Automated verification results

Captured 2026-05-20 during the AbortController refactor.

1. Listener-accumulation reproducer

Direct simulation of the listener-accumulation pattern observed in long sessions (1500+ abort listeners on a single AbortSignal). The script lives at listener-accumulation-repro.mjs.


$ node docs/verification/abort-controller-refactor/listener-accumulation-repro.mjs
Simulating 2000 rounds for each pattern.

OLD pattern listener count on long-lived parent: 2000
NEW pattern listener count on long-lived parent: 0
PASS: OLD pattern accumulated >1500 listeners (reproduces the bug).
PASS: NEW pattern kept listener count at 0 — the helper prevents accumulation.

This is a self-contained proof: the OLD pattern (raw addEventListener without {once:true} or reverse cleanup) accumulates 2000 listeners over 2000 rounds — well past the 1500 threshold the user observed. The NEW pattern (createChildAbortController from packages/core/src/utils/abortController.ts) keeps the parent listener count at 0 across 2000 rounds because each child’s reverse-cleanup listener removes the parent listener when the child aborts.

2. Migration scope (intentional)

Only the agent-runtime parent→child chain that actually accumulates listeners on a long-lived parent signal is migrated to the helper:

packages/core/src/agents/runtime/agent-interactive.ts (master + per-message round)
packages/core/src/agents/runtime/agent-core.ts (per-iteration round + waitForExternalInputs + processFunctionCalls try/finally)
packages/core/src/agents/runtime/agent-headless.ts (external → execution)
packages/core/src/hooks/promptHookRunner.ts (had a real cleanup leak: manual addEventListener without {once:true} and never removed)

Plus three {once:true}-only fixes (no helper switch, just defensive correctness):

packages/core/src/hooks/hookRunner.ts
packages/core/src/hooks/functionHookRunner.ts
packages/core/src/confirmation-bus/message-bus.ts

Independent short-lived controllers (per-shell-command in tools/shell.ts, per-monitor in tools/monitor.ts, per-arena-session in agents/arena/ArenaManager.ts, per-recall in core/client.ts, per-fetch in utils/fetch.ts, per-dream / per-title / per-judge / per-resume, etc.) stay on raw new AbortController() — they’re GC’d at end of use and do not accumulate on a long-lived parent.

See migration-completeness.txt for the actual grep + rationale.

3. Affected test suites

All 71 affected test files / 2085 tests pass (3 skipped — 1 is the GC test that requires --expose-gc, 2 are pre-existing skips in the headless suite).


 Test Files  71 passed (71)
      Tests  2085 passed | 3 skipped (2088)
   Duration  16.71s

Coverage:

packages/core/src/utils/abortController.test.ts — 26 tests: factory cap (default + custom), child propagation, reverse cleanup, fast path, undefined parent, custom-maxListeners passthrough, combineAbortSignals semantics (incl. cleanup-cancels-timeout, timeout-cleans-input-listeners, timeoutMs <= 0 boundary, mid-iteration defensive check), GC safety (best-effort).
packages/cli/src/utils/warningHandler.test.ts — 13 tests: idempotency, AbortSignal suppression (including [AbortSignal{...}] shape), generic EventTarget NOT suppressed, debug-mode passthrough, fan-out to prior listeners, spawned-child end-to-end stderr integration.
packages/core/src/hooks/httpHookRunner.test.ts — covers the migrated combineAbortSignals consumer (the deprecated createCombinedAbortSignal shim plus its test file were removed once the lone caller migrated).
packages/core/src/agents/runtime/{agent-core,agent-interactive,agent-headless,agent-context,agent-statistics}.test.ts — 102 tests covering the high-impact migrated files.
packages/core/src/core/openaiContentGenerator/** — 280+ tests including the pipeline that lost the raiseAbortListenerCap band-aid.
packages/core/src/followup/** — 100+ tests including the migrated speculation controller.
packages/core/src/tools/agent/**, packages/core/src/tools/shell.test.ts, packages/core/src/services/**, packages/core/src/hooks/**, packages/core/src/confirmation-bus/** — all migrated tool/hook/service files.

4. TypeScript strict-mode typecheck


$ node_modules/.bin/tsc -p packages/core/tsconfig.json --noEmit
(no output, exit 0)
 
$ node_modules/.bin/tsc -p packages/cli/tsconfig.json --noEmit
(no output, exit 0)

5. Prettier formatting


$ node_modules/.bin/prettier --check packages/core/src/agents/runtime/agent-core.ts \
    packages/core/src/agents/runtime/agent-headless.ts \
    packages/cli/src/utils/warningHandler.ts \
    packages/cli/src/utils/warningHandler.test.ts \
    packages/core/src/utils/abortController.ts \
    packages/core/src/utils/abortController.test.ts
Checking formatting...
All matched files use Prettier code style!

6. Build + binary smoke test


$ npm run build:packages
(succeeds for all 5 workspace packages)
 
$ NODE_OPTIONS=--trace-warnings node packages/cli/dist/index.js --version
0.15.11
EXIT=0
 
$ node packages/cli/dist/index.js --help
Usage: qwen [options] [command]
...

No warnings emitted during boot with --trace-warnings.

7. Codex independent review

Two full passes via the codex:codex-rescue agent (independent context each time). First pass surfaced 3 issues — all addressed in subsequent commits:

Throw between controller creation and explicit abort leaks listener in agent-core.ts’s per-iteration body and agent-headless.ts’s pre-try-block setup. Fixed by wrapping each in try { ... } finally { abortController.abort(); }.
Warning suppressor regex EventTarget too broad. Tightened to match only AbortSignal (any shape Node ≥20 produces).
process.removeAllListeners('warning') strips third-party listeners. Removed — rely on Node’s “no listeners → default printer fires” semantics so adding our handler implicitly disables the default print path while keeping third-party telemetry listeners intact.

Second pass confirmed all fixes correct, no further blockers.

What remains for interactive verification

The scenarios in README.md numbered 00–09 require a real interactive session against the model API (long mixed-tool conversations, Ctrl-C mid-stream, subagent cancellation, heap snapshots). Those are documented for human execution and the transcripts should be attached to the PR body when run.