Code

editor-diff.tsx

import { defineBasicExtension } from 'prosekit/basic'
import { createEditor, union } from 'prosekit/core'
import { defineCommitViewer, type Commit } from 'prosekit/extensions/commit'
import { defineReadonly } from 'prosekit/extensions/readonly'
import { ProseKit } from 'prosekit/react'
import { useMemo } from 'react'

export default function DiffViewer({ commit }: { commit: Commit }) {
  const editor = useMemo(() => {
    const extension = union(
      defineBasicExtension(),
      defineReadonly(),
      defineCommitViewer(commit),
    )
    return createEditor({ extension })
  }, [commit])

  return (
    <ProseKit editor={editor}>
      <div className='box-border h-full w-full min-h-36 overflow-y-hidden overflow-x-hidden rounded-md border border-solid border-gray-200 shadow dark:border-zinc-700 flex flex-col bg-white dark:bg-neutral-900'>
        <div className='relative w-full flex-1 box-border overflow-y-scroll'>
          <div ref={editor.mount} className='ProseMirror box-border min-h-full px-[max(4rem,_calc(50%-20rem))] py-8 outline-none outline-0 [&_span[data-mention="user"]]:text-blue-500 [&_span[data-mention="tag"]]:text-violet-500 [&_pre]:text-white [&_pre]:bg-zinc-800'></div>
        </div>
      </div>
    </ProseKit>
  )
}

editor-main.tsx

import 'prosekit/basic/style.css'

import { defineBasicExtension } from 'prosekit/basic'
import { createEditor, union, type NodeJSON } from 'prosekit/core'
import {
  type CommitRecorder,
  defineCommitRecorder,
} from 'prosekit/extensions/commit'
import { ProseKit } from 'prosekit/react'
import { useMemo } from 'react'

export default function Editor({
  commitRecorder,
  defaultContent,
}: {
  commitRecorder: CommitRecorder
  defaultContent?: NodeJSON
}) {
  const editor = useMemo(() => {
    const extension = union(
      defineBasicExtension(),
      defineCommitRecorder(commitRecorder),
    )
    return createEditor({ extension, defaultContent })
  }, [commitRecorder, defaultContent])

  return (
    <ProseKit editor={editor}>
      <div className='box-border h-full w-full min-h-36 overflow-y-hidden overflow-x-hidden rounded-md border border-solid border-gray-200 shadow dark:border-zinc-700 flex flex-col bg-white dark:bg-neutral-900'>
        <div className='relative w-full flex-1 box-border overflow-y-scroll'>
          <div ref={editor.mount} className='ProseMirror box-border min-h-full px-[max(4rem,_calc(50%-20rem))] py-8 outline-none outline-0 [&_span[data-mention="user"]]:text-blue-500 [&_span[data-mention="tag"]]:text-violet-500 [&_pre]:text-white [&_pre]:bg-zinc-800'></div>
        </div>
      </div>
    </ProseKit>
  )
}

editor.tsx

import 'prosekit/basic/style.css'

import type { NodeJSON } from 'prosekit/core'
import { CommitRecorder, type Commit } from 'prosekit/extensions/commit'
import { useCallback, useMemo, useState } from 'react'

import EditorDiff from './editor-diff'
import EditorMain from './editor-main'

export default function Editor() {
  const [commits, setCommits] = useState<
    { id: string; date: Date; commit: Commit }[]
  >([])
  const [key, setKey] = useState(0)
  const [defaultContent, setDefaultContent] = useState<NodeJSON | undefined>()
  const commitRecorder = useMemo(() => new CommitRecorder(), [])

  const handleCommit = useCallback(() => {
    const commit = commitRecorder.commit()
    if (!commit) return
    const id = Math.random().toString(36).slice(2, 9)
    setCommits((commits) => [{ id, date: new Date(), commit }, ...commits])
  }, [commitRecorder])

  const handleRestore = useCallback(
    (id: string) => {
      const index = commits.findIndex((commit) => commit.id === id)
      if (index === -1) return
      const doc = commits[index].commit.doc
      setDefaultContent(doc)
      setCommits((commits) => commits.slice(index))
      setKey((key) => key + 1)
    },
    [commits],
  )

  return (
    <div className="grid grid-cols-2 gap-2">
      <div className="flex flex-col gap-4">
        <div className="max-h-md">
          <EditorMain
            key={key}
            defaultContent={defaultContent}
            commitRecorder={commitRecorder}
          />
        </div>
        <button onClick={handleCommit} className='inline-flex items-center justify-center whitespace-nowrap rounded-md text-sm font-medium ring-offset-white dark:ring-offset-neutral-900 transition-colors focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-zinc-900 dark:focus-visible:ring-zinc-300 focus-visible:ring-offset-2 disabled:pointer-events-none disabled:opacity-50 border-0 bg-zinc-900 dark:bg-zinc-50 text-zinc-50 dark:text-zinc-900 hover:bg-zinc-900/90 dark:hover:bg-zinc-50/90 h-10 px-4 py-2'>
          Save
        </button>
      </div>
      <div className="flex flex-col gap-4">
        {commits.map((commit) => (
          <div key={commit.id}>
            <div className="max-h-md">
              <EditorDiff commit={commit.commit} />
            </div>
            <div className="w-full inline-flex justify-between p-1 text-sm">
              <span className="opacity-50">
                {commit.date.toLocaleTimeString()}
              </span>
              <button
                className="underline opacity-50 hover:opacity-100"
                onClick={() => handleRestore(commit.id)}
              >
                Restore
              </button>
            </div>
          </div>
        ))}
      </div>
    </div>
  )
}