code optimization

lib/middleware/serializer.js

@@ -0,0 +1,13 @@
+'use strict';
+
+const H004Serializer = require('../orders/H004/serializer');
+
+module.exports = {
+	use(order) {
+		const { version } = order;
+
+		if (version.toUpperCase() === 'H004') return H004Serializer.use(order);
+
+		throw Error('Error middleware/serializer.js: Invalid version number');
+	},
+};