Catch when nodejs request is aborted

When we receive a request, we start listening to the close event.
When fired, we check if the request was aborted using `incoming.aborted`,
if it was, we dispatch an abort event to the existing request abort
signal.

Without this, whe the client abortes the request, the signal on the
request was not being called with the abort event.

Signed-off-by: m4rc3l05 <[email protected]>

src/listener.ts

@@ -143,6 +143,13 @@ export const getRequestListener = (
     // so generate a pseudo Request object with only the minimum required information.
     const req = newRequest(incoming)
 
+    // Detect if request was aborted.
+    outgoing.on('close', () => {
+      if (incoming.socket.destroyed) {
+        req.signal.dispatchEvent(new Event('abort'))
+      }
+    })
+
     try {
       res = fetchCallback(req, { incoming, outgoing } as HttpBindings) as
         | Response

test/listener.test.ts

@@ -89,3 +89,42 @@ describe('Error handling - async fetchCallback', () => {
     expect(res.text).toBe('error handler did not return a response')
   })
 })
+
+describe('Abort request', () => {
+  const data: string[] = []
+
+  const fetchCallback = async (req: { signal: AbortSignal }) => {
+    await new Promise<void>(() => {
+      req.signal.addEventListener('abort', () => {
+        data.push('aborted')
+      })
+    })
+  }
+
+  const requestListener = getRequestListener(fetchCallback)
+
+  const server = createServer(async (req, res) => {
+    await requestListener(req, res)
+  })
+
+  beforeEach(() => {
+    data.length = 0
+  })
+
+  it('should emit an abort event when the nodejs request is aborted', (done) => {
+    const req = request(server)
+      .get('/abort')
+      .end(() => {})
+
+    setTimeout(() => {
+      req.abort()
+    }, 10)
+
+    const interval = setInterval(() => {
+      if (data.includes('aborted')) {
+        clearInterval(interval)
+        done()
+      }
+    })
+  })
+})