feat: enforce strict transclusion schema

packages/editor-ext/src/lib/transclusion/constants.ts

@@ -0,0 +1,41 @@
+/**
+ * Top-level block node types allowed inside a `transclusionSource`.
+ * Notably excludes:
+ * - `transclusionSource` — sync blocks cannot wrap other sync blocks (sources are leaves).
+ * - `transclusionReference` — sync blocks cannot transclude other sync blocks,
+ *   which keeps the transclusion graph acyclic and lets the renderer skip
+ *   cycle-aware traversal entirely.
+ *
+ * Also excludes child-only nodes (`listItem`, `tableRow`, `column`, etc.)
+ * — they're already constrained by their parent containers.
+ */
+export const TRANSCLUSION_SOURCE_ALLOWED_NODE_TYPES = [
+  'paragraph',
+  'heading',
+  'blockquote',
+  'codeBlock',
+  'horizontalRule',
+  'bulletList',
+  'orderedList',
+  'taskList',
+  'image',
+  'video',
+  'audio',
+  'attachment',
+  'callout',
+  'details',
+  'embed',
+  'mathBlock',
+  'table',
+  'drawio',
+  'excalidraw',
+  'pdf',
+  'subpages',
+  'columns',
+  'youtube',
+] as const;
+
+export type TransclusionSourceAllowedNodeType =
+  (typeof TRANSCLUSION_SOURCE_ALLOWED_NODE_TYPES)[number];
+
+export const TRANSCLUSION_SOURCE_CONTENT_EXPRESSION = `(${TRANSCLUSION_SOURCE_ALLOWED_NODE_TYPES.join(' | ')})+`;

packages/editor-ext/src/lib/transclusion/index.ts

@@ -1,2 +1,3 @@
+export * from "./constants";
 export * from "./transclusion-source";
 export * from "./transclusion-reference";

packages/editor-ext/src/lib/transclusion/transclusion-source.ts

@@ -1,6 +1,6 @@
 import { mergeAttributes, Node } from "@tiptap/core";
 import { ReactNodeViewRenderer } from "@tiptap/react";
-import { Plugin, PluginKey } from "@tiptap/pm/state";
+import { TRANSCLUSION_SOURCE_CONTENT_EXPRESSION } from "./constants";
 
 export interface TransclusionSourceOptions {
   HTMLAttributes: Record<string, any>;
@@ -34,7 +34,8 @@ export const TransclusionSource = Node.create<TransclusionSourceOptions>({
   },
 
   group: "block",
-  content: "block+",
+  // Schema-enforced allow-list. Excludes `transclusionSource` (no nesting)
+  content: TRANSCLUSION_SOURCE_CONTENT_EXPRESSION,
   defining: true,
   isolating: true,
 
@@ -130,30 +131,4 @@ export const TransclusionSource = Node.create<TransclusionSourceOptions>({
     this.editor.isInitialized = true;
     return ReactNodeViewRenderer(this.options.view);
   },
-
-  addProseMirrorPlugins() {
-    const typeName = this.name;
-    return [
-      new Plugin({
-        key: new PluginKey(`${typeName}-noNesting`),
-        filterTransaction: (tr) => {
-          if (!tr.docChanged) return true;
-          let nested = false;
-          tr.doc.descendants((node, pos) => {
-            if (nested) return false;
-            if (node.type.name !== typeName) return true;
-            const $pos = tr.doc.resolve(pos);
-            for (let depth = $pos.depth; depth > 0; depth -= 1) {
-              if ($pos.node(depth).type.name === typeName) {
-                nested = true;
-                return false;
-              }
-            }
-            return false;
-          });
-          return !nested;
-        },
-      }),
-    ];
-  },
 });