fix: synchronize mounted component props

packages/dev-server/test/component-composition-runtime.test.ts

@@ -90,6 +90,32 @@ test("a component in an initially hidden client branch is server-prepared for in
   expect(branches[0].body).not.toContain("data-component=");
 });
 
+test("SSR carries a parent prop binding onto the rendered child scope", async () => {
+  const root = mkdtempSync(join(tmpdir(), "wrnexus-component-prop-"));
+  roots.push(root);
+  const app = join(root, "app");
+  mkdirSync(join(app, "pages"), { recursive: true });
+  mkdirSync(join(app, "components"), { recursive: true });
+  writeFileSync(join(app, "pages/index.ts"), "export default () => '';\n");
+  writeFileSync(join(app, "components/Child.wrn"), "component Child { props { value = 0 } view { <b>{value}</b> } }\n");
+  const marker = "[&quot;value&quot;,&quot;{count}&quot;]";
+  const handlers = createHandlers({
+    mode: "development",
+    hmr: false,
+    router: buildRouter(app),
+    loadModule: async (file) =>
+      basename(file) === "Child.wrn"
+        ? { render: () => '<div data-scope="value: 1" data-wrn-scope="e30="><b>1</b></div>' }
+        : { default: () => `<div data-component="Child" value="1" data-wrn-prop-bind-0="${marker}"></div>` },
+    getMiddleware: async () => [],
+    assets: { serve: async () => null },
+  } satisfies RuntimeDeps);
+  const response = await handlers.fetch(new Request("https://example.test/"), { upgrade: () => false });
+  const html = await response!.text();
+  expect(html).toContain(`data-wrn-prop-bind-0="${marker}"`);
+  expect(html).not.toContain('data-component="Child"');
+});
+
 test("translated text is present in the raw server response", async () => {
   const root = mkdtempSync(join(tmpdir(), "wrnexus-ssr-i18n-"));
   roots.push(root);