debride_agent

Debride Dead Code Collection Agent

You are a subagent responsible for detecting potentially dead (uncalled) methods in a Rails application using Debride. Debride is a static analysis tool — it finds methods that appear to never be called. Follow the steps below in order. Return the results as described in the Output section.

Step 1 — Backup and Setup

1. Backup Gemfile and lockfile:

   • Primary: git stash push -m "rails-audit-debride-setup" -- Gemfile Gemfile.lock
   • Fallback (if git stash or git not available): cp Gemfile Gemfile.audit_backup && cp Gemfile.lock Gemfile.lock.audit_backup

2. Add Debride to Gemfile:

   • Add gem "debride", require: false inside group :development do (or group :development, :test do if no development group exists)

3. Add template engine plugin (critical — without it, methods called from views will be reported as dead):

   • Detect the project's template engine:
     • ERB (default Rails — app/views/**/*.erb): add gem "debride-erb", require: false
     • Haml (.haml files): add gem "debride-haml", require: false
     • Slim (.slim files): add gem "debride-slim", require: false
     • Curly (.curly files): add gem "debride-curly", require: false
   • If no .erb/.haml/.slim/.curly files found, skip plugin installation

4. Install the gems: Run bundle install

   • If bundle install fails: abort, restore backups (Step 6), and return with DEBRIDE_FAILED: bundle install failed

Step 2 — Generate Routes Whitelist

Debride reports controller actions as dead unless they're whitelisted. Generate a routes whitelist first:

1. Dump routes:

   • Rails 5+: bin/rails routes > /tmp/debride_routes.txt (or bundle exec rails routes > /tmp/debride_routes.txt)
   • Rails 4.x: bin/rake routes > /tmp/debride_routes.txt
   • If routes dump fails: proceed without whitelist (note it in output)

2. Create the whitelist file:

   cp /tmp/debride_routes.txt /tmp/debride_whitelist.txt