bun test: rank "no timeout" as the latest deadline for spawnSync in a concurrent group by robobun · Pull Request #46213 · oven-sh/bun

robobun · 2026-10-20T16:21:14Z

Problem

A concurrent sibling's timeout ends the Bun.spawnSync child of a test with timeout 0: child: null SIGTERM after 104 ms. Piped output is cut with exit code 0.
After an await, TestRunner::get_active_timeout() (src/runtime/test_runner/jest.rs:174) takes the latest deadline with Timespec::order. That order ranks EPOCH ("no timeout") below every deadline. Regression from spawnSync: drain piped stdio to EOF after the direct child exits #33832 (1.4.0).

Fix

Compare with Timespec::order_ignore_epoch: a running test with no timeout gives no deadline.
Skip a sequence that has not started: its EPOCH means "not set".
Verified: test/js/bun/spawn/spawnSync.test.ts (9 new cases, main fails 6). Also the bun:test timeout and concurrency suites.
Self-reviewed: 11 concerns raised, 8 addressed. Not taken: a far deadline for 0 (a timer per test), the file-timer fallback (as on main), docs (bun test: SIGKILL a spawnSync child that is still running 500 ms after the test's timeout #45792's line).

Background

Bun.spawnSync blocks the JS thread. Its wait loop asks the runner for a deadline, signals the child and closes its pipes.
Before its first await the runner knows the caller (on_stack_entry). After it, any running test can be the caller, so spawnSync: drain piped stdio to EOF after the direct child exits #33832 took the latest deadline.
Considered removing on_stack_entry, which names the wrong test in a microtask drain. bun test: Vitest compatibility #44833 repairs it, and without it a hung child fails every sibling.

Downsides

After an await, a timed test beside a running test with no timeout keeps its child. A child that never exits blocks the run, as on main beside an Infinity sibling.
It reads (pass) when the child ends by itself. bun test: time out a test or hook whose callback completes after its deadline #39440 reports the overrun, so this PR should land after bun test: time out a test or hook whose callback completes after its deadline #39440.
After an await: 11 more instructions per further running test, none otherwise. Text +256 bytes.

Notes

Repro (bun test ./sib.test.ts)

import { test } from "bun:test";
const ignore = { stdin: "ignore", stdout: "ignore", stderr: "ignore" } as const;
test.concurrent("times out", async () => {
  await new Promise(() => {});
}, 100);
test.concurrent("has no timeout", async () => {
  await new Promise(resolve => setImmediate(resolve));
  const start = performance.now();
  const r = Bun.spawnSync({ cmd: ["sleep", "1"], ...ignore });
  console.log("child:", r.exitCode, r.signalCode ?? null, "after", Math.round(performance.now() - start), "ms");
}, 0);

build	output
1.3.14	`child: 0 null after 1004 ms`
1.4.0, main	`child: null SIGTERM after 101 ms`
this branch	`child: 0 null after 1003 ms`

There is no issue for this. It turned up while reading the wait loop for #45792.

Where the rule comes from

get_active_timeout() has one caller, the wait loop in spawn_maybe_sync (src/runtime/api/bun/js_bun_spawn_bindings.rs:1844). child_process.spawnSync, execFileSync and execSync reach it through Bun.spawnSync.

Two comments on main say what the runner must not do:

Execution.rs:311, on the kill of dangling processes: "when using test.concurrent(), we can't do this because it could kill multiple tests at once."
js_bun_spawn_bindings.rs:1895: "There is a scenario where inside of spawnSync() a totally different test fails, and that SHOULD be okay."

#33832 made the loop signal the child at the runner's deadline. Its last commit took the latest deadline of the group "so a sibling never terminates early". The comparison it used treats EPOCH as the earliest time. An entry with no timeout has EPOCH (Execution::on_entry_started), so it never won.

docs/test/runtime-behavior.mdx gives 0 and Infinity as one setting. Infinity is stored as a deadline 49 days away (ScopeFunctions.rs:708), so it did win. With Infinity in the repro, main prints child: 0 null after 1173 ms. This change makes 0 behave as Infinity does.

