I am trying to create a library of functions in Mirth Connect, using Code Templates. Using logger.debug is painful. I tried copying the code to a dummy HTML page and use browser's debugging tools. Unfortunately, the javascript engines in Mirth v/s those in browsers are different and Mirth Javascript uses several deprecated syntax.
How do I debug or step through Javascript code in Mirth Connect?
You can use the Rhino debugger in embedded mode....its has some little nuances to it, but i think this is what your looking for.
Here is a thread to walk you through the process.