups.ts

@@ -57,6 +57,7 @@ export function add(user_group_raw: UserGroupRaw): UserGroup {
         direct_subgroup_ids: new Set(user_group_raw.direct_subgroup_ids),
         can_add_members_group: user_group_raw.can_add_members_group,
         can_join_group: user_group_raw.can_join_group,
+        can_leave_group: user_group_raw.can_leave_group,
         can_manage_group: user_group_raw.can_manage_group,
         can_mention_group: user_group_raw.can_mention_group,
         deactivated: user_group_raw.deactivated,
@@ -126,6 +127,12 @@ export function update(event: UserGroupUpdateEvent): void {
         user_group_name_dict.delete(group.name);
         user_group_name_dict.set(group.name, group);
     }
+
+    if (event.data.can_leave_group !== undefined) {
+        group.can_leave_group = event.data.can_leave_group;
+        user_group_name_dict.delete(group.name);
+        user_group_name_dict.set(group.name, group);
+    }
 }
 
 export function get_user_group_from_name(name: string): UserGroup | undefined {

web/tests/composebox_typeahead.test.js

@@ -450,6 +450,7 @@ const hamletcharacters = user_group_item({
     direct_subgroup_ids: new Set([]),
     can_add_members_group: 2,
     can_join_group: 2,
+    can_leave_group: 2,
     can_manage_group: 2,
     can_mention_group: 2,
     deactivated: false,
@@ -466,6 +467,7 @@ const backend = user_group_item({
     direct_subgroup_ids: new Set([1]),
     can_add_members_group: 1,
     can_join_group: 1,
+    can_leave_group: 2,
     can_manage_group: 1,
     can_mention_group: 1,
     deactivated: false,
@@ -482,6 +484,7 @@ const call_center = user_group_item({
     direct_subgroup_ids: new Set([]),
     can_add_members_group: 2,
     can_join_group: 2,
+    can_leave_group: 2,
     can_manage_group: 2,
     can_mention_group: 2,
     deactivated: false,

web/tests/lib/events.js

@@ -841,6 +841,7 @@ exports.fixtures = {
             direct_subgroup_ids: [2],
             can_add_members_group: 16,
             can_join_group: 16,
+            can_leave_group: 15,
             can_manage_group: 16,
             can_mention_group: 11,
             deactivated: false,

web/tests/settings_data.test.js

@@ -587,6 +587,129 @@ run_test("can_join_user_group", ({override}) => {
     assert.ok(settings_data.can_join_user_group(students.id));
 });
 
+run_test("can_leave_user_group", ({override}) => {
+    const admins = {
+        description: "Administrators",
+        name: "role:administrators",
+        id: 1,
+        members: new Set([1]),
+        is_system_group: true,
+        direct_subgroup_ids: new Set([]),
+        can_join_group: 4,
+        can_leave_group: 4,
+        can_manage_group: 4,
+        can_mention_group: 1,
+    };
+    const moderators = {
+        description: "Moderators",
+        name: "role:moderators",
+        id: 2,
+        members: new Set([2]),
+        is_system_group: true,
+        direct_subgroup_ids: new Set([1]),
+        can_join_group: 4,
+        can_leave_group: 4,
+        can_manage_group: 4,
+        can_mention_group: 1,
+    };
+    const members = {
+        description: "Members",
+        name: "role:members",
+        id: 3,
+        members: new Set([3, 4]),
+        is_system_group: true,
+        direct_subgroup_ids: new Set([1, 2]),
+        can_join_group: 4,
+        can_leave_group: 4,
+        can_manage_group: 4,
+        can_mention_group: 4,
+    };
+    const nobody = {
+        description: "Nobody",
+        name: "role:nobody",
+        id: 4,
+        members: new Set([]),
+        is_system_group: true,
+        direct_subgroup_ids: new Set([]),
+        can_join_group: 4,
+        can_leave_group: 4,
+        can_manage_group: 4,
+        can_mention_group: 2,
+    };
+    const students = {
+        description: "Students group",
+        name: "Students",
+        id: 5,
+        members: new Set([1, 2]),
+        is_system_group: false,
+        direct_subgroup_ids: new Set([4, 5]),
+        can_join_group: 1,
+        can_leave_group: 1,
+        can_manage_group: {
+            direct_members: [4],
+            direct_subgroups: [],
+        },
+        can_mention_group: 3,
+        creator_id: 4,
+    };
+    user_groups.initialize({
+        realm_user_groups: [admins, moderators, members, nobody, students],
+    });
+    override(realm, "realm_can_manage_all_groups", nobody.id);
+
+    page_params.is_spectator = true;
+    assert.ok(!settings_data.can_leave_user_group(students.id));
+
+    page_params.is_spectator = false;
+    // admin user
+    override(current_user, "user_id", 1);
+    assert.ok(settings_data.can_leave_user_group(students.id));
+
+    // moderator user
+    override(current_user, "user_id", 2);
+    assert.ok(!settings_data.can_leave_user_group(students.id));
+
+    let event = {
+        group_id: students.id,
+        data: {
+            can_leave_group: moderators.id,
+        },
+    };
+    user_groups.update(event);
+    assert.ok(settings_data.can_leave_user_group(students.id));
+
+    override(current_user, "user_id", 1);
+    assert.ok(settings_data.can_leave_user_group(students.id));
+
+    // Some other user.
+    override(current_user, "user_id", 5);
+    assert.ok(!settings_data.can_leave_user_group(students.id));
+
+    event = {
+        group_id: students.id,
+        data: {
+            can_leave_group: {
+                direct_members: [5],
+                direct_subgroups: [admins.id],
+            },
+        },
+    };
+    user_groups.update(event);
+    assert.ok(settings_data.can_leave_user_group(students.id));
+
+    override(current_user, "user_id", 2);
+    assert.ok(!settings_data.can_leave_user_group(students.id));
+
+    // User can leave the group if they can manage the group which
+    // depends on can_manage_group and realm.can_manage_all_groups settings.
+    override(current_user, "user_id", 4);
+    assert.ok(settings_data.can_leave_user_group(students.id));
+
+    override(realm, "realm_can_manage_all_groups", moderators.id);
+    override(current_user, "user_id", 2);
+    assert.ok(settings_data.can_leave_user_group(students.id));
+});
+
 run_test("can_add_members_user_group", () => {
     const admins = {
         description: "Administrators",

web/tests/user_groups.test.js

@@ -24,6 +24,7 @@ run_test("user_groups", () => {
         direct_subgroup_ids: new Set([4, 5]),
         can_add_members_group: 1,
         can_join_group: 1,
+        can_leave_group: 1,
         can_manage_group: 1,
         can_mention_group: 2,
         deactivated: false,
@@ -48,6 +49,7 @@ run_test("user_groups", () => {
         direct_subgroup_ids: new Set([]),
         can_add_members_group: 1,
         can_join_group: 1,
+        can_leave_group: 1,
         can_manage_group: 1,
         can_mention_group: 2,
         deactivated: false,
@@ -59,6 +61,7 @@ run_test("user_groups", () => {
         is_system_group: false,
         direct_subgroup_ids: new Set([4, 5, 6]),
         can_join_group: 1,
+        can_leave_group: 1,
         can_manage_group: 1,
         can_mention_group: 1,
         deactivated: false,
@@ -70,6 +73,7 @@ run_test("user_groups", () => {
         is_system_group: false,
         direct_subgroup_ids: new Set([4, 5, 6]),
         can_join_group: 1,
+        can_leave_group: 1,
         can_manage_group: 1,
         can_mention_group: 1,
         deactivated: true,