What each group gives (release builds, child sleep 1 unless noted)

caller, and the other test of the group	main	this branch
no timeout, after an `await`. Sibling hangs with 100 ms	`SIGTERM` at 114 ms	exit 0 at 1025 ms
100 ms, after an `await`. Sibling has no timeout and runs	`SIGTERM` at 122 ms, `(fail)`	exit 0 at 1018 ms, `(pass)`
100 ms, after an `await`. Sibling has `Infinity` and runs	exit 0 at 1002 ms, `(pass)`	exit 0 at 1005 ms, `(pass)`
100 ms, after an `await`. Sibling has 5000 ms and runs (child `sleep 3`)	exit 0 at 3002 ms, `(pass)`	exit 0 at 3005 ms, `(pass)`
800 ms, after an `await`. Sibling hangs with 100 ms (child `sleep 3`)	`SIGTERM` at 831 ms	`SIGTERM` at 850 ms
300 ms, after an `await`, `--max-concurrency 1` (child `sleep 2`)	`SIGTERM` at 315 ms	`SIGTERM` at 344 ms
100 ms, before its first `await`. Sibling has no timeout	`SIGTERM` at 126 ms	`SIGTERM` at 133 ms
300 ms, before its first `await`. Sibling has 3 s	`SIGTERM` at 319 ms	`SIGTERM` at 322 ms
no timeout, resumed in the microtask drain of a 100 ms sibling	`SIGTERM` at 124 ms	`SIGTERM` at 114 ms
no timeout, resumed while a 300 ms sibling waits in `expect().resolves`	`SIGTERM` at 319 ms	`SIGTERM` at 320 ms

The last two rows are the on_stack_entry arm. This change does not touch them. See "Not changed".

Row 4 is from 1.4.3-canary (367d939, the same runner code) and from the debug build of this branch.

On main, a timed caller after an await is ended at its own deadline only when every other running test has timeout 0. Beside Infinity or a later timeout it waits, as rows 3 and 4 show. A child that never exits then blocks the run until the later deadline, or for good beside Infinity. After this change 0 is in that group too.

Measurements (release builds of main 91e7e3b and of this change on it, same toolchain, Linux x64. Main has since added a main-thread check before the call. The function is the same.)

kill(2) to the child, main to this branch (gdb catch syscall kill): the repro 1 to 0. The timed caller beside a test with no timeout 1 to 0. Every other row of the table 1 to 1.
get_active_timeout is inlined into spawn_maybe_sync in both builds. Instructions per turn of the wait loop (gdb stepi from the load of the active file to the point where the deadline is ready, 5 to 100 calls per case, all equal):
- caller before its first await: 9 to 9, in a serial test and with 5 or 20 running tests.
- after an await: 46 to 46 in a serial test, 71 to 82 with 2 running tests, 146 to 190 with 5, 521 to 730 with 20, 771 to 785 with 20 running and 10 not started.
Calls per 100 piped Bun.spawnSync: outside bun test 0 to 0, inside bun test 101 to 100 (one per turn of the wait loop).
spawn_maybe_sync 24,521 to 24,601 bytes (nm -S). Text 107,072,443 to 107,072,699 bytes (size). Data, bss and the size of the stripped file do not change.
No allocation, queue entry or syscall is added.

Tests

The 9 cases are one block at the end of test/js/bun/spawn/spawnSync.test.ts. Each runs an inner bun test on a generated file. The child is a script run with the bun under test, so Windows runs the cases too. The one case that needs sh is POSIX only.

