readline regression since v24.2.0 on >= 1026 lines in input

To reproduce, apply the following diff to benchmarks:

diff --git a/benchmark/readline/readline-iterable.js b/benchmark/readline/readline-iterable.js
index 9be4ea1f52b..a023424edd3 100644
--- a/benchmark/readline/readline-iterable.js
+++ b/benchmark/readline/readline-iterable.js
@@ -20,7 +20,7 @@ Amet nisl suscipit adipiscing bibendum est ultricies integer.
 Sit amet dictum sit amet justo donec enim diam.
 Condimentum mattis pellentesque id nibh tortor id aliquet lectus proin.
 Diam in arcu cursus euismod quis viverra nibh.
-Rest of line`;
+Rest of line`.repeat(900);
 
 function oldWay() {
   const readable = new Readable({

Observed behavior:

readline/readline-iterable.js type="old" n=10: 3,372,871.300286141
node:internal/readline/interface:579
      throw new ERR_USE_AFTER_CLOSE('readline');
            ^

Error [ERR_USE_AFTER_CLOSE]: readline was closed
    at Interface.resume (node:internal/readline/interface:579:13)
    at Object.next (node:events:1074:19)
    at main (benchmark/readline/readline-iterable.js:78:20)
    at process.processTicksAndRejections (node:internal/process/task_queues:105:5) {
  code: 'ERR_USE_AFTER_CLOSE'
}

Node.js v24.10.0

Simplified testcase:

import readline from 'node:readline'
import { Readable } from 'node:stream'

const input = Readable.from([`Line\n`.repeat(1e4)])
const iterable = readline.createInterface({ input })
for await (const _ of iterable);

Any number of lines higher than 1025 (i.e. > highWaterMark + 1) reproduces this

main, 25, and 24 latest are affected.

First affected version is v24.2.0.

v24.1.0 was fine, v22 latest is fine.

#59431 might be related with a common cause, but that involves terminal, and this doesn't
I.e. after fixing this #59431 should be rechecked. The error is different though.

Bisect shows at 462c4b0
Caused by #58283

This iterates through all of lines except the last one, and then panics on the last one

Here is a simplified version of what is going on in async iterator

This also reproduces the issue, but without the async iterator

import readline from 'node:readline'
import { Readable } from 'node:stream'

const input = Readable.from('Line\n'.repeat(2000))
const iterable = readline.createInterface({ input })
let i = 0
// for await (const _ of iterable) i++

const [low, high] = [1, 1024]
let paused = false
let finished = false
const cache = []
const unconsumed = []
iterable.on('line', (l) => {
  if (unconsumed.length > 0) {
    unconsumed.shift()(l)
    return
  }
  cache.push(l)
  if (!paused && cache.length > high) {
    iterable.pause()
    paused = true
  }
})
iterable.on('close', () => {
  finished = true
  while (unconsumed.length > 0) unconsumed.shift()() // done
})
async function get() {
  if (cache.length > 0) {
    const res = cache.shift()
    if (paused && cache.length < low) {
      iterable.resume()
      paused = false
    }
    return res
  }
  if (finished) return undefined // done
  return new Promise(resolve => unconsumed.push(resolve))
}

while (await get() !== undefined) i++

console.log(i)

Any progress on fixing the regression or a known workaround for looping over readline interface?

@rv2673

@rv2673 Fix is in #60548, this is waiting for review

Any updates on when the fix is merged?

events: don't call resume after close

@ChALkeR

@ChALkeR I see the PR is merged. Any idea when this regression fix might land in a new release of node 24?

@ChALkeR I see the PR is merged. Any idea when this regression fix might land in a new release of node 24?

It doesn't seem to have been part of node 24.14.0 released last week.

events: don't call resume after close

ci: fix failing maxmind update script by bumping Node.js to 24.19.0 (#…

events: do not call resume() from on() after the iterator closes (#42896

Navigation Menu

Repository navigation

readline regression since v24.2.0 on >= 1026 lines in input #60507

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

readline regression since v24.2.0 on >= 1026 lines in input #60507

Description

Activity

ChALkeR commented on Nov 2, 2025

ChALkeR commented on Nov 2, 2025

ChALkeR commented on Nov 2, 2025

rv2673 commented on Jan 14, 2026

ChALkeR commented on Jan 18, 2026

KeesVNavara commented on Feb 10, 2026

rv2673 commented on Feb 24, 2026

rv2673 commented on Mar 2, 2026

Metadata

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

Issue actions