output.txt

$ echo "source 'https://rubygems.org'\ngem 'rails', '4.2.0'" > Gemfile && bundle install
[truncated]
Using rails 4.2.0
Your bundle is complete!
It was installed into ./.bundle

$ bundle exec ruby routing_issue.rb
Run options: --seed 9548

# Running:

....

Finished in 0.066622s, 60.0402 runs/s, 60.0402 assertions/s.

4 runs, 4 assertions, 0 failures, 0 errors, 0 skips

$ echo "source 'https://rubygems.org'\ngem 'rails', '4.2.1'" > Gemfile && bundle install
[truncated]
Using rails 4.2.1 (was 4.2.0)
Your bundle is complete!
It was installed into ./.bundle

$ bundle exec ruby routing_issue.rb
Run options: --seed 9252

# Running:

..F.

Finished in 0.111500s, 35.8744 runs/s, 35.8744 assertions/s.

  1) Failure:
BugTest#test_head_health_check_returns_503 [routing_issue.rb:56]:
Expected: 404
  Actual: 503

4 runs, 4 assertions, 1 failures, 0 errors, 0 skips

routing_issue.rb

require 'bundler'
Bundler.setup(:default)
require 'rails'
require 'action_controller/railtie'

class HealthCheck
  def call(env)
    [503, {}, 'not available']
  end
end

class TestApp < Rails::Application
  config.root = File.dirname(__FILE__)
  secrets.secret_token = 'secret_token'
  secrets.secret_key_base = 'secret_key_base'
  config.logger = Logger.new(File.open('/dev/null', 'a'))
  Rails.logger = config.logger

  routes.draw do
    get '/test' => 'test#index'
    mount HealthCheck.new, at: '/health_check'
  end
end

class TestController < ActionController::Base
  include Rails.application.routes.url_helpers
  def index
    render json: {}, status: 200
  end
end


require 'minitest/autorun'
require 'rack/test'

class BugTest < Minitest::Test
  include Rack::Test::Methods

  def test_get_test_returns_success
    get '/test'
    assert last_response.ok?
  end

  def test_head_test_returns_success
    head '/test'
    assert last_response.ok?
  end

  def test_get_health_check_returns_503
    get '/health_check'
    assert_equal last_response.status, 503
  end

  def test_head_health_check_returns_503
    head '/health_check'
    assert_equal last_response.status, 503
  end

  private

  def app
    Rails.application
  end
end