module.exports should default to an empty object.

sky/engine/core/app/Module.cpp

Index: sky/engine/core/app/Module.cpp
diff --git a/sky/engine/core/app/Module.cpp b/sky/engine/core/app/Module.cpp
index ed1f97223cc0ad39e675d3349ac472734092200d..02dc428899d5e9ce7226f46c9a7ac1ec3a49a33b 100644
--- a/sky/engine/core/app/Module.cpp
+++ b/sky/engine/core/app/Module.cpp
@@ -29,4 +29,14 @@ Application* Module::GetApplication() {
   return application();
 }
 
+void Module::setExports(ScriptState*, const ScriptValue& exports) {
+  exports_ = exports;
+}
+
+const ScriptValue& Module::exports(ScriptState* scriptState) const {
+  if (exports_.isEmpty())
+    exports_ = ScriptValue::createEmptyObject(scriptState);
+  return exports_;
+}
+
 } // namespace blink