Credit Card Validation Support

README.md

@@ -55,6 +55,11 @@ If you are using Carthage you will need to add this to your `Cartfile`
 ```bash
 github "jpotts18/SwiftValidator"
 ```
+## Dependencies
+
+CardNumberRule uses CardParser from => https://github.com/Raizlabs/CardParser.git
+Cards can be validated to ensure they conform to LUHN algorigthm. 
+
 
 ## Usage 
 

SwiftValidator/Parsers/CardParser.swift

@@ -0,0 +1,249 @@
+
+//
+//  CardParser.swift
+//
+//  Created by Jason Clark on 6/28/16.
+//  Copyright © 2016 Raizlabs. All rights reserved.
+//
+//MARK: - CardType
+enum CardType {
+    case amex
+    case diners
+    case discover
+    case jcb
+    case mastercard
+    case visa
+    case verve
+
+    static let allValues: [CardType] = [.visa, .mastercard, .amex, .diners, .discover, .jcb, .verve]
+
+    private var validationRequirements: ValidationRequirement {
+
+        let prefix: [PrefixContainable], length: [Int]
+
+        switch self {
+            /* // IIN prefixes and length requriements retreived from https://en.wikipedia.org/wiki/Bank_card_number on June 28, 2016 */
+
+            case .amex:
+                prefix = ["34", "37"]
+                length = [15]
+                break
+
+            case .diners:
+                prefix = ["300"..."305", "309", "36", "38"..."39"]
+                length = [14]
+                break
+
+            case .discover:
+                prefix = ["6011", "65", "644"..."649", "622126"..."622925"]
+                length = [16]
+                break
+
+            case .jcb:
+                prefix = ["3528"..."3589"]
+                length = [16]
+                break
+
+            case .mastercard:
+                prefix = ["51"..."55", "2221"..."2720"]
+                length = [16]
+                break
+
+            case .visa:
+                prefix = ["4"]
+                length = [13, 16, 19]
+                break
+
+            case .verve:
+                prefix = ["5060", "5061", "5078", "5079", "6500"]
+                length = [16, 19]
+                break
+
+        }
+
+        return ValidationRequirement(prefixes: prefix, lengths: length)
+    }
+
+
+
+    var segmentGroupings: [Int] {
+        switch self {
+            case .amex:
+                return [4, 6, 5]
+            case .diners:
+                return [4, 6, 4]
+            case .verve:
+                return [4, 4, 4, 6]
+            default:
+                return [4, 4, 4, 4]
+        }
+    }
+
+    var maxLength: Int {
+        return validationRequirements.lengths.max() ?? 16
+    }
+
+    var cvvLength: Int {
+        switch self {
+        case .amex:
+            return 4
+        default:
+            return 3
+        }
+    }
+
+    func isValid(_ accountNumber: String) -> Bool {
+        return validationRequirements.isValid(accountNumber) && CardType.luhnCheck(accountNumber)
+    }
+
+    func isPrefixValid(_ accountNumber: String) -> Bool {
+        return validationRequirements.isPrefixValid(accountNumber)
+    }
+
+}
+
+
+//MARK: Validation requirements and rules
+
+fileprivate extension CardType {
+
+    struct ValidationRequirement {
+        let prefixes: [PrefixContainable]
+        let lengths: [Int]
+
+        func isValid(_ accountNumber: String) -> Bool {
+            return isLengthValid(accountNumber) && isPrefixValid(accountNumber)
+        }
+
+        func isPrefixValid(_ accountNumber: String) -> Bool {
+
+            guard prefixes.count > 0 else { return true }
+            return prefixes.contains { $0.hasCommonPrefix(with: accountNumber) }
+        }
+
+        func isLengthValid(_ accountNumber: String) -> Bool {
+            guard lengths.count > 0 else { return true }
+            return lengths.contains { accountNumber.length == $0 }
+        }
+    }
+
+    // from: https://gist.github.com/cwagdev/635ce973e8e86da0403a
+    static func luhnCheck(_ cardNumber: String) -> Bool {
+
+        guard let _ = Int64(cardNumber) else {
+            //if string is not convertible to int, return false
+            return false
+        }
+        let numberOfChars = cardNumber.count
+        let numberToCheck = numberOfChars % 2 == 0 ? cardNumber : "0" + cardNumber
+
+        let digits = numberToCheck.map { Int(String($0)) }
+
+        let sum = digits.enumerated().reduce(0) { (sum, val: (offset: Int, element: Int?)) in
+            if (val.offset + 1) % 2 == 1 {
+                let element = val.element!
+                return sum + (element == 9 ? 9 : (element * 2) % 9)
+            }
+            // else
+            return sum + val.element!
+        }
+        let validates = sum % 10 == 0
+        print("card valid")
+        return validates
+    }
+
+}
+
+
+//MARK: - CardState
+enum CardState {
+    case identified(CardType)
+    case indeterminate([CardType])
+    case invalid
+}
+
+
+extension CardState: Equatable {}
+    func ==(lhs: CardState, rhs: CardState) -> Bool {
+        switch (lhs, rhs) {
+        case (.invalid, .invalid): return true
+        case (let .indeterminate(cards1), let .indeterminate(cards2)): return cards1 == cards2
+        case (let .identified(card1), let .identified(card2)): return card1 == card2
+        default: return false
+    }
+}
+
+
+extension CardState {
+
+    init(fromNumber number: String) {
+        if let card = CardType.allValues.first(where: { $0.isValid(number) }) {
+            print("card found \(card)")
+            self = .identified(card)
+        }
+        else {
+            self = .invalid
+        }
+    }
+
+    init(fromPrefix prefix: String) {
+        let possibleTypes = CardType.allValues.filter { $0.isPrefixValid(prefix) }
+        if possibleTypes.count >= 2 {
+            self = .indeterminate(possibleTypes)
+        }
+        else if possibleTypes.count == 1, let card = possibleTypes.first {
+            self = .identified(card)
+        }
+        else {
+            self = .invalid
+        }
+    }
+
+}
+
+//MARK: - PrefixContainable
+fileprivate protocol PrefixContainable {
+
+    func hasCommonPrefix(with text: String) -> Bool
+
+}
+
+extension ClosedRange: PrefixContainable {
+
+    func hasCommonPrefix(with text: String) -> Bool {
+        //cannot include Where clause in protocol conformance, so have to ensure Bound == String :(
+        guard let lower = lowerBound as? String, let upper = upperBound as? String else { return false }
+
+        let trimmedRange: ClosedRange<String> = {
+            let length = text.length
+            let trimmedStart = lower.prefix(length)
+            let trimmedEnd = upper.prefix(length)
+            return trimmedStart...trimmedEnd
+        }()
+
+        let trimmedText = text.prefix(trimmedRange.lowerBound.count)
+        return trimmedRange ~= trimmedText
+    }
+
+}
+
+
+extension String: PrefixContainable {
+
+    func hasCommonPrefix(with text: String) -> Bool {
+        return hasPrefix(text) || text.hasPrefix(self)
+    }
+
+}
+
+fileprivate extension String {
+
+    func prefix(_ maxLength: Int) -> String {
+        return String(maxLength)
+    }
+
+    var length: Int {
+        return count
+    }
+
+}

