[oyi77]

Adds performance.mark/measure to assembleStreamingPipeline in streamingPipeline.ts and request-body-size tracking in createSSEStream in stream.ts.

Both use Node.js 22 global performance API. Visible via performance.getEntriesByType("mark")/getEntriesByType("measure").

[gemini-code-assist]

Code Review

This pull request adds performance instrumentation and request body size tracking using Node's performance API in the streaming pipeline and SSE stream utilities. The review feedback highlights critical issues: potential memory leaks from failing to clear performance marks and measures, a performance bottleneck on the hot path due to inefficient byte-length calculation of the request body, and a style guide violation for not including tests with production code changes.

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[gemini-code-assist]

Using performance.mark and performance.measure without clearing them will cause performance entries to accumulate indefinitely in Node's global performance timeline, leading to a memory leak in a long-running production server.\n\nTo prevent this, clear the marks and measures immediately after creation. Registered PerformanceObserver instances will still receive the events.

  performance.mark(PIPELINE_END);
  performance.measure(PIPELINE_MEASURE, PIPELINE_START, PIPELINE_END);
  performance.clearMarks(PIPELINE_START);
  performance.clearMarks(PIPELINE_END);
  performance.clearMeasures(PIPELINE_MEASURE);

[diegosouzapw]

Looked into this closely (babysit pass) and I don't think this is actually an unbounded leak, so I left this file unchanged — flagging for a human call rather than resolving.

assembleStreamingPipeline clears PIPELINE_START/PIPELINE_END/PIPELINE_MEASURE at the start of every call, before creating this call's marks. Since performance.mark() with a name that already exists always adds a new entry, that clear-before-create keeps at most one lingering set (the previous call's) at any time — bounded to O(1) per fixed name, not O(n) growth. The function itself is fully synchronous (no await), so two calls can't interleave and clobber each other's still-being-read marks either.

This differs from the open-sse/utils/stream.ts "omni-request-body-size" mark fixed in 8b8cae2, which had no clearing at all and genuinely accumulated one entry per stream created — that one I fixed.

Applying the same "clear immediately after" pattern here would also break 3 existing tests in tests/unit/chatcore-streaming-pipeline.test.ts that assert the marks/measure are still readable via getEntriesByName() right after the call returns (a deliberate design choice for downstream buffer-based inspection). Happy to change it if the owner prefers immediate-clear-everywhere for consistency, but wanted to surface the tradeoff rather than silently rewrite the tests to make a non-bug go away.

[oyi77]

Reviewed via PR batch review. All gemini-code-assist feedback noted — no human review blocking items present. PR scope is narrow and verified.

[oyi77]

Updated PR — all bot review concerns addressed:

1. Memory leak ✅ — / called before each mark creation (commit 3d246072a)
2. Byte-length inefficiency ✅ — replaced allocation with native (commit 3d246072a)
3. Missing tests ✅ — added 3 tests covering mark/measure creation, re-entry clearing, and positive duration (commit 04ddac068)

Branch rebased on release/v3.8.49 and force-pushed.

[diegosouzapw]

Nice, thorough tests on the pipeline-assembly marks. Two things worth a look before merge: (1) the request-body-size metric does Buffer.byteLength(JSON.stringify(body), 'utf8') on every single stream — that's a brand-new full re-serialization of the parsed body on the hot path, which could get expensive for large multi-modal (base64 image) payloads; is there an already-available byte count (e.g. the original Content-Length header, or a raw-body string captured earlier in the pipeline) you could reuse instead of re-stringifying? (2) Since assembleStreamingPipeline uses fixed global mark/measure names cleared on every call, any consumer that polls performance.getEntriesByName (rather than subscribing via PerformanceObserver) will only ever see the most recent call's entry under concurrent requests — worth a one-line comment noting that's by design, if it is.

[diegosouzapw]

Babysit summary

Result: green. Fast Quality Gates (the only red) now passes, along with all 4 unit shards, Vitest, ESLint, Docs Gates, Merge integrity, and semgrep. dast-smoke was still running at time of writing.

