Fix inventory lost when returning to original island

CLAUDE.md

@@ -0,0 +1,35 @@
+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Project Overview
+
+InvSwitcher is a BentoBox addon for Minecraft (Spigot/Bukkit) that gives players separate inventories, ender chests, health, food, experience, advancements, game modes, and statistics per game-world. Nether and End dimensions are automatically grouped with their overworld.
+
+## Build Commands
+
+- **Build**: `mvn clean package`
+- **Run tests**: `mvn test -Dmaven.compiler.forceJavacCompilerUse=true`
+- **Run a single test class**: `mvn test -Dmaven.compiler.forceJavacCompilerUse=true -Dtest=StoreTest`
+- **Run a single test method**: `mvn test -Dmaven.compiler.forceJavacCompilerUse=true -Dtest=StoreTest#testMethodName`
+
+Requires Java 21. The build produces a shaded JAR in `target/`. The `-Dmaven.compiler.forceJavacCompilerUse=true` flag is needed to work around a compiler hashing bug with the current JDK.
+
+## Architecture
+
+This is a BentoBox Addon (extends `Addon`, not a standalone Bukkit plugin). Key flow:
+
+- **InvSwitcher** - Addon entry point. Loads config, resolves configured world names to `World` objects (including nether/end variants), creates the `Store`, and registers `PlayerListener`.
+- **Store** - Core logic. Maintains an in-memory `Map<UUID, InventoryStorage>` cache backed by BentoBox's `Database`. On world change: stores current player state to the old world's slot, clears the player, then loads the new world's slot. Handles XP math manually (Bukkit's `getTotalExperience()` is unreliable). Tracks per-player `currentKey` to map saves/loads to the correct storage slot.
+- **InventoryStorage** - `DataObject` (BentoBox DB entity) keyed by player UUID. All per-world data is stored as `Map<String, ...>` where the key is either the overworld name (e.g., `"oneblock_world"`) or an island-specific key (e.g., `"oneblock_world/islandId"`). Persisted via BentoBox's database abstraction (JSON, MySQL, etc. — **not** YAML, which is explicitly unsupported).
+- **PlayerListener** - Listens to `PlayerChangedWorldEvent`, `PlayerJoinEvent`, `PlayerQuitEvent`, `IslandEnterEvent`, and `PlayerRespawnEvent` to trigger store/load operations.
+- **Settings** - `ConfigObject` loaded from `config.yml`. Each switchable aspect (inventory, health, food, etc.) has a world-level boolean toggle and a per-island sub-toggle.
+
+## Key Design Details
+
+- World name normalization: nether (`_nether`) and end (`_the_end`) suffixes are stripped to map all three dimensions to the same overworld key.
+- **Per-island inventory switching**: When `islandsActive` is enabled and a player owns multiple concurrent islands, data is keyed as `"worldName/islandId"` instead of just `"worldName"`. Each data type (inventory, health, etc.) has its own per-island sub-toggle.
+- **Storage key transitions**: When a player goes from 1 island to multiple, their `currentKey` must be upgraded from a world-only key to an island-specific key. This is handled proactively in `PlayerListener.onIslandEnter` via `Store.upgradeWorldKeyToIsland()` before any save/load occurs.
+- **Backward compatibility migration**: `Store.getInventory()` migrates world-only data to island-specific keys on first load if no island-specific data exists yet.
+- Statistics saving runs asynchronously via `Bukkit.getScheduler()` except during shutdown (where scheduling is unavailable).
+- Tests use JUnit 5 + MockBukkit + Mockito. The surefire plugin requires extensive `--add-opens` flags (already configured in pom.xml).

pom.xml

@@ -53,9 +53,11 @@
         <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
         <java.version>21</java.version>
         <!-- Non-minecraft related dependencies -->
-        <mockito.version>5.12.0</mockito.version>
+        <mockito.version>5.17.0</mockito.version>
+        <junit.version>5.12.1</junit.version>
+        <byte-buddy.version>1.17.5</byte-buddy.version>
         <!-- More visible way how to change dependency versions -->
-        <spigot.version>1.21.3-R0.1-SNAPSHOT</spigot.version>
+        <paper.version>1.21.11-R0.1-SNAPSHOT</paper.version>
         <bentobox.version>2.7.1-SNAPSHOT</bentobox.version>
         <!-- Revision variable removes warning about dynamic version -->
         <revision>${build.version}-SNAPSHOT</revision>
@@ -112,6 +114,14 @@
     </profiles>
 
     <repositories>
+        <!-- jitpack first so MockBukkit snapshots resolve without hitting other repos -->
+        <repository>
+            <id>jitpack.io</id>
+            <url>https://jitpack.io</url>
+            <snapshots>
+                <enabled>true</enabled>
+            </snapshots>
+        </repository>
         <repository>
             <id>spigot-repo</id>
             <url>https://hub.spigotmc.org/nexus/content/repositories/snapshots</url>
@@ -120,16 +130,40 @@
             <id>codemc</id>
             <url>https://repo.codemc.org/repository/bentoboxworld/</url>
         </repository>
+        <repository>
+            <id>papermc</id>
+            <url>https://repo.papermc.io/repository/maven-public/</url>
+        </repository>
     </repositories>
 
