Implement nested tasks

features/task_nested_tasks.feature

@@ -0,0 +1,15 @@
+Feature: nested tasks
+
+  Background:
+    Given a recipe with:
+      """
+      task :outer_task do
+        task :inner_task do
+          echo 'OK'
+        end
+      end
+      """
+
+    Scenario: applies nested tasks
+      When I successfully execute the recipe
+      Then the output must match /\AOK/

lib/producer/core/task.rb

@@ -43,6 +43,10 @@ module Producer
         @condition
       end
 
+      def task(name, *args, &block)
+        @actions << self.class.evaluate(@env, name, *args, &block)
+      end
+
       def ask(question, choices, prompter: Prompter.new(@env.input, @env.output))
         prompter.prompt(question, choices)
       end

lib/producer/core/worker.rb

@@ -18,8 +18,12 @@ module Producer
         if task.condition_met?
           @env.log "Task: `#{task}' applying..."
           task.actions.each do |e|
-            @env.log " action: #{e}"
+            case e
-            e.apply unless @env.dry_run?
+            when Task then process_task e
+            else
+              @env.log " action: #{e}"
+              e.apply unless @env.dry_run?
+            end
           end
         else
           @env.log "Task: `#{task}' skipped"

spec/producer/core/task_spec.rb

@@ -126,6 +126,15 @@ module Producer::Core
       end
     end
 
+    describe '#task' do
+      before { described_class.define_action(:some_action, SomeAction) }
+
+      it 'registers a nested task as an action' do
+        task.task(:nested_task) { some_action }
+        expect(task.actions).to match [an_instance_of(Task)]
+      end
+    end
+
     describe '#ask' do
       let(:question)  { 'Which letter?' }
       let(:choices)   { [[:a, ?A], [:b, ?B]] }

spec/producer/core/worker_spec.rb

@@ -25,9 +25,9 @@ module Producer::Core
     end
 
     describe '#process_task' do
-      let(:env)       { instance_spy Env, dry_run?: false }
+      let(:env)     { instance_spy Env, dry_run?: false }
-      let(:action)    { double('action', to_s: 'echo').as_null_object }
+      let(:action)  { double('action', to_s: 'echo').as_null_object }
-      let(:task)      { Task.new(env, :some_task, [action]) }
+      let(:task)    { Task.new(env, :some_task, [action]) }
 
       it 'logs task info' do
         expect(env).to receive(:log).with /\ATask: `some_task'/
@@ -68,11 +68,21 @@ module Producer::Core
           worker.process_task task
         end
 
-        it 'logs the task as beeing skipped' do
+        it 'logs the task as being skipped' do
           expect(env).to receive(:log).with /some_task.+skipped\z/
           worker.process_task task
         end
       end
+
+      context 'when a task contains nested tasks' do
+        let(:inner_task)  { Task.new(env, :inner, [action]) }
+        let(:outer_task)  { Task.new(env, :outer, [inner_task]) }
+
+        it 'processes nested tasks' do
+          expect(action).to receive :apply
+          worker.process [outer_task]
+        end
+      end
     end
   end
 end