Implement condition DSL negated test prefix (no_*)

* Allow no_* to be used for every tests in condition DSL:
  condition { no_has_env :shell, '/bin/sh' };
* Modify Test constructor to accept negated: named argument, implement
  #negated? and #pass?;
* Rename #success? to #verify in all test classes.

features/tests/negated_test.feature

@@ -0,0 +1,44 @@
+@sshd
+Feature: negated test prefix (no_)
+
+  Scenario: prefixed test fails when non-prefixed test is successful
+    Given a recipe with:
+      """
+      target 'some_host.test'
+
+      task :successful_test do
+        condition { has_env :shell }
+
+        echo 'successful_test'
+      end
+
+      task :negated_test do
+        condition { no_has_env :shell }
+
+        echo 'negated_test'
+      end
+      """
+    When I successfully execute the recipe
+    Then the output must contain "successful_test"
+    And the output must not contain "negated_test"
+
+  Scenario: prefixed test fails when non-prefixed test is failing
+    Given a recipe with:
+      """
+      target 'some_host.test'
+
+      task :failing_test do
+        condition { has_env :inexistent_var }
+
+        echo 'failing_test'
+      end
+
+      task :negated_test do
+        condition { no_has_env :inexistent_var }
+
+        echo 'negated_test'
+      end
+      """
+    When I successfully execute the recipe
+    Then the output must not contain "failing_test"
+    And the output must contain "negated_test"

lib/producer/core/condition.rb

@@ -14,7 +14,7 @@ module Producer
 
       def met?
         return !!@return_value if @tests.empty?
-        @tests.each { |t| return false unless t.success? }
+        @tests.each { |t| return false unless t.pass? }
         true
       end
 

lib/producer/core/condition/dsl.rb

@@ -13,6 +13,9 @@ module Producer
             define_method(keyword) do |*args|
               @tests << klass.new(@env, *args)
             end
+            define_method("no_#{keyword}") do |*args|
+              @tests << klass.new(@env, *args, negated: true)
+            end
           end
         end
 

lib/producer/core/test.rb

@@ -3,9 +3,18 @@ module Producer
     class Test
       attr_reader :env, :arguments
 
-      def initialize(env, *arguments)
+      def initialize(env, *arguments, negated: false)
         @env        = env
         @arguments  = arguments
+        @negated    = negated
+      end
+
+      def negated?
+        @negated
+      end
+
+      def pass?
+        verify ^ negated?
       end
     end
   end

lib/producer/core/tests/has_env.rb

@@ -2,7 +2,7 @@ module Producer
   module Core
     module Tests
       class HasEnv < Test
-        def success?
+        def verify
           env.remote.environment.has_key? arguments.first.to_s.upcase
         end
       end

lib/producer/core/tests/has_file.rb

@@ -2,7 +2,7 @@ module Producer
   module Core
     module Tests
       class HasFile < Test
-        def success?
+        def verify
           env.remote.fs.has_file? arguments.first
         end
       end

spec/producer/core/condition/dsl_spec.rb

@@ -49,6 +49,10 @@ module Producer::Core
       it 'defines a new test keyword' do
         expect(dsl).to respond_to :some_test
       end
+
+      it 'defines the negated test' do
+        expect(dsl).to respond_to :no_some_test
+      end
     end
 
     describe '#initialize' do
@@ -96,6 +100,16 @@ module Producer::Core
           dsl.evaluate
           expect(dsl.tests).to include(some_test)
         end
+
+        context 'when keyword is prefixed with "no_"' do
+          let(:block) { proc { no_some_test :some, :args } }
+
+          it 'builds a negated test' do
+            expect(some_test_class)
+              .to receive(:new).with(env, :some, :args, negated: true)
+            dsl.evaluate
+          end
+        end
       end
     end
   end

spec/producer/core/test_spec.rb

@@ -14,6 +14,18 @@ module Producer::Core
       it 'assigns the arguments' do
         expect(test.instance_eval { @arguments }).to eq arguments
       end
+
+      it 'assigns negated as false by default' do
+        expect(test.instance_eval { @negated }).to be false
+      end
+
+      context 'when negated option is true' do
+        subject(:test) { Test.new(env, *arguments, negated: true) }
+
+        it 'assigns negated as true' do
+          expect(test.instance_eval { @negated }).to be true
+        end
+      end
     end
 
     describe '#env' do
@@ -27,5 +39,45 @@ module Producer::Core
         expect(test.arguments).to eq arguments
       end
     end
+
+    describe '#negated?' do
+      it 'returns false' do
+        expect(test.negated?).to be false
+      end
+
+      context 'when test is negated' do
+        subject(:test) { Test.new(env, *arguments, negated: true) }
+
+        it 'returns true' do
+          expect(test.negated?).to be true
+        end
+      end
+    end
+
+    describe '#pass?' do
+      it 'returns true when #verify is true' do
+        allow(test).to receive(:verify) { true }
+        expect(test.pass?).to be true
+      end
+
+      it 'returns false when #verify is false' do
+        allow(test).to receive(:verify) { false }
+        expect(test.pass?).to be false
+      end
+
+      context 'when test is negated' do
+        subject(:test) { Test.new(env, *arguments, negated: true) }
+
+        it 'returns false when #verify is true' do
+          allow(test).to receive(:verify) { true }
+          expect(test.pass?).to be false
+        end
+
+        it 'returns true when #verify is false' do
+          allow(test).to receive(:verify) { false }
+          expect(test.pass?).to be true
+        end
+      end
+    end
   end
 end

spec/producer/core/tests/has_env_spec.rb

@@ -10,7 +10,7 @@ module Producer::Core
       expect(has_env).to be_a Test
     end
 
-    describe '#success?' do
+    describe '#verify' do
       let(:environment) { double('environment') }
 
       before do
@@ -19,22 +19,22 @@ module Producer::Core
 
       it 'stringifies the queried variable name' do
         expect(environment).to receive(:has_key?).with(kind_of(String))
-        has_env.success?
+        has_env.verify
       end
 
       it 'upcases the queried variable name' do
         expect(environment).to receive(:has_key?).with('SOME_VARIABLE_NAME')
-        has_env.success?
+        has_env.verify
       end
 
       it 'returns true when remote environment var is defined' do
         allow(environment).to receive(:has_key?) { true }
-        expect(has_env.success?).to be true
+        expect(has_env.verify).to be true
       end
 
       it 'returns false when remote environment var is not defined' do
         allow(environment).to receive(:has_key?) { false }
-        expect(has_env.success?).to be false
+        expect(has_env.verify).to be false
       end
     end
   end

spec/producer/core/tests/has_file_spec.rb

@@ -10,18 +10,18 @@ module Producer::Core
       expect(has_file).to be_a Test
     end
 
-    describe '#success?', :ssh do
+    describe '#verify', :ssh do
       before { sftp_story }
 
       it 'delegates the call on remote FS' do
         expect(env.remote.fs).to receive(:has_file?).with(filepath)
-        has_file.success?
+        has_file.verify
       end
 
       it 'returns the file existence' do
         existence = double('existence')
         allow(env.remote.fs).to receive(:has_file?) { existence }
-        expect(has_file.success?).to be existence
+        expect(has_file.verify).to be existence
       end
     end
   end

spec/support/tests_helpers.rb

@@ -1,9 +1,9 @@
 module TestsHelpers
   def test_ok
-    double('test', success?: true)
+    double('test', pass?: true)
   end
 
   def test_ko
-    double('test', success?: false)
+    double('test', pass?: false)
   end
 end