otel-thread-ctx: address review feedback from #347

[szegedi]

Follow-up to review comments on #347 that landed after merge. Four independent, non-API-surface fixes.

Changes

• Accept optional third attributes arg in ThreadContext constructor. The TS ThreadContextCtor.new type declares attributes optional, but the C++ side hard-errored on args.Length() != 3. Loosen to < 2 || > 3; EncodeAttrs already handled undefined/null correctly. (review comment)

• Fold cleanup_registered into undefined_addr. Uses the field's zero / non-zero state as the "already-registered" flag: it starts at zero (thread-local zero-init), ResetDiscoveryStruct clears it back to zero (so a re-init on the same thread would re-register), and any real V8 undefined-singleton address is non-zero. Removes the separate thread_local bool.

• Coerce attribute values to strings in a pre-pass in EncodeAttrs, before touching the output buffer. Value->ToString may execute user JS (custom toString) which could re-enter into the same ThreadContext via appendAttributes and interleave with our writes. Separating the coerce phase from the encode phase keeps the encode phase re-entrancy-free.

• Make the "enterWithContext attaches the record to the current async scope" test callback async and await tcRun(...). Previously the callback returned a promise via void tcRun(...) and the promise's inner .then assertion could fire as an unhandled rejection instead of a proper test failure.

Test plan

• npm run test:docker — 150/150 passing (unchanged)
• Would also be good to add an explicit re-entrancy test (attribute value with a side-effecting toString that calls appendAttributes), but the two-phase encode already prevents interleaving; leaving that as a possible follow-up.

Related

These same concerns likely apply to the upstream vendored copy in polarsignals/custom-labels (PR #17). I'll port them there next.

[github-actions]

Overall package size

Self size: 2.4 MB
Deduped: 3.1 MB
No deduping: 3.1 MB

Dependency sizes

| name | version | self size | total size | |------|---------|-----------|------------| | pprof-format | 2.2.2 | 500.53 kB | 500.53 kB | | source-map | 0.7.6 | 185.63 kB | 185.63 kB | | node-gyp-build | 4.8.4 | 13.86 kB | 13.86 kB |

_{🤖 This report was automatically generated by heaviest-objects-in-the-universe}