refactor `CommandsTasks`

Extract a common method of `Rails::CommandsTasks` and
`Rails::Engine::CommandsTasks` to the module.

4 files changed, 132 insertions, 164 deletions

diff --git a/railties/lib/rails/commands/commands_tasks.rb b/railties/lib/rails/commands/commands_tasks.rb
index 02f6472330..43f9dd38f3 100644
--- a/railties/lib/rails/commands/commands_tasks.rb
+++ b/railties/lib/rails/commands/commands_tasks.rb
@@ -1,4 +1,6 @@
 require "rails/commands/rake_proxy"
+require "rails/commands/common_commands_tasks"
+require "active_support/core_ext/string/strip"
 
 module Rails
   # This is a class which takes in a rails command and initiates the appropriate
@@ -8,27 +10,10 @@ module Rails
   # it before they are run.
   class CommandsTasks # :nodoc:
     include Rails::RakeProxy
+    include Rails::CommonCommandsTasks
 
     attr_reader :argv
 
-    HELP_MESSAGE = <<-EOT
-Usage: rails COMMAND [ARGS]
-
-The most common rails commands are:
- generate    Generate new code (short-cut alias: "g")
- console     Start the Rails console (short-cut alias: "c")
- server      Start the Rails server (short-cut alias: "s")
- test        Run tests (short-cut alias: "t")
- dbconsole   Start a console for the database specified in config/database.yml
-             (short-cut alias: "db")
- new         Create a new Rails application. "rails new my_app" creates a
-             new application called MyApp in "./my_app"
-
-All commands can be run with -h (or --help) for more information.
-
-In addition to those commands, there are:
-EOT
-
     ADDITIONAL_COMMANDS = [
       [ "destroy", 'Undo code generated with "generate" (short-cut alias: "d")' ],
       [ "plugin new", "Generates skeleton for developing a Rails plugin" ],
@@ -36,34 +21,14 @@ EOT
         'Run a piece of code in the application environment (short-cut alias: "r")' ]
     ]
 
-    COMMAND_WHITELIST = %w(plugin generate destroy console server dbconsole runner new 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 plugin
       require_command!("plugin")
     end
 
-    def generate
-      generate_or_destroy(:generate)
-    end
-
-    def destroy
-      generate_or_destroy(:destroy)
-    end
-
     def console
       require_command!("console")
       options = Rails::Console.parse_arguments(argv)
@@ -91,10 +56,6 @@ EOT
       end
     end
 
-    def test
-      require_command!("test")
-    end
-
     def dbconsole
       require_command!("dbconsole")
       Rails::DBConsole.start
@@ -112,16 +73,6 @@ EOT
       end
     end
 
-    def version
-      argv.unshift "--version"
-      require_command!("application")
-    end
-
-    def help
-      write_help_message
-      write_commands ADDITIONAL_COMMANDS + formatted_rake_tasks
-    end
-
     private
 
       def exit_with_initialization_warning!
@@ -134,17 +85,6 @@ EOT
         argv.shift if argv.first && argv.first[0] != "-"
       end
 
-      def require_command!(command)
-        require "rails/commands/#{command}"
-      end
-
-      def generate_or_destroy(command)
-        require "rails/generators"
-        require_application_and_environment!
-        Rails.application.load_generators
-        require_command!(command)
-      end
-
       # Change to the application's path if there is no config.ru file in current directory.
       # This allows us to run `rails server` from other directories, but still get
       # the main config.ru and properly set the tmp directory.
@@ -152,29 +92,45 @@ EOT
         Dir.chdir(File.expand_path("../../", APP_PATH)) unless File.exist?(File.expand_path("config.ru"))
       end
 
