settings: Disable save button if nobody group is not allowed.

This commit adds code to disable the save button if there no
pills selected for the setting and the setting cannot be set
to "Nobody" group.

web/src/settings_components.ts

@@ -1353,6 +1353,40 @@ function should_disable_save_button_for_time_limit_settings(
     return disable_save_btn;
 }
 
+function should_disable_save_button_for_group_settings(settings: string[]): boolean {
+    for (const setting_name of settings) {
+        let group_setting_config;
+        if (setting_name.startsWith("realm_")) {
+            const setting_name_without_prefix = /^realm_(.*)$/.exec(setting_name)![1]!;
+            group_setting_config = group_permission_settings.get_group_permission_setting_config(
+                setting_name_without_prefix,
+                "realm",
+            );
+        } else {
+            // We do not have any stream settings using the new UI currently,
+            // so we know that this block will be called for group setting only.
+            group_setting_config = group_permission_settings.get_group_permission_setting_config(
+                setting_name,
+                "group",
+            );
+        }
+        assert(group_setting_config !== undefined);
+        if (group_setting_config.allow_nobody_group) {
+            continue;
+        }
+
+        const pill_widget = get_group_setting_widget(setting_name);
+        assert(pill_widget !== null);
+
+        const setting_value = get_group_setting_widget_value(pill_widget);
+        const nobody_group = user_groups.get_user_group_from_name("role:nobody")!;
+        if (setting_value === nobody_group.id) {
+            return true;
+        }
+    }
+    return false;
+}
+
 function enable_or_disable_save_button($subsection_elem: JQuery): void {
     const time_limit_settings = [...$subsection_elem.find(".time-limit-setting")];
 
@@ -1382,6 +1416,15 @@ function enable_or_disable_save_button($subsection_elem: JQuery): void {
         }
     }
 
+    if (!disable_save_btn) {
+        const group_settings = [...$subsection_elem.find(".pill-container")].map((elem) =>
+            extract_property_name($(elem)),
+        );
+        if (group_settings.length) {
+            disable_save_btn = should_disable_save_button_for_group_settings(group_settings);
+        }
+    }
+
     $subsection_elem.find(".subsection-changes-save button").prop("disabled", disable_save_btn);
 }
 

web/tests/settings_org.test.js

@@ -86,6 +86,7 @@ function createSaveButtons(subsection) {
 
     $save_button_controls.closest = () => $stub_save_button_header;
     $stub_save_button_header.set_find_results(".time-limit-setting", []);
+    $stub_save_button_header.set_find_results(".pill-container", []);
     $stub_save_button_header.set_find_results(".subsection-changes-save button", $stub_save_button);
 
     return {