Undo (Ctrl+Z) causes error when empty paragraphs are present, likely when reaching the end of the undo stack

[Matergi]

Precheck

• [x] Do a quick search and make sure the bug has not been reported yet.
• [ ] Please disclose security vulnerabilities privately at oss@kommit.co.
• [x] Finally, be nice and have fun!.

Description

When performing an undo (Ctrl+Z) action in a project containing empty paragraphs, an error occurs, seemingly when reaching the end of the undo stack. Writing content works as expected, but when undoing multiple actions, the error appears, likely triggered when all changes have been undone and the stack is exhausted. Subsequent undo actions function normally after the initial error.

https://github.com/user-attachments/assets/b5f24f82-3c94-4b99-b977-9acb350892ae

config

const undo = new Undo({ editor: this.editorJSRef });
if (initialData) {
  undo.initialize(initialData);
}

initialData

{
    "time": 1726488299703,
    "blocks": [
        {
            "id": "gQylYzS2g3",
            "data": {
                "text": "Preparazione",
                "level": 2
            },
            "type": "header"
        },
        {
            "id": "OEa17yeViK",
            "data": {
                "text": "ffff"
            },
            "type": "paragraph"
        },
        {
            "id": "tqnPuoDqad",
            "data": {
                "text": "Esecuzione",
                "level": 2
            },
            "type": "header"
        },
        {
            "id": "DXvmBu7NB1",
            "data": {
                "text": ""
            },
            "type": "paragraph"
        },
        {
            "id": "8JhJyLNqig",
            "data": {
                "text": "Varianti",
                "level": 2
            },
            "type": "header"
        },
        {
            "id": "-3r_em4xqt",
            "data": {
                "text": ""
            },
            "type": "paragraph"
        },
        {
            "id": "-PTRcHuD4d",
            "data": {
                "text": "Consigli",
                "level": 2
            },
            "type": "header"
        },
        {
            "id": "-I1jKL30IU",
            "data": {
                "text": ""
            },
            "type": "paragraph"
        },
        {
            "id": "ECVz89TiLC",
            "data": {
                "text": "Materiali",
                "level": 2
            },
            "type": "header"
        }
    ],
    "version": "2.30.3"
}

plugins:

paragraph: {
  class: Paragraph,
  inlineToolbar: true,
  config: {
    placeholder: strings.get('editorjs.start writing here'),
    preserveBlank: true,
  },
},

Environment

• Editor.js version:2.30.3
• Plugins you use with their versions:

  "@editorjs/embed": "2.7.4",
  "@editorjs/image": "2.9.1",
  "@editorjs/marker": "1.4.0",
  "@editorjs/paragraph": "2.11.6",
  "@editorjs/table": "2.3.0",
  "@editorjs/underline": "1.1.0",
  "editorjs-undo": "2.0.28",

• Device, Browser, OS: Chrome

Current behavior

(Ctrl+Z) at the end of the stack

Expected behavior

A clear and concise description of what you expected to happen.

Additional context

Add any other context about the problem here.

[Matergi]

It seems that if I don't include:

undo.initialize(initialData);

the issue doesn't occur, but in this case, performing Ctrl+Z clears everything

[Matergi]

Forgive me, it was my mistake, I was initializing EditorJS like this:

onReady: async () => {
    ...
    this.editorJSRef.blocks.render(data);
    ...
}

but I had also added the data prop in the EditorJS constructor:

new EditorJS({
    ...
    data
    ...
})

By removing this.editorJSRef.blocks.render(data);, everything works fine. Issue closed.