v1 distribution missing @actions/core – action fails at runtime

[tmbtech]

🐛 Bug Report

The published tmbtech/multi-codeowners@v1 GitHub Action fails at runtime with a module resolution error, preventing code owner enforcement workflows from functioning.

💥 Error Message

Error: Cannot find module '@actions/core'
Require stack:
- /home/runner/work/_actions/tmbtech/multi-codeowners/v1/dist/index.js

🔍 Root Cause

The published v1 tag contains a dist/index.js file that attempts to require @actions/core at runtime, but this dependency was not properly bundled into the distribution.

Technical Details

1. Missing Bundling Step: The action's build process should bundle all npm dependencies into the dist/ directory using a tool like @vercel/ncc or webpack
2. Runtime Dependency: In GitHub Actions environment, only the contents of the action's repository are available - npm packages are not installed automatically
3. Distribution Mismatch: The published v1 tag contains unbundled JavaScript that expects node_modules to be present

📋 Reproduction Steps

1. Create any workflow using tmbtech/multi-codeowners@v1
2. Trigger the workflow on a pull request
3. Observe runtime module resolution failure

📊 Evidence

• ✅ Unit tests pass - indicating the source code is functional
• ✅ Action builds successfully - confirming TypeScript compilation works
• ❌ Runtime failure - only occurs when action executes in GitHub Actions environment
• ❌ Missing bundled dependencies - @actions/core and other npm packages not in distribution

🛠️ Suggested Solution

Immediate Fix

1. Rebuild distribution: Run the proper build pipeline with bundling

   npm run build
   npm run package  # or equivalent bundling step using ncc/webpack

2. Publish fixed version: Release as v1.0.1 or v1.1.0

   git add dist/
   git commit -m "fix: bundle dependencies in distribution"
   git tag v1.0.1
   git push origin v1.0.1

Long-term Prevention

1. Add bundling check to CI pipeline
2. Test distribution in isolated environment before publishing
3. Automate releases with proper build/bundle/test workflow

🔗 Failing Examples

• Workflow run: https://github.com/tmbtech/multi-codeowners-test-project/actions/runs/17333418602
• Test repo: https://github.com/tmbtech/multi-codeowners-test-project

📈 Impact

Severity: High - Action completely non-functional
Status: 🔴 Blocking all workflows using v1 tag

💡 Workaround

We've created a temporary implementation in our test repo while waiting for the fix. Once resolved, we'll update to use the fixed upstream action.

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Report Generated: 2025-08-29

[tmbtech]

PR -> #1