Test parallel execution of sleeping commands in JavaScript and Rust

[konard]

Summary

Issue #22 asks for a test that 2-3 commands with a sleep inside can be started in parallel and that all of them execute. This PR adds that coverage to both implementations the repository ships — JavaScript (js/tests/parallel-sleep.test.mjs) and Rust (rust/tests/parallel_sleep.rs) — and merges the current main into the branch, which is what moved the JavaScript test from tests/ to js/tests/.

What each test asserts

Wall-clock timing alone is a weak signal on a loaded CI machine, so every test checks three independent properties:

1. Every command finished — exit code 0, and the expected output where the command produces some.
2. The execution windows overlap — each command's start and end instants are recorded and every pair is asserted to have been in flight at the same moment. This is the property "parallel" actually describes, and it holds regardless of machine load.
3. The wall clock beat the sequential total — the batch must finish below 75% of the sum of the sleeps, which fails loudly if the commands were serialized.

Cases covered (identical in both languages)

Test	What it covers
2 sleeping commands	Two sleep 0.5 commands started together
3 sleeping commands	Three sleep 0.5 commands started together
Mixed durations	0.2s / 0.5s / 0.3s finish in the time of the longest one, not the sum
Real sleep processes	Bypasses the built-in sleep (JS: disableVirtualCommands(), Rust: /bin/sleep) so actual child processes are spawned
Output preserved	sh -c 'echo start; sleep; echo end' × 3 — each command keeps its own output intact
Environment isolated	Each parallel sh -c keeps its own shell variable

The sh -c and real-process cases are skipped on Windows (test.skipIf(isWindows) / #[cfg(unix)]); the first three run everywhere, because sleep is a built-in virtual command in both implementations.

Language parity

The reviewer asked for parity across languages and for main to be synced into the branch. Both are done:

• main is merged (d7a7c11), so the branch sits on the current js/ + rust/ monorepo layout.
• The Rust tests mirror the JavaScript ones case for case, with the same thresholds and the same three assertions.
• Release triggers for both toolchains are included: js/.changeset/issue-22-parallel-sleep-tests.md and rust/changelog.d/20260916_091500_parallel_sleep_tests.md.

Verification

bun test js/tests/parallel-sleep.test.mjs --timeout 10000   # 6 pass, 0 fail, 74 expect() calls
cargo test --all-features --test parallel_sleep             # 6 passed; 0 failed
cargo fmt --all -- --check                                  # clean
cargo clippy --all-targets --all-features -- -D warnings    # clean
bun run lint && bun run format:check                        # clean

Full bun test js/tests/ and cargo test --all-features suites were run locally as well.

Fixes #22

[konard]

We need to check that we have programming language parity of all features, so all languages are supported, and latest version of main branch synced here.

[konard]

🤖 AI Work Session Started

Starting automated work session at 2026-09-16T09:07:46.080Z

The PR has been converted to draft mode while work is in progress.

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Runtime: solve v2.29.0 · tool claude · model opus · task image konard/hive-mind-dind:2.29.0@sha256:11a236d03854cbaea86fdd7ca06265c912cf0b67d1fcc9b3eb60bd84c43ff749

[konard]

@konard both points are addressed:

Latest main synced — merged origin/main into this branch in d7a7c11. The branch predated the monorepo restructuring, so the test file moved from tests/parallel-sleep.test.mjs to js/tests/parallel-sleep.test.mjs as part of that merge. HEAD..origin/main is now empty and the PR is MERGEABLE.

Language parity — the test exists in both languages with the same six cases, thresholds and assertions:

• js/tests/parallel-sleep.test.mjs
• rust/tests/parallel_sleep.rs

Case	JS	Rust
2 sleeping commands at the same time	✅	✅
3 sleeping commands at the same time	✅	✅
mixed durations finish in the time of the longest	✅	✅
real sleep processes (built-in bypassed)	✅	✅
output kept when a command sleeps between writes	✅	✅
each parallel command keeps its own environment	✅	✅

Each case asserts three independent things rather than wall clock alone: every command succeeded with the expected output, every pair of execution windows overlaps (which is what "parallel" actually means), and the batch finished under 75% of the sequential total.

Two implementation notes: JS disables virtual commands via disableVirtualCommands() for the real-process case, while Rust calls /bin/sleep by absolute path instead — Rust test threads share process-global state, so toggling it would race other tests. Process-dependent cases are skipped on Windows (test.skipIf(isWindows) / #[cfg(unix)]).

Release triggers for both languages are included: js/.changeset/issue-22-parallel-sleep-tests.md and rust/changelog.d/20260916_091500_parallel_sleep_tests.md.

All five CI runs are green on 35b7589: JavaScript checks and release, Rust checks and release, Language parity check, Repository quality checks, Security.

[konard]

🤖 Solution Draft Log

This log file contains the complete execution trace of the AI solution draft process.

💰 Cost: $6.168250

📊 Context and tokens usage:

Claude Opus 5: (2 sub-sessions)

1. 116.9K / 1M (12%) input tokens, 35.2K / 128K (28%) output tokens
2. 37.2K / 1M (4%) input tokens, 3.5K / 128K (3%) output tokens

Total: (2.3K new + 130.5K cache writes + 7.4M cache reads) input tokens, 46.8K output tokens, $6.168250 cost

🤖 Models used:

• Tool: Anthropic Claude Code
• Requested: opus (claude-opus-5)
• Thinking level: high (~23999 tokens)
• Model: Claude Opus 5 (claude-opus-5)

📎 Log file uploaded as Gist (2573KB)

• View complete solution draft log

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[konard]

🎉 Auto-merged

This pull request has been automatically merged by hive-mind.

• All CI checks have passed

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Auto-merged by hive-mind with --auto-merge flag