Parse CSV rows as objects, line-by-line.

csvjson-readline.js

"use strict";

const readline = require('readline');
const EventEmitter = require('events');

const dataPattern = /^['"|](.*)['"|]$/;

const trimData = function (str) {
  return String(str).trim().replace(dataPattern, '$1');
}

class CSVJSONReadLine extends EventEmitter {
  constructor (input, delimeter) {
    super();
    this.csvHeader = null;
    this.delimeter = typeof delimeter == 'string' ? delimeter : ',';
    this.readline = readline.createInterface({
      input: input,
      terminal: false
    });

    this.readline.on('line', (line) => {
      if (this.csvHeader === null) {
        this.csvHeader = line.split(this.delimeter).filter(trimData);
        return;
      }
      const row = line.split(this.delimeter).map(trimData);
      const data = this.csvHeader.reduce((d, header, i) => {
        let data = row[i];
        d[header] = typeof data == 'string' ? data : null;
        return d;
      }, {});
      this.emit('row', data, this.readline);
    });

    this.readline.on('close', () => {
      this.emit('close');
    });
  }
};

module.exports = CSVJSONReadLine;

index.js

"use strict";

const CSVJSONReadLine = require("./csvjson-readline");
const fs = require("fs");

var csvJSON = new CSVJSONReadLine(fs.createReadStream("/path/to/file.csv"));

csvJSON.on("row", console.log);
csvJSON.on("close", console.log);