I like my log messages to indicate automatically where in the code something happened, so that I can easily identify where a message originated from while tracking down problems.

In C/C++ this is nice and easy - write a logging routine, wrap it in macros for the different log levels and have that automatically output __FILE__, __LINE__ etc.

I wanted to do something similar in NodeJS, as I'd found myself manually writing the file name in the log message and then splitting functionality out into new files and it became a mess.

The only way I found to be able to do this was to create an "Error" object and access the "stack" member of it. This is a string containing a stack backtrace, suitable for writing to console/file. I just wanted the filename/line/routine.

So I ended up splitting the string into lines, then for each of the lines, trimming the surrounding spaces (or tabs?), and parsing them to see if the stack entry is inside my logger module. The first entry outside of that module must therefore be the thing that called it, so I then parse out the routine or object and method, filename and line number.

It's a lot of clumsy work but the output is pretty neat. I just wish it were simpler!