fix(nodejs#3975): do not unref timeout (nodejs#3977)

Author: metcoder95

lib/handler/retry-handler.js

@@ -133,7 +133,7 @@ class RetryHandler {
         ? Math.min(retryAfterHeader, maxTimeout)
         : Math.min(minTimeout * timeoutFactor ** (counter - 1), maxTimeout)
 
-    setTimeout(() => cb(null), retryTimeout).unref()
+    setTimeout(() => cb(null), retryTimeout)
   }
 
   onResponseStart (controller, statusCode, headers, statusMessage) {

test/fixtures/interceptors/retry-event-loop.js

@@ -0,0 +1,33 @@
+'use strict'
+
+const { createServer } = require('node:http')
+const { once } = require('node:events')
+const {
+  Client,
+  interceptors: { retry }
+} = require('../../..')
+
+const server = createServer()
+
+server.on('request', (req, res) => {
+  res.writeHead(418, { 'Content-Type': 'text/plain' })
+  res.end('teapot')
+})
+
+server.listen(0)
+once(server, 'listening').then(() => {
+  const client = new Client(
+    `http://localhost:${server.address().port}`
+  ).compose(
+    retry({
+      maxTimeout: 1000,
+      maxRetries: 3,
+      statusCodes: [418]
+    })
+  )
+
+  return client.request({
+    method: 'GET',
+    path: '/'
+  })
+})

test/interceptors/retry.js

@@ -4,6 +4,7 @@ const { tspl } = require('@matteo.collina/tspl')
 const { test, after } = require('node:test')
 const { createServer } = require('node:http')
 const { once } = require('node:events')
+const { spawnSync } = require('node:child_process')
 
 const { Client, interceptors } = require('../..')
 const { retry, redirect, dns } = interceptors
@@ -559,3 +560,16 @@ test('should not error if request is not meant to be retried', async t => {
   t.equal(response.statusCode, 400)
   t.equal(await response.body.text(), 'Bad request')
 })
+
+test('#3975 - keep event loop ticking', async t => {
+  const suite = tspl(t, { plan: 3 })
+
+  const res = spawnSync('node', ['./test/fixtures/interceptors/retry-event-loop.js'], {
+    stdio: 'pipe'
+  })
+
+  const output = res.stderr.toString()
+  suite.ok(output.includes("code: 'UND_ERR_REQ_RETRY'"))
+  suite.ok(output.includes('RequestRetryError: Request failed'))
+  suite.ok(output.includes('statusCode: 418'))
+})