Main fails 6.
- The four entry points: the test with no timeout asserts that its child exited with 0.
- A sibling that times out once and passes on its retry: the inner run exits 1 on main and 0 here. The signal alone made that run fail.
- A piped child whose grandchild writes after the deadline: main returns "early\n" with exit code 0, this branch "early\nlate\n".
Main passes 3. They pin what must not change.
- The latest timeout still ends the child when every running test has one.
- A test that has not started does not count as "no timeout" (--max-concurrency 1).
- A caller before its first await is still ended at its own timeout, also beside a test with no timeout.
Each clause is needed. With plain order the 6 cases fail. Without the executing filter the --max-concurrency 1 case fails. I checked both with a local build.
The block runs one case at a time on debug and ASAN builds. Five at once took up to 3.7 s per case on a debug build, against the 5 s limit.

Runs on the debug (ASAN) build:

test/js/bun/spawn/spawnSync.test.ts: 26 pass, 4 skip. The new block: 9 of 9 in 6 runs.
test/cli/test/test-timeout-behavior.test.ts, test/js/bun/test/concurrent_immediate.test.ts, bun_test.test.ts, failure-skip.test.ts, jest-hooks.test.ts, test-retry-repeats-basic.test.ts, test/js/node/test_runner/node-test.test.ts, test/js/bun/spawn/spawnsync-no-microtask-drain.test.ts, test/regression/issue/23865.test.ts: all pass.
test/js/bun/test/concurrent.test.ts runs into its 5 s limits on the debug build of main and of this branch alike. 0 to 6 of its 6 cases fail per run. It does not call spawnSync.
Not run: Windows and macOS.

The first shape of this change, and why it is gone

I first removed the on_stack_entry arm too, so that one rule covered every caller. A self-review rejected that shape. I checked its reasons:

bun test: Vitest compatibility #44833 keeps the arm and repairs the cell where it is set. Its doc comment says: "Cleared before the call's microtasks drain, because those can resume other tests in the group".
Without the arm, a hung child of a 100 ms caller blocks the thread until the latest deadline of the group. With siblings of 400 ms and 800 ms, main gives 2 pass and 1 fail. The build without the arm gave 0 pass and 3 fail.
bun test: on a timeout, kill only the processes the timed-out test or hook callback spawned #45081 and bun test: a matcher blocked on a promise that never settles fails with the test timeout #39089 read the cell.

This diff merges into #44833 (8130ea5), #45081, #39657, #39440 and #44613 with no conflict. It has one conflict with #45792: the harness import line of spawnSync.test.ts.

Self-review: the concerns

Addressed:

The body said that a timed caller is still reported as timed out. It now says (pass) for the one shape where that holds.
A hung child failed every sibling. The arm is back, so this is as on main.
The pipes of a child that has exited are closed with the signal. A case now pins the output.
The cases did not pin the arm. One case now does.
The regex for the verdict lines needed a duration. A test that takes no time has none. The duration is now optional.
The cases failed on a printed line only. The test with no timeout now asserts, and one case has a different exit code on main.
The entry-frame check that can prove a synchronous caller is named under "Not changed".
Measurement hygiene: every number here comes from a binary built from the named commit.

Not taken:

Store timeout 0 as a far deadline, as Infinity is. Then the fold is right as written. It arms the file timer for every test with no timeout. Every spawnSync wait in such a test then gets a deadline to wake for. A typed deadline on ExecutionEntry is the larger form of the same idea.
The file-timer value that the function returns outside the execution phase can be a stale deadline. It is the same on main.
A docs sentence for concurrent groups. docs/test/writing-tests.mdx:120 is the paragraph that bun test: SIGKILL a spawnSync child that is still running 500 ms after the test's timeout #45792 edits, and no doc describes the old behavior.

Review of the first push

The block now also runs one case at a time on ASAN builds.
"The 6 cases can pass on the unfixed build when the turn of the event loop takes more than 100 ms." They cannot. auto_tick (src/runtime/jsc_hooks.rs) runs the immediates before it polls and before it drains the timers, so the sibling is still running when the test with no timeout calls spawnSync. The wait loop then finds a deadline in the past and signals at once. With a 250 ms Bun.sleepSync before the await, 1.4.3-canary still prints spawned 251 ms after the sibling started: child exitCode null, signalCode SIGTERM, 3 of 3 runs.
"A child that never exits now blocks the run." That is the first Downside, and it now says so. The two rules proposed for it do not help. The latest deadline that is not EPOCH is what main computes: it is this defect. A far deadline for 0 is what Infinity has: the wait then lasts 49 days.

