The default configuration options for ImageStyle plugin are not properly cloned

[psmyrek]

📝 Provide detailed reproduction steps (if any)

It's difficult for me right now to prepare a few short steps to reproduce this bug, so let me just describe the problem.

The problem occurred during updating CKE5-related dependencies in the ckeditor5-angular repository, because one test started to fail in this line: https://github.com/ckeditor/ckeditor5-angular/blob/master/src/ckeditor/ckeditor.component.spec.ts#L324.

This test fails because unexpectedly the second component in this test also started to emit an error, but it shouldn't. The reason for this is that since CKE5 v29 we have an ImageInline plugin and the default options for ImageStyle have changed. It looks like they are not properly cloned when they are created, but they share the same arrays as modelElements in each editor, i.e.

ckeditor5/packages/ckeditor5-image/src/imagestyle/utils.js

Line 47 in f52226f

modelElements: [ 'imageInline' ],

✔️ Expected result

Editors do not share common properties.

❌ Actual result

Editors share common properties from ImageStyle plugin.

❓ Possible solution

Make sure that default options are properly cloned.

📃 Other details

• First affected CKEditor version: v29

---

If you'd like to see this fixed sooner, add a 👍 reaction to this post.

[pomek]

A similar problem we had in the font-size feature:

ckeditor5/packages/ckeditor5-font/src/fontsize/utils.js

Lines 29 to 39 in f52226f

	get tiny() {
	return {
	title: 'Tiny',
	model: 'tiny',
	view: {
	name: 'span',
	classes: 'text-tiny',
	priority: 7
	}
	};
	},

.

Scope:

• Add getters for default options.
• Write tests that cover the change (one for change in utils, one integration)

[Reinmar]

We'd need a better description of what's wrong from the editor's perspective (in the editor's code). This is, extending this:

It looks like they are not properly cloned when they are created, but they share the same arrays as modelElements in each editor, i.e.

[Reinmar]

Actually, what's needed is – how to crash the editor without Angular. Naturally, Angular uses its API, but then how it uses its API to make it crash.

[psmyrek]

I probably did not describe the problem precisely.

The problem is not that the editor crashes. The problem is that if we have a context watchdog that watches over at least 2 editors, then an error in one of them causes that all of them are restarted (not as expected). The necessary condition for such incorrect reboots to take place is that each of these editors must have Image and ImageStyle plugins. The ImageStyle plugin shares some of its default options among all editor instances, which makes all editors connected together.