ci(platform): shard macOS and WSL Vitest suites

[cjagwani]

Summary

The main platform watch now runs the full Vitest suite in four independent macOS shards and four independent WSL shards. This shortens platform feedback while preserving all tests, existing platform budgets, and the root-only WSL contracts.

Related Issue

Part of #7451

Changes

• Add four-way macOS and WSL matrices with fail-fast: false.
• Keep 30-minute macOS and 90-minute WSL shard budgets and run the root-required WSL contracts only on shard 1.
• Extend the workflow contract test and internal E2E operator documentation for the sharded execution shape.

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 internal CI scheduling only; the two internal E2E operator READMEs were updated, while supported platforms and user workflows are unchanged.
• 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: exact-head nine-category review found no findings. The diff adds only static matrix values, shard arguments, a shard-1 condition, contract assertions, and internal documentation; permissions, actions, dependencies, secrets, authentication, logging, cryptography, runner labels, and root-contract commands are unchanged.
• 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: docs-updated
• Evidence: test/e2e/README.md and test/e2e/docs/README.md accurately document four shards per platform, fail-fast: false, 30/90-minute per-shard budgets, and shard-1-only root WSL contracts. No Fern docs or changelog update is needed for this internal CI behavior.
• Agent: Codex Desktop

DGX Station Hardware Evidence

• Tested on DGX Station
• Tested commit:
• Station profile/scenario:
• Result:
• Supporting evidence:

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 check:diff passed when hooks were skipped or unavailable
• Targeted behavior tests pass for the current change set, or tests are marked not applicable above — npx vitest run --project integration test/platform-vitest-main-workflow.test.ts passed 2/2; npm run test:changed exited 0 with no additional fast-lane tests selected.
• Applicable broad gate passed — npm test for broad runtime/test-harness changes; npm run check for repo-wide validation/coverage changes — not run; this is a focused workflow-contract and internal-docs change.
• 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: Charan Jagwani cjagwani@nvidia.com

Summary by CodeRabbit

• Performance

  • Vitest checks now run in four parallel shards on macOS and WSL, improving CI execution efficiency.
  • WSL root-required contract checks run once per workflow instead of once per shard.

• Documentation

  • Added guidance describing the sharded platform test workflow, timing limits, and WSL-specific checks.

• Tests

  • Updated workflow validation to verify sharding, timeouts, and conditional root-required test execution.

[coderabbitai]

📝 Walkthrough

Walkthrough

macOS and WSL Vitest CI jobs now run in four parallel shards. WSL root-required contracts execute only on shard 1, with workflow tests and E2E documentation updated accordingly.

Changes

Platform Vitest CI

Layer / File(s)	Summary
Workflow shard orchestration .github/workflows/platform-vitest-main.yaml	macOS and WSL jobs run four non-failing matrix shards, with shard-aware Vitest commands and WSL root-required contracts gated to shard 1.
Workflow validation and documentation test/platform-vitest-main-workflow.test.ts, test/e2e/README.md, test/e2e/docs/README.md	Assertions and documentation describe the four-shard execution, time budgets, and shard-1-only WSL root contracts.

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

Sequence Diagram(s)

sequenceDiagram
  participant GitHubActions
  participant Vitest
  participant RootContracts
  GitHubActions->>Vitest: Run matrix shard 1/4 through 4/4
  Vitest-->>GitHubActions: Return shard results
  GitHubActions->>RootContracts: Run root-required contracts when shard is 1

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Possibly related issues

• ci: split E2E feedback-loop work into focused PRs #7451 — Covers the platform sharding work implemented for macOS and WSL Vitest suites.

Suggested labels: area: ci, github_actions

Suggested reviewers: cv, ericksoa, apurvvkumaria

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
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.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely describes the main change: sharding the macOS and WSL Vitest suites in CI.

✨ 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/7451-platform-vitest-shards

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_{Comment @coderabbitai help to get the list of available commands.}

[github-code-quality]

Code Coverage Overview

Languages: TypeScript

TypeScript / code-coverage/plugin

The overall coverage in commit 049c956 in the codex/7451-platform-... branch remains at 96%, unchanged from commit 3e54a83 in the main branch.

[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@test/e2e/docs/README.md`:
- Around line 286-289: Update the documentation entry for
.github/workflows/platform-vitest-main.yaml to explicitly state that the matrix
uses fail-fast: false, while preserving the existing shard count, per-shard time
budgets, and shard-1-only root-required contracts details.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Enterprise

Run ID: 4c8c9404-d352-49fe-9095-bd3d5293cda5

📥 Commits

Reviewing files that changed from the base of the PR and between 3e54a83 and 049c956.

📒 Files selected for processing (4)

• .github/workflows/platform-vitest-main.yaml
• test/e2e/README.md
• test/e2e/docs/README.md
• test/platform-vitest-main-workflow.test.ts

[github-actions]

PR Review Advisor — No blocking findings reported

Advisor assessment: No blocking advisor findings reported
Next action: No advisor follow-up needed.
Findings: 0 blockers · 0 warnings · 0 suggestions

Model lanes

• 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 E2E selections match; severity counts match.

Nemotron output stays in workflow artifacts and does not change the assessment above.

E2E guidance

Advisory only. E2E / PR Gate selects and runs jobs independently.

Recommended E2E: None

Workflow run details

This automated review informs maintainers. Warnings and suggestions do not require a response. A maintainer decides whether to merge.