Tonsole

Wrapper around Node's console that adds return values to logging calls.

This is useful for logging expressions and arrow functions without having to change any code.

const tonsole = require('tonsole');

let compute = (data) => data ? process(data.value) : data;

// normally we can't easily log what `compute` does without
// rewriting it to use statements
compute = (data) => {
    if (data) {
        const r = process(data.value);
        console.log('Processed data: ', r);
        return r;
    }
    console.error('Invalid data: ');
    return data;
};

// But with tonsole, we can add logging while still using
// expressions, just as the ancient ones of Lisp intended.
compute = (data) =>
    data
        ?tonsole.log('Processed data: ', process(data.value)
        :tonsole.error('Invalid data: ', data);

Usage

$ npm install --save tonsole

Tonsole provides a complete wrapper around the entire Node console api. All functions forward to the wrapped Node console implementation.

tonsole.Console(stdout [, stderr])

Wrapper around console.Console. Logging methods of this class return values besides logging.

tonsole.log(...args)

tonsole.info(...args)

tonsole.warn(...args)

tonsole.error(...args)

Each of these methods logs using the inner console.* method, but instead of returning undefined, they return the last argument value.

tonsole.log("%s : %s", 2, 3);
// Logs: "2 : 3"
// returns 3

tonsole.assert(value, ...args)

Verify that value is truthy using console.assert but returns value. If value is falsy, an AssertionError is thrown.

tonsole.assert(5, "sanity check") === 5

tonsole.assert(false, "should fail") // throws AssertionError 

tonsole.dir(obj, options)

Simply wrapper around console.dir that returns obj.

tonsole.time(label)

tonsole.timeEnd(label)

tonsole.trace(msg, ...)

Forward directly to console.* and continue to return undefined.