Implement Dead Code Hunter GitHub Action

[jonathanpopham]

Overview

Build a GitHub Action that uses Supermodel's call graph API to find unreachable functions (dead code) in a codebase.

Core Features

• Create zip archive of repository (respecting .gitignore)
• Call Supermodel /v1/graphs/call endpoint to get call graph
• Analyze graph to find functions with zero incoming calls
• Filter out false positives:
  • Entry points (main, exported functions)
  • Test files
  • User-specified ignore patterns
• Post findings as PR comment (with file links)
• Set action outputs (dead-code-count, dead-code-json)
• Optional: fail action if dead code found

Stretch Goals

• Auto-generate cleanup PR removing dead code
• Track dead code trends over time
• Integrate with GitHub code scanning (SARIF output)

Technical Notes

• Use @supermodel/typescript-sdk for API calls
• Use @actions/core and @actions/github for action scaffolding
• Build with @vercel/ncc for single-file distribution

Reference

• Supermodel API Docs
• Call Graph Endpoint