Isolate platform binding

- Add the PlatformBinding rule that binds a mock platform for a class or method, unbinds on teardown and restores the previous binding
- Add the PlatformLeakGuard rule that fails a class when a platform is still bound or a service is still registered at class start or end
- Add IrisRuntimeState so the guard reads the registered services without adding a test-only method to the SPI
- Replace the inline mock-platform setup and teardown of twenty test classes with the rule
- Guard the remaining sixty-four platform and service touching core test classes
- Rename the pack-compat pool fixtures to PackCompatFixtures so the two CompatFixtures names cannot collide
- Scope BukkitTestServer branding to a ServerBranding rule that restores the shared mock after each test

core/src/test/java/art/arcane/iris/core/IrisRuntimeSchedulerModeRoutingTest.java

@@ -1,6 +1,7 @@
 package art.arcane.iris.core;
 
 import art.arcane.iris.testsupport.BukkitTestServer;
+import org.junit.Rule;
 import org.junit.Test;
 
 
@@ -9,6 +10,9 @@ import static org.junit.Assume.assumeTrue;
 import static org.mockito.Mockito.mockingDetails;
 
 public class IrisRuntimeSchedulerModeRoutingTest {
+    @Rule
+    public final BukkitTestServer.ServerBranding branding = BukkitTestServer.branding();
+
     @Test
     public void autoResolvesToPaperLikeOnPurpurBranding() {
         installServer("Purpur", "git-Purpur-2562 (MC: 26.2)");
@@ -55,6 +59,6 @@ public class IrisRuntimeSchedulerModeRoutingTest {
 
     private void installServer(String name, String version) {
         assumeTrue(mockingDetails(BukkitTestServer.install()).isMock());
-        BukkitTestServer.brand(name, version);
+        branding.set(name, version);
     }
 }

core/src/test/java/art/arcane/iris/core/gui/NoiseExplorerGUITest.java

@@ -3,7 +3,9 @@ package art.arcane.iris.core.gui;
 import art.arcane.iris.engine.framework.MeteredCache;
 import art.arcane.iris.engine.framework.PreservationRegistry;
 import art.arcane.iris.spi.IrisServices;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.volmlib.util.function.NoiseProvider;
+import org.junit.ClassRule;
 import org.junit.Test;
 
 import javax.swing.SwingUtilities;
@@ -20,6 +22,9 @@ import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 
 public final class NoiseExplorerGUITest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Test
     public void openingInitialSourceBuildsSamplerExactlyOnce() throws Exception {
         AtomicInteger factoryCalls = new AtomicInteger();

core/src/test/java/art/arcane/iris/core/gui/PregeneratorJobShutdownDispatchTest.java

@@ -8,6 +8,7 @@ import art.arcane.iris.platform.bukkit.BukkitPlatform;
 import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.IrisServices;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.iris.util.common.scheduling.J;
 import art.arcane.volmlib.util.format.MemoryMonitor;
 import art.arcane.volmlib.util.scheduling.FoliaScheduler;
@@ -17,6 +18,7 @@ import org.bukkit.plugin.IllegalPluginAccessException;
 import org.bukkit.plugin.Plugin;
 import org.bukkit.plugin.PluginManager;
 import org.bukkit.scheduler.BukkitScheduler;
+import org.junit.ClassRule;
 import org.junit.Test;
 import org.mockito.MockedStatic;
 
@@ -45,6 +47,9 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 public class PregeneratorJobShutdownDispatchTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Test
     public void pluginDisableCanJoinAWorkerAlreadyDispatchingSaving() throws Exception {
         try (Fixture fixture = new Fixture()) {

core/src/test/java/art/arcane/iris/core/lifecycle/MissingWorldStorageLogTest.java

@@ -3,8 +3,10 @@ package art.arcane.iris.core.lifecycle;
 import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.LogLevel;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import org.junit.After;
 import org.junit.Before;
+import org.junit.ClassRule;
 import org.junit.Test;
 
 import java.nio.file.Path;
@@ -22,6 +24,9 @@ import static org.mockito.Mockito.mock;
  * console and the runtime log but never the instance's logs/latest.log - the only log most operators read.
  */
 public class MissingWorldStorageLogTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     private final List<String> emitted = new ArrayList<>();
     private final List<LogLevel> levels = new ArrayList<>();
     private IrisPlatform previousPlatform;