     <dependencies>
-        <!-- Spigot API -->
+        <!-- Paper API -->
         <dependency>
-            <groupId>org.spigotmc</groupId>
-            <artifactId>spigot-api</artifactId>
-            <version>${spigot.version}</version>
+            <groupId>io.papermc.paper</groupId>
+            <artifactId>paper-api</artifactId>
+            <version>${paper.version}</version>
             <scope>provided</scope>
         </dependency>
+        <!-- MockBukkit -->
+        <dependency>
+            <groupId>com.github.MockBukkit</groupId>
+            <artifactId>MockBukkit</artifactId>
+            <version>v1.21-SNAPSHOT</version>
+            <scope>test</scope>
+            <exclusions>
+                <exclusion>
+                    <groupId>org.junit.jupiter</groupId>
+                    <artifactId>junit-jupiter-api</artifactId>
+                </exclusion>
+            </exclusions>
+        </dependency>
+        <!-- JUnit 5 -->
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter</artifactId>
+            <version>${junit.version}</version>
+            <scope>test</scope>
+        </dependency>
         <!-- Mockito (Unit testing) -->
         <dependency>
             <groupId>org.mockito</groupId>
@@ -139,14 +173,21 @@
         </dependency>
         <dependency>
             <groupId>org.mockito</groupId>
-            <artifactId>mockito-inline</artifactId>
-            <version>5.0.0</version>
+            <artifactId>mockito-junit-jupiter</artifactId>
+            <version>${mockito.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <!-- ByteBuddy - explicit version for Java 25 support -->
+        <dependency>
+            <groupId>net.bytebuddy</groupId>
+            <artifactId>byte-buddy</artifactId>
+            <version>${byte-buddy.version}</version>
             <scope>test</scope>
         </dependency>
         <dependency>
-            <groupId>junit</groupId>
-            <artifactId>junit</artifactId>
-            <version>4.13.2</version>
+            <groupId>net.bytebuddy</groupId>
+            <artifactId>byte-buddy-agent</artifactId>
+            <version>${byte-buddy.version}</version>
             <scope>test</scope>
         </dependency>
         <dependency>

src/main/java/com/wasteofplastic/invswitcher/Settings.java

@@ -35,6 +35,28 @@ public class Settings implements ConfigObject {
     @ConfigEntry(path = "options.statistics")
     private boolean statistics = true;
 
+    @ConfigComment("Switch inventories based on island. Only applies if players own more than one island.")
+    @ConfigComment("Each sub-option controls whether that aspect is switched per-island.")
+    @ConfigComment("The world-level option must also be true for the island option to have any effect.")
+    @ConfigEntry(path = "options.islands.active")
+    private boolean islandsActive = true;
+    @ConfigEntry(path = "options.islands.inventory")
+    private boolean islandsInventory = true;
+    @ConfigEntry(path = "options.islands.health")
+    private boolean islandsHealth = false;
+    @ConfigEntry(path = "options.islands.food")
+    private boolean islandsFood = false;
+    @ConfigEntry(path = "options.islands.advancements")
+    private boolean islandsAdvancements = false;
+    @ConfigEntry(path = "options.islands.gamemode")
+    private boolean islandsGamemode = false;
+    @ConfigEntry(path = "options.islands.experience")
+    private boolean islandsExperience = false;
+    @ConfigEntry(path = "options.islands.ender-chest")
+    private boolean islandsEnderChest = true;
+    @ConfigEntry(path = "options.islands.statistics")
+    private boolean islandsStatistics = false;
+
     /**
      * @return the worlds
      */
@@ -143,6 +165,65 @@ public boolean isStatistics() {
     public void setStatistics(boolean statistics) {
         this.statistics = statistics;
     }
-
+    /**
+     * @return whether per-island switching is active
+     */
+    public boolean isIslandsActive() {
+        return islandsActive;
+    }
+    /**
+     * @param islandsActive whether to enable per-island switching
+     */
+    public void setIslandsActive(boolean islandsActive) {
+        this.islandsActive = islandsActive;
+    }
+    public boolean isIslandsInventory() {
+        return islandsInventory;
+    }
+    public void setIslandsInventory(boolean islandsInventory) {
+        this.islandsInventory = islandsInventory;
+    }
+    public boolean isIslandsHealth() {
+        return islandsHealth;
+    }
+    public void setIslandsHealth(boolean islandsHealth) {
+        this.islandsHealth = islandsHealth;
+    }
+    public boolean isIslandsFood() {
+        return islandsFood;
+    }
+    public void setIslandsFood(boolean islandsFood) {
+        this.islandsFood = islandsFood;
+    }
+    public boolean isIslandsAdvancements() {
+        return islandsAdvancements;
+    }
+    public void setIslandsAdvancements(boolean islandsAdvancements) {
+        this.islandsAdvancements = islandsAdvancements;
+    }
+    public boolean isIslandsGamemode() {
+        return islandsGamemode;
+    }
+    public void setIslandsGamemode(boolean islandsGamemode) {
+        this.islandsGamemode = islandsGamemode;
+    }
+    public boolean isIslandsExperience() {
+        return islandsExperience;
+    }
+    public void setIslandsExperience(boolean islandsExperience) {
+        this.islandsExperience = islandsExperience;
+    }
+    public boolean isIslandsEnderChest() {
+        return islandsEnderChest;
+    }
+    public void setIslandsEnderChest(boolean islandsEnderChest) {
+        this.islandsEnderChest = islandsEnderChest;
+    }
+    public boolean isIslandsStatistics() {
+        return islandsStatistics;
+    }
+    public void setIslandsStatistics(boolean islandsStatistics) {
+        this.islandsStatistics = islandsStatistics;
+    }
 
 }