node:net: keep 'end' off a destroyed socket and report the read error behind a write in flight

[robobun]

Fixes items 1, 2 and 4 of #43381.

Problem

• socket.destroy() emits 'end', then 'close'. Node emits 'close' only. finishSocketEnd (src/js/node/net.ts:978) pushes EOF into the destroyed stream.
• A peer resets a socket with an 'error' listener and a write in flight. The callbacks of that write, of queued writes and of end() never run. The close handlers (net.ts:1029, net.ts:1759) destroy the socket and return first.
• With no listener the reset throws ERR_SOCKET_CLOSED, not the read error. A peer close during the TLS handshake reports the same.

Fix

• finishSocketEnd returns when the socket is destroyed.
• The close handlers destroy with the read error when a write is in flight. Each exit then cancels that write with write ECANCELED.
• A stranded write fails on the next tick, after the EOF.
• Verified: node-net.test.ts ("socket teardown events") and node-tls-connect.test.ts (3 blocks). 11 of the 12 bun cases fail with main's net.ts. Other suites: Notes.

Background

• kwriteCallback holds the callback of the one _write that waits for the native drain. Later writes and end() queue behind it.
• In Node, uv_close settles a write in flight with ECANCELED.
• node:net: cancel the in-flight write when the socket is destroyed #43250 adds the same cancel to _destroy, for a local destroy() too.

Downsides

• A reset after the peer's FIN, with a write in flight and no 'error' listener: main emits no 'error'. This PR throws, as Node does.
• destroy() then connect() in one tick with a write in flight fails the new connection, as in Node. main reconnects.
• On an accepted socket the canceled write reports after 'close'. node:net: cancel the in-flight write when the socket is destroyed #43250 fixes the order.

Notes

All runs below: Linux x64, debug ASAN build of 3492dab813, Node v26.3.0 as the reference. The head 3a5b12b62b differs from that commit in comments only. "this head" means that build. "main" is the same build with src/js/node/net.ts from a407eae88a. That is the only source file this PR changes.

Scripts from the issue.

plain-destroy  node:      ["close false"]
               main:      ["end","close false"]
               this head: ["close false"]
no-listener    node:      ["uncaught ECONNRESET read","write ECANCELED write","queued ECONNRESET read","close true"]
               main:      ["write ERR_SOCKET_CLOSED","queued ERR_SOCKET_CLOSED","uncaught ERR_SOCKET_CLOSED","close true"]
               this head: ["uncaught ECONNRESET read","write ECANCELED write","queued ECONNRESET read","close true"]
not-reading    node:      ["write ECONNRESET write","queued ECONNRESET write","error ECONNRESET write","close true"]
               main:      ["error ECONNRESET read","close true"]
               this head: ["error ECONNRESET read","write ECANCELED write","queued ECONNRESET read","close true"]
tls-peer-close node:      ["end","error ECONNRESET","write ECANCELED write","close true"]
               main:      ["write ERR_SOCKET_CLOSED","error ERR_SOCKET_CLOSED","close true"]
               this head: ["end","write ERR_SOCKET_CLOSED","error ECONNRESET","close true"]

What stays different: in the TLS case the write callback runs before 'error' and gets ERR_SOCKET_CLOSED. On an accepted socket (its _destroy has no handle and emits 'close' on the next tick) the canceled write's callback runs after 'close'. #43250 moves the cancel into _destroy. Its body says that this fixes both. I did not run the two PRs together after this merge. Item 3 (the reset reaches a paused socket as a read error, drain_for_error in packages/bun-usockets/src/loop.c) and item 5 (Windows) are not changed.

The write callbacks after a peer reset, with an 'error' listener. A standalone script does write(32 MiB, cb), write("tail", cb), end(cb) against a peer that reads nothing and resets. It counts the calls of the three callbacks on a client socket and on an accepted socket. The script is in the comment of 2026-10-15.

node v26.3.0   client {1,1,1}   accepted {1,1,1}   await new Promise(r => socket.write(big, r)): settled, ECANCELED
main           client {0,0,0}   accepted {0,0,0}   still pending after 4 s
this head      client {1,1,1}   accepted {1,1,1}   settled, ECANCELED     (3 of 3 runs)

Writable's errorBuffer() (src/js/internal/streams/writable.ts) returns at once while a write is in flight. So the queued writes and end() wait for the one callback that main never calls. The third scenario of the fixture in node-net.test.ts ("peer reset, handled") pins the three counts on both sides.

