test(integration): cover cold-start module tracing

[joeyzhao2018]

What does this PR do?

Add seven local RIE integration cases for the existing cold-start tracing feature, covering npm redirect and layer handler entrypoints:

• Enabled tracing: one initialization/load span and the known module-load spans.
• Skip-library filtering, including the skipped module's subtree.
• Minimum-duration filtering.
• Disabled tracing.
• Suppression for provisioned concurrency and managed instances.

A shared handler loads real CommonJS modules under /var/task, /opt, and /var/runtime during initialization, then lazily loads another module on invocation two. Each case invokes the same environment nine times.

The raw-log checker verifies span cardinality across all exports, trace/parent relationships, path classification, initialization timing, warm-load parenting, and absence of stale replay. Module-load markers prove that suppression cases really execute the fixture modules. The managed fixture explicitly uses one worker so warm-cache assertions are meaningful.

Motivation

Existing cases disable cold-start tracing, so they do not protect this behavior during the Node.js migration. The new positive cases already exposed an existing dd-trace module-load bookkeeping bug.

These cases use structural assertions rather than new log goldens: real load durations change which non-fixture modules exceed the tracing threshold. Known fixture modules use a 50ms blocking wait against a 10ms threshold, avoiding machine-speed-dependent expectations about the entire tree.

Existing return-value snapshots and runtime-tag checks still apply. Existing log goldens, normalization, production code, and dependency pins are unchanged.

Testing Guidelines

• node --test integration_tests_local/check-*.test.js: 41 passing, including 32 new checker tests. Negative tests cover missing capture, duplicates, incorrect parenting/classification, orphaned/cyclic trees, filtering violations, and stale replay.
• bash -n integration_tests_local/run.sh: pass.
• Prettier checks for new JS files: pass.
• npm run lint and git diff --check: pass.
• Node18/20 arm64, unmodified dd-trace 5.126.0: all seven cold-start cases pass, nine invocations each.
• Node22/24/26 arm64, dd-trace 6.15.0 with only the fixed ritm.js mounted read-only: all seven cases pass, nine invocations each. This is isolated-fix validation, not a passing result for the unmodified release or the full migration candidate.
• Existing npm/layer ESM cases match unchanged goldens on Node22/24/26 with that overlay; the existing CJS case also matches on Node22.

The workflow runs the checker tests and new cases in the existing Node18/20/22/24/26 × amd64/arm64 matrix. Local validation above is arm64 only; this is emulator coverage, not deployed AWS certification.

Additional Notes

Draft / release dependency: DataDog/dd-trace-js#10535

The positive cases fail with the current v6 tracer pin: a caught module-loading error leaves the cold-start capture stack unfinished, so application module spans are missing. CI intentionally uses the normal released dependencies—no overlay, skipped assertions, or expected-failure exemption has been added. The current v6 integration jobs are therefore expected to remain red until the upstream fix is released and pinned here.

Before marking this ready:

• Merge and release the dd-trace fix.
• Update the affected tracer dependency pin/lockfile to that release.
• Run the full runtime/architecture matrix without an overlay; keep all assertions strict.

No golden capture or recapture is needed. Structural failures save raw logs under /tmp/l2-raw-*.log.

Types of Changes

• Bug fix
• New feature
• Breaking change
• Misc (integration tests and documentation)

Check all that apply

• This PR's description is comprehensive
• This PR contains breaking changes that are documented in the description
• This PR introduces new APIs or parameters that are documented and unlikely to change in the foreseeable future
• This PR impacts documentation, and it has been updated (or a ticket has been logged)
• This PR's changes are covered by the automated tests
• This PR collects user input/sensitive content into Datadog
• This PR passes the integration tests (blocked on the released tracer fix as described above)

[datadog-datadog-prod-us1]

✨ Unblock PR with BitsAI

❌ Errors

Your PR has failed checks. Please review the issues below and take necessary action before merging.

🚦 6 Pipeline jobs failed

local integration tests | nodejs22.x (amd64) — 🔧 Needs a code fix, caused by this PR

View more details · View in GitHub Actions

local integration tests | nodejs22.x (arm64) — 🔧 Needs a code fix, caused by this PR

View more details · View in GitHub Actions

local integration tests | nodejs24.x (amd64) — 🔧 Needs a code fix, caused by this PR

View more details · View in GitHub Actions

View all 6 failed jobs.

Useful? React with 👍 / 👎

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: 0f389cb | Docs | View more details | Give us feedback!}