Traceroute¶ ↑

A Rake task that helps you find dead routes and unused actions in your Rails 3+ app.

This Rake task investigates your Rails application’s routes definition, then shows you the unused routes and unreachable action methods.

• Ruby 1.8.7, 1.9.2, 1.9.3, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 3.0, 3.1 (trunk)

• Rails 3.0.x, 3.1.x, 3.2.x, 4.0.x, 4.1.x, 5.0.x, 5.1.x, 5.2.x, 6.0, 6.1, 7.0 (master)

Put this line in your Gemfile:

gem 'traceroute'

Then bundle:

% bundle

Just run the following command in your Rails app directory.

% rake traceroute

If you want the rake task to fail when errors are found.

% FAIL_ON_ERROR=1 rake traceroute

Consider you have the following routes.rb and a controller:

# config/routes.rb
YourRailsApp::Application.routes.draw do
  resources :users, :only => [:index, :show, :new, :create]
  match 'products/:id/purchase' => 'catalog#purchase', :as => :purchase
end

# app/controllers/users_controller.rb
class UsersController < ApplicationController
  def index
    @users = User.page(params[:page])
  end

  def index2
  end

  def show
    @user = User.find(params[:id])
  end
end

Running the Rake task will print something like this for you:

Unused routes (3):
  users#create
  users#new
  catalog#purchase
Unreachable action methods (1):
  users#index2

OMG super helpful, isn’t it?

Some gems out there that inject routes or actions into our app for testing. Jasmine-Rails does this. They can give you false negatives when running this in development mode. It can be useful to ignore said routes or actions.

Create a .traceroute.yaml (or .traceroute.yml or .traceroute) file in your root directory.

# .traceroute.yaml
ignore_unreachable_actions:
- ^jasmine_rails\/
ignore_unused_routes:
- ^users#index

Both yaml headers accept a list of regexes.

Q: It makes a fuss over the default route at the very bottom. WTF?
A: Please do not use that. Did you read the comment in your routes.rb? Actually this task will help you a lot to remove that evil route.

Q: "command not found: traceroute" Did you mean: tracert
A: I'm afraid you're using the wrong operating system.

Feel free to message me on Github (amatsuda) or Twitter (@a_matsuda) ☇3☇3☇3

• Fork, patch, then send me a pull request.

Copyright © 2011 Akira Matsuda. See MIT-LICENSE file for further details.