Fix memory leak in dev server

src/functions/server/bunext-req-handler.ts

@@ -26,7 +26,12 @@ export default async function bunextRequestHandler({
     server,
 }: Params): Promise<Response> {
     const is_dev = isDevelopment();
-    let req = initial_req.clone();
+    const middleware = global.BUNEXT_CONSTANTS.config?.middleware;
+
+    // Middleware may consume `initial_req`'s body, so it gets its own copy.
+    // Cloning tees the body stream and buffers whatever one side doesn't
+    // read, so only pay for it when middleware is configured.
+    let req = middleware ? initial_req.clone() : initial_req;
 
     try {
         let url = new URL(req.url);
@@ -40,12 +45,11 @@ export default async function bunextRequestHandler({
 
         let response: Response | undefined = undefined;
 
-        if (global.BUNEXT_CONSTANTS.config?.middleware) {
-            const middleware_res =
-                await global.BUNEXT_CONSTANTS.config.middleware({
-                    req: initial_req,
-                    url,
-                });
+        if (middleware) {
+            const middleware_res = await middleware({
+                req: initial_req,
+                url,
+            });
 
             if (middleware_res instanceof Response) {
                 return middleware_res;