fix: use a node deserialiser instead

Model/IWhen.cs

@@ -1,6 +1,6 @@
 using YamlDotNet.Core;
 using YamlDotNet.Core.Events;
-using YamlDotNet.Serialization.BufferedDeserialization.TypeDiscriminators;
+using YamlDotNet.Serialization;
 
 namespace TimePasses.Model;
 
@@ -11,25 +11,27 @@ public interface IWhen {
     bool IsValid(Plugin plugin);
 }
 
-public class WhenDiscriminator : ITypeDiscriminator {
-    public Type BaseType => typeof(IWhen);
-
-    public bool TryDiscriminate(IParser buffer, out Type? suggestedType) {
-        buffer.Consume<MappingStart>();
-        var name = buffer.Consume<Scalar>();
-        if (!name.IsKey) {
-            suggestedType = null;
+public class WhenNodeDeserialiser : INodeDeserializer
+{
+    public bool Deserialize(IParser reader, Type expectedType, Func<IParser, Type, object?> nestedObjectDeserializer, out object? value) {
+        if (expectedType != typeof(IWhen)) {
+            value = null;
             return false;
         }
 
+        reader.Consume<MappingStart>();
+        var name = reader.Consume<Scalar>();
+        if (!name.IsKey) {
+            throw new YamlException("invalid when: missing key");
+        }
+
         switch (name.Value) {
             case "quest": {
-                suggestedType = typeof(WhenQuest);
+                value = nestedObjectDeserializer(reader, typeof(WhenQuest));
                 break;
             }
             default: {
-                suggestedType = null;
-                return false;
+                throw new YamlException($"invalid when: unknown type \"{name.Value}\"");
             }
         }
 

Plugin.cs

@@ -27,10 +27,7 @@ public class Plugin : IDalamudPlugin {
 
     internal static IDeserializer Deserializer { get; } = new DeserializerBuilder()
         .WithNamingConvention(UnderscoredNamingConvention.Instance)
-        // .WithTypeConverter(new WhenConverter())
-        .WithTypeDiscriminatingNodeDeserializer(o => {
-            o.AddTypeDiscriminator(new WhenDiscriminator());
-        })
+        .WithNodeDeserializer(new WhenNodeDeserialiser())
         .Build();
 
     private static class Signatures {