fix: exit loop early if request was aborted

lib/fetch/index.js

@@ -1827,6 +1827,11 @@ async function httpNetworkFetch (
       let bytes
       try {
         const { done, value } = await fetchParams.controller.next()
+
+        if (isAborted(fetchParams)) {
+          break
+        }
+
         bytes = done ? undefined : value
       } catch (err) {
         if (fetchParams.controller.ended && !timingInfo.encodedBodySize) {

test/fetch/abort.js

@@ -0,0 +1,59 @@
+'use strict'
+
+const { test } = require('tap')
+const { fetch } = require('../..')
+const { createServer } = require('http')
+const { once } = require('events')
+
+/* global AbortController */
+
+test('parallel fetch with the same AbortController works as expected', async (t) => {
+  const body = {
+    fixes: 1389,
+    bug: 'Ensure request is not aborted before enqueueing bytes into stream.'
+  }
+
+  const server = createServer((req, res) => {
+    res.statusCode = 200
+    res.end(JSON.stringify(body))
+  })
+
+  t.teardown(server.close.bind(server))
+
+  const abortController = new AbortController()
+
+  async function makeRequest () {
+    const result = await fetch(`http://localhost:${server.address().port}`, {
+      signal: abortController.signal
+    }).then(response => response.json())
+
+    abortController.abort()
+    return result
+  }
+
+  server.listen(0)
+  await once(server, 'listening')
+
+  const requests = Array.from({ length: 10 }, makeRequest)
+  const result = await Promise.allSettled(requests)
+
+  // since the requests are running parallel, any of them could resolve first.
+  // therefore we cannot rely on the order of the requests sent.
+  const { resolved, rejected } = result.reduce((a, b) => {
+    if (b.status === 'rejected') {
+      a.rejected.push(b)
+    } else {
+      a.resolved.push(b)
+    }
+
+    return a
+  }, { resolved: [], rejected: [] })
+
+  t.equal(rejected.length, 9) // out of 10 requests, only 1 should succeed
+  t.equal(resolved.length, 1)
+
+  t.ok(rejected.every(rej => rej.reason?.code === 'ABORT_ERR'))
+  t.same(resolved[0].value, body)
+
+  t.end()
+})