COVIDSafe code from version 1.1

CovidSafe/PhoneNumberParser.swift

@@ -0,0 +1,47 @@
+//  Copyright © 2020 Australian Government All rights reserved.
+
+import Foundation
+
+final class PhoneNumberParser {
+    
+    // e.g. 412 345 678
+    static let numberOfDigits = 9
+    static let mobilePhoneNumberPrefix = "4"
+    
+    enum Error: Swift.Error {
+        case notDigits
+        case incorrectDigitCount
+        case incorrectMobilePhoneNumberPrefix
+    }
+    
+    static func parse(_ string: String) -> Result<String, Error> {
+        // Remove all spaces
+        var string = string.replacingOccurrences(of: " ", with: "")
+        
+        // Remove leading "+61"
+        if string.hasPrefix("+61") {
+            string.removeFirst(3)
+        }
+        
+        // Check for digit only
+        guard string.rangeOfCharacter(from: CharacterSet.decimalDigits.inverted) == nil else {
+            return .failure(.notDigits)
+        }
+        
+        // Remove leading "0"
+        if string.hasPrefix("0") {
+            string.removeFirst()
+        }
+        
+        guard string.hasPrefix(mobilePhoneNumberPrefix) else {
+            return .failure(.incorrectMobilePhoneNumberPrefix)
+        }
+        
+        // Check number of digits
+        guard string.count == Self.numberOfDigits else {
+            return .failure(.incorrectDigitCount)
+        }
+        
+        return .success(string)
+    }
+}