New email address suggestion as an example when to consequent entries are the same

Start at the generateMail() entry point in the supplied script and review the Iteration and naming-convention branches first. No file or test is named in the issue; completion should be confirmed by checking that consecutive collision iterations produce the intended email address examples for B, P, BP, and PB conventions.

// customer email naming convention
//
// This script generates an email address based on:
// - the configured name convention (B / P / BP / PB)
// - the HelloID-provided Iteration value (used for collision handling)
//
// Iteration logic (provided by HelloID):
// - Iteration 0  : first letter of first name (e.g. "j.")
// - Iteration 1  : initials with dots (e.g. "h.c.")
// - Iteration 2  : full first name (e.g. "janine.")
// - Iteration >=3: fallback to first letter of first name + numeric suffix
//
// Numeric suffix rules:
// - No suffix for Iteration 0, 1 and 2
// - Iteration 3 -> suffix "1"
// - Iteration 4 -> suffix "2"
// - Iteration 5 -> suffix "3"
// - etc.
//
// Naming conventions (examples):
//
// B  (Birth name)
//   Iteration 0 : [email protected]
//   Iteration 1 : [email protected]
//   Iteration 2 : [email protected]
//   Iteration 3 : [email protected]
//
// P  (Partner name)
//   Iteration 0 : [email protected]
//   Iteration 1 : [email protected]
//   Iteration 2 : [email protected]
//   Iteration 3 : [email protected]
//
// BP (Birth-Partner)
//   Iteration 0 : [email protected]
//   Iteration 1 : [email protected]
//   Iteration 2 : [email protected]
//   Iteration 3 : [email protected]
//
// PB (Partner-Birth)
//   Iteration 0 : [email protected]
//   Iteration 1 : [email protected]
//   Iteration 2 : [email protected]
//   Iteration 3 : [email protected]
//
// Normalization rules:
// - Output is lowercase
// - Diacritical characters are removed (e.g. é -> e)
// - Spaces are converted to dots (e.g. "Abdul Mohammed" -> "abdul.mohammed")
// - Only [0-9a-zA-Z . - _] are allowed; other characters are removed
// - No double dots are allowed (".." -> ".")
// - No leading or trailing dots
// - The local-part is truncated to fit within limits before appending suffix and domain
//
// Testing tip:
// - You can temporarily hardcode Iteration to validate outputs, for example:
   Iteration = 0

function generateMail() {
    const domain = 'customer.nl';

    let initials = Person.Name.Initials;
    let nickName = Person.Name.NickName;
    let middleName = Person.Name.FamilyNamePrefix;
    let lastName = Person.Name.FamilyName;
    let middleNamePartner = Person.Name.FamilyNamePartnerPrefix;
    let lastNamePartner = Person.Name.FamilyNamePartner;
    let convention = Person.Name.Convention;

    let mailNickName = '';

    let initialsWithoutDots = (initials || '').replace(/[^a-zA-Z]/g, '').toLowerCase();
    let firstLetterNickName = nickName.substring(0, 1).toLowerCase();
    let suffix = '';
        
    if (initialsWithoutDots !== firstLetterNickName && initialsWithoutDots != '') {
        // Build numeric suffix for Iteration >= 3: 1,2,3... (variation with initials)
        if (Iteration >= 3) {
            suffix = (Iteration - 2).toString();
        }
        
        // Build the "given name" prefix based on iteration (first letter nickname != initials (without dots))
        switch (Iteration) {
            case 0:
                // Iteration 0: first letter of first name
                mailNickName = nickName.substring(0, 1) + '.';
                break;

            case 1:
                // Iteration 1: initials with dots (letters only)
                mailNickName = initials
                    .replace(/[^a-zA-Z]/g, '') // keep letters only
                    .split('')
                    .join('.') + '.';
                break;

            case 2:
                // Iteration 2: full first name
                mailNickName = nickName + '.';
                break;

            default:
                // Iteration >= 3: fallback to first letter of first name
                mailNickName = nickName.substring(0, 1) + '.';
                break;
        }
    } else {
        // Build numeric suffix for Iteration >= 3: 1,2... (variation without initials)
        if (Iteration >= 2) {
            suffix = (Iteration - 1).toString();
        }

        // Build the "given name" prefix based on iteration (first letter nickname = initials (without dots))
        switch (Iteration) {
            case 0:
                // Iteration 0: first letter of first name
                mailNickName = nickName.substring(0, 1) + '.';
                break;

            case 1:
                // Iteration 2: full first name
                mailNickName = nickName + '.';
                break;

            default:
                // Iteration >= 3: fallback to first letter of first name
                mailNickName = nickName.substring(0, 1) + '.';
                break;
        }
    }   

    // Append birth/partner name parts based on convention
    switch (convention) {
        case "BP":
            if (typeof middleName !== 'undefined' && middleName) {
                mailNickName = mailNickName + middleName.replace(/ /g, '.') + '.';
            }
            mailNickName = mailNickName + lastName;

            mailNickName = mailNickName + '-';
            if (typeof middleNamePartner !== 'undefined' && middleNamePartner) {
                mailNickName = mailNickName + ' ' + middleNamePartner.replace(/ /g, '.') + '.';
            }
            mailNickName = mailNickName + lastNamePartner;
            break;

        case "PB":
            if (typeof middleNamePartner !== 'undefined' && middleNamePartner) {
                mailNickName = mailNickName + ' ' + middleNamePartner.replace(/ /g, '.') + '.';
            }
            mailNickName = mailNickName + lastNamePartner;

            mailNickName = mailNickName + '-';
            if (typeof middleName !== 'undefined' && middleName) {
                mailNickName = mailNickName + middleName.replace(/ /g, '.') + '.';
            }
            mailNickName = mailNickName + lastName;
            break;

        case "P":
            if (typeof middleNamePartner !== 'undefined' && middleNamePartner) {
                mailNickName = mailNickName + middleNamePartner.replace(/ /g, '.') + '.';
            }
            mailNickName = mailNickName + lastNamePartner;
            break;

        case "B":
        default:
            if (typeof middleName !== 'undefined' && middleName) {
                mailNickName = mailNickName + middleName.replace(/ /g, '.') + '.';
            }
            mailNickName = mailNickName + lastName;
            break;
    }

    // Remove whitespace at start/end
    mailNickName = mailNickName.trim();

    // Lowercase
    mailNickName = mailNickName.toLowerCase();

    // Remove diacritical characters (e.g. é -> e)
    mailNickName = deleteDiacriticalMarks(mailNickName);

    // Convert spaces to dots so multi-part names remain readable
    mailNickName = mailNickName.replace(/\s+/g, '.');

    // Remove characters outside the allowed set
    mailNickName = mailNickName.replace(/[^0-9a-zA-Z.\-_]/g, '');

    // Normalize dots: no "..", no leading/trailing "."
    mailNickName = mailNickName
        .replace(/\.{2,}/g, '.')
        .replace(/^\.|\.$/g, '');

    // Truncate local-part so suffix + "@domain" still fits within limits
    const maxAttributeLength = (256 - suffix.length - domain.length);
    mailNickName = mailNickName.substring(0, maxAttributeLength);

    // Append suffix (if any) and domain
    mailNickName = mailNickName + suffix;

    return mailNickName + '@' + domain;
}

generateMail();