core/src/test/java/art/arcane/iris/core/link/MultiverseGuardListenerTest.java

@@ -3,12 +3,14 @@ package art.arcane.iris.core.link;
 import art.arcane.iris.core.lifecycle.ManagedWorldLoader;
 import art.arcane.iris.engine.platform.BukkitChunkGenerator;
 import art.arcane.iris.spi.IrisServices;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import org.bukkit.Bukkit;
 import org.bukkit.Server;
 import org.bukkit.World;
 import org.bukkit.command.ConsoleCommandSender;
 import org.bukkit.event.server.ServerCommandEvent;
 import org.bukkit.plugin.PluginManager;
+import org.junit.ClassRule;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
@@ -29,6 +31,9 @@ import static org.mockito.Mockito.mockStatic;
 import static org.mockito.Mockito.when;
 
 public class MultiverseGuardListenerTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Rule
     public TemporaryFolder temporaryFolder = new TemporaryFolder();
 

core/src/test/java/art/arcane/iris/core/loader/IrisDataAuthoringCacheTest.java

@@ -4,8 +4,10 @@ import art.arcane.iris.core.IrisSettings;
 import art.arcane.iris.engine.framework.PreservationRegistry;
 import art.arcane.iris.engine.object.IrisGenerator;
 import art.arcane.iris.spi.IrisServices;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import org.junit.After;
 import org.junit.Before;
+import org.junit.ClassRule;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
@@ -22,6 +24,9 @@ import static org.junit.Assert.assertTrue;
 import static org.mockito.Mockito.mock;
 
 public class IrisDataAuthoringCacheTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Rule
     public final TemporaryFolder temporary = new TemporaryFolder();
 

core/src/test/java/art/arcane/iris/core/loader/IrisDataDatapackCompilerCacheTest.java

@@ -3,8 +3,10 @@ package art.arcane.iris.core.loader;
 import art.arcane.iris.engine.framework.MeteredCache;
 import art.arcane.iris.engine.framework.PreservationRegistry;
 import art.arcane.iris.spi.IrisServices;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import org.junit.After;
 import org.junit.Before;
+import org.junit.ClassRule;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
@@ -17,6 +19,9 @@ import static org.junit.Assert.assertSame;
 import static org.junit.Assert.assertTrue;
 
 public class IrisDataDatapackCompilerCacheTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Rule
     public TemporaryFolder temporaryFolder = new TemporaryFolder();
 

core/src/test/java/art/arcane/iris/core/loader/IrisDataEngineRegistryTest.java

@@ -4,9 +4,11 @@ import art.arcane.iris.engine.framework.Engine;
 import art.arcane.iris.engine.framework.MeteredCache;
 import art.arcane.iris.engine.framework.PreservationRegistry;
 import art.arcane.iris.spi.IrisServices;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.iris.util.project.context.IrisContext;
 import org.junit.After;
 import org.junit.Before;
+import org.junit.ClassRule;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
@@ -21,6 +23,9 @@ import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 public class IrisDataEngineRegistryTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Rule
     public TemporaryFolder temporaryFolder = new TemporaryFolder();
 

core/src/test/java/art/arcane/iris/core/loader/IrisDataRetainedPackTest.java

@@ -5,8 +5,10 @@ import art.arcane.iris.engine.history.GenerationRegistryContract;
 import art.arcane.iris.engine.object.IrisDimension;
 import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.IrisServices;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import org.junit.After;
 import org.junit.Before;
+import org.junit.ClassRule;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
@@ -20,6 +22,9 @@ import static org.mockito.Mockito.mockStatic;
 import static org.mockito.Mockito.spy;
 
 public class IrisDataRetainedPackTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Rule
     public TemporaryFolder temporaryFolder = new TemporaryFolder();
 

core/src/test/java/art/arcane/iris/core/loader/ResourceLoaderPrefetchTest.java

@@ -7,10 +7,12 @@ import art.arcane.iris.engine.object.IrisDimension;
 import art.arcane.iris.engine.object.IrisObject;
 import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.volmlib.util.collection.KMap;
 import art.arcane.volmlib.util.collection.KSet;
 import org.junit.After;
 import org.junit.Before;
+import org.junit.ClassRule;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
@@ -34,6 +36,9 @@ import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 public class ResourceLoaderPrefetchTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Rule
     public TemporaryFolder temporaryFolder = new TemporaryFolder();
 

core/src/test/java/art/arcane/iris/core/loader/ResourceLoaderStaticObjectValidationTest.java

