code: public JavaScriptActionBuilder javascript(Resource script, Charset charset) {
          JavaScriptAction action = new JavaScriptAction();
          try {
              action.setScript(FileUtils.readToString(script, charset));
          } catch (IOException e) {
              throw new CitrusRuntimeException("Failed to read script resource", e);
          }
          action(action);
          return new JavaScriptActionBuilder(action);
      }
docs: Execute JavaScript.