Introducing lotus runner command

lib/lotus/cli.rb

@@ -104,6 +104,24 @@ def routes
       end
     end
 
+    desc 'runner [FILE|EXPRESSION]', 'Evaluate a file or expression with the preloaded environment and application'
+    long_desc <<-EOS
+      `lotus runner` Evaluate a file or expression with the preloaded environment and application.
+
+      $ > lotus runner `puts Lotus.env` => The current environment
+
+      $ > lotus runner ./my_script.rb => Loads the file.
+    EOS
+    method_option :help, desc: 'displays the usage method'
+    def runner(expression_or_file)
+      if options[:help]
+        invoke :help, ['runner']
+      else
+        require 'lotus/commands/runner'
+        Lotus::Commands::Runner.new(options, expression_or_file).start
+      end
+    end
+
     require 'lotus/cli_sub_commands/db'
     register Lotus::CliSubCommands::DB, 'db', 'db [SUBCOMMAND]', 'manage set of DB operations'
 

lib/lotus/commands/runner.rb

@@ -0,0 +1,53 @@
+require 'lotus/environment'
+require 'lotus/application'
+
+module Lotus
+  module Commands
+    # Evaluate a file or expression with the preloaded environment and application.
+    #
+    # It is run with:
+    #
+    #   `bundle exec lotus runner ./my_script.rb`
+    #
+    # or
+    #
+    #   `bundle exec lotus runner 'puts Lotus.env'`
+    #
+    # @since x.x.x
+    # @api private
+    class Runner
+      # @since x.x.x
+      # @api private
+      class NoArgumentGivenException < ::StandardError
+      end
+
+      # @param options [Hash] Environment's options
+      # @param expression_or_file [String] Expression or file to evaluate
+      #
+      # @since x.x.x
+      # @see Lotus::Environment#initialize
+      # @see Lotus::Environment#require_application_environment
+      # @see Lotus::Application.preload!
+      def initialize(options, expression_or_file)
+        @expression_or_file = expression_or_file
+        raise NoArgumentGivenException.new if @expression_or_file.nil?
+
+        @environment = Lotus::Environment.new(options)
+        @environment.require_application_environment
+        Lotus::Application.preload!
+      end
+
+      # Evaluate a file or expression with the preloaded environment and application.
+      #
+      # @since x.x.x
+      def start
+        if File.exists?(@expression_or_file)
+          $0 = @expression_or_file
+          Kernel.load(@expression_or_file)
+        else
+          eval(@expression_or_file, binding, __FILE__, __LINE__)
+        end
+      end
+    end
+  end
+end

test/commands/runner_test.rb

@@ -0,0 +1,39 @@
+require 'test_helper'
+require 'lotus/commands/runner'
+
+describe Lotus::Commands::Runner do
+  before do
+    Lotus::Application.applications.clear
+    @old_pwd = Dir.pwd
+    Dir.chdir 'test/fixtures/microservices'
+  end
+
+  after do
+    Dir.chdir @old_pwd
+  end
+
+  describe '#start' do
+    it 'evaluate expression' do
+      command   = Lotus::Commands::Runner.new({}, 'puts Lotus.env')
+      output, _ = capture_io { command.start }
+      output.chomp.must_equal 'development'
+    end
+
+    it 'evaluate ruby file' do
+      command   = Lotus::Commands::Runner.new({}, 'apps/backend/scripts/script_001.rb')
+      output, _ = capture_io { command.start }
+      output.chomp.must_equal 'development'
+    end
+
+    it 'evaluate ruby file and return $0' do
+      filename  = 'apps/backend/scripts/script_002.rb'
+      command   = Lotus::Commands::Runner.new({}, filename)
+      output, _ = capture_io { command.start }
+      output.chomp.must_equal filename
+    end
+
+    it 'no argument given' do
+      -> { Lotus::Commands::Runner.new({}, nil) }.must_raise Lotus::Commands::Runner::NoArgumentGivenException
+    end
+  end
+end

test/fixtures/microservices/apps/backend/scripts/script_001.rb

@@ -0,0 +1 @@
+puts Lotus.env

test/fixtures/microservices/apps/backend/scripts/script_002.rb

@@ -0,0 +1 @@
+puts $0