Not changed

The on_stack_entry arm names the callback that the runner entered. A test that resumes in the microtask drain of that callback gets its deadline. So does a test that resumes while it waits in expect().resolves. These are the last two rows of the table. bun test: Vitest compatibility #44833 clears the cell before the drain and has no blocking matcher wait. A test that calls drainMicrotasks() itself still resumes a sibling under the cell on main. A check of the VM entry frame together with that clear would close that form.
Execution::kill_dangling_processes_on_timeout (Execution.rs:322) compares a deadline that can be EPOCH with the plain order. fix(test): preserve unlimited test children after stale deadlines #44613 and bun test: on a timeout, kill only the processes the timed-out test or hook callback spawned #45081 change that line.
A test that overruns its timeout inside spawnSync and then completes reads (pass). Main does that beside a sibling with a later timeout. bun test: time out a test or hook whose callback completes after its deadline #39440 reports such a test as timed out, and bun test: setDefaultTimeout() in a preload applies only to the first file, and a sync block after a timer escapes the timeout #45192 is a user report of that verdict. This change should land with or after bun test: time out a test or hook whose callback completes after its deadline #39440.
bun test: SIGKILL a spawnSync child that is still running 500 ms after the test's timeout #45792's case for concurrent groups uses killSignal: "SIGURG". With this change its child gets no signal, so the case no longer reaches the force_kill_at guard. A group where every test has a timeout still does.

no test proof · iteration 0 · platform-specific test(s) that do not run on this machine, deferring to CI, which covers all platforms: test/js/bun/spawn/spawnSync.test.ts

robobun · 2026-10-20T16:21:29Z

^{Updated 8:33 AM PT - Oct 22nd, 2026}

✅ @robobun, your commit ed52a5004523c7b1aad29a7bac062255eb4633a4 passed in Build #130927! 🎉

🧪 To try this PR locally:

bunx bun-pr 46213

That installs a local version of the PR into your bun-46213 executable, so you can run:

bun-46213 --bun

robobun · 2026-10-20T16:21:30Z

Status

Reproduced with the repro in the description (bun test ./sib.test.ts). Main and 1.4.0 print child: null SIGTERM after 101 ms. 1.3.14 and this branch print child: 0 null after about 1000 ms.
On a debug build of main, 6 of the 9 new cases in test/js/bun/spawn/spawnSync.test.ts fail. On this branch all 9 pass.
PR: bun test: rank "no timeout" as the latest deadline for spawnSync in a concurrent group #46213

coderabbitai · 2026-10-20T16:26:33Z

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Walkthrough

The test runner now skips sequences that have not started when selecting an active timeout. It uses epoch-aware ordering for running entries. New concurrent tests check timeout handling and output behavior for synchronous child processes.

Changes

Active timeout selection

Layer / File(s)	Summary
Select the latest active timeout `src/runtime/test_runner/jest.rs`	`get_active_timeout` skips sequences that are not executing and compares running entries with epoch-aware ordering.
Test concurrent synchronous child processes `test/js/bun/spawn/spawnSync.test.ts`	Added a concurrent test harness and tests for timeout ownership, retry behavior, output preservation, and child termination across synchronous child-process APIs. Tests also cover unstarted tests and calls made before the caller's first `await`.

Possibly related issues

oven-sh/bun#46373 — This change tests timeout ownership for concurrent synchronous child processes. The issue describes a remaining beforeAll ownership case, which the supplied summaries do not show this change addressing.

Suggested reviewers: jarred-sumner

Priority: ➖ Normal

Merge Risk: ⚪ Minimal · up to ed52a

The ASAN timeout concern is addressed, and the changed deadline behavior has targeted coverage. The PR is ready for normal merge checks.

