ci: enable npm caching in GitHub Actions workflow

[zeke]

Summary

• Add npm caching to actions/setup-node step

Benefits

This will speed up CI runs by caching node_modules between workflow runs, reducing install times and improving developer experience.

Test plan

• Verified workflow syntax is valid
• CI workflows will run faster on subsequent runs after this merge

[claude]

Claude finished @zeke's task —— View job

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PR Review: npm caching in GitHub Actions

Todo List

• Read repository setup instructions (CLAUDE.md) - No CLAUDE.md found
• Read the modified workflow file
• Analyze npm caching implementation
• Provide comprehensive review feedback

Review Feedback

✅ Overall Assessment: APPROVED

This is a clean, straightforward improvement that follows GitHub Actions best practices for npm caching.

Code Quality & Best Practices

Excellent - The implementation is minimal and follows the recommended approach:

• Uses actions/setup-node@v4 with cache: npm parameter (.github/workflows/build_and_publish.yml:23)
• Correctly placed before the npm ci step for optimal cache utilization
• Leverages the built-in caching mechanism rather than manual cache configuration

Performance Considerations

Positive Impact Expected

• Will cache ~/.npm directory automatically based on package-lock.json hash
• Should significantly reduce npm ci execution time on subsequent runs
• No performance overhead - the caching is handled efficiently by GitHub Actions

Security Concerns

No Issues Identified

• Uses the latest stable version of actions/setup-node@v4
• No security-sensitive changes introduced
• Caching mechanism is sandboxed per repository and branch

Potential Issues/Suggestions

Minor Considerations:

1. Cache invalidation: The cache will automatically invalidate when package-lock.json changes, which is the desired behavior
2. Fallback behavior: If cache miss occurs, workflow will fall back to normal npm ci behavior seamlessly
3. Node version consistency: Currently using Node 20, which is appropriate for the npm caching feature

Test Coverage

The change doesn't require additional test coverage as it's an infrastructure optimization. The existing test plan is appropriate:

• Workflow syntax validation (completed)
• Performance verification (will be evident in subsequent CI runs)

Recommendation

APPROVE - This is a well-implemented performance optimization with no downsides. The change is minimal, follows best practices, and will improve CI efficiency without any risk.