Validate CPF and CNPF

String+BrazilianDocuments.swift

extension StringProtocol {
    
    var isValidCNPJ: Bool {
        let numbers = compactMap(\.wholeNumberValue)
        guard numbers.count == 14 && Set(numbers).count != 1 else { return false }
        return numbers.prefix(12).digitoCNPJ == numbers[12] &&
               numbers.prefix(13).digitoCNPJ == numbers[13]
    }
    
    var isValidCPF: Bool {
        let numbers = compactMap(\.wholeNumberValue)
        guard numbers.count == 11 && Set(numbers).count != 1 else { return false }
        return numbers.prefix(9).digitoCPF == numbers[9] &&
               numbers.prefix(10).digitoCPF == numbers[10]
    }
    
}

extension Collection where Element == Int {
    
    var digitoCPF: Int {
        var number = count + 2
        let digit = 11 - reduce(into: 0) {
            number -= 1
            $0 += $1 * number
        } % 11
        return digit > 9 ? 0 : digit
    }
    
    var digitoCNPJ: Int {
        var number = 1
        let digit = 11 - reversed().reduce(into: 0) {
            number += 1
            $0 += $1 * number
            if number == 9 { number = 1 }
        } % 11
        return digit > 9 ? 0 : digit
    }
    
}