Where is nodejs messages generated

I’m using catkin_make on Kinetic. I defined a action file and I can see that during catkin_make the javascript files have been generated:

– Using these message generators: gencpp;geneus;genlisp;gennodejs;genpy

Scanning dependencies of target comm_agent_generate_messages_nodejs
[ 64%] Generating Javascript code from comm_agent/GotoActionGoal.msg
[ 67%] Generating Javascript code from comm_agent/GotoGoal.msg
[ 70%] Generating Javascript code from comm_agent/GotoAction.msg
[ 72%] Generating Javascript code from comm_agent/GotoActionResult.msg
[ 75%] Generating Javascript code from comm_agent/GotoResult.msg
[ 78%] Generating Javascript code from comm_agent/GotoFeedback.msg
[ 81%] Generating Javascript code from comm_agent/GotoActionFeedback.msg
[ 81%] Built target comm_agent_generate_messages_nodejs

But I cannot find where are those files after catkin_make.

For ROS Kinetic system-wide message installs, gennodejs places the built Javascript message files into:
/opt/ros/kinetic/share/gennodejs/ros/released_pkg_msgs

For your local workspace, assuming your workspace is in ~/ros_ws/ folder, gennodejs will place the messages into your devel space:
~/ros_ws/devel/share/gennodejs/ros/your_pkg_msgs