test: add test for marks on nodes

tests/y-prosemirror.test.js

@@ -23,7 +23,7 @@ import { findWrapping } from 'prosemirror-transform'
 import { schema as complexSchema } from './complexSchema.js'
 import * as promise from 'lib0/promise'
 
-const schema = /** @type {any} */ (basicSchema.schema)
+const schema = /** @type {import('prosemirror-model').Schema} */ (basicSchema.schema)
 
 /**
  * Verify that update events in plugins are only fired once.
@@ -452,6 +452,30 @@ export const testAddToHistoryIgnore = (_tc) => {
   )
 }
 
+/**
+ * @param {t.TestCase} tc
+ */
+export const testMarksOnNodes = (_tc) => {
+  const view = createNewProsemirrorView(new Y.Doc())
+  view.dispatch(
+    view.state.tr.insert(
+      0,
+      /** @type {any} */ (schema.node('image', { src: 'http://example.com', alt: null, title: null }, [], [schema.mark('link', { href: 'https://yjs.dev', title: null })]))
+    )
+  )
+  // convert to JSON and back because the ProseMirror schema messes with the constructors
+  const stateJSON = JSON.parse(JSON.stringify(view.state.doc.toJSON()))
+  // test if transforming back and forth from Yjs doc works
+  const backandforth = JSON.parse(JSON.stringify(yDocToProsemirrorJSON(
+    prosemirrorJSONToYDoc(/** @type {any} */ (schema), stateJSON)
+  )))
+  // Add the missing alt and title attributes, these are defaults for the image mark
+  backandforth.content[0].content[0].attrs.alt = null
+  backandforth.content[0].content[0].attrs.title = null
+
+  t.compare(stateJSON, backandforth, 'marks on nodes are preserved')
+}
+
 const createNewProsemirrorViewWithSchema = (y, schema, undoManager = false) => {
   const view = new EditorView(null, {
     // @ts-ignore