tests: add converter tests

src/StevesBot.Worker/Discord/Events/DiscordEventConverter.cs

@@ -2,12 +2,6 @@ namespace StevesBot.Worker.Discord.Events;
 
 internal sealed class DiscordEventConverter : JsonConverter<DiscordEvent>
 {
-  private readonly JsonSerializerOptions _jsonSerializerOptions = new()
-  {
-    ReferenceHandler = ReferenceHandler.IgnoreCycles,
-    PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
-  };
-
   private const string OpPropertyName = "op";
 
   public override DiscordEvent? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
@@ -15,29 +9,46 @@ internal sealed class DiscordEventConverter : JsonConverter<DiscordEvent>
     using var jsonDoc = JsonDocument.ParseValue(ref reader);
     var root = jsonDoc.RootElement;
     var op = root.GetProperty(OpPropertyName).GetInt32();
+    var modifiedOptions = CopyAndRemoveConverter(options);
 
     return op switch
     {
-      DiscordOpCodes.Dispatch => DeserializeDispatchEvent(root, options),
+      DiscordOpCodes.Dispatch => DeserializeDispatchEvent(root, options, modifiedOptions),
       DiscordOpCodes.Hello => JsonSerializer.Deserialize<HelloDiscordEvent>(root.GetRawText(), options),
       DiscordOpCodes.HeartbeatAck => JsonSerializer.Deserialize<HeartbeatAckDiscordEvent>(root.GetRawText(), options),
-      _ => JsonSerializer.Deserialize<DiscordEvent>(root.GetRawText(), _jsonSerializerOptions),
+      _ => JsonSerializer.Deserialize<DiscordEvent>(root.GetRawText(), modifiedOptions),
     };
   }
 
   public override void Write(Utf8JsonWriter writer, DiscordEvent value, JsonSerializerOptions options)
   {
-    JsonSerializer.Serialize(writer, value, value.GetType(), options);
+    var modifiedOptions = CopyAndRemoveConverter(options);
+    JsonSerializer.Serialize(writer, value, value.GetType(), modifiedOptions);
   }
 
-  private DiscordEvent? DeserializeDispatchEvent(JsonElement root, JsonSerializerOptions options)
+  private static DiscordEvent? DeserializeDispatchEvent(JsonElement root, JsonSerializerOptions options, JsonSerializerOptions modifiedOptions)
   {
     var type = root.GetProperty("t").GetString();
 
     return type switch
     {
       DiscordEventTypes.Ready => JsonSerializer.Deserialize<ReadyDiscordEvent>(root.GetRawText(), options),
-      _ => JsonSerializer.Deserialize<DiscordEvent>(root.GetRawText(), _jsonSerializerOptions),
+      _ => JsonSerializer.Deserialize<DiscordEvent>(root.GetRawText(), modifiedOptions),
     };
   }
+
+  private static JsonSerializerOptions CopyAndRemoveConverter(JsonSerializerOptions options)
+  {
+    var newOptions = new JsonSerializerOptions(options);
+
+    foreach (var converter in options.Converters)
+    {
+      if (converter is DiscordEventConverter)
+      {
+        newOptions.Converters.Remove(converter);
+      }
+    }
+
+    return newOptions;
+  }
 }