Issue #3086375 by zrpnr, lauriii, nod_: Deprecate domready and remove usages in core

core/core.libraries.yml

@@ -41,6 +41,7 @@ domready:
     gpl-compatible: true
   js:
     assets/vendor/domready/ready.min.js: { weight: -21, minified: true }
+  deprecated: The "%library_id%" asset library is deprecated in drupal:8.8.0 and is removed from drupal:9.0.0. See https://www.drupal.org/node/3086669
 
 drupal:
   version: VERSION
@@ -48,7 +49,6 @@ drupal:
     misc/drupal.js: { weight: -18 }
     misc/drupal.init.js: { weight: -17 }
   dependencies:
-    - core/domready
     - core/drupalSettings
   drupalSettings:
     suppressDeprecationErrors: true

core/lib/Drupal/Core/Render/theme.api.php

@@ -1040,7 +1040,7 @@ function hook_css_alter(&$css, \Drupal\Core\Asset\AttachedAssetsInterface $asset
  */
 function hook_page_attachments(array &$attachments) {
   // Unconditionally attach an asset to the page.
-  $attachments['#attached']['library'][] = 'core/domready';
+  $attachments['#attached']['library'][] = 'core/drupalSettings';
 
   // Conditionally attach an asset to the page.
   if (!\Drupal::currentUser()->hasPermission('may pet kittens')) {

core/misc/drupal.init.es6.js

@@ -8,10 +8,27 @@ document.documentElement.className += ' js';
 
 // JavaScript should be made compatible with libraries other than jQuery by
 // wrapping it in an anonymous closure.
+(function(Drupal, drupalSettings) {
+  /**
+   * Calls callback when document ready.
+   *
+   * @param {function} callback
+   *   The function to be called on document ready.
+   */
+  const domReady = callback => {
+    if (document.readyState !== 'loading') {
+      callback();
+    } else {
+      const listener = () => {
+        callback();
+        document.removeEventListener('DOMContentLoaded', listener);
+      };
+      document.addEventListener('DOMContentLoaded', listener);
+    }
+  };
 
-(function(domready, Drupal, drupalSettings) {
   // Attach all behaviors.
-  domready(() => {
+  domReady(() => {
     Drupal.attachBehaviors(document, drupalSettings);
   });
-})(domready, Drupal, window.drupalSettings);
+})(Drupal, window.drupalSettings);

core/misc/drupal.init.js

@@ -11,8 +11,20 @@ if (window.jQuery) {
 
 document.documentElement.className += ' js';
 
-(function (domready, Drupal, drupalSettings) {
-  domready(function () {
+(function (Drupal, drupalSettings) {
+  var domReady = function domReady(callback) {
+    if (document.readyState !== 'loading') {
+      callback();
+    } else {
+      var listener = function listener() {
+        callback();
+        document.removeEventListener('DOMContentLoaded', listener);
+      };
+      document.addEventListener('DOMContentLoaded', listener);
+    }
+  };
+
+  domReady(function () {
     Drupal.attachBehaviors(document, drupalSettings);
   });
-})(domready, Drupal, window.drupalSettings);
\ No newline at end of file
+})(Drupal, window.drupalSettings);
\ No newline at end of file

core/tests/Drupal/KernelTests/Core/Asset/AttachedAssetsTest.php

@@ -235,7 +235,7 @@ public function testHeaderHTML() {
     $query_string = $this->container->get('state')->get('system.css_js_query_string') ?: '0';
     $this->assertNotIdentical(strpos($rendered_js, '<script src="' . file_url_transform_relative(file_create_url('core/modules/system/tests/modules/common_test/header.js')) . '?' . $query_string . '"></script>'), FALSE, 'The JS asset in common_test/js-header appears in the header.');
     $this->assertNotIdentical(strpos($rendered_js, '<script src="' . file_url_transform_relative(file_create_url('core/misc/drupal.js'))), FALSE, 'The JS asset of the direct dependency (core/drupal) of common_test/js-header appears in the header.');
-    $this->assertNotIdentical(strpos($rendered_js, '<script src="' . file_url_transform_relative(file_create_url('core/assets/vendor/domready/ready.min.js'))), FALSE, 'The JS asset of the indirect dependency (core/domready) of common_test/js-header appears in the header.');
+    $this->assertNotIdentical(strpos($rendered_js, '<script src="' . file_url_transform_relative(file_create_url('core/misc/drupalSettingsLoader.js'))), FALSE, 'The JS asset of the indirect dependency (core/drupalSettings) of common_test/js-header appears in the header.');
   }
 
   /**
@@ -275,14 +275,13 @@ public function testBrowserConditionalComments() {
    */
   public function testVersionQueryString() {
     $build['#attached']['library'][] = 'core/backbone';
-    $build['#attached']['library'][] = 'core/domready';
     $assets = AttachedAssets::createFromRenderArray($build);
 
     $js = $this->assetResolver->getJsAssets($assets, FALSE)[1];
     $js_render_array = \Drupal::service('asset.js.collection_renderer')->render($js);
 
     $rendered_js = $this->renderer->renderPlain($js_render_array);
-    $this->assertTrue(strpos($rendered_js, 'core/assets/vendor/backbone/backbone-min.js?v=1.2.3') > 0 && strpos($rendered_js, 'core/assets/vendor/domready/ready.min.js?v=1.0.8') > 0, 'JavaScript version identifiers correctly appended to URLs');
+    $this->assertTrue(strpos($rendered_js, 'core/assets/vendor/backbone/backbone-min.js?v=1.2.3') > 0, 'JavaScript version identifiers correctly appended to URLs');
   }
 
   /**