console.log wrapper that keeps line numbers and supports most methods? [closed]

Answer 1

Crossposting from related question (A proper wrapper for console.log with correct line number?) but with updated solution to address multiple methods.

---

I liked @fredrik's answer, so I rolled it up with another answer which splits the Webkit stacktrace, and merged it with @PaulIrish's safe console.log wrapper. "Standardizes" the filename:line to a "special object" so it stands out and looks mostly the same in FF and Chrome.

Testing in fiddle: http://jsfiddle.net/drzaus/pWe6W/9/

_log = (function (methods, undefined) {

    var Log = Error; // does this do anything?  proper inheritance...?
    Log.prototype.write = function (args, method) {
        /// 

        /// Paulirish-like console.log wrapper.  Includes stack trace via @fredrik SO suggestion (see remarks for sources).
        /// 
        /// list of details to log, as provided by `arguments`
        /// the console method to use:  debug, log, warn, info, error
        /// Includes line numbers by calling Error object -- see
        /// * http://paulirish.com/2009/log-a-lightweight-wrapper-for-consolelog/
        /// * https://stackoverflow.com/questions/13815640/a-proper-wrapper-for-console-log-with-correct-line-number
        /// * https://stackoverflow.com/a/3806596/1037948
        /// 

        // via @fredrik SO trace suggestion; wrapping in special construct so it stands out
        var suffix = {
            "@": (this.lineNumber
                    ? this.fileName + ':' + this.lineNumber + ":1" // add arbitrary column value for chrome linking
                    : extractLineNumberFromStack(this.stack)
            )
        };

        args = args.concat([suffix]);
        // via @paulirish console wrapper
        if (console && console[method]) {
            if (console[method].apply) { console[method].apply(console, args); } else { console[method](args); } // nicer display in some browsers
        }
    };
    var extractLineNumberFromStack = function (stack) {
        /// 

        /// Get the line/filename detail from a Webkit stack trace.  See https://stackoverflow.com/a/3806596/1037948
        /// 
        /// the stack string

        // correct line number according to how Log().write implemented
        var line = stack.split('\n')[3];
        // fix for various display text
        line = (line.indexOf(' (') >= 0
            ? line.split(' (')[1].substring(0, line.length - 1)
            : line.split('at ')[1]
            );
        return line;
    };

    // method builder
    var logMethod = function(method) {
        return function (params) {
            /// 

            /// Paulirish-like console.log wrapper
            /// 
            /// list your logging parameters

            // only if explicitly true somewhere
            if (typeof DEBUGMODE === typeof undefined || !DEBUGMODE) return;

            // call handler extension which provides stack trace
            Log().write(Array.prototype.slice.call(arguments, 0), method); // turn into proper array & declare method to use
        };//--  fn  logMethod
    };
    var result = logMethod('log'); // base for backwards compatibility, simplicity
    // add some extra juice
    for(var i in methods) result[methods[i]] = logMethod(methods[i]);

    return result; // expose
})(['error', 'debug', 'info', 'warn']);//--- _log