Initial command structure.

4 files changed, 303 insertions, 0 deletions

diff --git a/railties/lib/rails/command/actions.rb b/railties/lib/rails/command/actions.rb
new file mode 100644
index 0000000000..52d3348db3
--- /dev/null
+++ b/railties/lib/rails/command/actions.rb
@@ -0,0 +1,18 @@
+module Rails
+  module Command
+    module Actions
+      private
+        # 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.
+        def set_application_directory!
+          Dir.chdir(File.expand_path("../../", APP_PATH)) unless File.exist?(File.expand_path("config.ru"))
+        end
+
+        def require_application_and_environment!
+          require APP_PATH
+          Rails.application.require_environment!
+        end
+    end
+  end
+end
diff --git a/railties/lib/rails/command/base.rb b/railties/lib/rails/command/base.rb
new file mode 100644
index 0000000000..2ef8393863
--- /dev/null
+++ b/railties/lib/rails/command/base.rb
@@ -0,0 +1,130 @@
+require "thor"
+require "erb"
+
+require "active_support/core_ext/string/filters"
+require "active_support/core_ext/string/inflections"
+
+require "rails/command/actions"
+
+module Rails
+  module Command
+    class Base < Thor
+      class Error < Thor::Error # :nodoc:
+      end
+
+      include Actions
+
+      class << self
+        # Tries to get the description from a USAGE file one folder above the command
+        # root.
+        def desc(usage = nil, description = nil)
+          if usage
+            super
+          else
+            @desc ||= ERB.new(File.read(usage_path)).result(binding) if usage_path
+          end
+        end
+
+        # Convenience method to get the namespace from the class name. It's the
+        # same as Thor default except that the Command at the end of the class
+        # is removed.
+        def namespace(name = nil)
+          if name
+            super
+          else
+            @namespace ||= super.chomp("_command").sub(/:command:/, ":")
+          end
+        end
+
+        # Convenience method to hide this command from the available ones when
+        # running rails command.
+        def hide_command!
+          Rails::Command.hidden_commands << self
+        end
+
+        def inherited(base) #:nodoc:
+          super
+
+          if base.name && base.name !~ /Base$/
+            Rails::Command.subclasses << base
+          end
+        end
+
+        def perform(command, args, config) # :nodoc:
+          command = nil if Thor::HELP_MAPPINGS.include?(args.first)
+
+          dispatch(command, args.dup, nil, config)
+        end
+
+        def printing_commands
+          namespace.sub(/^rails:/, "")
+        end
+
+        def executable
+          "bin/rails #{command_name}"
+        end
+
+        # Use Rails' default banner.
+        def banner(*)
+          "#{executable} #{arguments.map(&:usage).join(' ')} [options]".squish!
+        end
+
+        # Sets the base_name taking into account the current class namespace.
+        #
+        #   Rails::Command::TestCommand.base_name # => 'rails'
+        def base_name
+          @base_name ||= begin
+            if base = name.to_s.split("::").first
+              base.underscore
+            end
+          end
+        end
+
+        # Return command name without namespaces.
+        #
+        #   Rails::Command::TestCommand.command_name # => 'test'
+        def command_name
+          @command_name ||= begin
+            if command = name.to_s.split("::").last
+              command.chomp!("Command")
+              command.underscore
+            end
+          end
+        end
+
+        # Path to lookup a USAGE description in a file.
+        def usage_path
+          if default_command_root
+            path = File.join(default_command_root, "USAGE")
+            path if File.exist?(path)
+          end
+        end
+
+        # Default file root to place extra files a command might need, placed
+        # one folder above the command file.
+        #
+        # For a `Rails::Command::TestCommand` placed in `rails/command/test_command.rb`
+        # would return `rails/test`.
+        def default_command_root
+          path = File.expand_path(File.join(base_name, command_name), __dir__)
+          path if File.exist?(path)
+        end
+
+        private
+          # Allow the command method to be called perform.
+          def create_command(meth)
+            if meth == "perform"
+              alias_method command_name, meth
+            else
+              # Prevent exception about command without usage.
+              # Some commands define their documentation differently.
+              @usage ||= ""
+              @desc  ||= ""
+
+              super
+            end
+          end
+      end
+    end
+  end
+end
diff --git a/railties/lib/rails/command/behavior.rb b/railties/lib/rails/command/behavior.rb
new file mode 100644
index 0000000000..1d7bab6ab2
--- /dev/null
+++ b/railties/lib/rails/command/behavior.rb
@@ -0,0 +1,123 @@
+require "active_support"
+
+module Rails
+  module Command
+    module Behavior #:nodoc:
+      extend ActiveSupport::Concern
+
+      class_methods do
+        # Remove the color from output.
