chore: merge blocksuite source code (#9213)

blocksuite/presets/src/helpers/index.ts

@@ -0,0 +1,21 @@
+import { AffineSchemas } from '@blocksuite/blocks/schemas';
+import { DocCollection, Schema } from '@blocksuite/store';
+
+export function createEmptyDoc() {
+  const schema = new Schema().register(AffineSchemas);
+  const collection = new DocCollection({ schema });
+  collection.meta.initialize();
+  const doc = collection.createDoc();
+
+  return {
+    doc,
+    init() {
+      doc.load();
+      const rootId = doc.addBlock('affine:page', {});
+      doc.addBlock('affine:surface', {}, rootId);
+      const noteId = doc.addBlock('affine:note', {}, rootId);
+      doc.addBlock('affine:paragraph', {}, noteId);
+      return doc;
+    },
+  };
+}