Log Js File Name And Function Name

I would like my node.js project to generate log files that are a bit similar to log4j format in that I would like each log line to commence with the file name and the js function n

Solution 1:

Edit adding all stuff.

This is a basic example of filename, lines, columns and caller function. Maybe you need to adapt somethings. But this is the idea.

let log = {
	info: functioninfo(message) {
		const callerInfo = getFileName(info.caller.name);
		console.log(
			newDate() +
				' ' +
				arguments.callee.name.toUpperCase() +
				' ' +
				callerInfo.filename +
				':' +
				callerInfo.line +
				':' +
				callerInfo.column +
				' ' +
				info.caller.name +
				'() ' +
				message
		);
	},
};

functiongetFileName(caller) {
  constSTACK_FUNC_NAME = newRegExp(/at\s+((\S+)\s)?\((\S+):(\d+):(\d+)\)/);
	let err = newError();
	
	Error.captureStackTrace(err);

	let stacks = err.stack.split('\n').slice(1);

	let callerInfo = null;
	for (let i = 0; i < stacks.length; i++) {
		callerInfo = STACK_FUNC_NAME.exec(stacks[i]);
    
		if (callerInfo[2] === caller) {
			return {
				filename: callerInfo[3],
				line: callerInfo[4],
				column: callerInfo[5],
			};
		}
	}

	returnnull;
}

functioniWantToLog() {
	log.info('Testing my log');
}

iWantToLog();

Solution 2:

A colleague suggested using a Gulp PreProcess to solve this issue. The idea being I would not perform any of the manual steps 1) 2) and 3) described above, however before running/deploying my code, I would feed it through a Gulp preprocess which would update all my js source code, adding all of code described in steps 1) 2) and 3).

I have not used Gulp much, but on the surface, this sounds like a promising idea. On the upside:

1. as long as Gulp can update my source files as required it will work
2. should not cause any significant runtime js performance issues, no requirement for generation of js Error objects to create stack traces from which to extract script and function names
3. my source code will not be littered with any of this extra code to log script name and function name

On the down side:

1. need to make Gulp part of my workflow - that seems acceptable
2. I need to setup the gulp preprocessor to alter my js source - no idea how hard this will be, would gulp pre-process be my starting point?
3. when I make code changes to js source files Gulp will need to rerun each time, impacting my iteration time