Implement task evaluation feature

features/task.feature

@@ -0,0 +1,12 @@
+Feature: tasks
+
+  Scenario: evaluates ruby code grouped in task blocks
+    Given a recipe with:
+      """
+      task :hello do
+        puts 'hello from recipe'
+      end
+      """
+    When I execute the recipe
+    Then the exit status must be 0
+    And the output must contain "hello from recipe"

lib/producer/core.rb

@@ -1,3 +1,4 @@
 require 'producer/core/cli'
 require 'producer/core/recipe'
+require 'producer/core/task'
 require 'producer/core/version'

lib/producer/core/recipe.rb

@@ -13,11 +13,15 @@ module Producer
 
       def evaluate
         dsl = DSL.new(@code)
+        dsl.tasks.each.map(&:evaluate)
       end
 
 
       class DSL
+        attr_reader :tasks
+
         def initialize(code = nil, &block)
+          @tasks = []
           if code
             instance_eval code
           else
@@ -31,6 +35,10 @@ module Producer
         def source(filepath)
           instance_eval File.read("./#{filepath}.rb")
         end
+
+        def task(name, &block)
+          @tasks << Task.new(name, &block)
+        end
       end
     end
   end

lib/producer/core/task.rb

@@ -0,0 +1,16 @@
+module Producer
+  module Core
+    class Task
+      attr_reader :name
+
+      def initialize(name, &block)
+        @name   = name
+        @block  = block
+      end
+
+      def evaluate
+        instance_eval &@block
+      end
+    end
+  end
+end

spec/producer/core/recipe_spec.rb

@@ -54,6 +54,23 @@ module Producer::Core
           expect { dsl }.to raise_error(RuntimeError, 'error from recipe')
         end
       end
+
+      describe '#tasks' do
+        let(:code) { Proc.new { task(:some_task) } }
+
+        it 'returns registered tasks' do
+          expect(dsl.tasks[0].name).to eq :some_task
+        end
+      end
+
+      describe '#task' do
+        let(:code) { Proc.new { task(:one); task(:two) } }
+
+        it 'registers tasks in declaration order' do
+          expect(dsl.tasks[0].name).to eq :one
+          expect(dsl.tasks[1].name).to eq :two
+        end
+      end
     end
   end
 end

spec/producer/core/task_spec.rb

@@ -0,0 +1,23 @@
+require 'spec_helper'
+
+module Producer::Core
+  describe Task do
+    let(:name)      { :some_task }
+    let(:block)     { }
+    subject(:task)  { Task.new(name, &block) }
+
+    describe '#name' do
+      it 'returns its name' do
+        expect(task.name).to eq name
+      end
+    end
+
+    describe 'evaluate' do
+      let(:block) { Proc.new { raise 'error from task' } }
+
+      it 'evaluates its block' do
+        expect { task.evaluate }.to raise_error(RuntimeError, 'error from task')
+      end
+    end
+  end
+end