Покидаемся исключениями?

src/main/kotlin/ru/dbotthepony/kstarbound/io/json/BuilderAdapter.kt

@@ -10,6 +10,7 @@ import com.google.gson.stream.JsonWriter
 import it.unimi.dsi.fastutil.objects.ObjectArraySet
 import it.unimi.dsi.fastutil.objects.ObjectOpenHashSet
 import org.apache.logging.log4j.LogManager
+import ru.dbotthepony.kstarbound.util.NotNullVar
 import kotlin.reflect.KClass
 import kotlin.reflect.KMutableProperty1
 import kotlin.reflect.full.isSubclassOf
@@ -37,7 +38,7 @@ class BuilderAdapter<T : Any> private constructor(
 	/**
 	 * Свойства объекта [T], которые можно выставлять
 	 */
-	val properties: ImmutableMap<String, WrappedProperty<T, Any?>>,
+	val properties: ImmutableMap<String, WrappedProperty<T, *>>,
 
 	/**
 	 * Ключи, которые необходимо игнорировать при чтении JSON
@@ -51,7 +52,7 @@ class BuilderAdapter<T : Any> private constructor(
 	}
 
 	override fun read(reader: JsonReader): T {
-		val missing = ObjectArraySet<WrappedProperty<T, Any?>>()
+		val missing = ObjectArraySet<WrappedProperty<T, *>>()
 		missing.addAll(properties.values)
 
 		reader.beginObject()
@@ -73,17 +74,17 @@ class BuilderAdapter<T : Any> private constructor(
 					val peek = reader.peek()
 
 					if (!property.returnType.isMarkedNullable && peek == JsonToken.NULL) {
-						throw NullPointerException("Property ${property.property.name} of ${instance::class.qualifiedName} does not accept nulls")
+						throw NullPointerException("Property ${property.name} of ${instance::class.qualifiedName} does not accept nulls")
 					} else if (peek == JsonToken.NULL) {
-						property.property.set(instance, null)
+						property.set(instance, null)
 						reader.nextNull()
 					} else {
 						val readValue = property.adapter.read(reader)
-						property.property.set(instance, readValue)
+						property.set(instance, readValue)
 						check(missing.remove(property))
 					}
 				} catch(err: Throwable) {
-					throw JsonSyntaxException("Reading property ${property.property.name} of ${instance::class.qualifiedName} near ${reader.path}", err)
+					throw JsonSyntaxException("Reading property ${property.name} of ${instance::class.qualifiedName} near ${reader.path}", err)
 				}
 			} else {
 				if (!loggedMisses.contains(name)) {
@@ -98,8 +99,24 @@ class BuilderAdapter<T : Any> private constructor(
 		reader.endObject()
 
 		for (property in missing) {
-			if (property.mustBePresent == null) {
-				// null - проверяем, есть ли делегат
+			if (property.mustBePresent == true) {
+				throw JsonSyntaxException("${instance::class.qualifiedName} demands for ${property.name} to be present, however, it is missing")
+			} else if (property.mustBePresent == null) {
+				if (property.returnType.isMarkedNullable) {
+					continue
+				}
+
+				val delegate = property.property.getDelegate(instance)
+
+				if (delegate is NotNullVar<*> && !delegate.isInitialized) {
+					throw JsonSyntaxException("${property.name} in ${instance::class.qualifiedName} can not be null, but it is missing from JSON structure")
+				} else {
+					try {
+						property.property.get(instance)
+					} catch (err: Throwable) {
+						throw JsonSyntaxException("${property.name} in ${instance::class.qualifiedName} does not like it being missing from JSON structure", err)
+					}
+				}
 			}
 		}
 
@@ -109,10 +126,21 @@ class BuilderAdapter<T : Any> private constructor(
 	data class WrappedProperty<T, V : Any?>(
 		val property: KMutableProperty1<T, V>,
 		val adapter: TypeAdapter<V>,
+		/**
+		 * @see PropertyConfigurator.mustBePresent
+		 */
 		val mustBePresent: Boolean?,
 	) {
+		inline val name get() = property.name
 		// кеш
 		val returnType = property.returnType
+
+		// так как дженерики тут немного слабенькие
+		// Так что вот так...
+		@Suppress("unchecked_cast")
+		fun set(receiver: T, value: Any?) {
+			property.set(receiver, value as V)
+		}
 	}
 
 	class PropertyConfigurator<T, V : Any?>(
@@ -121,6 +149,10 @@ class BuilderAdapter<T : Any> private constructor(
 	) {
 		/**
 		 * Обязана ли присутствовать эта переменная внутри JSON структуры.
+		 *
+		 * * `true` - всегда кидать исключения
+		 * * `false` - никогда не кидать исключения
+		 * * `null` - кидать исключения на усмотрение реализации (по умолчанию)
 		 */
 		var mustBePresent: Boolean? = null
 	}
@@ -165,7 +197,7 @@ class BuilderAdapter<T : Any> private constructor(
 				throw IllegalArgumentException("${property.name} is a Map, please use autoMap() method instead")
 			}
 
-			@Suppress("unchecked_cast")
+			@Suppress("unchecked_cast") // classifier.java не имеет обозначенного типа
 			return add(property, LazyTypeProvider(classifier.java) as TypeAdapter<V>, configurator)
 		}
 
@@ -178,12 +210,11 @@ class BuilderAdapter<T : Any> private constructor(
 			return this
 		}
 
-		@Suppress("unchecked_cast")
 		fun build(): BuilderAdapter<T> {
-			val map = ImmutableMap.Builder<String, WrappedProperty<T, Any?>>()
+			val map = ImmutableMap.Builder<String, WrappedProperty<T, *>>()
 
 			for (property in properties)
-				map.put(property.property.name, property as WrappedProperty<T, Any?>)
+				map.put(property.property.name, property)
 
 			return BuilderAdapter(factory, map.build(), ImmutableSet.copyOf(ignoreKeys))
 		}