feat(compiler): commit deferred client state writes

packages/compiler/test/v060-targets.test.ts

@@ -145,3 +145,42 @@ test("browser codegen binds peer client functions through the scoped function ta
   functions.run?.();
   expect(state.value).toBe(1);
 });
+
+test("deferred timer state writes commit after the client function returns", async () => {
+  const targets = generateTargets(
+    parse(`component DeferredWrite {
+      state { value: number = 0 }
+      functions {
+        client function later(): void { setTimeout(() => { value = 2 }, 0) }
+      }
+      view { <button @click='later()'>{value}</button> }
+    }`),
+  );
+  const executable = new Function(
+    `${targets.browser.replace(/^export\s+/gm, "")}\nreturn { bindClientScope };`,
+  )() as { bindClientScope: (context: Record<string, unknown>) => Record<string, () => void> };
+  let rendered = "0";
+  const state = new Proxy(
+    { value: 0 },
+    {
+      set(target, property, value) {
+        Reflect.set(target, property, value);
+        rendered = String(value);
+        return true;
+      },
+    },
+  );
+  const functions = executable.bindClientScope({
+    state,
+    props: {},
+    output: {},
+    server: {},
+    refs: {},
+  });
+
+  functions.later?.();
+  expect(state.value).toBe(0);
+  await new Promise((resolve) => setTimeout(resolve, 10));
+  expect(state.value).toBe(2);
+  expect(rendered).toBe("2");
+});