Discussion on: CSV Challenge

#!/usr/bin/env node
let fs = require('fs');
let { Transform } = require('stream');
let StreamArray = require("stream-json/utils/StreamArray");
let stream = StreamArray.make();

function escapeCSV(str) {
  if (str == null) { return ''; }
  return /[",]/.test(str) ? `"${str.replace(/"/g, '\\"')}"` : str;
}

class CsvStream extends Transform {
  constructor() {
    super({objectMode: true});
  }
  _transform(chunk, enc, cb) {
    let { name, creditcard } = chunk.value;
    let line = [name, creditcard].map(escapeCSV).join(',');
    this.push(`${line}\n`);
    cb();
  }
}

process.stdin
  .pipe(stream.input);

stream.output
  .pipe(new CsvStream())
  .pipe(process.stdout);