Merge with main (a407eae88a, 2026-10-15). The branch was 281 commits behind. It conflicted in src/js/node/net.ts (6 hunks) and in one hunk of each test file. The merge is 6678ba2359. The old head bc04a5a94d is its first parent, so the commit ids in the review threads still resolve.

• Both close handlers keep main's kReadError exits (tls: consolidate the open TLS fixes (both engines, node:tls, node:https, WebSocket, SQL) #44618) and leftToTLSSocket path (node:tls: report a closed connection on the TLS socket, not on the socket it wraps #42487). The gate takes a write in flight, and every exit of the branch cancels it.
• The last block of SocketEmitEndNT keeps main's condition from node:net: finish an accepted socket whose native close leaves a write parked #43698 (kclosed or destroyed). It fails the parked write through failPendingWriteAfterClose.
• A write that the TLS engine rejected sits in the same kwriteCallback slot (kRejectedWrite, tls: consolidate the open TLS fixes (both engines, node:tls, node:https, WebSocket, SQL) #44618 and node:tls: keep the peer's answer when a pending write is rejected #45124). It is not a write in flight. The gate of SocketEmitEndNT does not count it, and failPendingWriteAfterClose leaves it to failRejectedWrite. It then fails with its own error at the close, as on main. SocketHandlers2.close needs no such check, because failRejectedWrite runs before its gate.
• Two hunks of this PR are gone. _destroy closed the adopted net.Socket, and the adoption tick destroyed the accepted socket. main does both now: closeWithTLSSocket and closeOwedRaw (node:tls: report a closed connection on the TLS socket, not on the socket it wraps #42487) for an adopted socket, transportToDestroy in _destroy (tls: consolidate the open TLS fixes (both engines, node:tls, node:https, WebSocket, SQL) #44618) for one that is not adopted yet. The three "allowHalfOpen" cases pass without the two hunks. With main's net.ts they fail on the 'end' that finishSocketEnd still emits there.
• The two test files take both sides.

After the merge.

• 7f375aaec7: the "peer reset, handled" scenario (above).
• 3492dab813: the two kReadError exits also cancel the write in flight. main added these exits after this PR was written. They serve a net.Socket that has unflushed writes when a TLS socket wraps it (the stream-level TLS engine). Test: "a peer reset with a write in flight on the socket that a TLS socket wraps" in node-tls-connect.test.ts.
• 5c3c4c94e9, 3a5b12b62b: comments only.

a net.Socket with one write in flight and one queued is wrapped (tls.connect({ socket }) or new TLSSocket(socket, { isServer: true })), the peer resets
node:                  ["tls error ECONNRESET read","raw close false","tls close true"]   both write callbacks run once
main, merge 6678ba2359: the same three events                                             no write callback runs
this head:             the same three events                                             both write callbacks run once

Downsides, measured.

destroy(), then connect() in the same tick, one write in flight
node:      ["error ECANCELED write","close false","close true"]
main:      ["close false","reconnected"]
this head: ["error ERR_SOCKET_CLOSED","close false","close true"]

accepted socket, allowHalfOpen, no 'error' listener: the peer's FIN, then one write in flight, then the peer's reset
node:      ["end","write EPIPE write","uncaught EPIPE write","close true"]
main:      ["end","write EPIPE read","close false"]
this head: ["end","uncaught EPIPE read","close true","write ECANCELED write"]

Found by reading, not run: a TLS socket over the stream-level engine with a write in flight before the handshake completes, no 'error' listener, and a read error of its transport. onUpgradedReadError calls SocketEmitEndNT with kclosed unset, so main closes it silently and this PR throws the read error.

Tests.

