Fix ConfigHelper#defineObject not working when the default value was …

…an empty list

changelog.md

@@ -1,3 +1,6 @@
+# 3.0.0.5
+* Fix ConfigHelper#defineObject not working when the default value was an empty list
+
 # 3.0.0.4
 * Fix sublibrary dependencies not working in dev environments
 

gradle.properties

@@ -1,5 +1,5 @@
 
 modid = databuddy
-mod_version = 3.0.0.4
-mc_version = 1.19
-forge_version = 41.0.98
+mod_version = 3.0.0.5
+mc_version = 1.19.2
+forge_version = 43.1.0

src/examplemod/java/commoble/databuddy/examplecontent/ExampleConfig.java

@@ -8,6 +8,7 @@
 
 import commoble.databuddy.config.ConfigHelper;
 import commoble.databuddy.config.ConfigHelper.ConfigObject;
+import commoble.databuddy.examplecontent.ExampleConfig.TestObject;
 import net.minecraft.core.BlockPos;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraftforge.common.ForgeConfigSpec;
@@ -16,7 +17,8 @@
 public record ExampleConfig(
 	ConfigValue<Integer> bones,
 	ConfigValue<Double> bananas,
-	ConfigObject<TestObject> testObject)
+	ConfigObject<TestObject> testObject,
+	ConfigObject<List<Long>> list)
 {
 	public static ExampleConfig create(ForgeConfigSpec.Builder builder)
 	{
@@ -42,9 +44,12 @@ public static ExampleConfig create(ForgeConfigSpec.Builder builder)
 					new ResourceLocation("minecraft:iron")),
 					true));
 
+		builder.comment("Empty list");
+		ConfigObject<List<Long>> list = ConfigHelper.defineObject(builder, "list", Codec.LONG.listOf(), List.of());
+
 		builder.pop();
 
-		return new ExampleConfig(bones, bananas, testObject);
+		return new ExampleConfig(bones, bananas, testObject, list);
 	}
 
 	public static record TestObject(BlockPos pos, List<ResourceLocation> ids, boolean bool)

src/main/java/commoble/databuddy/config/ConfigHelper.java

@@ -26,6 +26,7 @@ of this software and associated documentation files (the "Software"), to deal
 import java.time.temporal.Temporal;
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.List;
 import java.util.Objects;
 import java.util.Optional;
 import java.util.function.Function;
@@ -291,6 +292,17 @@ public Object createString(String value)
 		{
 			return value;
 		}
+
+		@Override
+		public DataResult<Object> mergeToList(Object list, List<Object> values)
+		{
+			// default mergeToList returns the null object if list is empty;
+			// toml doesn't support null values so we need to convert to an empty list
+			return DynamicOps.super.mergeToList(list, values)
+				.map(obj -> obj == this.empty()
+					? new ArrayList<>()
+					: obj);
+		}
 
 		@Override
 		public DataResult<Object> mergeToList(Object list, Object value)