Implement `has_executable' condition keyword

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