• The tests of this PR: 24 cases pass (12 under bun, 12 under Node). With main's net.ts, 11 of the 12 bun cases fail. The twelfth (accepted socket, no listener, peer reset) records no write callbacks and passes on main.
• Node scripts test-net-*, test-tls-*, test-https-*, test-http-*, test-http2-*: 1087 in parallel/ and 29 in sequential/ on the merge 6678ba2359, with the command line of scripts/runner.node.ts. 11 failed in the first pass. I ran those 3 more times on each build, each with its own tmp dir. 5 pass on both builds: my first pass gave all scripts one tmp dir. 6 fail on both builds: test-http2-forget-closed-streams.js and test-https-timeout.js (60 s limit), test-http-client-timeout-option.js, test-http-agent-keepalive.js, test-http-outgoing-end-cork.js, test-http-abort-queued.js (each of the last three passes in 1 of 3 runs on at least one build). The 519 tls, https and http2 scripts again on this head: the same 2 time out.
• test/js/node/net, tls, http, http2: 86 files, 3142 tests on this head, two files at a time, --timeout 30000. 8 fail. 7 of them also fail with main's net.ts: should trigger error when aborted even if connection failed #13126 (no DNS in the container), should have peer certificate and should work with alpnProtocols (each in tls.connect and tls.connect using duplex proxy, they connect to bun.sh), unref should exit when no more work pending, and reports the reset that arrives while the socket is paused as ECONNRESET, not 'end'. The eighth is should not crash on abort (node-http-uaf-fixture.ts), which ran into its 60 s limit. Alone it takes 54 s on this head and 59 s with main's net.ts.
• With the default 5 s timeout and four files at a time, most failure lines on both builds are timeouts of the debug binary (260 of 274 on the merge, 143 of 173 on main). I did not use those runs.
• net.Socket write > should allow reconnecting after end() failed one time in a sweep of the merge. It reconnects 3 ms after end(). Alone it passes 12 of 12 runs on both builds. With 10 busy loops beside it, 11 of 30 runs fail on the merge and 8 of 30 with main's net.ts.
• bun x tsc --noEmit -p src/js/tsconfig.json, bun lint src/js/node/net.ts and bun fmt --check on the three files: clean.
• Not run: macOS, Windows, a release build.

The node:http client case from the comment of 2026-09-21 (a close-delimited response, req.destroy() in the middle of the body) still holds. The test of 03f3d129b2 passes 4 of 4 on this head. With main's net.ts, 2 of 4 fail with ["data","end"]. That test is not in this PR.

Related PRs. #43250 (above). #43877 parks a TLS write in kwriteCallback until the transport has the ciphertext. #35386 (draft) changes the ERR_SOCKET_CLOSED block for TLS sockets.

Other notes.

• A write that still holds _pendingData (parked until 'connect' or the TLS attach) is left to its own 'close' listener. Before, the close handler failed it with ERR_SOCKET_CLOSED and the listener called the callback a second time.
• failPendingWriteNT knows the write only by its callback, and a stream passes the same callback to every _write. That is why the deferred failure reaches the connection of a connect() made in the same tick (Downsides).
• Found outside this PR, by reading, not run: the code behind Http2SecureServer.emit("connection", raw) attaches 'data', 'end', 'drain' and 'close' to the raw socket and no 'error' listener (src/js/node/_http2_upgrade.ts:393). The TLS engine writes to that socket.
• Self-review before the merge: 9 concerns raised. Addressed: the related PRs are listed, and the write settlement uses the same error as node:net: cancel the in-flight write when the socket is destroyed #43250 and Node. Not taken: stacking this PR on node:net: cancel the in-flight write when the socket is destroyed #43250, folding the two read-error-on-close blocks into one helper (the SocketEmitEndNT copy has the Windows codeless-errno branch), and recording the write callbacks on the accepted socket (their position differs until node:net: cancel the in-flight write when the socket is destroyed #43250).
• Review of the merge: two read-only passes over the resolution. No defect found in it. 1 concern taken (the kReadError exits). 3 reported here and not changed: the two behavior changes under Downsides, and the order on an accepted socket.

---

no test proof · iteration 2 · platform-specific test(s) that do not run on this machine, deferring to CI, which covers all platforms: test/js/node/net/node-net.test.ts

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Walkthrough

Socket handling now suppresses EOF for destroyed sockets, defers pending-write failures, and cancels eligible in-flight writes after read-close errors. Bun and Node tests cover net and TLS teardown, peer resets, event ordering, and callback counts.