Pre-merge checks: 4

Check name	Status	Explanation
Title check		The title clearly and concisely describes the main change: treating no-timeout as the latest deadline for spawnSync in concurrent tests.
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.
Description check		The description is complete and relevant. It explains the problem, fix, scope, known downsides, and verification results, including test coverage and untested platforms. It does not use the exact temp…

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Actionable comments posted: 1

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Inline comments:
Review comments at @test/js/bun/spawn/spawnSync.test.ts:
- Around line 288-289: Update the test harness import to include isASAN, then
change the suite selector for “spawnSync after an await in a group of concurrent
tests” so it uses describe when either isDebug or isASAN is true, retaining
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claude

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

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

🟣 src/runtime/test_runner/jest.rs — Users with a no-timeout concurrent test that resumes inside a sibling's callback still get their spawnSync child killed at the sibling's deadline, the exact symptom this change says it removes. At src/runtime/test_runner/jest.rs:163-165 on_stack_entry names whichever callback is on the stack, so a continuation resumed in that drain is charged the sibling's timespec and never reaches the new loop at :170-182. Fix: resolve the caller for the after-await path from the entry that owns the resumed continuation, or at least exclude on_stack_entry when it is not the active entry of the running sequence, so timeout 0 means no deadline on every path.

Why this was flagged

Trigger: a test.concurrent with timeout 0 awaits a promise that a sibling resolves synchronously inside the sibling's callback. The runner runs the sibling's callback through run_test_callback (Execution.rs:1031) with on_stack_entry set to the sibling at Execution.rs:1020 and drains microtasks before the scopeguard at :1026 restores it, so the no-timeout test's continuation runs while jest.rs:163 returns the sibling's timespec. The wait loop at js_bun_spawn_bindings.rs:1838-1911 then kills the child at that deadline and closes the pipes. The PR's own table records SIGTERM for this row on both builds, so the base behaves the same; the change is what newly documents (jest.rs:161-162 and spawnSync.test.ts:283-286) that the latest running deadline governs after an await, which is false for this population. Remedy: resolve the caller for a resumed continuation from its own entry rather than the on-stack sibling.

Verification: pre-existing; acknowledged in diff: the PR description's table records SIGTERM for this row on both builds. src/runtime/test_runner/jest.rs:163-166 returns on_stack_entry's timespec before the new loop at :170-182; Execution.rs:1020 pins the sibling until run_test_callback (:1031) returns. Result: the timeout-0 test's spawnSync child is SIGTERMed at the sibling's deadline.

claude · 2026-10-20T16:35:23Z

+                    // Not started yet: its `EPOCH` is "not set", not "no timeout".
+                    if !seq.executing {
+                        continue;
+                    }
                    let Some(entry) = seq.active_entry else { continue };
                    // SAFETY: arena-owned entry, alive for the lifetime of BunTest.
                    let ts = unsafe { entry.as_ref() }.timespec;
-                    if latest.is_none_or(|l| ts.order(&l) == core::cmp::Ordering::Greater) {
+                    // A running entry with no timeout (`EPOCH`) is the latest of all.
+                    if latest.is_none_or(|l| bun_core::Timespec::order_ignore_epoch(ts, l).is_gt()) {


🔴 A timed concurrent test that calls spawnSync after an await now keeps a hung child forever when any running sibling has timeout 0, hanging the whole bun test run. At src/runtime/test_runner/jest.rs:179 a running EPOCH entry wins as latest, so the wait loop in js_bun_spawn_bindings.rs:1841 gets no deadline at all. On the base branch the timed test's own deadline still ended the child. Fix: when the caller is unknown, keep a deadline for the timed entries (for example the latest non-EPOCH deadline, or a far deadline for 0 as Infinity already uses) so a test's timeout still ends its child; the PR lists the (pass) overrun as a downside, but the never-exiting-child case is a hang, not an overrun. [also at: src/runtime/test_runner/jest.rs:184 - A timed concurrent test whose spawnSync child never exits now hangs the whole bun test run forever when a sibling with timeout 0 is also running; on the base it is killed at its own deadline and fails.]

