--- name: openclaw-test-heap-leaks description: Investigate `pnpm test` memory growth, Vitest worker OOMs, and suspicious RSS increases in OpenClaw using the `scripts/test-parallel.mjs` heap snapshot tooling. Use when Codex needs to reproduce test-lane memory growth, collect repeated `.heapsnapshot` files, compare snapshots from the same worker PID, triage likely transformed-module retention versus likely runtime leaks, and fix or reduce the impact by patching cleanup logic or isolating hotspot tests. --- # OpenClaw Test Heap Leaks Use this skill for test-memory investigations. Do not guess from RSS alone when heap snapshots are available. Treat snapshot-name deltas as triage evidence, not proof, until retainers or dominators support the call. ## Workflow 1. Reproduce the failing shape first. - Match the real entrypoint if possible. For Linux CI-style unit failures, start with: - `pnpm canvas:a2ui:bundle && OPENCLAW_TEST_MEMORY_TRACE=1 OPENCLAW_TEST_HEAPSNAPSHOT_INTERVAL_MS=60000 OPENCLAW_TEST_HEAPSNAPSHOT_DIR=.tmp/heapsnap OPENCLAW_TEST_WORKERS=2 OPENCLAW_TEST_MAX_OLD_SPACE_SIZE_MB=6144 pnpm test` - Keep `OPENCLAW_TEST_MEMORY_TRACE=1` enabled so the wrapper prints per-file RSS summaries alongside the snapshots. - If the report is about a specific shard or worker budget, preserve that shape. - Before you analyze snapshots, identify the real lane names from `[test-parallel] start ...` lines or `pnpm test --plan`. Do not assume a single `unit-fast` lane; local plans often split into `unit-fast-batch-*`. 2. Wait for repeated snapshots before concluding anything. - Take at least two intervals from the same lane. - Compare snapshots from the same PID inside the real lane directory such as `.tmp/heapsnap/unit-fast-batch-2/`. - Use `.agents/skills/openclaw-test-heap-leaks/scripts/heapsnapshot-delta.mjs` to compare either two files directly or the earliest/latest pair per PID in one lane directory. - If the helper suggests transformed-module retention, confirm the top entries in DevTools retainers/dominators before calling it solved. 3. Classify the growth before choosing a fix. - If growth is dominated by Vite/Vitest transformed source strings, `Module`, `system / Context`, bytecode, descriptor arrays, or property maps, treat it as likely retained module graph growth in long-lived workers. - If growth is dominated by app objects, caches, buffers, server handles, timers, mock state, sqlite state, or similar runtime objects, treat it as a likely cleanup or lifecycle leak. - If the names are ambiguous, stop short of a confident label and inspect retainers/dominators in DevTools for the top deltas. 4. Fix the right layer. - For likely retained transformed-module growth in shared workers: - Prefer timing and hotspot-driven scheduling fixes first. Check whether the file is already represented in `test/fixtures/test-timings.unit.json` and whether `scripts/test-update-memory-hotspots.mjs` should refresh the measured hotspot manifest before hand-editing behavior overrides. - Move hotspot files out of the real shared lane by updating `test/fixtures/test-parallel.behavior.json` only when timing-driven peeling is insufficient. - Prefer `singletonIsolated` for files that are safe alone but inflate shared worker heaps. - If the file should already have been peeled out by timings but is absent from `test/fixtures/test-timings.unit.json`, call that out explicitly. Missing timings are a scheduling blind spot. - For real leaks: - Patch the implicated test or runtime cleanup path. - Look for missing `afterEach`/`afterAll`, module-reset gaps, retained global state, unreleased DB handles, or listeners/timers that survive the file. 5. Verify with the most direct proof. - Re-run the targeted lane or file with heap snapshots enabled if the suite still finishes in reasonable time. - If snapshot overhead pushes tests over Vitest timeouts, fall back to the same lane without snapshots and confirm the RSS trend or OOM is reduced. - For wrapper-only changes, at minimum verify the expected lanes start and the snapshot files are written. ## Heuristics - Do not call everything a leak. In this repo, large `unit-fast` or `unit-fast-batch-*` growth can be a worker-lifetime problem rather than an application object leak. - `scripts/test-parallel.mjs` and `scripts/test-parallel-memory.mjs` are the primary control points for wrapper diagnostics. - The lane names printed by `[test-parallel] start ...` and `[test-parallel][mem] summary ...` tell you where to focus. - When one or two files account for most of the delta and they are missing from timings, reducing impact by isolating them is usually the first pragmatic fix. - When the same retained object families grow across multiple intervals in the same worker PID, trust the snapshots over intuition, then confirm ambiguous calls with retainer evidence. ## Snapshot Comparison - Direct comparison: - `node .agents/skills/openclaw-test-heap-leaks/scripts/heapsnapshot-delta.mjs before.heapsnapshot after.heapsnapshot` - Auto-select earliest/latest snapshots per PID within one lane: - `node .agents/skills/openclaw-test-heap-leaks/scripts/heapsnapshot-delta.mjs --lane-dir .tmp/heapsnap/unit-fast-batch-2` - Useful flags: - `--top 40` - `--min-kb 32` - `--pid 16133` Read the top positive deltas first. Large positive growth in module-transform artifacts suggests lane isolation; large positive growth in runtime objects suggests a real leak. If the names alone do not settle it, open the same snapshot pair in DevTools and inspect retainers/dominators for the top rows before declaring root cause. ## Output Expectations When using this skill, report: - The exact reproduce command. - Which lane and PID were compared. - The dominant retained object families from the snapshot delta. - Whether the issue is a likely real leak or likely shared-worker retained module growth, plus whether retainers/dominators confirmed it. - The concrete fix or impact-reduction patch. - What you verified, and what snapshot overhead prevented you from verifying.