From 3ce75bf7a80fa18ac67b690059748a75f4656d4b Mon Sep 17 00:00:00 2001
From: zml <zml@stellardrift.ca>
Date: Sat, 21 Dec 2024 19:40:16 -0800
Subject: [PATCH] fix(text-serializer-gson): correctly handle removed data
 components

Fixes GH-1131
---
 .../serializer/gson/ShowItemSerializer.java   | 26 ++++++++++++++---
 .../json/ShowItemSerializerTest.java          | 28 +++++++++++++++++++
 2 files changed, 50 insertions(+), 4 deletions(-)

diff --git a/text-serializer-gson/src/main/java/net/kyori/adventure/text/serializer/gson/ShowItemSerializer.java b/text-serializer-gson/src/main/java/net/kyori/adventure/text/serializer/gson/ShowItemSerializer.java
index b46bbdc3f..3de4ee2b1 100644
--- a/text-serializer-gson/src/main/java/net/kyori/adventure/text/serializer/gson/ShowItemSerializer.java
+++ b/text-serializer-gson/src/main/java/net/kyori/adventure/text/serializer/gson/ShowItemSerializer.java
@@ -25,6 +25,7 @@
 
 import com.google.gson.Gson;
 import com.google.gson.JsonElement;
+import com.google.gson.JsonNull;
 import com.google.gson.JsonParseException;
 import com.google.gson.TypeAdapter;
 import com.google.gson.stream.JsonReader;
@@ -49,6 +50,7 @@
 final class ShowItemSerializer extends TypeAdapter<HoverEvent.ShowItem> {
   @SuppressWarnings("deprecation")
   private static final String LEGACY_SHOW_ITEM_TAG = net.kyori.adventure.text.serializer.json.JSONComponentConstants.SHOW_ITEM_TAG;
+  private static final String DATA_COMPONENT_REMOVAL_PREFIX = "!";
 
   private final Gson gson;
   private final boolean emitDefaultQuantity;
@@ -94,12 +96,22 @@ public HoverEvent.ShowItem read(final JsonReader in) throws IOException {
       } else if (fieldName.equals(SHOW_ITEM_COMPONENTS)) {
         in.beginObject();
         while (in.peek() != JsonToken.END_OBJECT) {
-          final Key id = Key.key(in.nextName());
+          final String name = in.nextName();
+          final Key id;
+          final boolean removed;
+          if (name.startsWith(DATA_COMPONENT_REMOVAL_PREFIX)) {
+            id = Key.key(name.substring(1));
+            removed = true;
+          } else {
+            id = Key.key(name);
+            removed = false;
+          }
+
           final JsonElement tree = this.gson.fromJson(in, JsonElement.class);
           if (dataComponents == null) {
             dataComponents = new HashMap<>();
           }
-          dataComponents.put(id, GsonDataComponentValue.gsonDataComponentValue(tree));
+          dataComponents.put(id, removed ? DataComponentValue.removed() : GsonDataComponentValue.gsonDataComponentValue(tree));
         }
         in.endObject();
       } else {
@@ -137,8 +149,14 @@ public void write(final JsonWriter out, final HoverEvent.ShowItem value) throws
       out.name(SHOW_ITEM_COMPONENTS);
       out.beginObject();
       for (final Map.Entry<Key, GsonDataComponentValue> entry : value.dataComponentsAs(GsonDataComponentValue.class).entrySet()) {
-        out.name(entry.getKey().asString());
-        this.gson.toJson(entry.getValue().element(), out);
+        final JsonElement el = entry.getValue().element();;
+        if (el instanceof JsonNull) { // removed
+          out.name(DATA_COMPONENT_REMOVAL_PREFIX + entry.getKey().asString());
+          out.beginObject().endObject();
+        } else {
+          out.name(entry.getKey().asString());
+          this.gson.toJson(el, out);
+        }
       }
       out.endObject();
     } else if (this.itemDataMode != JSONOptions.ShowItemHoverDataMode.EMIT_DATA_COMPONENTS) {
diff --git a/text-serializer-json/src/testFixtures/java/net/kyori/adventure/text/serializer/json/ShowItemSerializerTest.java b/text-serializer-json/src/testFixtures/java/net/kyori/adventure/text/serializer/json/ShowItemSerializerTest.java
index 2a1286655..2c8729058 100644
--- a/text-serializer-json/src/testFixtures/java/net/kyori/adventure/text/serializer/json/ShowItemSerializerTest.java
+++ b/text-serializer-json/src/testFixtures/java/net/kyori/adventure/text/serializer/json/ShowItemSerializerTest.java
@@ -23,6 +23,7 @@
  */
 package net.kyori.adventure.text.serializer.json;
 
+import com.google.gson.JsonObject;
 import java.io.IOException;
 import java.util.Collections;
 import net.kyori.adventure.key.Key;
@@ -31,6 +32,7 @@
 import net.kyori.adventure.nbt.TagStringIO;
 import net.kyori.adventure.nbt.api.BinaryTagHolder;
 import net.kyori.adventure.text.Component;
+import net.kyori.adventure.text.event.DataComponentValue;
 import net.kyori.adventure.text.event.HoverEvent;
 import org.junit.jupiter.api.Test;
 
@@ -124,4 +126,30 @@ void testDeserializeWithCountOfOne() throws IOException {
       }
     );
   }
+
+  @Test
+  void testDeserializeWithRemovedComponent() {
+    this.testObject(
+      Component.text().hoverEvent(
+        HoverEvent.showItem(
+          Key.key("minecraft", "diamond"),
+          2,
+          Collections.singletonMap(Key.key("minecraft", "damage"), DataComponentValue.removed())
+        )
+      ).build(),
+      json -> {
+        json.addProperty(JSONComponentConstants.TEXT, "");
+        json.add(JSONComponentConstants.HOVER_EVENT, object(hover -> {
+          hover.addProperty(JSONComponentConstants.HOVER_EVENT_ACTION, name(HoverEvent.Action.SHOW_ITEM));
+          hover.add(JSONComponentConstants.HOVER_EVENT_CONTENTS, object(contents -> {
+            contents.addProperty(JSONComponentConstants.SHOW_ITEM_ID, "minecraft:diamond");
+            contents.addProperty(JSONComponentConstants.SHOW_ITEM_COUNT, 2);
+            contents.add(JSONComponentConstants.SHOW_ITEM_COMPONENTS, object(comps -> {
+              comps.add("!minecraft:damage", new JsonObject());
+            }));
+          }));
+        }));
+      }
+    );
+  }
 }