[JS] feat: standalone express router

js/flow/src/flow.ts

@@ -831,31 +831,50 @@ function wrapAsAction<
   );
 }
 
-export function startFlowsServer(params?: {
+export function createFlowsExpressRouter(params?: {
   flows?: Flow<any, any, any>[];
-  port?: number;
   cors?: CorsOptions;
   pathPrefix?: string;
 }) {
+  const router = express.Router();
+  router.use(bodyParser.json());
+  router.use(cors(params?.cors));
+
   const port =
     params?.port || (process.env.PORT ? parseInt(process.env.PORT) : 0) || 3400;
   const pathPrefix = params?.pathPrefix ?? '';
-  const app = express();
-  app.use(bodyParser.json());
-  app.use(cors(params?.cors));
-
   const flows = params?.flows || createdFlows();
-  logger.info(`Starting flows server on port ${port}`);
   flows.forEach((f) => {
     const flowPath = `/${pathPrefix}${f.name}`;
     logger.info(` - ${flowPath}`);
     // Add middlware
     f.middleware?.forEach((m) => {
-      app.post(flowPath, m);
+      router.post(flowPath, m);
     });
-    app.post(flowPath, f.expressHandler);
+    router.post(flowPath, f.expressHandler);
   });
 
+  return router;
+}
+
+export function startFlowsServer(params?: {
+  flows?: Flow<any, any, any>[];
+  port?: number;
+  cors?: CorsOptions;
+  pathPrefix?: string;
+}) {
+  const port =
+    params?.port || (process.env.PORT ? parseInt(process.env.PORT) : 0) || 3400;
+  const router = createFlowsExpressRouter({
+    flows: params?.flows,
+    cors: params?.cors,
+    pathPrefix: params?.pathPrefix,
+  });
+
+  logger.info(`Starting flows server on port ${port}`);
+  const app = express();
+  app.use(router);
+
   app.listen(port, () => {
     console.log(`Flows server listening on port ${port}`);
   });