Implement way to get country code and province code

[phantom-factotum]

I was looking to use node-sales-tax in a small expense tracking project and I wanted to automatically set the sales tax base on the user location. While reading the documentation, I found that the country code and province code are needed to get the sales tax, but I did not see any helpers for converting a location into these codes. After searching for a bit, I found the answer from the U.S. Customs and Border Patrol of all places. They provide an excel sheet that has the country and province code for 1637 provinces.

I wrote some code to download the xlsx and convert it to a json file ( I am a novice, so I apologize for all issues with the code):

const XLSX = require('xlsx')
const fs = require('fs')
const axios = require('axios')
const path = require('path')

let currentDir = process.cwd()
let xlsxFileName = path.join(currentDir,'./international-province-codes.xls')
let jsonFileName = path.join(currentDir,'./codes.json')
// excel sheet has 3 columns
const columns = {
	countryCode:'A',
	provinceCode:'B',
	provinceName:'C'
}
async function getFile(){
	// customs and border patrol provides a xlsx file with all international state/province codes
	let xlsxUrl = 'https://www.cbp.gov/sites/default/files/documents/codes_7.xls'
	const response = await axios.get(xlsxUrl,{
		responseType:'stream',
	})
	await response.data.pipe(fs.createWriteStream(xlsxFileName))
	return xlsxFileName
}
async function parseXlsx(){
	let sheet
	try{
		sheet = XLSX.readFile(await getFile())
	}catch(err){
		if(err.errno === -4058){
			console.error('Excel sheet not found')
			process.exit()
		}
	}
	sheet = sheet.Sheets.Sheet1
	// remove unnecessary keys
	let validKeys = Object.keys(sheet).filter(key=>
		// keys are a letter and a number e.g 'A1'
		key && sheet[key]?.w && (
			key[0] == columns.countryCode || 
			key[0] == columns.provinceCode ||
			key[0] == columns.provinceName
		)
	)
	// convert validKeys into json object
	let provinceCodes = {}
	validKeys.forEach(key=>{
		let rowNumber = parseInt(key.substring(1))
		let countryCell = columns.countryCode + rowNumber
		let provinceCell = columns.provinceCode + rowNumber
		let nameCell = columns.provinceName+rowNumber
		
		// even after filtering to make sure the cells exist
		// the cell values are sometimes null ???
		let countryCode = sheet[countryCell]?.w
		let provinceCode = sheet[provinceCell]?.w
		let provinceName = sheet[nameCell]?.w
		
		// remove diacritical/accent characters found solution here: 
	  // https://stackoverflow.com/questions/990904/remove-accents-diacritics-in-a-string-in-javascript
		provinceName = provinceName?.normalize("NFD").replace(/\p{Diacritic}/gu, "").toLowerCase()
		provinceCodes[provinceName] = { countryCode,provinceCode}
	})
	// write to file 
	fs.writeFileSync(jsonFileName,JSON.stringify(provinceCodes,null,2))
}
parseXlsx()

The resulting json should allow users to to use states/provinces to get both country and province codes