fix EnderDragon#bossBar()

Author: MrHell228

SpongeAPI

@@ -0,0 +1,36 @@
+/*
+ * This file is part of Sponge, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) SpongePowered <https://www.spongepowered.org>
+ * Copyright (c) contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package org.spongepowered.common.accessor.world.level.dimension.end;
+
+import net.minecraft.server.level.ServerBossEvent;
+import net.minecraft.world.level.dimension.end.EndDragonFight;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.gen.Accessor;
+
+@Mixin(EndDragonFight.class)
+public interface EndDragonFightAccessor {
+
+    @Accessor("dragonEvent") ServerBossEvent accessor$dragonEvent();
+}

src/accessors/java/org/spongepowered/common/accessor/world/level/dimension/end/EndDragonFightAccessor.java

@@ -194,6 +194,7 @@
         "world.level.chunk.storage.RegionFileAccessor",
         "world.level.chunk.storage.SimpleRegionStorageAccessor",
         "world.level.dimension.DimensionTypeAccessor",
+        "world.level.dimension.end.EndDragonFightAccessor",
         "world.level.entity.EntityTickListAccessor",
         "world.level.entity.PersistentEntitySectionManagerAccessor",
         "world.level.levelgen.NoiseSettingsAccessor",

src/accessors/resources/mixins.sponge.accessors.json

@@ -25,8 +25,12 @@
 package org.spongepowered.common.data.provider.entity;
 
 import net.minecraft.world.entity.boss.enderdragon.EnderDragon;
+import net.minecraft.world.level.dimension.end.EndDragonFight;
+import org.checkerframework.checker.nullness.qual.Nullable;
 import org.spongepowered.api.data.Keys;
 import org.spongepowered.api.entity.explosive.EndCrystal;
+import org.spongepowered.common.accessor.world.level.dimension.end.EndDragonFightAccessor;
+import org.spongepowered.common.adventure.SpongeAdventure;
 import org.spongepowered.common.data.provider.DataProviderRegistrator;
 
 public final class EnderDragonData {
@@ -40,7 +44,16 @@ public static void register(final DataProviderRegistrator registrator) {
                 .asMutable(EnderDragon.class)
                     .create(Keys.HEALING_CRYSTAL)
                         .get(h -> (EndCrystal) h.nearestCrystal)
-                        .set((h, v) -> h.nearestCrystal = (net.minecraft.world.entity.boss.enderdragon.EndCrystal) v);
+                        .set((h, v) -> h.nearestCrystal = (net.minecraft.world.entity.boss.enderdragon.EndCrystal) v)
+                    .create(Keys.BOSS_BAR)
+                        .get(h -> {
+                            final @Nullable EndDragonFight fight = h.getDragonFight();
+                            if (fight != null) {
+                                return SpongeAdventure.asAdventure(((EndDragonFightAccessor) fight).accessor$dragonEvent());
+                            } else {
+                                return null;
+                            }
+                        });
     }
     // @formatter:on
 }