4 files changed, 121 insertions, 35 deletions
diff --git a/railties/lib/rails/engine/commands.rb b/railties/lib/rails/engine/commands.rb
index a6d87b78e4..7bbd9ef744 100644
--- a/railties/lib/rails/engine/commands.rb
+++ b/railties/lib/rails/engine/commands.rb
@@ -1,3 +1,5 @@
+require 'rails/engine/commands_tasks'
+
 ARGV << '--help' if ARGV.empty?
 
 aliases = {
@@ -9,35 +11,4 @@ aliases = {
 command = ARGV.shift
 command = aliases[command] || command
 
-require ENGINE_PATH
-engine = ::Rails::Engine.find(ENGINE_ROOT)
-
-case command
-when 'generate', 'destroy', 'test'
-  require 'rails/generators'
-  Rails::Generators.namespace = engine.railtie_namespace
-  engine.load_generators
-  require "rails/commands/#{command}"
-
-when '--version', '-v'
-  ARGV.unshift '--version'
-  require 'rails/commands/application'
-
-else
-  puts "Error: Command not recognized" unless %w(-h --help).include?(command)
-  puts <<-EOT
-Usage: rails COMMAND [ARGS]
-
-The common Rails commands available for engines are:
- generate    Generate new code (short-cut alias: "g")
- destroy     Undo code generated with "generate" (short-cut alias: "d")
- test        Run tests (short-cut alias: "t")
-
-All commands can be run with -h for more information.
-
-If you want to run any commands that need to be run in context
-of the application, like `rails server` or `rails console`,
-you should do it from application's directory (typically test/dummy).
-  EOT
-  exit(1)
-end
+Rails::Engine::CommandsTasks.new(ARGV).run_command!(command)
diff --git a/railties/lib/rails/engine/commands_tasks.rb b/railties/lib/rails/engine/commands_tasks.rb
new file mode 100644
index 0000000000..fa3ee59b7d
--- /dev/null
+++ b/railties/lib/rails/engine/commands_tasks.rb
@@ -0,0 +1,116 @@
+require 'rails/commands/rake_proxy'
+
+module Rails
+  class Engine
+    class CommandsTasks # :nodoc:
+      include Rails::RakeProxy
+
+      attr_reader :argv
+
+      HELP_MESSAGE = <<-EOT
+Usage: rails COMMAND [ARGS]
+
+The common Rails commands available for engines are:
+ generate    Generate new code (short-cut alias: "g")
+ destroy     Undo code generated with "generate" (short-cut alias: "d")
+ test        Run tests (short-cut alias: "t")
+
+All commands can be run with -h for more information.
+
+If you want to run any commands that need to be run in context
+of the application, like `rails server` or `rails console`,
+you should do it from application's directory (typically test/dummy).
+
+In addition to those commands, there are:
+  EOT
+
+      COMMAND_WHITELIST = %w(generate destroy version help test)
+
+      def initialize(argv)
+        @argv = argv
+      end
+
+      def run_command!(command)
+        command = parse_command(command)
+
+        if COMMAND_WHITELIST.include?(command)
+          send(command)
+        else
+          run_rake_task(command)
+        end
+      end
+
+      def generate
+        generate_or_destroy(:generate)
+      end
+
+      def destroy
+        generate_or_destroy(:destroy)
+      end
+
+      def test
+        require_command!("test")
+      end
+
+      def version
+        argv.unshift '--version'
+        require_command!("application")
+      end
+
+      def help
+        write_help_message
+        write_commands(formatted_rake_tasks)
+      end
+
+      private
+
+        def require_command!(command)
+          require "rails/commands/#{command}"
+        end
+
+        def generate_or_destroy(command)
+          load_generators
+          require_command!(command)
+        end
+
+        def load_generators
+          require 'rails/generators'
+          require ENGINE_PATH
+
+          engine = ::Rails::Engine.find(ENGINE_ROOT)
+          Rails::Generators.namespace = engine.railtie_namespace
+          engine.load_generators
+        end
+
+        def write_help_message
+          puts HELP_MESSAGE
+        end
+
+        def write_commands(commands)
+          width = commands.map { |name, _| name.size }.max || 10
+          commands.each { |command| printf(" %-#{width}s   %s\n", *command) }
+        end
+
+        def parse_command(command)
+          case command
+          when '--version', '-v'
+            'version'
+          when '--help', '-h'
+            'help'
+          else
+            command
+          end
+        end
+
+        def rake_tasks
+          return @rake_tasks if defined?(@rake_tasks)
+
+          load_generators
+          Rake::TaskManager.record_task_metadata = true
+          Rake.application.init('rails')
+          Rake.application.load_rakefile
+          @rake_tasks = Rake.application.tasks.select(&:comment)
+        end
+    end
+  end
+end
diff --git a/railties/lib/rails/generators/app_base.rb b/railties/lib/rails/generators/app_base.rb
index c629459d95..51394de824 100644
--- a/railties/lib/rails/generators/app_base.rb
+++ b/railties/lib/rails/generators/app_base.rb
@@ -344,7 +344,6 @@ module Rails
         return [] if options[:skip_action_cable]
         comment = 'Action Cable dependencies for the Redis adapter'
         gems = []
-        gems << GemfileEntry.new("em-hiredis", '~> 0.3.0', comment)
         gems << GemfileEntry.new("redis", '~> 3.0', comment)
         gems
       end
diff --git a/railties/lib/rails/tasks/engine.rake b/railties/lib/rails/tasks/engine.rake
index c51524f8f6..e678103f63 100644
--- a/railties/lib/rails/tasks/engine.rake
+++ b/railties/lib/rails/tasks/engine.rake
@@ -4,8 +4,8 @@ task "load_app" do
   end
   task :environment => "app:environment"
 
-  if !defined?(ENGINE_PATH) || !ENGINE_PATH
-    ENGINE_PATH = find_engine_path(APP_RAKEFILE)
+  if !defined?(ENGINE_ROOT) || !ENGINE_ROOT
+    ENGINE_ROOT = find_engine_path(APP_RAKEFILE)
   end
 end