Changes

Socket close behavior

Layer / File(s)	Summary
Close and pending-write ordering src/js/node/net.ts	Destroyed sockets suppress EOF. Pending-write failures are deferred, and eligible in-flight writes are canceled when read-close errors are handled.
Teardown regression tests test/js/node/net/node-net.test.ts, test/js/node/tls/node-tls-connect.test.ts	Bun and Node tests cover net and TLS teardown and peer resets. They check event ordering, error codes, clean raw-socket closes, and write callback counts.

Suggested reviewers: cirospaciari

Priority: ⬇️ Low

Merge Risk: 🔵 Low · up to 3a5b1

This change alters node:net socket teardown ordering and write cancellation. The author discloses two edge-case differences from the current behavior, and the change was not tested on macOS, Windows or a release build. Owners should be aware of these before merging, but no concrete failure is established.

Pre-merge checks: 4

Check name	Status	Explanation
Title check		The title clearly summarizes the primary changes: preventing 'end' on destroyed sockets and preserving read errors during in-flight writes.
Description check		The description explains the problem, fix, scope, known differences, and verification results. It does not use the exact template headings, but it provides the required information in equivalent secti…
Linked Issues check		Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check		Check skipped because no linked issues were found for this pull request.

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[claude]

Findings marked 🟡 are optional suggestions and need no follow-up push.

[coderabbitai]

Actionable comments posted: 1

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• 🪄 Fix CodeRabbit comments on this PR

🤖 Prompt to fix review comments

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only still-valid issues, skip the rest with a brief reason, keep changes
minimal, and validate.

Inline comments:
In `@test/js/node/tls/node-tls-connect.test.ts`:
- Around line 2136-2140: Update the skipped “closes the wrapped accepted socket”
test and the preceding client assertion to destructure the result from run, then
assert events, stderr, and exitCode separately in that order. Keep the existing
expected values unchanged.

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[claude]

Nothing blocking. The comments below are optional suggestions. There is no need to push a fix for them before merging.

The follow-up commits address what I raised last round: the write in flight is now settled with ECANCELED after the read-error destroy in both close handlers, _destroy closes the adopted raw socket directly, the fixture exits nonzero instead of throwing, and the macOS skip is explained. Beyond the inline findings, I also checked the behavior change where a peer reset with a write in flight and no 'error' listener now surfaces as an uncaught read ECONNRESET (net.ts:718 / :1411) rather than the silent close on main — it matches Node's contract, so I ruled it out as intentional.

Extended reasoning...

The diff since the prior review adds cancelPendingWriteAfterClose after every self.destroy(er) in SocketEmitEndNT and SocketHandlers2.close, adds the kAdoptedTLSRaw branch in Socket.prototype._destroy, and reworks the fixtures (process.exit(1) on setup failure, macOS reason in the skip comment), which covers each earlier inline point. The remaining candidate examined this run, the uncaught ECONNRESET with no 'error' listener, is a deliberate Node-parity change rather than a regression, so it is not a finding. The two inline findings (server-side ECANCELED ordering after 'close', and no test exercising the ECANCELED delivery) are posted separately and are not restated here.

[claude]

Nothing blocking. The comments below are optional suggestions. There is no need to push a fix for them before merging.

Additional findings (outside the current diff — GitHub can't attach inline comments there):

• 🟣 src/js/node/net.ts — Pre-existing, and the new parent-close branch does not reach it: a server that destroys a new tls.TLSSocket(raw, { isServer: true }) in the same tick it wrapped it leaves raw open forever. The adopt step is deferred to process.nextTick at src/js/node/net.ts:2440; when the TLS socket is already destroyed, src/js/node/net.ts:2442 calls this.destroy() (a no-op) and returns, and nothing ever closes the accepted socket, so server._connections never drops and server.close() never completes. Fix: when the wrapper is destroyed before the adopt tick, destroy the wrapped connection too, as the client-side sibling at src/js/node/net.ts:2103-2106 already does, or make the new _destroy branch at :2222 cover a kupgraded net.Socket that has not been adopted yet. [also at: src/js/node/net.ts:2226 - pre-existing: destroying a TLS socket over a net.Socket still leaves that parent open on the two wrap paths the new branch does not reach, where Node's TLSWrap closes it. src/js/node/net.ts:2220-2226 only closes a Socket parent whose handle carries kAdoptedTLSRaw.]

  Extended reasoning...

