Update CKEditor 5 to 35.1.0

Oops!

22 minutes ago: https://github.com/ckeditor/ckeditor5/releases/tag/v35.1.0

EDIT: cross-posted 😄

1. 👍 Confirmed to be fixed by accessibility maintainer @bnjmnm:
   • #3283800: [upstream] CKE5 dropdowns keyboard support
   • #3283801: [upstream] CKE5 dropdown focus handling is not fully accessible
   • #3283803: [upstream] CKE5 toggleable toolbar items not enough contrast
   • #3283804: [upstream] CKE5 dropdown screenreader support

2. +++ b/core/modules/ckeditor5/js/ckeditor5_plugins/drupalMedia/src/drupalmediacaption/drupalmediacaptionui.js
   @@ -70,6 +70,7 @@ export default class DrupalMediaCaptionUI extends Plugin {
   +        editor.editing.view.focus();
   

   👍 This is a change that was added for accessibility purposes, to be in line with the (many!) accessibility fixes in the 35.1.0 release.

   Accessibility maintainer @bnjmnm reviewed this together with @lauriii, so … 👍

3. +++ b/core/modules/ckeditor5/js/ckeditor5_plugins/drupalMedia/src/mediaimagetextalternative/mediaimagetextalternativeediting.js
   @@ -74,10 +74,6 @@ export default class MediaImageTextAlternativeEditing extends Plugin {
   -          const tooltip = new TooltipView();
   -          tooltip.text = message;
   -          tooltip.position = 'sw';
   -
              const html = new Template({
                tag: 'span',
                children: [
   @@ -85,9 +81,9 @@ export default class MediaImageTextAlternativeEditing extends Plugin {
   
   @@ -85,9 +81,9 @@ export default class MediaImageTextAlternativeEditing extends Plugin {
                    tag: 'span',
                    attributes: {
                      class: 'drupal-media__metadata-error-icon',
   +                  'data-cke-tooltip-text': message,
                    },
                  },
   -              tooltip,
                ],
   

   👍 This is matching the upstream change of adopting the new tooltip API: https://github.com/ckeditor/ckeditor5/commit/002c96be1e910aeee4a4b7f0d97... + https://github.com/ckeditor/ckeditor5/commit/89f78f45995a23022207e6bc808....

   The new API: https://github.com/ckeditor/ckeditor5/commit/1acdf50abc397aa5d0b0f1c3e5b....

   To be precise:

   MINOR BREAKING CHANGE (ui): The TooltipView UI component has been removed, please use the new tooltip API instead. Please note that this change does not affect integrations that configure tooltips using ButtonView#tooltip property.
   

   Apparently there is no explicit documentation for this change, because the CKEditor 5 team considers to be a transparent change for 98% of integrators (of which Drupal is one). We're one of the very rare exceptions, because we did use the TooltipView class which now no longer exists. I was pointed to https://ckeditor5.github.io/docs/nightly/ckeditor5/latest/api/module_ui_....

4. +++ b/core/modules/ckeditor5/tests/src/FunctionalJavascript/CKEditor5OffCanvasTest.php
   @@ -42,7 +42,7 @@ public function testOffCanvasStyles() {
   -    $this->assertEquals('rgb(250, 250, 250)', $ckeditor_toolbar_bg_color, 'Toolbar background-color should be unaffected by off-canvas');
   +    $this->assertEquals('rgb(255, 255, 255)', $ckeditor_toolbar_bg_color, 'Toolbar background-color should be unaffected by off-canvas');
   

   👍 This is an upstream change, to improve contrast.

   Before

   

   After

   

5. 🥳 And of course, the very thorough test suite still passes!

Update for #9.3: they're now working to expand their "migration guide" (to migrate/upgrade to 35.1.0), see https://github.com/ckeditor/ckeditor5/pull/12385/files. That confirms the changes made here! 👍

(Please credit @oleq for making that happen upstream!)

Doing

curl -O https://www.drupal.org/files/issues/2022-08-31/3306153-8-95x.patch
curl -O https://www.drupal.org/files/issues/2022-09-01/3306153-21-94x.patch
diff 3306153-8-95x.patch 3306153-21-94x.patch

yields a tiny diff, which shows that it's only the context in core/package.json that is slightly different (see output attached).

This is confirmed by doing git diff origin/9.4.x origin/9.5.x -- core/package.json — or rather by using the latest 9.4.x and the 9.5.x just prior to the above commit: git diff f20c0a2030cb19bafa2f54d7e5da8c75459410fd 74c6519^ -- core/package.json, which outputs:

diff --git a/core/package.json b/core/package.json
index 950c9da8e0..81d9d34910 100644
--- a/core/package.json
+++ b/core/package.json
@@ -70,8 +70,7 @@
     "chromedriver": "^98.0.1",
     "ckeditor5": "35.0.x",
     "cross-env": "^7.0.2",
-    "cross-env": "^7.0.2",
-    "cspell": "^5.0.0",
+    "cspell": "^6.0.0",
     "css.escape": "1.5.x",
     "dotenv-safe": "^8.2.0",
     "es6-promise": "4.2.x",

IOW the 9.4.x patch in #21 is perfect! 💯