settings_data: Add 'user_can_invite_others_to_realm' helper.

This commit adds 'user_can_invite_others_to_realm' function
in settings_data.js which replaces all the instances of
'page_params.can_invite_others_to_realm'.

This change makes it possible to remove the complex logic of
updating 'page_params.can_invite_others_to_realm' on
'realm_update' event as we are using above added helper instead
of using page_params object and thus we always use the updated
value to check whether user can invite others or not.

The 'user_has_permission' helper will be used by functions added
for create_stream_policy and invite_to_stream_policy in further
commits and will help in avoiding code duplication.

frontend_tests/node_tests/settings_data.js

@@ -6,6 +6,7 @@ const {zrequire} = require("../zjsunit/namespace");
 const {run_test} = require("../zjsunit/test");
 const {page_params} = require("../zjsunit/zpage_params");
 
+const people = zrequire("people");
 const settings_data = zrequire("settings_data");
 const settings_config = zrequire("settings_config");
 
@@ -19,7 +20,10 @@ const settings_config = zrequire("settings_config");
 const isaac = {
     email: "isaac@example.com",
     delivery_email: "isaac-delivery@example.com",
+    user_id: 30,
+    full_name: "Isaac",
 };
+people.add_active_user(isaac);
 
 run_test("email_for_user_settings", () => {
     const email = settings_data.email_for_user_settings;
@@ -102,3 +106,33 @@ run_test("user_can_change_logo", () => {
     page_params.zulip_plan_is_not_limited = true;
     assert.equal(can_change_logo(), false);
 });
+
+run_test("user_can_invite_others_to_realm", () => {
+    const can_invite_others_to_realm = settings_data.user_can_invite_others_to_realm;
+
+    page_params.is_admin = true;
+    page_params.realm_invite_to_realm_policy =
+        settings_config.common_policy_values.by_admins_only.code;
+    assert.equal(can_invite_others_to_realm(), true);
+
+    page_params.is_admin = false;
+    assert.equal(can_invite_others_to_realm(), false);
+
+    page_params.is_guest = true;
+    page_params.realm_invite_to_realm_policy = settings_config.common_policy_values.by_members.code;
+    assert.equal(can_invite_others_to_realm(), false);
+
+    page_params.is_guest = false;
+    assert.equal(can_invite_others_to_realm(), true);
+
+    page_params.realm_invite_to_realm_policy =
+        settings_config.common_policy_values.by_full_members.code;
+    page_params.user_id = 30;
+    people.add_active_user(isaac);
+    isaac.date_joined = new Date(Date.now());
+    page_params.realm_waiting_period_threshold = 10;
+    assert.equal(can_invite_others_to_realm(), false);
+
+    isaac.date_joined = new Date(Date.now() - 20 * 86400000);
+    assert.equal(can_invite_others_to_realm(), true);
+});

static/js/admin.js

@@ -124,7 +124,7 @@ export function build_page() {
         msg_delete_limit_dropdown_values: settings_config.msg_delete_limit_dropdown_values,
         bot_creation_policy_values: settings_bots.bot_creation_policy_values,
         email_address_visibility_values: settings_config.email_address_visibility_values,
-        can_invite_others_to_realm: page_params.can_invite_others_to_realm,
+        can_invite_others_to_realm: settings_data.user_can_invite_others_to_realm(),
         ...settings_org.get_organization_settings_options(),
     };
 

static/js/server_events_dispatch.js

@@ -231,11 +231,6 @@ export function dispatch_normal_event(event) {
                             page_params.can_invite_to_stream =
                                 page_params.is_admin ||
                                 page_params.realm_invite_to_stream_policy === 1;
-                        } else if (event.property === "invite_to_realm_policy") {
-                            // TODO: Add waiting period threshold logic here.
-                            page_params.can_invite_others_to_realm =
-                                page_params.is_admin ||
-                                page_params.realm_invite_to_realm_policy === 1;
                         }
 
                         if (event.property === "name" && window.electron_bridge !== undefined) {

static/js/settings_data.js

@@ -1,4 +1,5 @@
 import {page_params} from "./page_params";
+import * as people from "./people";
 import * as settings_config from "./settings_config";
 
 /*
@@ -80,3 +81,32 @@ export function user_can_change_avatar() {
 export function user_can_change_logo() {
     return page_params.is_admin && page_params.zulip_plan_is_not_limited;
 }
+
+function user_has_permission(policy_value) {
+    if (page_params.is_admin) {
+        return true;
+    }
+
+    if (page_params.is_guest) {
+        return false;
+    }
+
+    if (policy_value === settings_config.common_policy_values.by_admins_only.code) {
+        return false;
+    }
+
+    if (policy_value === settings_config.common_policy_values.by_members.code) {
+        return true;
+    }
+
+    const person = people.get_by_user_id(page_params.user_id);
+    const current_datetime = new Date(Date.now());
+    const person_date_joined = new Date(person.date_joined);
+    const days = (current_datetime - person_date_joined) / 1000 / 86400;
+
+    return days >= page_params.realm_waiting_period_threshold;
+}
+
+export function user_can_invite_others_to_realm() {
+    return user_has_permission(page_params.realm_invite_to_realm_policy);
+}