+        def no_color!
+          Thor::Base.shell = Thor::Shell::Basic
+        end
+
+        # Track all command subclasses.
+        def subclasses
+          @subclasses ||= []
+        end
+
+        protected
+
+          # This code is based directly on the Text gem implementation.
+          # Copyright (c) 2006-2013 Paul Battley, Michael Neumann, Tim Fletcher.
+          #
+          # Returns a value representing the "cost" of transforming str1 into str2
+          def levenshtein_distance(str1, str2)
+            s = str1
+            t = str2
+            n = s.length
+            m = t.length
+
+            return m if (0 == n)
+            return n if (0 == m)
+
+            d = (0..m).to_a
+            x = nil
+
+            # avoid duplicating an enumerable object in the loop
+            str2_codepoint_enumerable = str2.each_codepoint
+
+            str1.each_codepoint.with_index do |char1, i|
+              e = i+1
+
+              str2_codepoint_enumerable.with_index do |char2, j|
+                cost = (char1 == char2) ? 0 : 1
+                x = [
+                     d[j+1] + 1, # insertion
+                     e + 1,      # deletion
+                     d[j] + cost # substitution
+                    ].min
+                d[j] = e
+                e = x
+              end
+
+              d[m] = x
+            end
+
+            x
+          end
+
+          # Prints a list of generators.
+          def print_list(base, namespaces) #:nodoc:
+            return if namespaces.empty?
+            puts "#{base.camelize}:"
+
+            namespaces.each do |namespace|
+              puts("  #{namespace}")
+            end
+
+            puts
+          end
+
+          # Receives namespaces in an array and tries to find matching generators
+          # in the load path.
+          def lookup(namespaces) #:nodoc:
+            paths = namespaces_to_paths(namespaces)
+
+            paths.each do |raw_path|
+              lookup_paths.each do |base|
+                path = "#{base}/#{raw_path}_#{command_type}"
+
+                begin
+                  require path
+                  return
+                rescue LoadError => e
+                  raise unless e.message =~ /#{Regexp.escape(path)}$/
+                rescue Exception => e
+                  warn "[WARNING] Could not load #{command_type} #{path.inspect}. Error: #{e.message}.\n#{e.backtrace.join("\n")}"
+                end
+              end
+            end
+          end
+
+          # This will try to load any command in the load path to show in help.
+          def lookup! #:nodoc:
+            $LOAD_PATH.each do |base|
+              Dir[File.join(base, *file_lookup_paths)].each do |path|
+                begin
+                  path = path.sub("#{base}/", "")
+                  require path
+                rescue Exception
+                  # No problem
+                end
+              end
+            end
+          end
+
+          # Convert namespaces to paths by replacing ":" for "/" and adding
+          # an extra lookup. For example, "rails:model" should be searched
+          # in both: "rails/model/model_generator" and "rails/model_generator".
+          def namespaces_to_paths(namespaces) #:nodoc:
+            paths = []
+            namespaces.each do |namespace|
+              pieces = namespace.split(":")
+              paths << pieces.dup.push(pieces.last).join("/")
+              paths << pieces.join("/")
+            end
+            paths.uniq!
+            paths
+          end
+      end
+    end
+  end
+end
diff --git a/railties/lib/rails/command/environment_argument.rb b/railties/lib/rails/command/environment_argument.rb
new file mode 100644
index 0000000000..d4221d142b
--- /dev/null
+++ b/railties/lib/rails/command/environment_argument.rb
@@ -0,0 +1,32 @@
+require "active_support"
+
+module Rails
+  module Command
+    module EnvironmentArgument #:nodoc:
+      extend ActiveSupport::Concern
+
+      included do
+        argument :environment, optional: true, banner: "environment"
+      end
+
+      private
+        def extract_environment_option_from_argument
+          if environment
+            self.options = options.merge(environment: acceptable_environment(environment))
+          end
+        end
+
+        def acceptable_environment(env = nil)
+          if available_environments.include? env
+            env
+          else
+            %w(production development test).detect { |e| e =~ /^#{env}/ } || env
+          end
+        end
+
+        def available_environments
+          Dir["config/environments/*.rb"].map { |fname| File.basename(fname, ".*") }
+        end
+    end
+  end
+end