Why this was flagged

Trigger: a concurrent group with test A timeout: 100 that does await x; Bun.spawnSync(hangingCmd) and test B timeout: 0 that is executing at the same time. The wait loop at src/runtime/api/bun/js_bun_spawn_bindings.rs:1841 calls get_active_timeout; on_stack_entry is None after the await, so the loop at src/runtime/test_runner/jest.rs:170-182 runs. B's entry has timespec EPOCH (Execution.rs:627) and executing true, so order_ignore_epoch(EPOCH, A_deadline) is Greater (src/bun_core/util.rs:4946) and latest becomes EPOCH, returned at jest.rs:184. The wait loop then has has_bun_test_timeout == false and waits for the child indefinitely. On the base branch ts.order(&l) ranked EPOCH lowest, so A's 100 ms deadline was returned and the child was signalled at that deadline. After merging, a child that never exits blocks the JS thread forever; A's timeout never fires because the thread is blocked, and the run only ends when CI kills it. The PR description acknowledges the timed test reading (pass) beside a 0-timeout sibling but not the hang.

Verification: order_ignore_epoch (src/bun_core/util.rs:4942-4953) returns Greater when ts == EPOCH, so jest.rs:183-185 returns EPOCH directly. In the wait loop (src/runtime/api/bun/js_bun_spawn_bindings.rs:1838-1858) has_bun_test_timeout is then false and tick_with_timeout(None) blocks until the child exits. On the base commit the child was signalled at A's deadline (js_bun_spawn_bindings.rs:1895-1911).

This is the first Downside of the description, in its worst case. The description now says it in those words: a child that never exits blocks the run.

The two rules proposed here do not remove it:

The latest deadline that is not EPOCH is what main computes today. It is the defect of this PR: the child of the test with timeout 0 is signalled at the deadline of its sibling. The 6 new cases fail with it.

A far deadline for 0 is what Infinity has on main (ScopeFunctions.rs:708, 49 days). The fold then returns that deadline, and the wait lasts 49 days.

After an await the runner does not know which running test called spawnSync. It can signal at a deadline that can belong to another test, or it can wait while one running test has no timeout. #33832 chose the second ("so a sibling never terminates early"), and the comment at js_bun_spawn_bindings.rs:1895 says the same.

Main keeps the own deadline of a timed caller only when every other running test has timeout 0. On 1.4.3-canary, with a 100 ms caller after an await and a sleep 3 child:

timeout of the running sibling child

0 SIGTERM after 101 ms

Infinity exit 0 after 3001 ms

5000 exit 0 after 3002 ms

On this branch all three rows are exit 0 after about 3000 ms. So 0 now behaves as Infinity does, and docs/test/runtime-behavior.mdx gives the two as one setting. 1.3.14 did not signal a sync child in a concurrent group at all.

A rule that ends the child of the timed caller, and never the child of the test with no timeout, needs the identity of the caller. #44833 works on that for the callback that is on the stack. I leave this thread open for a maintainer to decide.

New measurements for this thread, on Linux x64. The caller has a 300 ms timeout and calls spawnSync on sleep 2 after an await. The other test of the group has timeout 0 and is still running.

where the call is 1.3.13 main (5c6d4e2) this PR this PR with #39440 and #44613

in the test body fail at 300 ms, child not signalled fail, SIGTERM at 301 ms pass at 2103 ms fail at 2599 ms, child not signalled

in a Promise.all arm fail fail, SIGTERM at 302 ms pass at 2051 ms fail at 2097 ms

in expect(() => execSync("sleep 2")).not.toThrow() fail fail pass at 2313 ms fail at 2378 ms

in the test body, beside a 5000 ms test fail pass at 2014 ms pass at 2064 ms fail at 2018 ms

The two right columns are debug builds.

With #39440 the verdict is the verdict of 1.3.13 in each row. The child is still not ended, so a child that never exits still blocks the run. This PR should land after #39440.