@@ -5,9 +5,11 @@ import art.arcane.iris.engine.object.IrisDimension;
 import art.arcane.iris.engine.object.IrisPosition;
 import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import com.google.gson.Gson;
 import org.junit.After;
 import org.junit.Before;
+import org.junit.ClassRule;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
@@ -26,6 +28,9 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 public class ResourceLoaderStaticObjectValidationTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Rule
     public TemporaryFolder temporaryFolder = new TemporaryFolder();
 

core/src/test/java/art/arcane/iris/core/pack/PackDownloaderTest.java

@@ -27,9 +27,11 @@ import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.IrisServices;
 import art.arcane.iris.spi.PlatformStructureHooks;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import org.junit.Assume;
 import org.junit.After;
 import org.junit.Before;
+import org.junit.ClassRule;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
@@ -67,6 +69,9 @@ import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 public class PackDownloaderTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Rule
     public TemporaryFolder temp = new TemporaryFolder();
 

core/src/test/java/art/arcane/iris/core/pack/PackImageMapValidatorTest.java

@@ -3,8 +3,10 @@ package art.arcane.iris.core.pack;
 import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformRegistries;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import org.junit.After;
 import org.junit.Before;
+import org.junit.ClassRule;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
@@ -25,6 +27,9 @@ import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 public class PackImageMapValidatorTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Rule
     public TemporaryFolder temporaryFolder = new TemporaryFolder();
 

core/src/test/java/art/arcane/iris/core/pack/PackValidationCacheTest.java

@@ -7,6 +7,8 @@ import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformRegistries;
 import art.arcane.iris.spi.PlatformStructureHooks;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
+import org.junit.ClassRule;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.Assume;
@@ -30,6 +32,9 @@ import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 public class PackValidationCacheTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Rule
     public TemporaryFolder temporaryFolder = new TemporaryFolder();
 

core/src/test/java/art/arcane/iris/core/pack/PackValidatorStructureGraphTest.java

@@ -4,6 +4,8 @@ import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformStructureHooks;
 import art.arcane.iris.spi.PlatformStructureHooks.JigsawSourceMetadata;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
+import org.junit.ClassRule;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
@@ -27,6 +29,9 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 public class PackValidatorStructureGraphTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Rule
     public TemporaryFolder temporaryFolder = new TemporaryFolder();
 

core/src/test/java/art/arcane/iris/core/pregenerator/cache/PregenCacheExecutorRegistrationTest.java

@@ -3,7 +3,9 @@ package art.arcane.iris.core.pregenerator.cache;
 import art.arcane.iris.engine.framework.MeteredCache;
 import art.arcane.iris.engine.framework.PreservationRegistry;
 import art.arcane.iris.spi.IrisServices;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import org.junit.After;
+import org.junit.ClassRule;
 import org.junit.Test;
 
 import java.io.File;
@@ -16,6 +18,9 @@ import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 
 public class PregenCacheExecutorRegistrationTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     private static final class RecordingPreservation implements PreservationRegistry {
         private final List<ExecutorService> executors = new CopyOnWriteArrayList<>();
 

core/src/test/java/art/arcane/iris/core/project/ExternalBlockSchemaTest.java

@@ -7,9 +7,11 @@ import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformBlockProperty;
 import art.arcane.iris.spi.PlatformRegistries;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.volmlib.util.json.JSONObject;
 import org.junit.After;
 import org.junit.Before;
+import org.junit.ClassRule;
 import org.junit.Test;
 
 import java.util.List;
@@ -20,6 +22,9 @@ import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 public class ExternalBlockSchemaTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     private static final String QUALIFIED_BLOCK = "craftengine:example/ores/copper";
 
     private IrisPlatform previous;

core/src/test/java/art/arcane/iris/core/project/IrisCodeWorkspaceTest.java

@@ -8,10 +8,12 @@ import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.IrisServices;
 import art.arcane.iris.spi.PlatformRegistries;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.volmlib.util.json.JSONArray;
 import art.arcane.volmlib.util.json.JSONObject;
 import org.junit.After;
 import org.junit.Before;
+import org.junit.ClassRule;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
@@ -34,6 +36,9 @@ import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 public class IrisCodeWorkspaceTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Rule
     public TemporaryFolder temporaryFolder = new TemporaryFolder();
 

core/src/test/java/art/arcane/iris/core/project/IrisRiverSchemaTest.java

@@ -8,6 +8,7 @@ import art.arcane.iris.engine.object.IrisBlockData;
 import art.arcane.iris.engine.object.IrisExpression;
 import art.arcane.iris.engine.object.IrisHydrology;
 import art.arcane.iris.engine.object.IrisRiverPolicy;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.volmlib.util.collection.KList;
 import art.arcane.volmlib.util.collection.KMap;
 import art.arcane.volmlib.util.json.JSONArray;
@@ -17,6 +18,7 @@ import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformRegistries;
 import org.junit.After;
 import org.junit.Before;
+import org.junit.ClassRule;
 import org.junit.Test;
 
 import java.util.ArrayList;
@@ -30,6 +32,9 @@ import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 public class IrisRiverSchemaTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     private IrisPlatform previousPlatform;
 