  The PR adds the else-if at src/js/node/net.ts:2222 so that a destroyed TLS socket closes its adopted parent ("as node's TLSWrap does"). The guard is upgraded._handle?.[kAdoptedTLSRaw], which is only true after adoption at :2487.
  Trigger: in a net.createServer 'connection' handler, const s = new tls.TLSSocket(raw, { isServer: true, key, cert }); s.destroy(); (an address filter or rate limiter deciding synchronously).
  TLSSocket constructor (src/js/node/tls.ts:846) calls the server-upgrade method. At :2439 this[kupgraded] = connection is set synchronously; the fd adoption is scheduled with process.nextTick at :2440. The TLS _handle stays unset (tls.ts:823-826).
  s.destroy() runs _destroy (:2211). upgraded is the raw net.Socket, an instance of Socket, so :2220 is false. upgraded._handle is the plain…

  Verification: pre-existing (the base takes the same route through the untouched deferred-adoption callback, so merging makes nothing worse; but it is a gap in the class this PR sets out to close and its new test pins only the post-'secure' case). Trigger: a net.createServer 'connection' listener does const s = new tls.TLSSocket(raw, { isServer: true, key, cert }); s.destroy(); in the same tick (or any…

[robobun]

^{Updated 3:03 PM PT - Oct 15th, 2026}

❌ @robobun, your commit 3a5b12b has 3 failures in Build #126114 (All Failures):

• test/js/sql/sql-close-pending-connection.test.ts - code 1 on 🍎 27 aarch64
• test/cli/install/bun-run.test.ts - crash reported on 🍎 27 aarch64
• test/js/node/net/node-net.test.ts - code 1 on 🍎 27 aarch64

---

🧪   To try this PR locally:

bunx bun-pr 43392

That installs a local version of the PR into your bun-43392 executable, so you can run:

bun-43392 --bun

[claude]

Code review completed

Nothing new to post: everything this review found is already covered by existing comments on this pull request or didn't merit a separate one.

[robobun]

This change also corrects a node:http client case that the description does not list. I checked it against a build of this branch.

The case. A response with no Content-Length and no Transfer-Encoding is framed by connection close. The client destroys the request while the body streams (req.destroy() in 'data', or req.on('timeout', () => req.destroy()), or abort()). On main the response ends with a clean 'end', so a truncated download looks complete. Node reports 'aborted' and ECONNRESET. The cause is the 'end' that a destroyed net.Socket emits: it reaches socketOnEnd in _http_client.ts, which finishes the parser and marks the body complete before socketCloseListener runs its abort check.

Result. Debug builds, same machine. "main" is this branch with only src/js/node/net.ts reverted to the merge-base (367d939). Each row is the same for http and https.

close-delimited body        node v26.3.0 and this PR (bc04a5a94d)               main
destroy in 'data'           data,aborted,res-error:ECONNRESET                   data,end
'timeout' then destroy()    data,timeout,aborted,res-error:ECONNRESET           data,timeout,end
'timeout' then abort()      data,timeout,aborted,res-error:ECONNRESET           data,timeout,end

• All 6 close-delimited cells (3 triggers, http and https) match Node on this branch. All 6 are wrong on main.
• The 6 chunked cells match Node on both builds. They are the control.
• A custom createConnection Duplex that pushes EOF inside its own destroy() still gives data,end | complete=true, as Node does. This change does not touch that path.

Test. An http-level regression test for this case is on the branch robobun/c7c32d26/http-client-destroy-test, commit 03f3d12. It is one commit on top of bc04a5a and adds one file, test/js/node/http/node-http-client-destroy.test.ts (http and https, close-delimited and chunked). With net.ts at the merge-base, 2 of 4 tests fail (["data","end"]). On this branch, 4 of 4 pass. It is the test that was on #33256 before that PR was closed as stale, with the https rows added.

I did not push the test to this branch. CI on bc04a5a is green (build 118184), and a push starts it again. To take the test: git cherry-pick 03f3d129b2.

[robobun]

I merged main (a407eae88a) into this branch. The PR merges again. The new head is 3a5b12b62b.

