Initial

resources/app/common/prosemirror/extensions.mjs

@@ -0,0 +1,21 @@
+import {ResolvedPos} from "prosemirror-model";
+
+/**
+ * Determine whether a given position has an ancestor node of the given type.
+ * @param {NodeType} other  The other node type.
+ * @param {object} [attrs]  An object of attributes that must also match, if provided.
+ * @returns {boolean}
+ */
+ResolvedPos.prototype.hasAncestor = function(other, attrs) {
+  if ( !this.depth ) return false;
+  for ( let i = this.depth; i > 0; i-- ) { // Depth 0 is the root document, so we don't need to test that.
+    const node = this.node(i);
+    if ( node.type === other ) {
+      const nodeAttrs = foundry.utils.deepClone(node.attrs);
+      delete nodeAttrs._preserve; // Do not include our internal attributes in the comparison.
+      if ( attrs ) return foundry.utils.objectsEqual(nodeAttrs, attrs);
+      return true;
+    }
+  }
+  return false;
+};