fix: cut the connection when a response body errors before its first chunk

src/listener.ts

@@ -356,6 +356,7 @@ const responseViaResponseObject = async (
 
     const values: Uint8Array[] = []
     let done = false
+    let readError: unknown
     let currentReadPromise: Promise<ReadableStreamReadResult<Uint8Array>> | undefined = undefined
 
     if (resHeaderRecord['transfer-encoding'] !== 'chunked') {
@@ -364,10 +365,15 @@ const responseViaResponseObject = async (
       for (let i = 0; i < maxReadCount; i++) {
         currentReadPromise ||= reader.read()
         const chunk = await readWithoutBlocking(currentReadPromise).catch((e) => {
-          console.error(e)
-          done = true
+          // An errored body must not be answered as a complete, empty 200:
+          // record the error and keep `done` false so the streaming path
+          // below tears the connection down instead.
+          readError = e
         })
         if (!chunk) {
+          if (readError) {
+            break
+          }
           if (i === 1) {
             // XXX: In Node.js v24, some response bodies are not read all the way through until the next task queue,
             // so wait a moment and retry. (e.g. new Blob([new Uint8Array(contents)]) )

test/listener.test.ts

@@ -14,6 +14,10 @@ import { GlobalRequest, Request as LightweightRequest, RequestError } from '../s
 import { GlobalResponse, Response as LightweightResponse } from '../src/response'
 import { requestServer } from './helpers/request'
 
+// The `overrideGlobalObjects` block further down mutates globalThis.Response, so capture the
+// native constructor here for tests that need it.
+const NativeResponse = Response
+
 const withTimeout = async <T>(promise: Promise<T>, message: string): Promise<T> => {
   let timeoutId: ReturnType<typeof setTimeout> | undefined
 
@@ -725,3 +729,21 @@ describe('overrideGlobalObjects', () => {
     })
   })
 })
+
+describe('Response body stream erroring before the first chunk', () => {
+  it('Should cut the connection rather than return a complete empty 200 with overrideGlobalObjects: false', async () => {
+    const requestListener = getRequestListener(
+      () =>
+        new NativeResponse(
+          new ReadableStream({
+            start(controller) {
+              controller.error(new Error('failed'))
+            },
+          }),
+        ),
+      { overrideGlobalObjects: false }
+    )
+    const server = createServer(requestListener)
+    await expect(requestServer(server, { method: 'GET', path: '/' })).rejects.toThrow('aborted')
+  })
+})