Transform stream/`.pipe` are not working as expected

[mStirner]

I have a very simple setup, where i extend the bunyan logger:

const { Writable, Transform, PassThrough } = require("stream");
const { createLogger } = require("bunyan");

const formatter = require("./formatter");

function Records(options) {

    options = Object.assign({
        // default options
    }, options);

    return new Transform({
        transform: (chunk, encoding, cb) => {

            let rec = JSON.parse(chunk);
            console.log("transform", rec);

            delete rec.v;
            //delete rec.fields;
            delete rec.hostname;
            delete rec.pid;

            rec.time = Date.now();
            rec.msg = formatter(rec);

            cb(null, JSON.stringify(rec));

        }
    });

}

const myWritable = new Writable({
    write(chunk, encoding, cb) {

        let rec = JSON.parse(chunk);

        //console.log("myWritable input", rec)

        delete rec.v;
        //delete rec.fields;
        delete rec.hostname;
        delete rec.pid;

        rec.time = Date.now();
        rec.msg = formatter(rec);

        //console.log("myWritable output", rec);

        console.log(rec.msg);

        if (rec.err) {
            console.log(rec.err.stack)
        }

        cb(null);

    }
});

module.exports = class Logger extends createLogger {

    constructor(options = {}) {

        options = Object.assign({
            streams: [{
                level: "trace",
                type: "stream",
                stream: Records()
            }],
        }, options);

        super(options);

        this.tracer = (desc, count) => {

            let counter = 0;
            let fired = false;

            return (...args) => {

                counter += 1;

                this.trace(`${desc}; ${counter}/${count};`, ...args);

                if (counter === count && !fired) {
                    this.trace(`${desc}; finishd!`);
                    fired = true;
                }

            };
        };

    }

    static create(name, options = {}) {
        return new Logger({
            name,
            ...options
        });
    }

};

I wanted a generic transform stream where i can delete some fields, like hostname & v, but when i pipe be transform stream, the transform stream does not work.

When i use the following stream setup:

 streams: [{
   level: "trace",
   type: "stream",
   stream: Records().pipe(process.stdout)
 }],

my console.log("transform", rec); does log nothing, like the transform stream does nothing. When is use my myWritable instead, it work as expected.

const Logger = require("./class.logger.js");

const logger = Logger.create("system");

//console.log(logger, logger.fucker, logger.tracer)

const trace = logger.tracer("Count down to 3", 3);

logger.trace("Trace");
trace("called 1");
trace("called 2");
trace("called 3");

logger.debug("Debug");
logger.info("Info");
logger.warn("Warning");
logger.error("error");

logger.fatal("Fuck off, im done...")

The reason for the transform stream is, that i want to use multiple streams, like fs.createWriteStream & process.stdout or what ever, and dont want to code for very stream a filter that deleted the unwanted fields.

Any help/hint is appreciated.

I cant wrap my head around why this dosnt work, and the transform stream is ignored as soon it is somewhere piped.

BTW: I switched from winston to bunyan, because its has less dependencies & got faster results "hacking" bunyan than winston.