What the push holds

• 6678ba2359: the merge. The old head bc04a5a94d is its first parent, so the commit ids in the review threads still resolve.
• 7f375aaec7: one more scenario in the teardown fixture of node-net.test.ts.
• 3492dab813: the two kReadError exits cancel the write in flight too, with a test in node-tls-connect.test.ts.
• 5c3c4c94e9, 3a5b12b62b: comments only. The runs below are from 3492dab813.

The conflicts

src/js/node/net.ts had 6 conflicted hunks. Each test file had one. Since this PR was written, main rewrote the TLS adoption and teardown code and changed the last block of both close handlers. The description has the full account under Notes. Three points need a reviewer's eye:

• Two hunks of this PR are gone. _destroy closed the adopted net.Socket, and the adoption tick destroyed the accepted socket. main does both now (closeWithTLSSocket, closeOwedRaw, transportToDestroy). The three "allowHalfOpen" cases of this PR pass without the two hunks.
• A rejected TLS write is not a write in flight. main parks a write that the TLS engine rejected in the same kwriteCallback slot (kRejectedWrite). The merge does not count it at the gate and does not fail it from failPendingWriteAfterClose. failRejectedWrite still fails it with its own error at the close, as on main.
• The kReadError exits. main added them after this PR was written. They destroyed the wrapped socket and returned before the cancel, so the write in flight of that socket never reported. 3492dab813 adds the cancel there.

The hang with an 'error' listener

This PR also fixes a hang that its description did not name before. A socket with an 'error' listener has a write in flight, and the peer resets. 'error' and 'close' come, and the callbacks of write() and end() never run. This script shows it. It runs under bun and under node. Exit 86 means that a callback never ran.

net-write-callback-never-after-reset.cjs

// usage: bun net-write-callback-never-after-reset.cjs      (also runs on node; loopback only; starts one child of itself: the peer; no files; about 12 s)
// exit 86 = after the peer resets the connection in the middle of a large write, 'error' and 'close' come but the callbacks of write() and end() are never called; 0 = every callback is called once; 2 = a control failed.
// The law: every callback of a write and of end exactly once. A program that awaits a promisified socket.write() waits for ever.
const net = require("node:net"), cp = require("node:child_process"), BIG = Buffer.alloc(32 << 20, 97);
if (process.argv[2] === "peer") { // port A: reads all. port B: reads nothing and closes after 150 ms with data unread, which the kernel turns into a reset. C: connects to the port on stdin and does as B
  const a = net.createServer(c => c.resume().on("error", () => {})), b = net.createServer(c => { c.pause(); c.on("error", () => {}); setTimeout(() => c.destroy(), 150); });
  a.listen(0, "127.0.0.1", () => b.listen(0, "127.0.0.1", () => console.log(a.address().port + " " + b.address().port)));
  process.stdin.on("data", d => { const c = net.connect(+d, "127.0.0.1"); c.pause(); c.on("error", () => {}); setTimeout(() => c.destroy(), 150); }); return; }
const kid = cp.spawn(process.execPath, [__filename, "peer"], { stdio: ["pipe", "pipe", "inherit"] });
const sleep = ms => new Promise(r => setTimeout(r, ms));
async function run(s, twin) { // write(32 MiB, cb), write("tail", cb), end(cb); then 'close' and 3 s more
  const seen = [], cbs = { write1: 0, write2: 0, end: 0 }; s.on("error", e => seen.push("error " + e.code));
  const closed = new Promise(r => s.on("close", () => { seen.push("close");
    if (twin) { const k = Object.getOwnPropertySymbols(s).find(y => y.description === "writeCallback"), f = k && s[k]; seen.push("parked: " + typeof f); if (typeof f === "function") { s[k] = null; f(new Error("failed from outside")); } } r(); }));
  s.write(BIG, () => cbs.write1++); s.write("tail", () => cbs.write2++); s.end(() => cbs.end++);
  await Promise.race([closed, sleep(5000)]); await sleep(1000); const early = JSON.stringify(cbs); await sleep(2000);
  return { events: seen.join(", "), cbs, text: `${seen.join(", ")}; callbacks 1 s behind close ${early}, 3 s behind close ${JSON.stringify(cbs)}` }; }
const connect = port => new Promise(r => { const s = net.connect(port, "127.0.0.1", () => r(s)); });
(async () => {
  const [A, B] = (await new Promise(r => kid.stdout.once("data", d => r(String(d))))).trim().split(" ").map(Number), once = o => Object.values(o.cbs).every(n => n === 1), never = o => Object.values(o.cbs).some(n => n === 0);
  const ctl = await run(await connect(A)); console.log("control: a peer that reads all: " + ctl.text);
  const cl = await run(await connect(B)); console.log("client socket, the peer resets: " + cl.text);
  const sv = net.createServer(), got = new Promise(r => sv.once("connection", r)); await new Promise(r => sv.listen(0, "127.0.0.1", r)); kid.stdin.write(String(sv.address().port));
  const se = await run(await got); console.log("server-side socket, the peer resets: " + se.text); sv.close();
  const tw = await run(await connect(B), true); console.log("the same client, and the 'close' listener calls the function parked in socket[Symbol(writeCallback)] (bun only): " + tw.text);
  const s = await connect(B); s.on("error", () => {}); const p = await Promise.race([new Promise(r => s.write(BIG, e => r("settled: " + (e ? e.code : "ok")))), sleep(4000).then(() => "still pending after 4 s")]);
  console.log("await new Promise(r => socket.write(big, r)), the peer resets: " + p); kid.kill();
  if (!once(ctl)) { console.log("RESULT: a control failed"); process.exit(2); }
  if (never(cl) || never(se)) { console.log(`RESULT: broken: callbacks never called: client ${never(cl)}, server side ${never(se)}; the promisified write: ${p}`); process.exit(86); }
  console.log("RESULT: holds: every callback is called once"); process.exit(0);
})();

