Ticket #193 - alias_task first implementation

lib/capistrano/configuration.rb

@@ -1,5 +1,6 @@
 require 'capistrano/logger'
 
+require 'capistrano/configuration/alias_task'
 require 'capistrano/configuration/callbacks'
 require 'capistrano/configuration/connections'
 require 'capistrano/configuration/execution'
@@ -33,7 +34,7 @@ module Capistrano
 
     # The includes must come at the bottom, since they may redefine methods
     # defined in the base class.
-    include Connections, Execution, Loading, Namespaces, Roles, Servers, Variables
+    include AliasTask, Connections, Execution, Loading, Namespaces, Roles, Servers, Variables
 
     # Mix in the actions
     include Actions::FileTransfer, Actions::Inspect, Actions::Invocation

lib/capistrano/configuration/alias_task.rb

@@ -0,0 +1,19 @@
+module Capistrano
+  class Configuration
+    module AliasTask
+      # Attempts to find the task at the given fully-qualified path, and
+      # alias it. If arguments don't have correct task names, an ArgumentError
+      # wil be raised. If no such task exists, a Capistrano::NoSuchTaskError
+      # will be raised.
+      def alias_task(new_name, old_name)
+        if !new_name.respond_to?(:to_sym) or !old_name.respond_to?(:to_sym)
+          raise ArgumentError, "expected a valid task name"
+        end
+
+        task = find_task(old_name) or raise NoSuchTaskError, "the task `#{old_name}' does not exist"
+
+        task(new_name, task.options, &task.body)
+      end
+    end
+  end
+end

lib/capistrano/configuration/execution.rb

@@ -140,4 +140,4 @@ module Capistrano
       end
     end
   end
-end
+end

test/configuration/alias_task_test.rb

@@ -0,0 +1,63 @@
+require 'utils'
+require 'capistrano/configuration/alias_task'
+require 'capistrano/configuration/execution'
+require 'capistrano/configuration/namespaces'
+require 'capistrano/task_definition'
+
+class AliasTaskTest < Test::Unit::TestCase
+  class MockConfig
+    attr_reader :options
+    attr_accessor :logger
+
+    def initialize(options={})
+      @options = {}
+      @logger = options.delete(:logger)
+    end
+
+    include Capistrano::Configuration::AliasTask
+    include Capistrano::Configuration::Execution
+    include Capistrano::Configuration::Namespaces
+  end
+
+  def setup
+    @config = MockConfig.new( :logger => stub(:debug => nil, :info => nil, :important => nil) )
+  end
+
+  def test_makes_a_copy_of_the_task
+    @config.task(:foo) { 42 }
+    @config.alias_task 'new_foo', 'foo'
+
+    assert @config.tasks.key?(:new_foo)
+  end
+
+  def test_aliased_task_do_the_same
+    @config.task(:foo) { 42 }
+    @config.alias_task 'new_foo', 'foo'
+
+    assert_equal 42, @config.find_and_execute_task('new_foo')
+  end
+
+  def test_raise_exception_when_task_doesnt_exist
+    assert_raises(Capistrano::NoSuchTaskError) { @config.alias_task 'non_existant_task', 'fail_miserably' }
+  end
+
+  def test_convert_task_names_using_to_str
+    @config.task(:foo, :role => :app) { 42 }
+
+    @config.alias_task 'one', 'foo'
+    @config.alias_task :two, 'foo'
+    @config.alias_task 'three', :foo
+    @config.alias_task :four, :foo
+
+    assert @config.tasks.key?(:one)
+    assert @config.tasks.key?(:two)
+    assert @config.tasks.key?(:three)
+    assert @config.tasks.key?(:four)
+  end
+
+  def test_raise_an_exception_when_task_names_can_not_be_converted
+    @config.task(:foo, :role => :app) { 42 }
+
+    assert_raises(ArgumentError) { @config.alias_task mock('x'), :foo }
+  end
+end