fix: added exception if invalid json keys are passed

FitConnect/ClientFactory.cs

@@ -4,6 +4,7 @@ using FitConnect.Interfaces;
 using FitConnect.Interfaces.Subscriber;
 using Microsoft.Extensions.Logging;
 using Microsoft.IdentityModel.Logging;
+using Newtonsoft.Json.Linq;
 
 namespace FitConnect;
 
@@ -47,6 +48,9 @@ public static class ClientFactory {
         List<string> privateDecryptionKeys,
         string privateSigningKey,
         ILogger? logger = null) {
+
+        CheckKeysForValidJsonFormat(privateDecryptionKeys, privateSigningKey);
+
         if (privateDecryptionKeys.Count != 1)
             throw new FitConnectInitialisationException(
                 "Only one private key for decryption is supported");
@@ -61,6 +65,27 @@ public static class ClientFactory {
     }
 
 
+    private static void CheckKeysForValidJsonFormat(List<string> privateDecryptionKeys,
+        string privateSigningKey) {
+        foreach (var key in privateDecryptionKeys) {
+            try {
+                var json = JObject.Parse(key);
+            }
+            catch (Exception e) {
+                throw new FitConnectInitialisationException(
+                    "Private decryption key is not in valid JSON format", e);
+            }
+        }
+
+        try {
+            var json = JObject.Parse(privateSigningKey);
+        }
+        catch (Exception e) {
+            throw new FitConnectInitialisationException(
+                "Private signing key is not in valid JSON format", e);
+        }
+    }
+
     /// <summary>
     ///     Returns a Router API implementation
     /// </summary>

Tests/BasicUnitTest/SubscriberTests.cs

+using System;
+using System.Collections.Generic;
+using Autofac;
+using FitConnect;
+using FitConnect.Exceptions;
+using FitConnect.Interfaces;
+using FluentAssertions;
+using NUnit.Framework;
+
+namespace BasicUnitTest;
+
+[TestFixture]
+public class SubscriberTests {
+
+    IFitConnectSettings _settings = null!;
+
+    [SetUp]
+    public void Setup() {
+        var container = MockContainer.Container.Create();
+        _settings = container.Resolve<IFitConnectSettings>();
+    }
+
+    [Test]
+    public void CreateSubscriber_ShouldPass() {
+        // Arrange
+        var clientId = Guid.NewGuid().ToString();
+        var clientSecret = "VerySecret";
+        var privateDecryptionKeys =  _settings.PrivateDecryptionKeys;
+        var publicKey = _settings.PrivateSigningKey;
+
+        // Act
+        var subscriber = FitConnect.ClientFactory.GetSubscriberClient(FitConnectEnvironment.Test,
+            clientId, clientSecret, privateDecryptionKeys, publicKey);
+
+        // Assert
+        subscriber.Should().NotBeNull();
+    }
+
+    [Test]
+    public void CreateSubscriber_InvalidKeys_ShouldFail() {
+        // Arrange
+        var clientId = Guid.NewGuid().ToString();
+        var clientSecret = "VerySecret";
+        var privateDecryptionKeys = new List<string>() { "C:\\temp.key" };
+        var publicKey = "C:\\temp.key";
+
+        // Act & Assert
+        var exception = Assert.Throws<FitConnectInitialisationException>(() => {
+            var subscriber = FitConnect.ClientFactory.GetSubscriberClient(FitConnectEnvironment.Test,
+                clientId, clientSecret, privateDecryptionKeys, publicKey);
+        });
+
+        Console.WriteLine(exception?.Message);
+    }
+}