     @Before

core/src/test/java/art/arcane/iris/core/project/IrisStaticObjectSchemaTest.java

@@ -12,11 +12,13 @@ import art.arcane.iris.engine.object.annotations.ArrayType;
 import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformRegistries;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.volmlib.util.collection.KList;
 import art.arcane.volmlib.util.collection.KMap;
 import art.arcane.volmlib.util.json.JSONObject;
 import org.junit.After;
 import org.junit.Before;
+import org.junit.ClassRule;
 import org.junit.Test;
 
 import java.lang.reflect.Field;
@@ -30,6 +32,9 @@ import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 public class IrisStaticObjectSchemaTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     private IrisPlatform previousPlatform;
 
     @Before

core/src/test/java/art/arcane/iris/core/project/SchemaBuilderParityTest.java

@@ -55,12 +55,14 @@ import art.arcane.iris.spi.PlatformRegistries;
 import art.arcane.iris.spi.PlatformScheduler;
 import art.arcane.iris.spi.PlatformStructureHooks;
 import art.arcane.iris.spi.PlatformWorld;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.volmlib.util.collection.KList;
 import art.arcane.volmlib.util.collection.KMap;
 import art.arcane.volmlib.util.json.JSONArray;
 import art.arcane.volmlib.util.json.JSONObject;
 import org.junit.After;
 import org.junit.Before;
+import org.junit.ClassRule;
 import org.junit.Test;
 
 import java.io.File;
@@ -76,6 +78,9 @@ import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 public class SchemaBuilderParityTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     private static final List<String> POTION_KEYS = List.of("minecraft:speed", "minecraft:slow_falling", "sniffer_mod:mega_boost");
     private static final List<String> ENCHANT_KEYS = List.of("minecraft:sharpness", "cool_mod:vorpal");
     private static final List<String> ITEM_KEYS = List.of("minecraft:stone", "minecraft:diamond_sword", "cool_mod:ruby");

core/src/test/java/art/arcane/iris/core/service/BoardSVCSavedBiomeTest.java

@@ -17,6 +17,7 @@ import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformBlockState;
 import art.arcane.iris.spi.PlatformRegistries;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.iris.util.common.scheduling.J;
 import art.arcane.volmlib.util.board.Board;
 import art.arcane.volmlib.util.board.BoardSettings;
@@ -24,6 +25,7 @@ import org.bukkit.Location;
 import org.bukkit.World;
 import org.bukkit.entity.Player;
 import org.bukkit.event.player.PlayerChangedWorldEvent;
+import org.junit.ClassRule;
 import org.junit.Test;
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
@@ -53,6 +55,9 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 public class BoardSVCSavedBiomeTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     private static IrisPlatform previousPlatform;
 
     @BeforeClass

core/src/test/java/art/arcane/iris/core/service/JigsawStudioMenuControllerTest.java

@@ -7,6 +7,7 @@ import art.arcane.iris.core.runtime.jigsaw.JigsawStudioPieceRules;
 import art.arcane.iris.core.runtime.jigsaw.JigsawStudioToolAction;
 import art.arcane.iris.core.runtime.jigsaw.JigsawStudioToolPayload;
 import art.arcane.iris.spi.IrisServices;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.iris.util.common.scheduling.J;
 import org.bukkit.ChatColor;
 import org.bukkit.Location;
@@ -15,6 +16,7 @@ import org.bukkit.World;
 import org.bukkit.entity.Player;
 import org.bukkit.event.player.PlayerChangedWorldEvent;
 import org.bukkit.plugin.java.JavaPlugin;
+import org.junit.ClassRule;
 import org.junit.Test;
 import org.mockito.MockedStatic;
 
@@ -41,6 +43,9 @@ import static org.mockito.Mockito.verifyNoInteractions;
 import static org.mockito.Mockito.when;
 
 public class JigsawStudioMenuControllerTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     private static final UUID WORLD_ID = UUID.fromString("22222222-2222-2222-2222-222222222222");
     private static final UUID REQUEST_ID = UUID.fromString("77777777-7777-7777-7777-777777777777");
     private static final JigsawStudioPieceRules RULES = new JigsawStudioPieceRules(1, 12, 2, 8, false);

core/src/test/java/art/arcane/iris/core/service/JigsawStudioServiceCaptureTest.java