build (Linux x64)	exit	client: write, write, end	accepted socket	await new Promise(r => socket.write(big, r))
Node v26.3.0	0	1, 1, 1	1, 1, 1	settled, ECANCELED
main a407eae88a	86	0, 0, 0	0, 0, 0	still pending after 4 s
this head, 3 of 3 runs	0	1, 1, 1	1, 1, 1	settled, ECANCELED

The new scenario in node-net.test.ts pins the three counts on the client and on the accepted socket. With main's net.ts both cases report calls {"write":0,"queued":0,"end":0}.

What changes for code that works on main

Each of these is measured against Node and against main. The outputs are in the description under "Downsides, measured".

• A reset after the peer's FIN, with a write in flight and no 'error' listener, on an accepted socket. main emits no 'error'. This head throws EPIPE with syscall read. Node throws EPIPE with syscall write.
• destroy() then connect() in the same tick, with a write in flight. main reconnects. This head and Node fail the new connection.

Tests

Linux x64, debug ASAN build. "main" is the same build with net.ts from a407eae88a.

• The tests of this PR: 24 cases pass, 12 under bun and 12 under Node. With main's net.ts, 11 of the 12 bun cases fail.
• 1087 + 29 Node scripts (test-net-*, test-tls-*, test-https-*, test-http-*, test-http2-*): 6 fail, and the same 6 fail with main's net.ts.
• test/js/node/net, tls, http, http2: 86 files, 3142 tests. 8 fail. 7 of them fail with main's net.ts too. The eighth is a 60 s timeout that takes 54 s alone on this head and 59 s with main's net.ts.
• The node:http case from the comment above still holds: the test of 03f3d129b2 passes 4 of 4 on this head, and 2 of 4 fail with main's net.ts.
• Not run: macOS, Windows, a release build.

Not done here

#43250 cancels the same write in _destroy. It also conflicts with main now. I did not run the two PRs together after this merge.

[claude]

Nothing blocking. The comments below are optional suggestions. There is no need to push a fix for them before merging.

[claude]

Code review found no issues

No high-confidence issues detected in this change.

Still open from earlier reviews (1):

• Unresolved: 1 minor or pre-existing.

[robobun]

One more case for this PR: an https request that ends with no error on main. The finishSocketEnd change of this PR fixes it.

Case. https.get() through a keep-alive agent, against a TLS 1.2 server that keeps its side open. The caller calls socket.end() in the 'socket' event, and socket.destroy() 500 ms later. agent.destroy() in place of socket.destroy() gives the same lines.

Runtime	Events of the request
Node v26.3.0	error ECONNRESET, close
Bun 1.4.2	error ECONNRESET, close
main (f0c6cbc, debug build)	close and no error, 3 of 3 runs
main with the finishSocketEnd line of this PR	error ECONNRESET, close

Cause.

