Build conditions with DSL evaluated tests:

In Condition:

  * Modify constructor to accepts tests and a default return value;
  * Implement #met?;
  * Modify #! so that it return the negated value returned by #met?.

  In Condition::DSL:

  * Modify .evaluate to build the condition with tests and the value
    returned by a the evaluated condition block.

  Add a basic Test base class, with env and arguments as attributes.

  Add some spec helpers to build some easily testable kind of Test
instances (as test doubles).

lib/producer/core.rb

@@ -1,6 +1,11 @@
+# task actions
 require 'producer/core/action'
 require 'producer/core/actions/echo'
 require 'producer/core/actions/shell_command'
+
+# condition tests (need to be defined before the condition DSL)
+require 'producer/core/test'
+
 require 'producer/core/cli'
 require 'producer/core/condition'
 require 'producer/core/condition/dsl'

lib/producer/core/condition.rb

@@ -7,12 +7,19 @@ module Producer
         end
       end
 
-      def initialize(expression)
-        @expression = expression
+      def initialize(tests, return_value = nil)
+        @tests        = tests
+        @return_value = return_value
+      end
+
+      def met?
+        return !!@return_value if @tests.empty?
+        @tests.each { |t| return false unless t.success? }
+        true
       end
 
       def !
-        !@expression
+        !met?
       end
     end
   end

lib/producer/core/condition/dsl.rb

@@ -5,7 +5,8 @@ module Producer
         class << self
           def evaluate(env, &block)
             dsl = new(env, &block)
-            Condition.new(dsl.evaluate)
+            return_value = dsl.evaluate
+            Condition.new(dsl.tests, return_value)
           end
 
           def define_test(keyword, klass)

lib/producer/core/test.rb

@@ -0,0 +1,12 @@
+module Producer
+  module Core
+    class Test
+      attr_reader :env, :arguments
+
+      def initialize(env, *arguments)
+        @env        = env
+        @arguments  = arguments
+      end
+    end
+  end
+end