index.js

module.exports = {
    /**
     * Create a logger
     * @param {string} prefix
     * @param {object] options
     *  - indent (number of spaces to indent)
     */
    create(prefix, options = {}) {
        if (typeof options.indent === 'undefined') {
            options.indent = 0;
        }
        let totalIndent = '';
        if (options.indent !== 0) {
            totalIndent += Array.apply(null, Array(options.indent))
                .map(() => {
                    return '  ';
                })
                .join('');
        }

        return function(data, options = {}) {
            let indent = totalIndent;
            if (typeof options.indent === 'undefined') {
                options.indent = 0;
            }
            if (options.indent !== 0) {
                indent += Array.apply(null, Array(options.indent))
                    .map(() => {
                        return '  ';
                    })
                    .join('');
            }

            if (typeof data === 'object') {
                data = JSON.stringify(data, null, 2);
            }
            data = data.replace(/(\r?\n)/g, `$1${indent}  `);
            console.log(`${indent}${getTimestamp()}: ${prefix}: ${data}`);
        };
    },
    // logOutErrBuffer
    // Takes a logger and uses it to log stdin/stdout data that comes from
    // child_process.spawn
    // @param {function} log - the log method to call
    // @returns {function} callback - the callback to pass to child_process.spawn
    logOutErrBuffer(log = console.log) {
        return function(data) {
            if (data.stdout) {
                log(data.stdout);
            }
            if (data.stderr) {
                log(data.stderr);
            }
        };
    },
};

/**
 * getTimeStamp
 * @param {date}
 * @returns {string} timestamp
 */
const getTimestamp = (function() {
    const pad = (num) => {
        return num > 9 ? num : `0${num}`;
    };

    return function(d) {
        if (!d) {
            d = new Date();
        }
        return [
            `${d.getFullYear()}-${pad(d.getMonth() + 1)}-${pad(d.getDate())}`,
            `${pad(d.getHours())}:${pad(d.getMinutes())}:${pad(
                d.getSeconds(),
            )}`,
        ].join(' ');
    };
})();

Logger.js

// this file exists just to name the gist, and because gist ordering is asciibetical, it's name starts with a capital letter.

package.json

{
  "name": "logger",
  "version": "0.1.0"
}