remove all fetchParam event handlers (nodejs#2823)

Author: KhafraDev

lib/web/fetch/index.js

@@ -81,12 +81,6 @@ class Fetch extends EE {
     this.connection = null
     this.dump = false
     this.state = 'ongoing'
-    // 2 terminated listeners get added per request,
-    // but only 1 gets removed. If there are 20 redirects,
-    // 21 listeners will be added.
-    // See https://github.com/nodejs/undici/issues/1711
-    // TODO (fix): Find and fix root cause for leaked listener.
-    this.setMaxListeners(21)
   }
 
   terminate (reason) {
@@ -1967,6 +1961,7 @@ async function httpNetworkFetch (
   // 19. Run these steps in parallel:
 
   //    1. Run these steps, but abort when fetchParams is canceled:
+  fetchParams.controller.onAborted = onAborted
   fetchParams.controller.on('terminated', onAborted)
   fetchParams.controller.resume = async () => {
     // 1. While true
@@ -2235,6 +2230,10 @@ async function httpNetworkFetch (
             fetchParams.controller.off('terminated', this.abort)
           }
 
+          if (fetchParams.controller.onAborted) {
+            fetchParams.controller.off('terminated', fetchParams.controller.onAborted)
+          }
+
           fetchParams.controller.ended = true
 
           this.body.push(null)

test/fetch/issue-1711.js

@@ -0,0 +1,33 @@
+'use strict'
+
+const assert = require('node:assert')
+const { once } = require('node:events')
+const { createServer } = require('node:http')
+const { test } = require('node:test')
+const { fetch } = require('../..')
+
+test('Redirecting a bunch does not cause a MaxListenersExceededWarning', async (t) => {
+  let redirects = 0
+
+  const server = createServer((req, res) => {
+    if (redirects === 15) {
+      res.end('Okay goodbye')
+      return
+    }
+
+    res.writeHead(302, {
+      Location: `/${redirects++}`
+    })
+    res.end()
+  }).listen(0)
+
+  t.after(server.close.bind(server))
+  await once(server, 'listening')
+
+  process.emitWarning = assert.bind(null, false)
+
+  const url = `http://localhost:${server.address().port}`
+  const response = await fetch(url, { redirect: 'follow' })
+
+  assert.deepStrictEqual(response.url, `${url}/${redirects - 1}`)
+})