@@ -36,6 +36,7 @@ import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformBlockState;
 import art.arcane.iris.spi.PlatformRegistries;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.iris.util.common.data.B;
 import art.arcane.iris.util.common.math.IrisBlockVector;
 import art.arcane.iris.util.common.plugin.VolmitPlugin;
@@ -72,6 +73,7 @@ import org.bukkit.event.player.PlayerCommandPreprocessEvent;
 import org.bukkit.event.player.PlayerInteractEvent;
 import org.bukkit.event.world.ChunkLoadEvent;
 import org.bukkit.event.world.WorldUnloadEvent;
+import org.junit.ClassRule;
 import org.junit.Test;
 import org.mockito.MockedStatic;
 
@@ -115,6 +117,9 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 public class JigsawStudioServiceCaptureTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
 
     @Test
     public void shutdownQuiesceIsIdempotentAndResetsOnEnable() throws Exception {

core/src/test/java/art/arcane/iris/core/service/MultiverseSVCTest.java

@@ -4,6 +4,7 @@ import art.arcane.iris.core.link.MultiverseCoreLink;
 import art.arcane.iris.core.link.MultiverseGuardListener;
 import art.arcane.iris.platform.bukkit.BukkitPlatform;
 import art.arcane.iris.spi.IrisServices;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.iris.util.common.plugin.VolmitPlugin;
 import org.bukkit.Bukkit;
 import org.bukkit.event.Listener;
@@ -11,6 +12,7 @@ import org.bukkit.event.server.PluginDisableEvent;
 import org.bukkit.event.server.PluginEnableEvent;
 import org.bukkit.plugin.Plugin;
 import org.junit.After;
+import org.junit.ClassRule;
 import org.junit.Test;
 import org.mockito.MockedStatic;
 
@@ -24,6 +26,9 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 public class MultiverseSVCTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @After
     public void unbindLink() {
         IrisServices.remove(MultiverseCoreLink.class);

core/src/test/java/art/arcane/iris/core/service/StudioSVCWorldPackPublishTest.java

@@ -8,9 +8,11 @@ import art.arcane.iris.core.pack.PackValidationRegistry;
 import art.arcane.iris.core.pack.PackValidationResult;
 import art.arcane.iris.engine.framework.PreservationRegistry;
 import art.arcane.iris.spi.IrisServices;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import org.junit.Assume;
 import org.junit.After;
 import org.junit.Before;
+import org.junit.ClassRule;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
@@ -32,6 +34,9 @@ import static org.junit.Assert.assertTrue;
 import static org.mockito.Mockito.mock;
 
 public class StudioSVCWorldPackPublishTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Rule
     public TemporaryFolder temporaryFolder = new TemporaryFolder();
 

core/src/test/java/art/arcane/iris/core/structure/StructureIndexServiceTest.java

@@ -7,8 +7,10 @@ import art.arcane.iris.engine.history.GenerationPackFingerprint;
 import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformStructureHooks;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import org.junit.After;
 import org.junit.Before;
+import org.junit.ClassRule;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
@@ -30,6 +32,9 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 public class StructureIndexServiceTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Rule
     public TemporaryFolder temporaryFolder = new TemporaryFolder();
 

core/src/test/java/art/arcane/iris/core/structure/authoring/IrisDataStructureRecoveryTest.java

@@ -4,8 +4,10 @@ import art.arcane.iris.core.loader.IrisData;
 import art.arcane.iris.engine.framework.MeteredCache;
 import art.arcane.iris.engine.framework.PreservationRegistry;
 import art.arcane.iris.spi.IrisServices;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import org.junit.After;
 import org.junit.Before;
+import org.junit.ClassRule;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
@@ -22,6 +24,9 @@ import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertFalse;
 
 public class IrisDataStructureRecoveryTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Rule
     public TemporaryFolder temporaryFolder = new TemporaryFolder();
 

core/src/test/java/art/arcane/iris/core/structure/export/VanillaJigsawDatapackExporterTest.java

@@ -20,6 +20,7 @@ import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformBlockState;
 import art.arcane.iris.spi.PlatformRegistries;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.volmlib.util.collection.KList;
 import art.arcane.volmlib.util.nbt.io.NBTUtil;
 import art.arcane.volmlib.util.nbt.tag.CompoundTag;
@@ -28,6 +29,7 @@ import com.google.gson.JsonObject;
 import com.google.gson.JsonParser;
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
+import org.junit.ClassRule;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
@@ -53,6 +55,9 @@ import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 public class VanillaJigsawDatapackExporterTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     private static PlatformBlockState stone;
 