To end the child at the caller's own timeout, the runner has to know the caller. I built that from the await chain of the async function that is running. The code is on the branch robobun/3524c085/spawnsync-caller-from-await-chain. I do not propose it, for these reasons:

It names the caller for a direct await, an awaited helper and a Promise.race arm. It does not name a Promise.all arm, a .then() job, a timer callback, a .finally() hop or a call inside expect(() => ...). Those callers stay on the rule of this PR.

The result changes with the JIT. With the call written as child.bind(null)(), the test fails at 301 ms. With BUN_JSC_useJIT=0 it passes at 1203 ms.

A test with no timeout that returns a shared promise loses its child at the 100 ms timeout of the sibling that awaits the same promise. main and this PR let that child finish.

The other mechanism is an identity that the runner gives to each callback and that its continuations carry, as #38880 does with the async context. It has a cost for every test callback. I leave that choice to a maintainer.

… concurrent group `TestRunner::get_active_timeout()` gives the spawnSync wait loop the deadline at which the child is sent its kill signal and its pipes are closed. After an `await` the callback of the caller is no longer on the stack, and the function takes the latest deadline of the group. It compared with `Timespec::order`, which ranks `EPOCH` ("no timeout") below every deadline. The timeout of one test then ended the spawnSync child of a concurrent test that has no timeout. Compare with `Timespec::order_ignore_epoch`, so a running entry with no timeout gives no deadline. Skip a sequence that has not started: its `EPOCH` is "not set", and it would otherwise keep the child of a test that times out under `--max-concurrency`.

robobun · 2026-10-21T22:53:03Z

On the finding outside the diff (on_stack_entry, jest.rs:163): this is the behaviour on main, and this PR does not change it. The description lists it under "Not changed", with the last two rows of the table. #44833 clears that cell before the microtask drain.

The comment above the new test block now says "when no test callback is on the stack", because that is the case the changed loop answers.

claude

Code review found no new issues

No new issues were found in this update; 1 finding from earlier reviews is still open above.

Still open from earlier reviews (1):

🔴 src/runtime/test_runner/jest.rs:179 — A timed concurrent test that calls spawnSync after an await now keeps a hung child forever when any running sibling has…

If you have decided not to act on one of these findings, resolve its thread (a reply alone leaves it open) and the next review stops counting it. To review this commit again now, use Re-run on its "Claude Code Review" check.

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Comment thread test/js/bun/spawn/spawnSync.test.ts Resolved

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robobun force-pushed the robobun/31c3e4c6/spawnsync-concurrent-no-timeout branch from 4f99cb7 to 7c35783 Compare October 21, 2026 22:51

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ci: retrigger

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robobun mentioned this pull request Oct 23, 2026

bun test: time out a test or hook whose callback completes after its deadline #39440

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This was referenced Nov 8, 2026

bun test: Infinity means no timeout in test(), hooks, setDefaultTimeout() and jest.setTimeout() #48225

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bun test: decide timeouts when the timeout timer fires #48237

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bun test: rank "no timeout" as the latest deadline for spawnSync in a concurrent group - #46213

bun test: rank "no timeout" as the latest deadline for spawnSync in a concurrent group#46213
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timeout of the running sibling	child
`0`	`SIGTERM` after 101 ms
`Infinity`	exit 0 after 3001 ms
`5000`	exit 0 after 3002 ms

where the call is	1.3.13	main (`5c6d4e2`)	this PR	this PR with #39440 and #44613
in the test body	fail at 300 ms, child not signalled	fail, `SIGTERM` at 301 ms	pass at 2103 ms	fail at 2599 ms, child not signalled
in a `Promise.all` arm	fail	fail, `SIGTERM` at 302 ms	pass at 2051 ms	fail at 2097 ms
in `expect(() => execSync("sleep 2")).not.toThrow()`	fail	fail	pass at 2313 ms	fail at 2378 ms
in the test body, beside a 5000 ms test	fail	pass at 2014 ms	pass at 2064 ms	fail at 2018 ms

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