From 8f6860863e34cb1cbe24161f1c4e7c79007e93dc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Federico=20Jaramillo=20Marti=CC=81nez?=
 <federicojaramillom@gmail.com>
Date: Thu, 22 Aug 2019 09:20:30 -0500
Subject: [PATCH] Fixed #30722 -- Added default rate-limiting requests to
 admin's Select2 widget.

---
 django/contrib/admin/widgets.py                 |  1 +
 tests/admin_views/test_autocomplete_view.py     | 13 +++++++++++++
 tests/admin_widgets/test_autocomplete_widget.py |  1 +
 3 files changed, 15 insertions(+)

diff --git a/django/contrib/admin/widgets.py b/django/contrib/admin/widgets.py
index aa4b613894..7db57f4098 100644
--- a/django/contrib/admin/widgets.py
+++ b/django/contrib/admin/widgets.py
@@ -410,6 +410,7 @@ class AutocompleteMixin:
         attrs.setdefault('class', '')
         attrs.update({
             'data-ajax--cache': 'true',
+            'data-ajax--delay': 250,
             'data-ajax--type': 'GET',
             'data-ajax--url': self.get_url(),
             'data-theme': 'admin-autocomplete',
diff --git a/tests/admin_views/test_autocomplete_view.py b/tests/admin_views/test_autocomplete_view.py
index 5855aa71d4..2734a45606 100644
--- a/tests/admin_views/test_autocomplete_view.py
+++ b/tests/admin_views/test_autocomplete_view.py
@@ -1,4 +1,5 @@
 import json
+import time
 
 from django.contrib import admin
 from django.contrib.admin.tests import AdminSeleniumTestCase
@@ -189,6 +190,12 @@ class SeleniumTests(AdminSeleniumTestCase):
         self.assertEqual(len(results), PAGINATOR_SIZE + 11)
         # Limit the results with the search field.
         search.send_keys('Who')
+        # Ajax request is delayed.
+        self.assertTrue(result_container.is_displayed())
+        results = result_container.find_elements_by_css_selector('.select2-results__option')
+        self.assertEqual(len(results), PAGINATOR_SIZE + 12)
+        # Wait for ajax delay.
+        time.sleep(0.25)
         self.assertTrue(result_container.is_displayed())
         results = result_container.find_elements_by_css_selector('.select2-results__option')
         self.assertEqual(len(results), 1)
@@ -223,6 +230,12 @@ class SeleniumTests(AdminSeleniumTestCase):
         self.assertEqual(len(results), 31)
         # Limit the results with the search field.
         search.send_keys('Who')
+        # Ajax request is delayed.
+        self.assertTrue(result_container.is_displayed())
+        results = result_container.find_elements_by_css_selector('.select2-results__option')
+        self.assertEqual(len(results), 32)
+        # Wait for ajax delay.
+        time.sleep(0.25)
         self.assertTrue(result_container.is_displayed())
         results = result_container.find_elements_by_css_selector('.select2-results__option')
         self.assertEqual(len(results), 1)
diff --git a/tests/admin_widgets/test_autocomplete_widget.py b/tests/admin_widgets/test_autocomplete_widget.py
index 601929fd37..2cb2e8fbf5 100644
--- a/tests/admin_widgets/test_autocomplete_widget.py
+++ b/tests/admin_widgets/test_autocomplete_widget.py
@@ -52,6 +52,7 @@ class AutocompleteMixinTests(TestCase):
         self.assertEqual(attrs, {
             'class': 'my-class admin-autocomplete',
             'data-ajax--cache': 'true',
+            'data-ajax--delay': 250,
             'data-ajax--type': 'GET',
             'data-ajax--url': '/admin_widgets/band/autocomplete/',
             'data-theme': 'admin-autocomplete',