How to enable Brazil CPF number validation without creating extra fields?

When customizing the Magento 2 checkout page due to Brazilian market, we should enable CPF/CNPJ fields. There is also a way to let users specify their identification numbers without creating extra fields. Let’s do it here.

We will apply a field mask and validation code during typing a code.

Note: learn more about field masks.

Now please follow the steps.

• Create a custom.js
• Put this js code in your custom.js file.

define([
    'jquery',
    'underscore',
    'Swissup_Firecheckout/js/utils/form-field/mask',
    'Swissup_Firecheckout/js/utils/form-field/validator'
], function ($, _, mask, validator) {
    'use strict';

    //define address form in which need to use the CPF/CNPJ code
    var scopes = [
        '.form-shipping-address',
        '.billing-address-form'
    ];

    _.each(scopes, function (scope) {

        //set a field mask according to cpf/cnpj code
        mask(scope + ' [name="vat_id"]', {
            guide: false,
            mask: function (raw) {
                var mask = [/\d/, /\d/,'.',/\d/,/\d/,/\d/,'.',/\d/,/\d/,/\d/,'/',/\d/,/\d/,/\d/,/\d/,'-',/\d/,/\d/];

                if (raw.length == 14) {
                    mask = [/\d/, /\d/, /\d/,'.',/\d/,/\d/,/\d/,'.',/\d/,/\d/,/\d/,'-',/\d/,/\d/];
                }

                return mask;
            }
        });

        //validation cpf/cnpj code
         validator(scope + ' [name="vat_id"]', {
            'lazy': false,
            'fc-custom-rule-vatid': {
                    handler: function (value) {
                    var strNumbers, splNumbers;
                        splNumbers = value.split(/[\/\.-]/);
                        strNumbers = splNumbers.join("");

                    if (value.length == 18) {

                        var cnpj = new RegExp(/^([0-9]{2}(.)[0-9]{3}(.)[0-9]{3}(\/)[0-9]{4}(-)[0-9]{2})$/).test(value);

                        // Checking for known cnpj invalid code
                        if ( cnpj &&  strNumbers == "00000000000000" ||
                                      strNumbers == "11111111111111" ||
                                      strNumbers == "22222222222222" ||
                                      strNumbers == "33333333333333" ||
                                      strNumbers == "44444444444444" ||
                                      strNumbers == "55555555555555" ||
                                      strNumbers == "66666666666666" ||
                                      strNumbers == "77777777777777" ||
                                      strNumbers == "88888888888888" ||
                                      strNumbers == "99999999999999"
                            )
                                { return false; }

                        var numSize, numbers, lastDigits, sum, pos, result;

                            numSize = strNumbers.length - 2
                            numbers = strNumbers.substring(0,numSize);
                            lastDigits = strNumbers.substring(numSize);
                            sum = 0;
                            pos = numSize - 7;

                        for (i = numSize; i >= 1; i--) {
                          sum += numbers.charAt(numSize - i) * pos--;
                          if (pos < 2) pos = 9;
                        }
                        result = sum % 11 < 2 ? 0 : 11 - sum % 11;
                        if (result != lastDigits.charAt(0)) return false;

                        numSize = numSize + 1;
                        numbers = strNumbers.substring(0,numSize);
                        sum = 0;
                        pos = numSize - 7;
                        for (i = numSize; i >= 1; i--) {
                          sum += numbers.charAt(numSize - i) * pos--;
                          if (pos < 2) pos = 9;
                        }
                        result = sum % 11 < 2 ? 0 : 11 - sum % 11;
                        if (result != lastDigits.charAt(1)) return false;

                        return cnpj;

                    }else {
                        var cpf, sum = 0,
                            firstCN, secondCN, checkResult;

                        cpf = new RegExp(/^([0-9]{3}(.)[0-9]{3}(.)[0-9]{3}(-)[0-9]{2})$/).test(value);

                        firstCN = parseInt(strNumbers.substring(9, 10), 10);
                        secondCN = parseInt(strNumbers.substring(10, 11), 10);

                        checkResult = function(sum, cn) {
                        var result = (sum * 10) % 11;
                        if ((result === 10) || (result === 11)) {result = 0;}
                            return (result === cn);
                        };

                        // Checking for known cpf invalid code
                         if (cpf && strNumbers == "00000000000" ||
                                    strNumbers == "11111111111" ||
                                    strNumbers == "22222222222" ||
                                    strNumbers == "33333333333" ||
                                    strNumbers == "44444444444" ||
                                    strNumbers == "55555555555" ||
                                    strNumbers == "66666666666" ||
                                    strNumbers == "77777777777" ||
                                    strNumbers == "88888888888" ||
                                    strNumbers == "99999999999"
                            )
                            { return false; }

                        // validate first Check Number:
                        for (var i = 1; i <= 9; i++ ) {
                            sum = sum + parseInt(strNumbers.substring(i - 1, i), 10) * (11 - i);
                        }

                        // validate second Check Number:
                        if ( checkResult(sum, firstCN) ) {
                            sum = 0;
                            for (var i = 1; i <= 10; i++ ) {
                            sum = sum + parseInt(strNumbers.substring(i - 1, i), 10) * (12 - i);
                            }
                            return checkResult(sum, secondCN);
                        }

                      return false;

                    }

                },
                message: $t('Invalid vat ID ')
            }
        });


    });
});

• Save the file and run the following bash commands to deploy the script:

cd magento/root/folder
rm -rf var/view_preprocessed pub/static/frontend
bin/magento setup:static-content:deploy