Implement `has_executable' condition keyword

features/tests/has_executable.feature

@@ -0,0 +1,30 @@
+@sshd
+Feature: `has_executable' condition keyword
+
+  Scenario: succeeds when remote executable is available
+    Given a recipe with:
+      """
+      target 'some_host.test'
+
+      task :testing_executable_availability do
+        condition { has_executable 'true' }
+
+        echo 'evaluated'
+      end
+      """
+    When I successfully execute the recipe
+    Then the output must contain "evaluated"
+
+  Scenario: succeeds when remote executable is available
+    Given a recipe with:
+      """
+      target 'some_host.test'
+
+      task :testing_executable_availability do
+        condition { has_executable 'some_non_existent_executable' }
+
+        echo 'evaluated'
+      end
+      """
+    When I successfully execute the recipe
+    Then the output must not contain "evaluated"

lib/producer/core.rb

@@ -19,6 +19,7 @@ require 'producer/core/test'
 require 'producer/core/tests/file_contains'
 require 'producer/core/tests/has_dir'
 require 'producer/core/tests/has_env'
+require 'producer/core/tests/has_executable'
 require 'producer/core/tests/has_file'
 
 require 'producer/core/cli'

lib/producer/core/condition/dsl.rb

@@ -13,10 +13,11 @@ module Producer
           end
         end
 
-        define_test :file_contains, Tests::FileContains
-        define_test :has_env,       Tests::HasEnv
-        define_test :has_dir,       Tests::HasDir
-        define_test :has_file,      Tests::HasFile
+        define_test :file_contains,   Tests::FileContains
+        define_test :has_env,         Tests::HasEnv
+        define_test :has_executable,  Tests::HasExecutable
+        define_test :has_dir,         Tests::HasDir
+        define_test :has_file,        Tests::HasFile
 
         attr_reader :block, :env, :tests
 

lib/producer/core/tests/has_executable.rb

@@ -0,0 +1,14 @@
+module Producer
+  module Core
+    module Tests
+      class HasExecutable < Test
+        def verify
+          remote.execute("type #{arguments.first}")
+          true
+        rescue RemoteCommandExecutionError
+          false
+        end
+      end
+    end
+  end
+end

spec/producer/core/condition/dsl_spec.rb

@@ -7,7 +7,13 @@ module Producer::Core
       let(:env)     { double 'env' }
       subject(:dsl) { DSL.new(env, &block) }
 
-      %w[file_contains has_dir has_env has_file].each do |test|
+      %w[
+        file_contains
+        has_dir
+        has_env
+        has_executable
+        has_file
+      ].each do |test|
         it "has `#{test}' test defined" do
           expect(dsl).to respond_to test.to_sym
         end

spec/producer/core/tests/has_executable_spec.rb

@@ -0,0 +1,29 @@
+require 'spec_helper'
+
+module Producer::Core
+  module Tests
+    describe HasExecutable, :env do
+      subject(:has_env) { HasExecutable.new(env, executable) }
+
+      it_behaves_like 'test'
+
+      describe '#verify' do
+        context 'executable exists' do
+          let(:executable) { 'true' }
+
+          it 'returns true' do
+            expect(has_env.verify).to be true
+          end
+        end
+
+        context 'executable does not exist' do
+          let(:executable) { 'some_non_existent_executable' }
+
+          it 'returns false' do
+            expect(has_env.verify).to be false
+          end
+        end
+      end
+    end
+  end
+end