Implement `file_eq' condition keyword

lib/producer/core/condition/dsl.rb

@@ -25,6 +25,7 @@ module Producer
         define_test :`,               Tests::ShellCommandStatus
         define_test :sh,              Tests::ShellCommandStatus
         define_test :file_contains,   Tests::FileContains
+        define_test :file_eq,         Tests::FileEq
         define_test :env?,            Tests::HasEnv
         define_test :executable?,     Tests::HasExecutable
         define_test :dir?,            Tests::HasDir

lib/producer/core/tests/file_eq.rb

@@ -0,0 +1,22 @@
+module Producer
+  module Core
+    module Tests
+      class FileEq < Test
+        def verify
+          file_content ? file_content == expected_content : false
+        end
+
+
+        private
+
+        def file_content
+          @file_content ||= fs.file_read(arguments[0])
+        end
+
+        def expected_content
+          arguments[1]
+        end
+      end
+    end
+  end
+end