add a new getHtmlFromFragment method that is used in the editor and in the stand-alone generateHtml helper

packages/core/src/utils/getHtmlFromFragment.ts

@@ -0,0 +1,14 @@
+import { Node as ProseMirrorNode, DOMSerializer } from 'prosemirror-model'
+import { Schema } from 'prosemirror-model'
+
+export default function getHtmlFromFragment(doc: ProseMirrorNode, schema: Schema): string {
+  const fragment = DOMSerializer
+    .fromSchema(schema)
+    .serializeFragment(doc.content)
+
+  const temporaryDocument = document.implementation.createHTMLDocument()
+  const container = temporaryDocument.createElement('div')
+  container.appendChild(fragment)
+
+  return container.innerHTML
+}