Merge pull request #50 from rgo/ticket-193-alias-task

Alias Task.

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 @@ def initialize(options={}) #:nodoc:
 
     # 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 +1,25 @@
+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.
+      #
+      # Usage:
+      #
+      #   alias_task :original_deploy, :deploy
+      #
+      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.name = new_name
+
+        define_task(task)
+      end
+    end
+  end
+end

lib/capistrano/configuration/execution.rb

@@ -140,4 +140,4 @@ def invoke_task_directly(task)
       end
     end
   end
-end
+end

lib/capistrano/configuration/namespaces.rb

@@ -97,12 +97,17 @@ def task(name, options={}, &block)
           raise ArgumentError, "defining a task named `#{name}' would shadow an existing #{thing} with that name"
         end
 
-        tasks[name] = TaskDefinition.new(name, self, {:desc => next_description(:reset)}.merge(options), &block)
 
-        if !task_already_defined
-          metaclass = class << self; self; end
-          metaclass.send(:define_method, name) { execute_task(tasks[name]) }
-        end
+        task = TaskDefinition.new(name, self, {:desc => next_description(:reset)}.merge(options), &block)
+
+        define_task(task)
+      end
+
+      def define_task(task)
+        tasks[task.name] = task
+
+        metaclass = class << self; self; end
+        metaclass.send(:define_method, task.name) { execute_task(tasks[task.name]) }
       end
 
       # Find the task with the given name, where name is the fully-qualified
@@ -189,9 +194,10 @@ def method_missing(sym, *args, &block)
             end
           end
 
+          include Capistrano::Configuration::AliasTask
           include Capistrano::Configuration::Namespaces
           undef :desc, :next_description
         end
     end
   end
-end
+end

lib/capistrano/task_definition.rb

@@ -29,6 +29,11 @@ def fully_qualified_name
         end
       end
     end
+
+    def name=(value)
+      raise ArgumentError, "expected a valid task name" if !value.respond_to?(:to_sym)
+      @name = value.to_sym
+    end
 
     # Returns the description for this task, with newlines collapsed and
     # whitespace stripped. Returns the empty string if there is no

test/configuration/alias_task_test.rb

@@ -0,0 +1,110 @@
+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_aliased_task_should_preserve_description
+    @config.task(:foo, :desc => "the Ultimate Question of Life, the Universe, and Everything" ) { 42 }
+    @config.alias_task 'new_foo', 'foo'
+
+    task = @config.find_task('foo')
+    new_task = @config.find_task('new_foo')
+
+    assert_equal task.description, new_task.description
+  end
+
+  def test_aliased_task_should_preserve_on_error
+    @config.task(:foo, :on_error => :continue) { 42 }
+    @config.alias_task 'new_foo', 'foo'
+
+    task = @config.find_task('foo')
+    new_task = @config.find_task('new_foo')
+
+    assert_equal task.on_error, new_task.on_error
+  end
+
+  def test_aliased_task_should_preserve_max_hosts
+    @config.task(:foo, :max_hosts => 5) { 42 }
+    @config.alias_task 'new_foo', 'foo'
+
+    task = @config.find_task('foo')
+    new_task = @config.find_task('new_foo')
+
+    assert_equal task.max_hosts, new_task.max_hosts
+  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
+
+  def test_should_include_namespace
+    @config.namespace(:outer) do
+      task(:foo) { 42 }
+      alias_task 'new_foo', 'foo'
+
+      namespace(:inner) do
+        task(:foo) { 43 }
+        alias_task 'new_foo', 'foo'
+      end
+    end
+
+    assert_equal 42, @config.find_and_execute_task('outer:new_foo')
+    assert_equal 42, @config.find_and_execute_task('outer:foo')
+    assert_equal 43, @config.find_and_execute_task('outer:inner:new_foo')
+    assert_equal 43, @config.find_and_execute_task('outer:inner:foo')
+  end
+end

test/task_definition_test.rb

@@ -25,6 +25,19 @@ def test_fqn_at_top_level_when_default_should_be_default
     assert_equal "default", task.fully_qualified_name
   end
 
+  def test_name_should_change_task_name
+    task = new_task(:foo)
+    task.name = :bar
+
+    assert_equal :bar, task.name
+  end
+
+  def test_raise_an_exception_when_task_names_can_not_be_converted
+    task = new_task('valid task name')
+
+    assert_raises(ArgumentError) { task.name = ['invalid task name'] }
+  end
+
   def test_deprecation_warning_on_method_name_beginning_with_before_underscore
     name = "before_test"
     Kernel.expects(:warn).with("[Deprecation Warning] Naming tasks with before_ and after_ is deprecated, please see the new before() and after() methods. (Offending task name was #{name})")
@@ -113,4 +126,4 @@ def test_brief_description_should_not_break_at_period_in_middle_of_sentence
     task = new_task(:testing, @namespace, :desc => "Take file.txt and copy it. Then do something else.")
     assert_equal "Take file.txt and copy it.", task.brief_description
   end
-end
+end