     @Rule

core/src/test/java/art/arcane/iris/core/tools/IrisToolbeltPackReferenceTest.java

@@ -2,8 +2,10 @@ package art.arcane.iris.core.tools;
 
 import art.arcane.iris.core.service.StudioSVC;
 import art.arcane.iris.spi.IrisServices;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import org.bukkit.World;
 import org.junit.After;
+import org.junit.ClassRule;
 import org.junit.Test;
 
 import java.lang.reflect.Proxy;
@@ -14,6 +16,9 @@ import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 
 public class IrisToolbeltPackReferenceTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @After
     public void cleanServices() {
         IrisServices.remove(StudioSVC.class);

core/src/test/java/art/arcane/iris/core/tools/TreePlausibilizerTest.java

@@ -1,13 +1,10 @@
 package art.arcane.iris.core.tools;
 
 import art.arcane.iris.engine.object.IrisObject;
-import art.arcane.iris.spi.IrisPlatform;
-import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformBlockState;
-import art.arcane.iris.spi.PlatformRegistries;
+import art.arcane.iris.testsupport.PlatformBinding;
 import art.arcane.iris.util.common.math.IrisBlockVector;
-import org.junit.AfterClass;
+import org.junit.ClassRule;
-import org.junit.BeforeClass;
 import org.junit.Test;
 
 import java.util.ArrayDeque;
@@ -22,11 +19,11 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
-import static org.mockito.ArgumentMatchers.anyString;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.when;
 
 public class TreePlausibilizerTest {
+    @ClassRule
+    public static final PlatformBinding PLATFORM = PlatformBinding.mockPlatform();
+
     private static final String OAK_LOG = "minecraft:oak_log[axis=y]";
     private static final String BIRCH_LOG = "minecraft:birch_log[axis=y]";
     private static final String OAK_LEAVES = "minecraft:oak_leaves[distance=7,persistent=true,waterlogged=false]";
@@ -42,22 +39,6 @@ public class TreePlausibilizerTest {
     private record Pos(int x, int y, int z) {
     }
 
-    @BeforeClass
-    public static void bindPlatform() {
-        IrisPlatforms.unbind();
-        PlatformBlockState defaultBlock = mock(PlatformBlockState.class);
-        PlatformRegistries registries = mock(PlatformRegistries.class);
-        IrisPlatform platform = mock(IrisPlatform.class);
-        when(registries.block(anyString())).thenReturn(defaultBlock);
-        when(platform.registries()).thenReturn(registries);
-        IrisPlatforms.bind(platform);
-    }
-
-    @AfterClass
-    public static void unbindPlatform() {
-        IrisPlatforms.unbind();
-    }
-
     private static final class TestState implements PlatformBlockState {
         private final String key;
 

core/src/test/java/art/arcane/iris/engine/EngineShutdownDrainTest.java

@@ -27,6 +27,7 @@ import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformBlockState;
 import art.arcane.iris.spi.PlatformRegistries;
 import art.arcane.iris.testsupport.DurabilityMode;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
 import org.junit.ClassRule;
@@ -71,6 +72,9 @@ import static org.mockito.Mockito.verifyNoInteractions;
 import static org.mockito.Mockito.when;
 
 public class EngineShutdownDrainTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @ClassRule
     public static final DurabilityMode DURABILITY = DurabilityMode.relaxed();
 

core/src/test/java/art/arcane/iris/engine/ResolvedTerrainProviderTest.java

@@ -17,11 +17,13 @@ import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformRegistries;
 import art.arcane.iris.spi.PlatformBlockState;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.iris.util.project.context.ChunkContext;
 import art.arcane.iris.util.project.context.IrisContext;
 import art.arcane.iris.util.project.hunk.Hunk;
 import art.arcane.iris.util.project.stream.ProceduralStream;
 import art.arcane.volmlib.util.collection.KList;
+import org.junit.ClassRule;
 import org.junit.Test;
 import org.mockito.MockedStatic;
 
@@ -59,6 +61,9 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 public final class ResolvedTerrainProviderTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Test
     public void cachedTransitionTerrainRetainsDeferredBlocksWhenCopied() {
         Fixture fixture = new Fixture();

core/src/test/java/art/arcane/iris/engine/actuator/IrisBiomeActuatorCoordinateTest.java

