Report unused ignore lines in config

lib/tasks/traceroute.rake

@@ -19,9 +19,25 @@ task :traceroute => :environment do
     unreachable_action_methods.each {|action| puts "  #{action}"}
   end
 
+  unused_action_checks = traceroute.unused_ignored_unreachable_action_methods
+  unless unused_action_checks.empty?
+    puts "Unused action method ignores present (#{unused_action_checks.count}):"
+    unused_action_checks.each {|action| puts "  #{action}"}
+  end
+
+  unused_route_checks = traceroute.unused_ignored_unused_routes
+  unless unused_route_checks.empty?
+    puts "Unused route ignores present (#{unused_route_checks.count}):"
+    unused_route_checks.each {|route| puts "  #{route}"}
+  end
+
   if ENV['FAIL_ON_ERROR'] && ((!ENV['UNREACHABLE_ACTION_METHODS_ONLY'] && unused_routes.any?) || (!ENV['UNUSED_ROUTES_ONLY'] && unreachable_action_methods.any?))
     fail "Unused routes or unreachable action methods detected."
   end
+
+  if ENV['FAIL_ON_ERROR'] && (unused_action_checks.any? || unused_route_checks.any?)
+    fail "Unused routes or unreachable action ignore lines detected in config."
+  end
 end
 
 namespace :traceroute do

lib/traceroute.rb

@@ -16,9 +16,10 @@ def initialize(app)
     @app = app
 
     @ignored_unreachable_actions = []
-    @ignored_unused_routes = [/^\/cable$/]
+    @ignored_unused_routes = default_unused_routes.dup
 
-    @ignored_unused_routes << %r{^#{@app.config.assets.prefix}} if @app.config.respond_to? :assets
+    @used_ignored_unreachable_actions = []
+    @used_ignored_unused_routes = []
 
     config_filename = %w(.traceroute.yaml .traceroute.yml .traceroute).detect {|f| File.exist?(f)}
     if config_filename && (config = YAML.load_file(config_filename))
@@ -50,14 +51,22 @@ def unreachable_action_methods
     defined_action_methods - routed_actions
   end
 
+  def unused_ignored_unused_routes
+    @ignored_unused_routes - @used_ignored_unused_routes - default_unused_routes
+  end
+
+  def unused_ignored_unreachable_action_methods
+    @ignored_unreachable_actions - @used_ignored_unreachable_actions
+  end
+
   def defined_action_methods
     @defined_action_methods ||= [ActionController::Base, (ActionController::API if defined?(ActionController::API))].compact.map do |klass|
       klass.descendants.map do |controller|
         controller.action_methods.reject {|a| (a =~ /\A(_conditional)?_callback_/) || (a == '_layout_from_proc')}.map do |action|
           "#{controller.controller_path}##{action}"
         end
       end.flatten
-    end.flatten.reject {|r| @ignored_unreachable_actions.any? { |m| r.match(m) } }
+    end.compact.flatten.reject {|r| check_match_and_store_used(r, @ignored_unreachable_actions, @used_ignored_unreachable_actions) }
   end
 
   def routed_actions
@@ -71,7 +80,7 @@ def routed_actions
       else
         ((String === r.path) && r.path.to_s) || r.path.spec.to_s  # unknown routes
       end
-    end.compact.flatten.reject {|r| @ignored_unused_routes.any? { |m| r.match(m) } }
+    end.compact.flatten.reject { |r| check_match_and_store_used(r, @ignored_unused_routes, @used_ignored_unused_routes) }
   end
 
   def routes
@@ -96,4 +105,24 @@ def collect_routes(routes)
 
     routes
   end
+
+  private
+
+  def check_match_and_store_used(item, ignores, used)
+    ignores.any? { |m|
+      if item.match(m)
+        used << m
+        true
+      end
+    }
+  end
+
+  def default_unused_routes
+    @default_unused_routes ||=
+      begin
+        defaults = [/^\/cable$/]
+        defaults << %r{^#{@app.config.assets.prefix}} if @app.config.respond_to? :assets
+        defaults.freeze
+      end
+  end
 end

test/yaml_test.rb

@@ -26,8 +26,10 @@ def setup
     File.open ".traceroute.yaml", "w" do |file|
       file.puts 'ignore_unreachable_actions:'
       file.puts '- ^jasmine_rails\/'
+      file.puts '- foo_unused'
       file.puts 'ignore_unused_routes:'
       file.puts '- ^users'
+      file.puts '- bar_unused'
     end
 
     DummyApp::Application.routes.draw do
@@ -58,6 +60,16 @@ def test_unreachable_actions_are_ignored
   def test_used_routes_are_ignored
     assert_routed_actions 'admin/shops#index', 'api/books#index'
   end
+
+  def test_unused_ignored_unused_routes_are_reported
+    @traceroute.routed_actions # Trigger the check
+    assert_equal @traceroute.unused_ignored_unused_routes, [/bar_unused/]
+  end
+
+  def test_unused_ignored_unreachable_action_methods_are_reported
+    @traceroute.defined_action_methods # Trigger the check
+    assert_equal @traceroute.unused_ignored_unreachable_action_methods, [/foo_unused/]
+  end
 end
 
 class EmptyFileTest < Minitest::Test