test(onboard): preserve runtime fixture isolation

[jyaunches]

Summary

cloneSession from #8546 returned the caller-owned session when normalization rejected its serialized copy. This follow-up keeps the serialized copy as the fallback so fixture mutations cannot alter caller-owned top-level or nested state.

Changes

• Use the serialized session copy as both the normalization input and fallback.
• Add a regression test with an invalid session version. The test proves that normalization rejection still returns independent top-level and nested state.
• Record the detection gap: test(onboard): add an in-memory machine runtime fixture #8546 exercised valid sessions only, so normalization always succeeded and did not reach the aliasing fallback.
• Close the complete test(onboard): add an in-memory machine runtime fixture #8546 review set. The CodeRabbit isolation finding is fixed. The docstring-coverage warning is advisory because local exports have JSDoc and re-export documentation remains source-owned. The PR Review Advisor reported no findings and failed only because its model request returned HTTP 429.
• Inspect the equivalent local clone helpers in test/helpers/onboard-final-flow-phases.ts, src/lib/onboard/resume-machine-repair.test.ts, src/lib/onboard/runtime-boundary-step-result.test.ts, and src/lib/onboard/runtime-boundary.test.ts. Their callers construct valid sessions and do not expose test(onboard): add an in-memory machine runtime fixture #8546's independent-mutation contract, so this PR does not change them.

Type of Change

• Code change (feature, bug fix, or refactor)
• Code change with doc updates
• Doc only (prose changes, no code sample modifications)
• Doc only (includes code sample changes)

Quality Gates

• Tests added or updated for changed behavior
• Existing tests cover changed behavior — justification:
• Tests not applicable — justification:
• Docs updated for user-facing behavior changes
• Docs not applicable — justification: this changes an internal test fixture and its regression coverage. No CLI, configuration, output, workflow, default, API, policy schema, or supported user behavior changes.
• Sensitive paths changed (security, policy, credentials, preflight, onboarding, inference, runner, sandbox, or messaging)
• Sensitive-path review completed or maintainer-approved waiver recorded — reviewer/approval link/justification:
• Non-success, skipped, or missing CI check accepted by maintainer — check name, approval link, and follow-up issue:

Documentation Writer Review

• Documentation writer subagent reviewed the completed changes
• Result: no-docs-needed
• Evidence: the completed diff changes only test/helpers/onboard-machine-runtime-fixture.ts and test/helpers/onboard-machine-runtime-fixture.test.ts. The reviewer found no user-visible behavior or documentation impact and approved the test title and existing JSDoc ownership.
• Agent: Codex Desktop

DGX Station Hardware Evidence

• Tested on DGX Station
• Tested commit: Not applicable; scripts/prepare-dgx-station-host.sh does not change.
• Station profile/scenario: Not applicable.
• Result: Not applicable.
• Supporting evidence: Not applicable.

Verification

• PR description includes a Signed-off-by: line and every commit appears as Verified in GitHub
• Normal pre-commit, commit-msg, and pre-push hooks passed, or npm run validate:pr passed after refreshing origin/main when hooks were skipped or unavailable
• Targeted behavior tests pass for the current change set, or tests are marked not applicable above — command/result or justification: npx vitest run --project integration test/helpers/onboard-machine-runtime-fixture.test.ts passed 1/1; the eight test(onboard): add an in-memory machine runtime fixture #8546 CLI suites passed 63/63; npm run typecheck:cli passed; npm run test:projects:check reported exact membership for 2,231 candidate files across seven projects.
• Applicable broad gate passed — npm test for broad runtime/test-harness changes; npm run check for repo-wide validation/coverage changes — command/result: not applicable. The change updates one fixture fallback and adds one focused test; targeted validation covers every test(onboard): add an in-memory machine runtime fixture #8546 consumer.
• Quality Gates section completed with required justifications or waivers
• No secrets, API keys, or credentials committed
• npm run docs builds without warnings (doc changes only)
• Doc pages follow the style guide (doc changes only)
• New doc pages include SPDX header and frontmatter (new pages only)

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Signed-off-by: Julie Yaunches jyaunches@nvidia.com

Summary by CodeRabbit

• Bug Fixes

  • Improved session cloning so copied sessions remain independent even when normalization fails.
  • Prevented changes to a cloned session from affecting the original session.

• Tests

  • Added regression coverage for cloning invalid-version sessions and nested steps.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Enterprise

Run ID: c542674b-8ed9-4e1f-a483-35e7cc2cc2e1

📥 Commits

Reviewing files that changed from the base of the PR and between 0da798a and 64c19cf.

📒 Files selected for processing (2)

• test/helpers/onboard-machine-runtime-fixture.test.ts
• test/helpers/onboard-machine-runtime-fixture.ts

---

📝 Walkthrough

Walkthrough

cloneSession now preserves its deep copy when normalization fails. A regression test verifies that mutating the clone does not change the original session or its nested steps.

Changes

Clone session isolation

Layer / File(s)	Summary
Clone fallback and regression coverage test/helpers/onboard-machine-runtime-fixture.ts, test/helpers/onboard-machine-runtime-fixture.test.ts	cloneSession returns the deep-copied session when normalization returns no value. The regression test verifies isolation of the session and nested steps after mutation.

Estimated code review effort: 2 (Simple) | ~10 minutes

Possibly related PRs

• NVIDIA/NemoClaw#8546: Directly modifies and tests the shared cloneSession helper addressed by this change.

Suggested reviewers: aasthajh

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly identifies the onboard runtime fixture isolation fix and matches the main change.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch codex/fix-onboard-runtime-clone

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[github-code-quality]

Code Coverage Overview

Languages: TypeScript

TypeScript / code-coverage/plugin

The overall coverage in commit 64c19cf in the codex/fix-onboard-ru... branch remains at 96%, unchanged from commit 0da798a in the main branch.

[github-actions]

PR Review Advisor — No blocking findings reported

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Findings: 0 blockers · 0 warnings · 0 suggestions

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• GPT-5.6 Terra (primary): Completed · high confidence · 0 blockers · 0 warnings · 0 suggestions
• Nemotron 3 Ultra (second opinion): Completed · high confidence · 0 blockers · 0 warnings · 0 suggestions
• Model comparison: normalized findings match; normalized terminology decisions match; normalized E2E selections match; severity counts match.

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