tiptap/packages/core/src/commands/setContent.ts

import { Editor } from '../Editor'
import { TextSelection } from 'prosemirror-state'

declare module '../Editor' {
  interface Editor {
    setContent(content: string, emitUpdate?: Boolean, parseOptions?: any): Editor,
  }
}

export default function setContent(
  next: Function,
  editor: Editor,
  content = null,
  emitUpdate = false,
  parseOptions = {},
): void {
  if (content === null) {
    next()
    return
  }

  const { view, state, createDocument } = editor
  const { doc, tr } = state
  const document = createDocument(content, parseOptions)
  const selection = TextSelection.create(doc, 0, doc.content.size)
  const transaction = tr
    .setSelection(selection)
    .replaceSelectionWith(document, false)
    .setMeta('preventUpdate', !emitUpdate)

  view.dispatch(transaction)
  next()
}