How do I convert an Error object in node js to a string properly?

To get the full stack use stack property of the Error object:

console.log(error.stack)

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error/stack

I thought I had to use JSON for this problem because of the way the Error object was formatted. How I solved this one was just to use

err.toString()

For future reference, just in case you wish to extract the Error messsage. Use error.message to extract the message. Here is a reference: https://nodejs.org/api/errors.html#errors_error_message