@himorishige/noren-plugin-jp/dist/validators.js

Japan-specific PII detection plugin for Noren (phone numbers, postal codes, MyNumber)

// Validation utilities for Japanese PII types
/**
 * Validates Japanese My Number (マイナンバー) with checksum verification
 */
export function validateMyNumber(input) {
    const digits = input.replace(/[^\d]/g, '');
    if (digits.length !== 12) {
        return { valid: false, reason: 'invalid_length' };
    }
    // Check for repeating digits pattern
    if (/^(\d)\1{11}$/.test(digits)) {
        return { valid: false, reason: 'repeating_digits' };
    }
    // Calculate checksum using official algorithm
    // Weights: [6,5,4,3,2,7,6,5,4,3,2] applied from left to right
    const weights = [6, 5, 4, 3, 2, 7, 6, 5, 4, 3, 2];
    const base = digits.slice(0, 11);
    const checkDigit = Number(digits[11]);
    let sum = 0;
    for (let i = 0; i < 11; i++) {
        sum += Number(base[i]) * weights[i];
    }
    const remainder = sum % 11;
    const calculatedCheck = remainder <= 1 ? 0 : 11 - remainder;
    const isValid = calculatedCheck === checkDigit;
    return {
        valid: isValid,
        reason: isValid ? 'checksum_valid' : 'checksum_invalid',
        confidence: isValid ? 0.95 : 0.3,
        normalized: `${digits.slice(0, 4)}-${digits.slice(4, 8)}-${digits.slice(8)}`,
    };
}