Update Elixir Dependencies Skill

update-deps.md

Update Elixir Dependencies

Update all outdated dependencies in this Elixir project, handling both safe updates and breaking changes.

Workflow

1. Identify Outdated Dependencies

Run mix hex.outdated to get a list of all outdated dependencies. Parse the output to identify:

• Safe updates: Dependencies where only the patch or minor version has changed (no major version bump)
• Breaking updates: Dependencies with a major version change (e.g., 1.x.x → 2.x.x)

2. Apply Safe Updates

Run mix deps.update --all to update all dependencies. This will apply updates within the version constraints specified in mix.exs.

3. Handle Breaking Changes

For each dependency with a breaking major version change:

1. Update the version constraint in mix.exs to allow the new major version

2. Find the changelog or upgrade guide using this approach:

   • First, try https://hexdocs.pm/{package_name}/changelog.html
   • If not found, go to the project root at https://hexdocs.pm/{package_name} and look for:
     • Links to "Changelog", "CHANGELOG", "Upgrade Guide", or "Migration Guide" in the sidebar navigation
     • Any "Upgrading" or "Breaking Changes" sections in the documentation
   • Extract the relevant breaking changes between your current version and the target version

3. Review breaking changes and apply necessary code modifications

4. Run verification after each breaking change update before moving to the next

4. Verification

After updates, run these commands and fix any issues:

# Compile with warnings as errors
mix compile --warnings-as-errors

# Check formatting
mix format --check-formatted

# Run tests
mix test

If any verification step fails:

• For compile warnings: Fix the warning in the code
• For format issues: Run mix format to auto-fix
• For test failures: Debug and fix the failing tests

5. Final Steps

Once all verifications pass:

1. Run mix hex.outdated again to confirm all dependencies are up to date
2. Summarize what was updated, including any breaking changes that required code modifications