Forward standard error stream from remote execution

lib/producer/core/action.rb

@@ -2,7 +2,7 @@ module Producer
   module Core
     class Action
       extend Forwardable
-      def_delegators :@env, :input, :output, :remote
+      def_delegators :@env, :input, :output, :error_output, :remote
       def_delegators :remote, :fs
 
       attr_reader :env, :arguments

lib/producer/core/actions/shell_command.rb

@@ -7,7 +7,7 @@ module Producer
         end
 
         def apply
-          remote.execute(arguments.first, output)
+          remote.execute(arguments.first, output, error_output)
         end
       end
     end

lib/producer/core/cli.rb

@@ -31,7 +31,7 @@ module Producer
         @arguments  = args
         @stdin      = stdin
         @stdout     = stdout
-        @env        = Env.new(input: stdin, output: stdout)
+        @env        = Env.new(input: stdin, output: stdout, error_output: stderr)
       end
 
       def parse_arguments!

lib/producer/core/env.rb

@@ -1,15 +1,16 @@
 module Producer
   module Core
     class Env
-      attr_reader   :input, :output, :registry, :logger
+      attr_reader   :input, :output, :error_output, :registry, :logger
       attr_accessor :target, :verbose, :dry_run
 
-      def initialize(input: $stdin, output: $stdout, remote: nil, registry: {})
-        @verbose  = @dry_run = false
-        @input    = input
-        @output   = output
-        @remote   = remote
-        @registry = registry
+      def initialize(input: $stdin, output: $stdout, error_output: $stderr, remote: nil, registry: {})
+        @verbose      = @dry_run = false
+        @input        = input
+        @output       = output
+        @error_output = error_output
+        @remote       = remote
+        @registry     = registry
       end
 
       def remote

lib/producer/core/remote.rb

@@ -24,13 +24,17 @@ module Producer
         @fs ||= Remote::FS.new(session.sftp.connect)
       end
 
-      def execute(command, output = '')
+      def execute(command, output = '', error_output = '')
         channel = session.open_channel do |channel|
           channel.exec command do |ch, success|
             ch.on_data do |c, data|
               output << data
             end
 
+            ch.on_extended_data do |c, type, data|
+              error_output << data
+            end
+
             ch.on_request 'exit-status' do |c, data|
               exit_status = data.read_long
               fail RemoteCommandExecutionError, command if exit_status != 0

lib/producer/core/testing/mock_remote.rb

@@ -6,13 +6,18 @@ module Producer
           fail 'no session for mock remote!'
         end
 
-        def execute(command, output = '')
-          tokens = command.split
+        def execute(command, output = '', error_output = '')
+          tokens = command.gsub(/\d?>.*/, '').split
           program = tokens.shift
 
           case program
           when 'echo'
-            output << tokens.join(' ') << "\n"
+            out = tokens.join(' ') << "\n"
+            if command =~ />&2\z/
+              error_output << out
+            else
+              output << out
+            end
           when 'true'
             output << ''
           when 'false'