Currency database should know if a currency is still in use

[bdewater]

For example 'NLG' is the ISO4217 code for the Dutch guilder that got replaced by the Euro in 2002. The euro was introduced as legal tender in 1999.

Use case: generating a list of valid and currently in use ISO codes to show in a dropdown for the user to select, while having a database validation on all valid currency codes.

The Unicode CLDR has this data:

• Docs: http://www.unicode.org/cldr/charts/latest/supplemental/detailed_territory_currency_information.html
• XML: https://www.currency-iso.org/en/home/tables/table-a3.html
• JSON: https://github.com/unicode-cldr/cldr-core/blob/master/supplemental/currencyData.json

[elfassy]

#!/usr/bin/env ruby

$LOAD_PATH.unshift(File.join(File.dirname(__FILE__), 'lib'))

require 'json'
require 'open-uri'
require 'pry'
require 'money'

LOCALE = 'en-US-POSIX'

local_file = File.read('config/currency_iso.json')
local_hash = JSON.parse(local_file)
local_version = local_hash.delete('_version')

currencies_uri = URI.parse("https://raw.githubusercontent.com/unicode-cldr/cldr-numbers-modern/master/main/#{LOCALE}/currencies.json")
currencies = JSON.parse(File.read(currencies_uri.open))
currency_data = URI.parse('https://raw.githubusercontent.com/unicode-cldr/cldr-core/master/supplemental/currencyData.json')
currency_data = JSON.parse(File.read(currency_data.open))

data = currencies['main'][LOCALE]["numbers"]["currencies"].merge(currency_data["supplemental"]["currencyData"]["fractions"])

data.each do |iso, api_data|
  unless currency = Money::Currency.find(iso)
    next #p "#{iso}: Missing currency"
  end

  api_name = api_data['displayName']&.gsub(/\(.*\)/, '')
  # p "#{iso}: {name:[#{currency.name}, #{api_name}]}" unless currency.name == api_name
  
  unless currency.minor_units.to_i == (api_data["_digits"] || 2).to_i
    p "#{iso}: {minor_units:[#{currency.minor_units}, #{(api_data["_digits"] || 2).to_i}]}" 
  end
end

gives this list of incorrect currency minor units [our value, unicode-cldr value]

"AFN: {minor_units:[2, 0]"
"ALL: {minor_units:[2, 0]"
"AMD: {minor_units:[2, 0]"
"COP: {minor_units:[2, 0]"
"GYD: {minor_units:[2, 0]"
"HUF: {minor_units:[0, 2]"
"IDR: {minor_units:[2, 0]"
"IQD: {minor_units:[3, 0]"
"IRR: {minor_units:[2, 0]"
"KPW: {minor_units:[2, 0]"
"LAK: {minor_units:[2, 0]"
"LBP: {minor_units:[2, 0]"
"MGA: {minor_units:[1, 0]"
"MMK: {minor_units:[2, 0]"
"MNT: {minor_units:[2, 0]"
"MRO: {minor_units:[1, 0]"
"MUR: {minor_units:[2, 0]"
"PKR: {minor_units:[2, 0]"
"RSD: {minor_units:[2, 0]"
"SLL: {minor_units:[2, 0]"
"SOS: {minor_units:[2, 0]"
"STD: {minor_units:[2, 0]"
"SYP: {minor_units:[2, 0]"
"TMM: {minor_units:[2, 0]"
"TZS: {minor_units:[2, 0]"
"UZS: {minor_units:[2, 0]"
"XAG: {minor_units:[0, 2]"
"XAU: {minor_units:[0, 2]"
"XBA: {minor_units:[0, 2]"
"XBB: {minor_units:[0, 2]"
"XBC: {minor_units:[0, 2]"
"XBD: {minor_units:[0, 2]"
"XDR: {minor_units:[0, 2]"
"XPD: {minor_units:[0, 2]"
"XPT: {minor_units:[0, 2]"
"XTS: {minor_units:[0, 2]"
"YER: {minor_units:[2, 0]"
"ZMK: {minor_units:[2, 0]"
"ZWD: {minor_units:[2, 0]"