fix(editor): type nested attribute expressions

packages/syntax/test/syntax.test.ts

@@ -1,5 +1,5 @@
 import { expect, test } from "bun:test";
-import { diagnose, formatDiagnostic, parse } from "../src/index.ts";
+import { diagnose, extractInterpolations, formatDiagnostic, parse } from "../src/index.ts";
 
 test("parses explicit rendering modes and the never hydration alias", () => {
   const ast = parse(`page Marketing {
@@ -337,3 +337,14 @@ test("a block comment inside props is still refused with its own message", () =>
 `;
   expect(() => parse(source)).toThrow("Block comments are not allowed inside props");
 });
+
+test("extracts nested object and array interpolation as one expression", () => {
+  const value = `prefix {[{ label: 'One', meta: { count: 1 } }, { label: "Two" }]} suffix`;
+  expect(extractInterpolations(value)).toEqual([
+    {
+      expression: `[{ label: 'One', meta: { count: 1 } }, { label: "Two" }]`,
+      start: 7,
+      end: value.length - 7,
+    },
+  ]);
+});