improve code input rule

packages/core/src/utils/undoInputRule.ts

@@ -0,0 +1,32 @@
+import { EditorState, Transaction } from 'prosemirror-state'
+
+// source: https://github.com/ProseMirror/prosemirror-inputrules/blob/2d3ae3abe3428a1b4d343808915aafeff8563371/src/inputrules.js#L101
+export default function undoInputRule(state: EditorState, dispatch?: (tr: Transaction<any>) => void) {
+  let plugins = state.plugins
+
+  for (let i = 0; i < plugins.length; i++) {
+    let plugin = plugins[i], undoable
+    // @ts-ignore
+    if (plugin.spec.isInputRules && (undoable = plugin.getState(state))) {
+      if (dispatch) {
+        let tr = state.tr, toUndo = undoable.transform
+
+        for (let j = toUndo.steps.length - 1; j >= 0; j--) {
+          tr.step(toUndo.steps[j].invert(toUndo.docs[j]))
+        }
+
+        let marks = tr.doc.resolve(undoable.from).marks()
+
+        if (!undoable.text) {
+          return false
+        }
+
+        dispatch(tr.replaceWith(undoable.from, undoable.to, state.schema.text(undoable.text, marks)))
+      }
+
+      return true
+    }
+  }
+
+  return false
+}