+      def commands
+        ADDITIONAL_COMMANDS + formatted_rake_tasks
+      end
+
+      def command_whitelist
+        %w(plugin generate destroy console server dbconsole runner new version help test)
+      end
+
+      def help_message
+        <<-EOT.strip_heredoc
+          Usage: rails COMMAND [ARGS]
+
+          The most common rails commands are:
+           generate    Generate new code (short-cut alias: "g")
+           console     Start the Rails console (short-cut alias: "c")
+           server      Start the Rails server (short-cut alias: "s")
+           test        Run tests (short-cut alias: "t")
+           dbconsole   Start a console for the database specified in config/database.yml
+                       (short-cut alias: "db")
+           new         Create a new Rails application. "rails new my_app" creates a
+                       new application called MyApp in "./my_app"
+
+          All commands can be run with -h (or --help) for more information.
+
+          In addition to those commands, there are:
+        EOT
+      end
+
       def require_application_and_environment!
         require APP_PATH
         Rails.application.require_environment!
       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) }
+      def load_tasks
+        Rails.application.load_tasks
       end
 
-      def parse_command(command)
-        case command
-        when "--version", "-v"
-          "version"
-        when "--help", "-h"
-          "help"
-        else
-          command
-        end
+      def load_generators
+        Rails.application.load_generators
       end
   end
 end
diff --git a/railties/lib/rails/commands/common_commands_tasks.rb b/railties/lib/rails/commands/common_commands_tasks.rb
new file mode 100644
index 0000000000..c1484d7ae2
--- /dev/null
+++ b/railties/lib/rails/commands/common_commands_tasks.rb
@@ -0,0 +1,68 @@
+module Rails
+  module CommonCommandsTasks # :nodoc:
+    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(commands)
+    end
+
+    private
+
+      def generate_or_destroy(command)
+        require "rails/generators"
+        require_application_and_environment!
+        load_generators
+        require_command!(command)
+      end
+
+      def require_command!(command)
+        require "rails/commands/#{command}"
+      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
+  end
+end
diff --git a/railties/lib/rails/commands/rake_proxy.rb b/railties/lib/rails/commands/rake_proxy.rb
index b9e50f3e5a..f8da71831a 100644
--- a/railties/lib/rails/commands/rake_proxy.rb
+++ b/railties/lib/rails/commands/rake_proxy.rb
@@ -26,7 +26,7 @@ module Rails
 
         Rake::TaskManager.record_task_metadata = true
         Rake.application.instance_variable_set(:@name, "rails")
-        Rails.application.load_tasks
+        load_tasks
         @rake_tasks = Rake.application.tasks.select(&:comment)
       end
 
diff --git a/railties/lib/rails/engine/commands_tasks.rb b/railties/lib/rails/engine/commands_tasks.rb
index e21a7183fc..d6effdb732 100644
--- a/railties/lib/rails/engine/commands_tasks.rb
+++ b/railties/lib/rails/engine/commands_tasks.rb
@@ -1,118 +1,62 @@
 require "rails/commands/rake_proxy"
+require "rails/commands/common_commands_tasks"
+require "active_support/core_ext/string/strip"
 
 module Rails
   class Engine
     class CommandsTasks # :nodoc:
       include Rails::RakeProxy
+      include Rails::CommonCommandsTasks
 
       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)
+      private
 
-        if COMMAND_WHITELIST.include?(command)
-          send(command)
-        else
-          run_rake_task(command)
+        def commands
+          formatted_rake_tasks
         end
-      end
 
-      def generate
-        generate_or_destroy(:generate)
-      end
+        def command_whitelist
+          %w(generate destroy version help test)
+        end
 
-      def destroy
-        generate_or_destroy(:destroy)
-      end
+        def help_message
+          <<-EOT.strip_heredoc
+            Usage: rails COMMAND [ARGS]
 
-      def test
-        require_command!("test")
-      end
+            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")
 
-      def version
-        argv.unshift "--version"
-        require_command!("application")
-      end
+            All commands can be run with -h for more information.
 
-      def help
-        write_help_message
-        write_commands(formatted_rake_tasks)
-      end
+            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).
 
-      private
+            In addition to those commands, there are:
+          EOT
+        end
 
-        def require_command!(command)
-          require "rails/commands/#{command}"
+        def require_application_and_environment!
+          require ENGINE_PATH
         end
 
-        def generate_or_destroy(command)
-          load_generators
-          require_command!(command)
+        def load_tasks
+          Rake.application.init("rails")
+          Rake.application.load_rakefile
         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
-          require_rake
-
-          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