• Since node:tls: send a client's FIN after the first step of its handshake #43962 the ClientHello leaves before the FIN of an early end(). On TLS 1.2 the handshake cannot complete after that FIN. So the socket is still secureConnecting when the caller destroys it.
• destroy() emits 'end' (the first item of this PR). onConnectEnd runs on that 'end'. It sets _hadError and calls destroy(error) on a socket that is already destroyed, so the error is dropped.
• The 'end' and 'close' listeners of the HTTP client then see _hadError and do not report socket hang up.

With if (self[kended] || self.destroyed) return; in finishSocketEnd the socket emits no 'end', and the close listener of the HTTP client reports ECONNRESET, as in Node. I tested only that one line on main, not the rest of this PR. The PR conflicts with main at the moment.

Script

It needs node on the PATH and a self-signed pair for localhost next to it (openssl req -x509 -newkey rsa:2048 -nodes -keyout k.pem -out c.pem -days 5 -subj "/CN=localhost" -addext "subjectAltName=DNS:localhost").

// <runtime> https-agent-end.mjs [destroy | agent-destroy] [stays | closes] [TLSv1.2 | TLSv1.3]
// https.get() through a keep-alive agent, a trusted chain, socket.end() by hand in 'socket', then socket.destroy() or agent.destroy().
// The far side is node in its own process: an https server.
import https from "node:https"; import fs from "node:fs"; import { spawn } from "node:child_process";
const [action = "destroy", far = "stays", version = "TLSv1.2"] = process.argv.slice(2);
const dir = new URL(".", import.meta.url).pathname;
const peer = spawn("node", ["-e", `
  const https = require("https"), fs = require("fs");
  const srv = https.createServer({ key: fs.readFileSync("${dir}k.pem"), cert: fs.readFileSync("${dir}c.pem"), maxVersion: "${version}", allowHalfOpen: ${far === "stays"} }, (req, res) => res.end("ok"));
  srv.on("tlsClientError", () => {}); srv.on("clientError", () => {});
  srv.listen(0, "127.0.0.1", () => console.log(srv.address().port));
  setTimeout(() => process.exit(0), 10000);`], { stdio: ["ignore", "pipe", "inherit"] });
const port = await new Promise(r => peer.stdout.once("data", d => r(+String(d))));
peer.stdout.destroy(); peer.unref();
const ev = [];
const agent = new https.Agent({ keepAlive: true });
const req = https.get({ host: "127.0.0.1", port, servername: "localhost", ca: fs.readFileSync(dir + "c.pem"), agent, maxVersion: version });
req.on("socket", s => {
  for (const e of ["connect", "secureConnect", "finish", "end", "close"]) s.on(e, () => ev.push("socket " + e));
  s.on("error", e => ev.push("socket error " + e.code));
  ev.push("socket.end()"); s.end();
  setTimeout(() => {
    if (action === "destroy") { ev.push("socket.destroy()"); s.destroy(); }
    else { ev.push("agent.destroy()"); agent.destroy(); }
  }, 500);
});
req.on("response", res => { ev.push("response " + res.statusCode); res.resume(); });
req.on("error", e => ev.push("REQ ERROR " + e.code));
req.on("close", () => ev.push("req close"));
let said = false;
setTimeout(() => { said = true; console.log(`${action} ${far} ${version}: ${ev.join(", ")} | STILL ALIVE after 3 s`); process.exit(0); }, 3000).unref();
process.on("exit", () => { if (!said) console.log(`${action} ${far} ${version}: ${ev.join(", ")} | exited by itself`); });

Full lines for destroy stays TLSv1.2:

node v26.3.0:  socket.end(), socket connect, socket finish, socket.destroy(), REQ ERROR ECONNRESET, req close, socket close
bun 1.4.2:     socket.end(), socket connect, socket secureConnect, socket finish, REQ ERROR ECONNRESET, socket end, req close, socket close, socket.destroy()
main:          socket.end(), socket connect, socket finish, socket.destroy(), socket end, req close, socket close
main + line:   socket.end(), socket connect, socket finish, socket.destroy(), REQ ERROR ECONNRESET, req close, socket close