SwiftValidator/Rules/CardExpiryRule.swift

@@ -0,0 +1,65 @@
+//
+//  CardExpiryRule.swift
+//  SwiftValidator
+//
+//  Created by Mark Boleigha on 13/03/2019.
+//  Copyright © 2019 jpotts18. All rights reserved.
+//
+
+import Foundation
+
+
+
+/**
+ `CardExpiryRule` is a subclass of `Rule` that defines how a credit/debit's card number field is validated
+ */
+public class CardExpiryRule: Rule {
+    /// Error message to be displayed if validation fails.
+    private var message : String
+    /**
+     Initializes `CardExpiryRule` object with error message. Used to validate a card's expiry year.
+
+     - parameter message: String of error message.
+     - returns: An initialized `CardExpiryRule` object, or nil if an object could not be created for some reason that would not result in an exception.
+     */
+    public init(message : String = "Card expiry date is invalid"){
+        self.message = message
+    }
+
+    /**
+     Validates a field.
+
+     - parameter value: String to check for validation. must be a card expiry date in MM/YY format
+     - returns: Boolean value. True on successful validation, otherwise False on failed Validation.
+     */
+    public func validate(_ value: String) -> Bool {
+        guard value.count > 4 else{
+            return false
+        }
+        let date = value.replacingOccurrences(of: "/", with: "")
+        let monthIndex = date.index(date.startIndex, offsetBy: 2)
+        let Month = Int(date[..<monthIndex])
+
+        let yearIndex = date.index(date.endIndex, offsetBy: -2)
+        let Year = Int(date[yearIndex...])
+
+        ///Holds the current year
+        let thisYear = String(NSCalendar.current.component(Calendar.Component.year, from: Date()))
+        let thisYearLast2 = thisYear.index(thisYear.startIndex, offsetBy: 2)
+        let thisYearTwoDigits = Int(thisYear[thisYearLast2...])!
+
+
+        return Month! <= 12 && Year! >= thisYearTwoDigits
+
+    }
+
+    /**
+     Used to display error message when validation fails.
+
+     - returns: String of error message.
+     */
+    public func errorMessage() -> String {
+        return message
+    }
+
+}

SwiftValidator/Rules/CardNumberRule.swift

@@ -0,0 +1,51 @@
+//
+//  CardNumberRule.swift
+//  Validator
+//
+//  Created by Boleigha Mark on 08/03/2018.
+//  Copyright © 2017 jpotts18. All rights reserved.
+//
+import Foundation
+
+/**
+ `CardNumberRule` is a subclass of `Rule` that defines how a credit/debit's card number field is validated
+ */
+public class CardNumberRule: Rule {
+    /// Error message to be displayed if validation fails.
+    private var message : String
+    /**
+     Initializes `CardNumberRule` object with error message. Used to validate a card's expiry month.
+
+     - parameter message: String of error message.
+     - returns: An initialized `CardNumberRule` object, or nil if an object could not be created for some reason that would not result in an exception.
+     */
+    public init(message : String = "Card is Invalid"){
+        self.message = message
+    }
+
+    /**
+     Validates a field.
+
+     - parameter value: String to check for validation.
+     - returns: Boolean value. True on successful validation, otherwise False on failed Validation.
+     */
+    public func validate(_ value: String) -> Bool {
+        let cardNoFull = value.replacingOccurrences(of: " ", with: "")
+        guard CardState(fromNumber: cardNoFull) != .invalid else {
+            return false
+        }
+
+        return true
+
+    }
+
+    /**
+     Used to display error message when validation fails.
+
+     - returns: String of error message.
+     */
+    public func errorMessage() -> String {
+        return message
+    }
+
+}