🔧 fix: #1747 parsing request from mount hang

Author: SaltyAom

CHANGELOG.md

@@ -3,6 +3,7 @@ Bug fix:
 - [#1755](https://github.com/elysiajs/elysia/issues/1755) deduplicate local handler from global event
 - [#1752](https://github.com/elysiajs/elysia/issues/1752) system router with trailing path doesn't match with non-trailing
 - url format redos
+- [#1747](https://github.com/elysiajs/elysia/issues/1747) parsing request from mount hang
 
 # 1.4.25 - 12 Feb 2025
 Feature:

example/a.ts

@@ -1,53 +1,37 @@
 import { Elysia } from '../src'
 
-// ❌ BROKEN: Using separate instances with .use()
-const typesRoutes = new Elysia({ prefix: '/types' })
-	.get('/', () => 'List all types')
-	.get('/:id', ({ params }) => `Get type: ${params.id}`)
-
-const itemsRoutes = new Elysia()
-	.get('/', () => 'List all items')
-	.get('/:id', ({ params }) => `Get item: ${params.id}`)
-
-const brokenModule = new Elysia({ prefix: '/items' })
-	.use(typesRoutes) // Static prefix - should match first
-	.use(itemsRoutes) // Has /:id catch-all
-
-const typesRoutesNoPrefix = new Elysia()
-	.get('/', () => 'List all types')
-	.get('/:id', ({ params }) => `Get type: ${params.id}`)
-
-const brokenModuleWithGroup = new Elysia({ prefix: '/items' })
-	.group('/types', (app) => app.use(typesRoutesNoPrefix))
-	.use(itemsRoutes)
-
-// ✅ WORKS: All routes in single instance
-const workingModule = new Elysia({ prefix: '/items' })
-	.get('/:id', ({ params }) => `Get item: ${params.id}`)
-	.get('/', () => 'List all items')
-	.get('/types', () => 'List all types')
-	.get('/types/:id', ({ params }) => `Get type: ${params.id}`)
-
-const work = new Elysia({ systemRouter: true })
-	.use(workingModule) // GET /items/types returns "List all types" ✅
-	// .listen(3000)
-
-const notWork = new Elysia({ systemRouter: true })
-	.use(brokenModule) // GET /items/types returns "Get item: types" ❌
-	.use(brokenModuleWithGroup) // GET /items/types returns "Get item: types" ❌
-	.listen(3001)
-
-Bun.serve({
-	port: 3002,
-	routes: {
-		'/items/types/': {
-			GET: () => new Response('/items/types/')
-		},
-		'/items/types/:id': {
-			GET: () => new Response('/items/types/:id')
+const useMount = true // true => hangs, false => works
+
+const handler = async (request: Request) => {
+	console.log("A")
+	// Rebuild request with new headers (problematic in mount mode)
+	const headers = new Headers(request.headers)
+	headers.set('x-request-id', 'req_test')
+	const patched = new Request(request, { headers })
+
+	// This is where it hangs when mounted
+	const body = await patched.text()
+
+	return Response.json({
+		ok: true,
+		body,
+		requestId: patched.headers.get('x-request-id')
+	})
+}
+
+const app = useMount
+	? new Elysia().mount('/v1/', handler)
+	: new Elysia().all('/v1/*', ({ request }) => handler(request))
+
+app.listen(3000)
+
+app.handle(
+	new Request('http://localhost:3000/v1/test', {
+		headers: {
+			'content-type': 'hello'
 		},
-		'/items/:id': {
-			GET: () => new Response('/items/:id')
-		}
-	}
-})
+		body: 'hello'
+	})
+)
+	.then((x) => x.status)
+	.then(console.log)

src/index.ts

@@ -5582,21 +5582,7 @@ export default class Elysia<
 									})()
 
 			const handler: Handler = ({ request, path }) =>
-				run(
-					new Request(replaceUrlPath(request.url, path), {
-						method: request.method,
-						headers: request.headers,
-						signal: request.signal,
-						credentials: request.credentials,
-						referrerPolicy: request.referrerPolicy as any,
-						duplex: request.duplex,
-						redirect: request.redirect,
-						mode: request.mode,
-						keepalive: request.keepalive,
-						integrity: request.integrity,
-						body: request.body
-					})
-				)
+				run(new Request(replaceUrlPath(request.url, path), request))
 
 			this.route('ALL', '/*', handler as any, {
 				parse: 'none',
@@ -5632,19 +5618,7 @@ export default class Elysia<
 			handle(
 				new Request(
 					replaceUrlPath(request.url, path.slice(length) || '/'),
-					{
-						method: request.method,
-						headers: request.headers,
-						signal: request.signal,
-						credentials: request.credentials,
-						referrerPolicy: request.referrerPolicy as any,
-						duplex: request.duplex,
-						redirect: request.redirect,
-						mode: request.mode,
-						keepalive: request.keepalive,
-						integrity: request.integrity,
-						body: request.body
-					}
+					request
 				)
 			)