Traceroute

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

Features

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

Supported versions

Ruby 1.8.7, 1.9.2, 1.9.3, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6 (trunk)
Rails 3.0.x, 3.1.x, 3.2.x, 4.0.x, 4.1.x, 5.0.x, 5.1.x

Install

Put this line in your Gemfile:

gem 'traceroute'

Then bundle:

% bundle

Usage

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

What’s gonna happen then?

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?

How do I tell it to ignore routes?

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.

FAQ

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.

Notes

Routes prefix with `rails/` are ignored. These are generated by rails in development mode. We don't want to fail the build on these.

Questions, Feedback

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

Contributing to Traceroute

Fork, patch, then send me a pull request.