Fix ItemStack amount issues with Chat Components (#12216)

paper-api/src/main/java/org/bukkit/inventory/ItemFactory.java

@@ -210,12 +210,12 @@ public interface ItemFactory {
     @Deprecated(since = "1.19.3") // Paper
     ItemStack enchantItem(@NotNull final ItemStack item, final int level, final boolean allowTreasures);
 
-    // Paper start - Adventure
     /**
      * Creates a hover event for the given item.
      *
      * @param item The item
      * @return A hover event
+     * @throws IllegalArgumentException if the {@link ItemStack#getAmount()} is not between 1 and 99
      */
     @NotNull
     net.kyori.adventure.text.event.HoverEvent<net.kyori.adventure.text.event.HoverEvent.ShowItem> asHoverEvent(final @NotNull ItemStack item, final @NotNull java.util.function.UnaryOperator<net.kyori.adventure.text.event.HoverEvent.ShowItem> op);
@@ -223,12 +223,13 @@ public interface ItemFactory {
     /**
      * Get the formatted display name of the {@link ItemStack}.
      *
+     * @apiNote this component include a {@link net.kyori.adventure.text.event.HoverEvent item hover event}.
+     * When used in chat, make sure to follow the ItemStack rules regarding amount, type, and other properties.
      * @param itemStack the {@link ItemStack}
      * @return display name of the {@link ItemStack}
      */
     @NotNull
     net.kyori.adventure.text.Component displayName(@NotNull ItemStack itemStack);
-    // Paper end - Adventure
 
     // Paper start - add getI18NDisplayName
     /**

paper-api/src/main/java/org/bukkit/inventory/ItemStack.java

@@ -9,6 +9,7 @@ import java.util.Map;
 import java.util.function.Consumer;
 import java.util.function.Predicate;
 import net.kyori.adventure.text.Component;
+import net.kyori.adventure.text.event.HoverEvent;
 import org.bukkit.Bukkit;
 import org.bukkit.Material;
 import org.bukkit.NamespacedKey;
@@ -706,6 +707,13 @@ public class ItemStack implements Cloneable, ConfigurationSerializable, Translat
         return Bukkit.getItemFactory().enchantWithLevels(this, levels, keySet, random);
     }
 
+    /**
+     * {@inheritDoc}
+     *
+     * @param op transformation on value
+     * @return a hover event
+     * @throws IllegalArgumentException if the {@link ItemStack#getAmount()} is not between 1 and 99
+     */
     @NotNull
     @Override
     public net.kyori.adventure.text.event.HoverEvent<net.kyori.adventure.text.event.HoverEvent.ShowItem> asHoverEvent(final @NotNull java.util.function.UnaryOperator<net.kyori.adventure.text.event.HoverEvent.ShowItem> op) {
@@ -715,6 +723,8 @@ public class ItemStack implements Cloneable, ConfigurationSerializable, Translat
     /**
      * Get the formatted display name of the {@link ItemStack}.
      *
+     * @apiNote this component include a {@link net.kyori.adventure.text.event.HoverEvent item hover event}.
+     * When used in chat, make sure to follow the ItemStack rules regarding amount, type, and other properties.
      * @return display name of the {@link ItemStack}
      */
     public net.kyori.adventure.text.@NotNull Component displayName() {

paper-server/src/main/java/org/bukkit/craftbukkit/inventory/CraftItemFactory.java

@@ -214,9 +214,9 @@ public final class CraftItemFactory implements ItemFactory {
         return CraftItemStack.asCraftMirror(EnchantmentHelper.enchantItem(source, craft.handle, level, registry, optional));
     }
 
-    // Paper start - Adventure
     @Override
     public net.kyori.adventure.text.event.HoverEvent<net.kyori.adventure.text.event.HoverEvent.ShowItem> asHoverEvent(final ItemStack item, final java.util.function.UnaryOperator<net.kyori.adventure.text.event.HoverEvent.ShowItem> op) {
+        Preconditions.checkArgument(item.getAmount() > 1 && item.getAmount() <= 99, "ItemStack amount must be between 1 and 99 but was %s", item.getAmount());
         return net.kyori.adventure.text.event.HoverEvent.showItem(op.apply(
             net.kyori.adventure.text.event.HoverEvent.ShowItem.showItem(
                 item.getType().getKey(),
@@ -229,7 +229,6 @@ public final class CraftItemFactory implements ItemFactory {
     public net.kyori.adventure.text.@org.jetbrains.annotations.NotNull Component displayName(@org.jetbrains.annotations.NotNull ItemStack itemStack) {
         return io.papermc.paper.adventure.PaperAdventure.asAdventure(CraftItemStack.asNMSCopy(itemStack).getDisplayName());
     }
-    // Paper end - Adventure
 
     // Paper start - ensure server conversions API
     // TODO: DO WE NEED THIS?