Refactored shasher payfast confirmation response handling

LiteCharms.Features.Tests/HashServiceFeatureTests.cs

@@ -1,4 +1,6 @@
 using LiteCharms.Features.Hasher;
+using LiteCharms.Features.Models;
+using static LiteCharms.Features.Extensions.Hash;
 
 namespace LiteCharms.Features.Tests;
 
@@ -65,17 +67,18 @@ public class HashServiceFeatureTests(Fixture fixture) : IClassFixture<Fixture>
     {
         var paymentId = hashService.HashEncodeLongId(1001).Value;
 
-        var incomingForm = new Dictionary<string, string>
+        var payload = new PayfastWebhookPayload
         {
-            { "m_payment_id", paymentId },
-            { "amount", "350.00" },
-            { "item_name", "System Architecture Book" }
+            Amount = "350.00",
+            ItemName = "System Architecture Book",
+            MPaymentId = paymentId,            
         };
 
-        var rawPayload = $"amount=350.00&item_name=System+Architecture+Book&m_payment_id={paymentId}&passphrase={payfastPassphrase}";
+        var rawPayload = payload.ToRawPayfastPayload(payfastPassphrase);
+
         var generatedSignature = HashService.ToMd5Hash(rawPayload).Value;
 
-        var result = hashService.VerifyPayfastWebhookSignature(incomingForm, generatedSignature);
+        var result = hashService.VerifyPayfastWebhookSignature(payload, generatedSignature);
 
         Assert.True(result.IsSuccess);
         Assert.True(result.Value);