settings: Improve error message when deactivating the last user.

This PR was originally started by Rishi Gupta (see #10383).

static/js/settings_account.js

@@ -440,8 +440,18 @@ exports.set_up = function () {
                     window.location.href = "/login";
                 },
                 error: function (xhr) {
+                    var error_last_admin = i18n.t("Error: Cannot deactivate the only organization administrator.");
+                    var error_last_user = i18n.t("Error: Cannot deactivate the only user. You can deactivate the whole organization though in your <a target=\"_blank\" href=\"/#organization/organization-profile\">Organization profile settings</a>.");
+                    var rendered_error_msg;
+                    if (xhr.responseJSON.code === "CANNOT_DEACTIVATE_LAST_USER") {
+                        if (xhr.responseJSON.is_last_admin) {
+                            rendered_error_msg = error_last_admin;
+                        } else {
+                            rendered_error_msg = error_last_user;
+                        }
+                    }
                     $("#deactivate_self_modal").modal("hide");
-                    ui_report.error(i18n.t("Error deactivating account"), xhr, $('#account-settings-status').expectOne());
+                    $("#account-settings-status").addClass("alert-error").html(rendered_error_msg).show();
                 },
             });
         }, 5000);

tools/lib/capitalization.py

@@ -93,6 +93,8 @@ IGNORED_PHRASES = [
     r"was too large; the maximum file size is 25MiB.",
     r"selected message",
     r"a-z",
+    r"organization administrator",
+    r"user",
 
     # SPECIAL CASES
     # Enter is usually capitalized

zerver/lib/exceptions.py

@@ -32,6 +32,7 @@ class ErrorCode(AbstractEnum):
     BAD_IMAGE = ()
     REALM_UPLOAD_QUOTA = ()
     BAD_NARROW = ()
+    CANNOT_DEACTIVATE_LAST_USER = ()
     MISSING_HTTP_EVENT_HEADER = ()
     STREAM_DOES_NOT_EXIST = ()
     UNAUTHORIZED_PRINCIPAL = ()
@@ -139,6 +140,18 @@ class StreamDoesNotExistError(JsonableError):
     def msg_format() -> str:
         return _("Stream '{stream}' does not exist")
 
+class CannotDeactivateLastUserError(JsonableError):
+    code = ErrorCode.CANNOT_DEACTIVATE_LAST_USER
+    data_fields = ['is_last_admin', 'entity']
+
+    def __init__(self, is_last_admin: bool) -> None:
+        self.is_last_admin = is_last_admin
+        self.entity = _("organization administrator") if is_last_admin else _("user")
+
+    @staticmethod
+    def msg_format() -> str:
+        return _("Cannot deactivate the only {entity}.")
+
 class RateLimited(PermissionDenied):
     def __init__(self, msg: str="") -> None:
         super().__init__(msg)

zerver/tests/test_signup.py

@@ -23,6 +23,7 @@ from confirmation import settings as confirmation_settings
 
 from zerver.forms import HomepageForm, WRONG_SUBDOMAIN_ERROR, check_subdomain_available
 from zerver.lib.actions import do_change_password
+from zerver.lib.exceptions import CannotDeactivateLastUserError
 from zerver.decorator import do_two_factor_login
 from zerver.views.auth import login_or_register_remote_user, \
     redirect_and_log_into_subdomain, start_two_factor_auth
@@ -2886,7 +2887,7 @@ class DeactivateUserTest(ZulipTestCase):
         user = self.example_user('iago')
         self.assertTrue(user.is_active)
         result = self.client_delete('/json/users/me')
-        self.assert_json_error(result, "Cannot deactivate the only organization administrator")
+        self.assert_json_error(result, "Cannot deactivate the only organization administrator.")
         user = self.example_user('iago')
         self.assertTrue(user.is_active)
         self.assertTrue(user.is_realm_admin)
@@ -2898,6 +2899,14 @@ class DeactivateUserTest(ZulipTestCase):
         self.assert_json_success(result)
         do_change_is_admin(user, True)
 
+    def test_do_not_deactivate_final_user(self) -> None:
+        realm = get_realm('zulip')
+        UserProfile.objects.filter(realm=realm, is_realm_admin=False).update(is_active=False)
+        email = self.example_email("iago")
+        self.login(email)
+        result = self.client_delete('/json/users/me')
+        self.assert_json_error(result, "Cannot deactivate the only user.")
+
 class TestLoginPage(ZulipTestCase):
     def test_login_page_wrong_subdomain_error(self) -> None:
         result = self.client_get("/login/?subdomain=1")

zerver/views/users.py

@@ -22,7 +22,7 @@ from zerver.lib.actions import do_change_avatar_fields, do_change_bot_owner, \
     do_update_user_custom_profile_data
 from zerver.lib.avatar import avatar_url, get_gravatar_url, get_avatar_field
 from zerver.lib.bot_config import set_bot_config
-from zerver.lib.exceptions import JsonableError
+from zerver.lib.exceptions import JsonableError, CannotDeactivateLastUserError
 from zerver.lib.integrations import EMBEDDED_BOTS
 from zerver.lib.request import has_request_variables, REQ
 from zerver.lib.response import json_error, json_success
@@ -48,9 +48,11 @@ def deactivate_user_backend(request: HttpRequest, user_profile: UserProfile,
     return _deactivate_user_profile_backend(request, user_profile, target)
 
 def deactivate_user_own_backend(request: HttpRequest, user_profile: UserProfile) -> HttpResponse:
-
+    if UserProfile.objects.filter(realm=user_profile.realm, is_active=True).count() == 1:
+        raise CannotDeactivateLastUserError(is_last_admin=False)
     if user_profile.is_realm_admin and check_last_admin(user_profile):
-        return json_error(_('Cannot deactivate the only organization administrator'))
+        raise CannotDeactivateLastUserError(is_last_admin=True)
+
     do_deactivate_user(user_profile, acting_user=user_profile)
     return json_success()