@@ -13,6 +13,7 @@ import art.arcane.iris.spi.PlatformBlockState;
 import art.arcane.iris.spi.PlatformBiome;
 import art.arcane.iris.spi.PlatformBiomeWriter;
 import art.arcane.iris.spi.PlatformRegistries;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.iris.util.project.context.ChunkContext;
 import art.arcane.iris.util.project.context.ChunkedDataCache;
 import art.arcane.iris.util.project.hunk.Hunk;
@@ -21,6 +22,7 @@ import art.arcane.volmlib.util.math.RNG;
 import art.arcane.volmlib.util.matter.Matter;
 import art.arcane.volmlib.util.matter.MatterBiomeInject;
 import org.junit.After;
+import org.junit.ClassRule;
 import org.junit.Test;
 
 import java.util.ArrayList;
@@ -43,6 +45,9 @@ import static org.mockito.Mockito.verifyNoMoreInteractions;
 import static org.mockito.Mockito.when;
 
 public class IrisBiomeActuatorCoordinateTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @After
     public void unbindPlatform() {
         IrisPlatforms.unbind();

core/src/test/java/art/arcane/iris/engine/actuator/IrisDimensionStackActuatorMetadataTest.java

@@ -7,6 +7,7 @@ import art.arcane.iris.spi.PlatformBlockState;
 import art.arcane.iris.spi.PlatformRegistries;
 import art.arcane.iris.engine.hydrology.cave.HydrologyCaveAction;
 import art.arcane.iris.engine.mantle.TerrainMatterView;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.iris.util.project.matter.IrisMatterSupport;
 import art.arcane.iris.util.project.matter.slices.PreObjectMatterTest;
 import art.arcane.volmlib.util.matter.IrisMatter;
@@ -23,6 +24,7 @@ import art.arcane.volmlib.util.matter.Matter;
 import art.arcane.volmlib.util.matter.MatterSlice;
 import org.junit.After;
 import org.junit.Before;
+import org.junit.ClassRule;
 import org.junit.Test;
 
 import static org.mockito.ArgumentMatchers.anyString;
@@ -32,6 +34,9 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 public class IrisDimensionStackActuatorMetadataTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Before
     public void bindPlatform() {
         IrisPlatforms.unbind();

core/src/test/java/art/arcane/iris/engine/actuator/IrisTerrainNormalActuatorHydrologyTest.java

@@ -9,14 +9,11 @@ import art.arcane.iris.engine.object.IrisDecorationStep;
 import art.arcane.iris.engine.object.IrisMaterialPalette;
 import art.arcane.iris.engine.object.IrisRiverMaterialConfig;
 import art.arcane.iris.spi.PlatformBlockState;
-import art.arcane.iris.spi.IrisPlatform;
+import art.arcane.iris.testsupport.PlatformBinding;
-import art.arcane.iris.spi.IrisPlatforms;
-import art.arcane.iris.spi.PlatformRegistries;
 import art.arcane.volmlib.util.collection.KList;
 import art.arcane.volmlib.util.math.RNG;
+import org.junit.Rule;
 import org.junit.Test;
-import org.junit.Before;
-import org.junit.After;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -28,7 +25,6 @@ import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyDouble;
-import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.ArgumentMatchers.same;
 import static org.mockito.Mockito.mock;
@@ -37,27 +33,9 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 public class IrisTerrainNormalActuatorHydrologyTest {
-    private IrisPlatform previousPlatform;
+    @Rule
+    public final PlatformBinding platform = PlatformBinding.mockPlatform();
 
-    @Before
-    public void bindPlatform() {
-        previousPlatform = IrisPlatforms.isBound() ? IrisPlatforms.get() : null;
-        IrisPlatforms.unbind();
-        PlatformBlockState block = mock(PlatformBlockState.class);
-        PlatformRegistries registries = mock(PlatformRegistries.class);
-        when(registries.block(anyString())).thenReturn(block);
-        IrisPlatform platform = mock(IrisPlatform.class);
-        when(platform.registries()).thenReturn(registries);
-        IrisPlatforms.bind(platform);
-    }
-
-    @After
-    public void restorePlatform() {
-        IrisPlatforms.unbind();
-        if (previousPlatform != null) {
-            IrisPlatforms.bind(previousPlatform);
-        }
-    }
 
     @Test
     public void hydrologyOwnedFluidBypassesBiomeSeaLayers() {

core/src/test/java/art/arcane/iris/engine/actuator/IrisTransitionGeometryActuatorTest.java

