convert.js

const fs = require('fs');
const csv = require('csv-parser');
const readlineSync = require('readline-sync');

const filename = 'MyHeritage_raw_dna_data.csv';
const headers = ['rsid', 'chromosome', 'position', 'genotype'];

function readCSVData(filename) {
  return new Promise((resolve, reject) => {
    const data = [];
    fs.createReadStream(filename)
        .pipe(csv({ headers, skipComments: true }))
        .on('data', (row) => {
          data.push(row);
        })
        .on('end', () => {
          resolve(data);
        })
        .on('error', (error) => {
          reject(error);
        });
  });
}

async function convertData() {
  try {
    const data = await readCSVData(filename);

    const currentDateTime = new Date().toLocaleString('en-US', {
      year: 'numeric',
      month: 'short',
      day: 'numeric',
      hour: '2-digit',
      minute: '2-digit',
      second: '2-digit',
    });

    const comments = `# This data file generated by 23andMe at: ${currentDateTime}
#
# Below is a text version of your data.  Fields are TAB-separated
# Each line corresponds to a single SNP.  For each SNP, we provide its identifier 
# (an rsid or an internal id), its location on the reference human genome, and the 
# genotype call oriented with respect to the plus strand on the human reference sequence.
# We are using reference human assembly build 37 (also known as Annotation Release 104).
# Note that it is possible that data downloaded at different times may be different due to ongoing 
# improvements in our ability to call genotypes. More information about these changes can be found at:
# https://www.23andme.com/you/download/revisions/
# 
# More information on reference human assembly build 37 (aka Annotation Release 104):
# http://www.ncbi.nlm.nih.gov/mapview/map_search.cgi?taxid=9606
#
# rsid	chromosome	position	genotypeJ`;

    const firstname =
        readlineSync.question("What is your first name? [Joseph] :") || 'Joseph';

    const lastname =
        readlineSync.question("What is your last name? [Anson] :") || 'Anson';

    const outputFilename = `genome_${firstname}_${lastname}_Full_${currentDateTime.replace(
        /\W+/g,
        ''
    )}.txt`;

    const csv = data
        .map(e => Object.values(e).join(" "))
        .join("\n");

    fs.writeFileSync(outputFilename, comments + "\n" + csv);

    console.log('Done :)')
  } catch (error) {
    console.error('Error occurred:', error);
  }
}

convertData();