se-panfilov/jsvat

import { Country } from '../jsvat';

export const estonia: Country = {
  name: 'Estonia',
  codes: ['EE', 'EST', '233'],
  calcFn: (vat: string): boolean => {
    let total = 0;
    let expect;

    // Extract the next digit and multiply by the counter.
    for (let i = 0; i < 8; i++) {
      total += Number(vat.charAt(i)) * estonia.rules.multipliers.common[i];
    }

    // Establish check digits using modulus 10.
    total = 10 - (total % 10);
    if (total === 10) total = 0;

    // Compare it with the last character of the VAT number. If it's the same, then it's valid.
    expect = Number(vat.slice(8, 9));
    return total === expect;
  },
  rules: {
    multipliers: {
      common: [3, 7, 1, 3, 7, 1, 3, 7]
    },
    regex: [/^(EE)(10\d{7})$/]
  }
};