adds JWT parser

Author: Nelson Cardaci

Sources/Marvin/Marvin-shared/Parsers/JWT.swift

@@ -0,0 +1,43 @@
+//
+//  File.swift
+//  
+//
+//  Created by Nelson Cardaci on 12/09/2019.
+//
+
+import Foundation
+struct JWT {
+    func decode<T: Codable>(jwtToken jwt: String) -> T? {
+        
+        func base64UrlDecode(_ value: String) -> Data? {
+            var base64 = value
+                .replacingOccurrences(of: "-", with: "+")
+                .replacingOccurrences(of: "_", with: "/")
+            
+            let length = Double(base64.lengthOfBytes(using: String.Encoding.utf8))
+            let requiredLength = 4 * ceil(length / 4.0)
+            let paddingLength = requiredLength - length
+            if paddingLength > 0 {
+                let padding = "".padding(toLength: Int(paddingLength), withPad: "=", startingAt: 0)
+                base64 = base64 + padding
+            }
+            return Data(base64Encoded: base64, options: .ignoreUnknownCharacters)
+        }
+        
+        func decodeJWTPart(_ value: String) -> T? {
+            guard let data = base64UrlDecode(value) else {
+                return nil
+            }
+            do {
+                return try JSONDecoder().decode(T.self, from: data)
+            } catch  {
+                print("Error while decoding json:\(error.localizedDescription )")
+                return nil
+            }
+            
+        }
+        
+        let segments = jwt.components(separatedBy: ".")
+        return decodeJWTPart(segments[1])
+    }
+}

Tests/MarvinTests/MarvinTests.swift

@@ -1,15 +1,15 @@
-//import XCTest
-//@testable import Marvin
-//
-//final class MarvinTests: XCTestCase {
-//    func testExample() {
-//        // This is an example of a functional test case.
-//        // Use XCTAssert and related functions to verify your tests produce the correct
-//        // results.
-//        XCTAssertEqual(Marvin().text, "Hello, World!")
-//    }
-//
-//    static var allTests = [
-//        ("testExample", testExample),
-//    ]
-//}
+import XCTest
+@testable import Marvin
+
+final class MarvinTests: XCTestCase {
+    func testExample() {
+        // This is an example of a functional test case.
+        // Use XCTAssert and related functions to verify your tests produce the correct
+        // results.
+        XCTAssertEqual(Marvin, "Hello, World!")
+    }
+
+    static var allTests = [
+        ("testExample", testExample),
+    ]
+}