Added a dry-run option to see what commands will be run without actually running them

lib/capistrano/cli/execute.rb

@@ -23,6 +23,7 @@ module Capistrano
       def execute!
         config = instantiate_configuration
         config.debug = options[:debug]
+        config.dry_run = options[:dry_run]
         config.logger.level = options[:verbose]
 
         set_pre_vars(config)

lib/capistrano/cli/options.rb

@@ -31,6 +31,10 @@ module Capistrano
             "Prompts before each remote command execution."
           ) { |value| options[:debug] = true }
 
+          opts.on("-n", "--dry-run",
+            "Prints out commands without running them."
+          ) { |value| options[:dry_run] = true }
+
           opts.on("-e", "--explain TASK",
             "Displays help (if available) for the task."
           ) { |value| options[:explain] = value }

lib/capistrano/configuration.rb

@@ -19,10 +19,11 @@ module Capistrano
   # define roles, and set configuration variables.
   class Configuration
     # The logger instance defined for this configuration.
-    attr_accessor :debug, :logger
+    attr_accessor :debug, :logger, :dry_run
 
     def initialize #:nodoc:
       @debug = false
+      @dry_run = false
       @logger = Logger.new
     end
 

lib/capistrano/configuration/actions/invocation.rb

@@ -46,7 +46,7 @@ module Capistrano
           block ||= self.class.default_io_proc
           logger.debug "executing #{cmd.strip.inspect}"
 
-          return if debug && continue_execution(cmd) == false
+          return if dry_run || (debug && continue_execution(cmd) == false)
 
           options = add_default_command_options(options)
 

test/cli/execute_test.rb

@@ -15,7 +15,7 @@ class CLIExecuteTest < Test::Unit::TestCase
   def setup
     @cli = MockCLI.new
     @logger = stub_everything
-    @config = stub(:logger => @logger, :debug= => nil)
+    @config = stub(:logger => @logger, :debug= => nil, :dry_run= => nil)
     @config.stubs(:set)
     @config.stubs(:load)
     @config.stubs(:trigger)

test/cli/options_test.rb

@@ -30,6 +30,18 @@ class CLIOptionsTest < Test::Unit::TestCase
     assert @cli.options[:debug]
   end
 
+  def test_parse_options_with_n_should_set_dry_run_option
+    @cli.args << "-n"
+    @cli.parse_options!
+    assert @cli.options[:dry_run]
+  end
+
+  def test_parse_options_with_dry_run_should_set_dry_run_option
+    @cli.args << "--dry-run"
+    @cli.parse_options!
+    assert @cli.options[:dry_run]
+  end
+
   def test_parse_options_with_e_should_set_explain_option
     @cli.args << "-e" << "sample"
     @cli.parse_options!

test/configuration/actions/invocation_test.rb

@@ -5,6 +5,7 @@ class ConfigurationActionsInvocationTest < Test::Unit::TestCase
   class MockConfig
     attr_reader :options
     attr_accessor :debug
+    attr_accessor :dry_run
 
     def initialize
       @options = {}
@@ -40,6 +41,12 @@ class ConfigurationActionsInvocationTest < Test::Unit::TestCase
     @config.run "ls", :foo => "bar"
   end
 
+  def test_run_will_return_if_dry_run
+    @config.expects(:dry_run).returns(true)
+    @config.expects(:execute_on_servers).never
+    @config.run "ls", :foo => "bar"
+  end
+
   def test_run_without_block_should_use_default_io_proc
     @config.expects(:execute_on_servers).yields(%w(s1 s2 s3).map { |s| server(s) })
     @config.expects(:sessions).returns(Hash.new { |h,k| h[k] = k.host.to_sym }).times(3)