processLogger.js

const sc = require("./shellColors");
const logfmt = require("logfmt");

const processColors = {
    sr: sc.fgMagenta,
    router: sc.fgCyan,
    worker: sc.fgGreen,
};

const levelColors = {
    error: sc.fgRed,
    warn: sc.fgYellow,
    help: sc.fgCyan,
    data: sc.fgBlue,
    info: sc.fgGreen,
    debug: sc.fgNormal,
    prompt: sc.fgNormal,
    verbose: sc.fgCyan,
    input: sc.fgNormal,
    silly: sc.fgMagenta,
};

const remainingColors = [
    sc.fgBlue,
    sc.fgRed,
    sc.fgYellow,
    sc.fgBoldMagenta,
    sc.fgBoldCyan,
    sc.fgBoldGreen,
    sc.fgBoldBlue,
    sc.fbBoldRed,
    sc.fgBoldYellow,
];

let packageNameLength = 0;

module.exports.bindStreams = function(childProcess, packageName, buffered) {
    let shortName = packageName.replace("blank-", "").replace("node-", "");
    packageNameLength = shortName.length > packageNameLength ? shortName.length : packageNameLength;
    if (!processColors[shortName]) {
        processColors[shortName] = remainingColors.shift();
    }
    childProcess.stdout.on("data", _outHandler.bind(this, shortName, false));
    childProcess.stderr.on("data", _outHandler.bind(this, shortName, true));
    childProcess.on("close", code => {
        console.log(`${packageName} exited with code ${code}`);
    });
};

function _outHandler(name, stdErr, data) {
    if (typeof data !== "string") {
        var str = data.toString(),
            lines = str.split(/(\r?\n)/g);
        for (var i = 0; i < lines.length; i++) {
            if (lines[i].trim()) {
                _log(name, lines[i], stdErr);
            }
        }
    } else {
        _log(name, data, stdErr);
    }
}

function _log(process, msg, err) {
    let out = "";

    let pColor = sc.fgNormal;
    if (processColors.hasOwnProperty(process)) {
        pColor = processColors[process];
    }
    let pName =
        pColor +
        Array(packageNameLength + 1)
            .join(" ")
            .slice(process.length) +
        "[" +
        process +
        "] " +
        sc.fgNormal;

    let m;
    try {
        m = JSON.parse(msg);
    } catch (e) {
        m = logfmt.parse(msg);
    }
    out += formatDate(m.timestamp || m.time || new Date());
    out += formatLevel(m.level || "info", m);
    out += pName;
    out += m.message || m.msg || msg;

    out += sc.fgNormal;
    console.log(out);
}

function formatLevel(l, m) {
    try {
        l = l.replace("warning", "warn");
    } catch (err) {
        console.error(err);
    }
    let c = levelColors[l] || sc.fgNormal;
    try {
        c = c + Array(Math.max(6 - l.length, 0)).join(" ") + l + sc.fgNormal + ": ";
    } catch (err) {
        console.error(err);
    }

    return c;
}

function formatDate(d) {
    if (!(d instanceof Date)) {
        d = new Date(d);
    }
    let h = d.getHours() + "",
        m = d.getMinutes() + "",
        s = d.getSeconds() + "",
        ms = d.getMilliseconds() + "";
    return addLZero(h) + ":" + addLZero(m) + ":" + addLZero(s) + "." + addLZero(ms).replace(/^(\d{2})$/, "0$1") + " ";
}

function addLZero(s) {
    return s.replace(/^(\d)$/, "0$1");
}