rawCensusDataToZipCodeObj.js

//file path related imports
const path = require('path');
const fs = require('fs');
const util = require('util');

//read file
const readline = require('readline');

let zipCodes = {}

//census file to js object to file
const rawToZipCodeObj= async() =>{
    const fileStream = fs.createReadStream('./raw_zcta_cities_geoid_to_zipcodes.txt');

    const rl = readline.createInterface({
        input: fileStream,
        crlfDelay: Infinity
    }); 
    // Note: the crlfDelay option to recognize all instances of CR LF
 
    for (const line of rl) {
        // Each line in raw_zcta_cities_geoid_to_zipcodes.txt will be successively available here as `line`.
        str = line.trim().split(',')
        console.log(`Line from file: ${line}`);
        console.log(`Line from file: ${str}`);
      
        //add object keys with the first column value in the text file
        zipCodes[str[0]] = {
            state: { code: str[1] },
            // here I handle multiple cities that belong to same zipcode
            place: (zipCodes[str[0]] && zipCodes[str[0]].place) ? [...zipCodes[str[0]].place, str[2]] : [str[2]],
            geoID: (zipCodes[str[0]] && zipCodes[str[0]].geoID) ? [...zipCodes[str[0]].geoID, str[4]] : [str[4]],
        }

    }
    //write the JSON Parsed Zipcodes Object to the fill allZipCodes
    fs.writeFileSync('./allZipCodes.js', 'module.exports.allZipCodes = ' + util.inspect(JSON.stringify(zipCodes)), 'utf-8')
}

rawToZipCodeObj();