Fixes

#	Commit	What	Why
1	08e427ad7	Restore config/quality/file-size-baseline.json	This was the whole red. The earlier rebaseline commit (9efdd636d) accidentally replaced the entire 405-line baseline with the literal string test content, so JSON.parse() threw in check-file-size.mjs on every run (SyntaxError: Unexpected token 'e', "test content" is not valid JSON). Restored the full baseline from origin/release/v3.8.49 and re-applied the intended open-sse/utils/stream.ts bump.
2	8b8cae25c	Clear the omni-request-body-size performance mark + add regression tests	Addresses the review-flagged leak in open-sse/utils/stream.ts (see thread reply). New file tests/unit/stream-request-body-size-mark-7045.test.ts (3 tests).
3	b914b4c3c	Baseline off-by-one correction	check-file-size.mjs counts via split("\n").length = wc -l + 1 for a trailing-newline file. Baselined 2814 (the script's own metric), not 2813.

Net baseline change vs the release tip is one entry: open-sse/utils/stream.ts 2796 → 2814 (+18), documented with a _rebaseline_2026_07_15_7045_perf_instrumentation justification. No other frozen value touched; no gate, workflow, or suppression file edited; no assertion weakened.

Review threads

• ✅ Resolved — stream.ts memory leak (high): genuine, fixed in 8b8cae25c. The mark had no clearing at all and accumulated one entry per stream created.
• ✅ Resolved — "add tests" (medium): already satisfied by 7912f34f9 (10 tests in chatcore-streaming-pipeline.test.ts); I added 3 more for the previously-uncovered request-body-size metric.
• ⚠️ Left open for your call — streamingPipeline.ts memory leak (high): I believe this one is a false positive. The function clears its 3 fixed-name entries at the start of every call, so at most one stale set lingers — O(1), not unbounded. Applying the suggested "clear immediately after" would also break 3 existing tests that deliberately assert the marks are readable after the call returns. I did not want to rewrite passing tests to satisfy a non-bug, so I flagged it instead. Full reasoning in the thread.

Verified locally (worktree, before each push)

check:file-size · check:complexity-ratchets (complexity 2056 = baseline, cognitive 890 = baseline — both unchanged) · typecheck:core · check:test-discovery · check:mutation-test-coverage · check:provider-consistency · check:fetch-targets · check:deps · check:error-helper · check:migration-numbering · check:public-creds · check:db-rules · check:known-symbols · check:route-guard-membership · check:test-runner-api · check:any-budget:t11 · check:build-scope · check:pack-policy · eslint on changed files · chatcore-streaming-pipeline.test.ts (10/10) · stream-request-body-size-mark-7045.test.ts (3/3)

All fix commits preserve @oyi77's authorship. Not merging — ready for human review.

[diegosouzapw]

Babysit follow-up — dast-smoke (advisory) triage

Correcting my note above ("still running"): dast-smoke finished as cancelled — a 30min runner-level timeout that hung in the Build CLI bundle step, never reaching Schemathesis or promptfoo. gh pr checks renders cancelled as fail, which is misleading here.

It is not caused by this PR. The per-SHA history isolates it cleanly:

head SHA	contains	dast-smoke
64040c9d9	original PR code	✅ success (9m19s)
08e427ad7	+ baseline restore	✅ success (8m52s)
8b8cae25c	+ all stream.ts code changes + new test	✅ success (9m08s)
b914b4c3c	+ 2813→2814 in a quality-gate JSON	⚠️ cancelled (30m, hung in build)

Every line of production code in this PR passed dast-smoke on 8b8cae25c. The only delta in the cancelled run is two digits in config/quality/file-size-baseline.json — a gate metric that is not part of the CLI build graph and cannot affect a Turbopack/esbuild bundle. The workflow's own comment documents this exact failure mode ("Build CLI bundle alone varies 6-11min on GitHub-hosted runners (3 consecutive timeouts observed on 2026-07-14)").

For the record dast-smoke is continue-on-error: true (advisory, not blocking) on this ref, so it does not gate the merge either way. I re-triggered the job to get a clean signal rather than leave a red-looking check on the PR.

All blocking checks are green — Fast Quality Gates (the original red), 4/4 unit shards, Vitest, ESLint, Docs Gates, Merge integrity, Change Classification, semgrep ×2.

[oyi77]

Re: the ⚠️ streamingPipeline.ts memory leak thread (babysit summary) — confirmed false positive. The 3 fixed-name entries are cleared at every call start (O(1), not unbounded). Closing this thread — all other items resolved, branch ready for merge.

[diegosouzapw]

Thanks @oyi77! Merged into release/v3.8.49 after batch validation in the local merge-train (combined-tree static gates + tests + vitest all green). Where the file-size ratchet complained we compacted/extracted inside your branch keeping you as author.