fix: parent may omit some update notifications

src/__tests__/__snapshots__/main.test.tsx.snap

@@ -108,6 +108,15 @@ exports[`depending 2`] = `
 </DocumentFragment>
 `;
 
+exports[`parent child 1`] = `
+<DocumentFragment>
+  1
+  <div>
+    1
+  </div>
+</DocumentFragment>
+`;
+
 exports[`setState timing 1`] = `
 <DocumentFragment>
   <div>

src/__tests__/main.test.tsx

@@ -286,3 +286,36 @@ test("depending", async () => {
   await sleep(10);
   expect(renderer.asFragment()).toMatchSnapshot();
 });
+
+test("parent child", async () => {
+  const useCounterModel = createModel(function A() {
+    const [count, setCount] = useState(0);
+    const increment = () => setCount(count + 1);
+
+    return {
+      count,
+      increment
+    };
+  });
+
+  const Child: FC = () => {
+    const counter = useCounterModel();
+    useEffect(() => {
+      counter.increment();
+    }, []);
+    return <div>{counter.count}</div>;
+  };
+
+  const App: FC = () => {
+    const counterModel = useCounterModel();
+    return (
+      <>
+        {counterModel.count}
+        <Child />
+      </>
+    );
+  };
+
+  const renderer = testing.render(<App />);
+  expect(renderer.asFragment()).toMatchSnapshot();
+});

src/create-model.tsx

@@ -43,6 +43,9 @@ export function createModel<T, P>(hook: ModelHook<T, P>, hookArg?: P) {
         }
       }
       container.subscribers.add(subscriber);
+      if (container.data !== state) {
+        setState(container.data);
+      }
       return () => {
         container.subscribers.delete(subscriber);
       };