@@ -12,10 +12,12 @@ import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformBiome;
 import art.arcane.iris.spi.PlatformBlockState;
 import art.arcane.iris.spi.PlatformRegistries;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.iris.util.project.context.ChunkContext;
 import art.arcane.iris.util.project.hunk.Hunk;
 import org.junit.After;
 import org.junit.Before;
+import org.junit.ClassRule;
 import org.junit.Test;
 
 import java.util.ArrayList;
@@ -31,6 +33,9 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 public class IrisTransitionGeometryActuatorTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     private IrisPlatform previous;
     private PlatformRegistries registries;
     private PlatformBlockState stone;

core/src/test/java/art/arcane/iris/engine/decorator/IrisDecoratorCaveContextTest.java

@@ -14,7 +14,9 @@ import art.arcane.iris.spi.PlatformBlockState;
 import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformRegistries;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.iris.util.project.hunk.Hunk;
+import org.junit.ClassRule;
 import org.junit.Test;
 import org.junit.BeforeClass;
 import org.junit.AfterClass;
@@ -31,6 +33,9 @@ import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.mock;
 
 public class IrisDecoratorCaveContextTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @BeforeClass
     public static void bindPlatform() {
         IrisPlatforms.unbind();

core/src/test/java/art/arcane/iris/engine/decorator/IrisShoreLineDecoratorTest.java

@@ -14,10 +14,12 @@ import art.arcane.iris.spi.PlatformBlockState;
 import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformRegistries;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.iris.util.project.hunk.Hunk;
 import art.arcane.iris.util.project.stream.ProceduralStream;
 import org.bukkit.block.BlockSupport;
 import org.bukkit.block.data.BlockData;
+import org.junit.ClassRule;
 import org.junit.Test;
 import org.junit.BeforeClass;
 import org.junit.AfterClass;
@@ -35,6 +37,9 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 public class IrisShoreLineDecoratorTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     private static final int FLUID_HEIGHT = 4;
 
     @BeforeClass

core/src/test/java/art/arcane/iris/engine/framework/EngineComponentTest.java

@@ -19,8 +19,10 @@
 package art.arcane.iris.engine.framework;
 
 import art.arcane.iris.spi.IrisServices;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.volmlib.util.math.RollingSequence;
 import org.junit.After;
+import org.junit.ClassRule;
 import org.junit.Test;
 
 import java.util.concurrent.atomic.AtomicReference;
@@ -28,6 +30,9 @@ import java.util.concurrent.atomic.AtomicReference;
 import static org.junit.Assert.assertSame;
 
 public class EngineComponentTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @After
     public void removeCleanup() {
         IrisServices.remove(EngineComponentCleanup.class);

core/src/test/java/art/arcane/iris/engine/framework/EngineHostHeightTest.java

@@ -12,8 +12,10 @@ import art.arcane.iris.spi.PlatformBiome;
 import art.arcane.iris.spi.PlatformBiomeWriter;
 import art.arcane.iris.spi.PlatformBlockState;
 import art.arcane.iris.spi.PlatformRegistries;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import org.junit.After;
 import org.junit.Before;
+import org.junit.ClassRule;
 import org.junit.Test;
 
 import java.util.List;
@@ -30,6 +32,9 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 public class EngineHostHeightTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Before
     public void bindPlatform() {
         IrisPlatforms.unbind();

core/src/test/java/art/arcane/iris/engine/framework/EngineModeBurstAroundTest.java

@@ -1,14 +1,12 @@
 package art.arcane.iris.engine.framework;
 
+import art.arcane.iris.testsupport.PlatformBinding;
 import art.arcane.iris.util.common.parallel.MultiBurst;
 import art.arcane.iris.util.project.context.ChunkContext;
 import art.arcane.iris.core.IrisSettings;
-import art.arcane.iris.spi.IrisPlatform;
-import art.arcane.iris.spi.IrisPlatforms;
-import art.arcane.iris.spi.PlatformBlockState;
-import art.arcane.iris.spi.PlatformRegistries;
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
+import org.junit.ClassRule;
 import org.junit.Test;
 
 import java.util.List;
@@ -19,29 +17,24 @@ import java.util.concurrent.CopyOnWriteArrayList;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
-import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.Mockito.CALLS_REAL_METHODS;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 public class EngineModeBurstAroundTest {
+    @ClassRule
+    public static final PlatformBinding PLATFORM = PlatformBinding.mockPlatform();
+
     private static IrisSettings previousSettings;
 
     @BeforeClass
     public static void bindPlatform() {
         previousSettings = IrisSettings.settings;
         IrisSettings.settings = new IrisSettings();
-        IrisPlatforms.unbind();
-        PlatformRegistries registries = mock(PlatformRegistries.class);
-        IrisPlatform platform = mock(IrisPlatform.class);
-        when(registries.block(anyString())).thenReturn(mock(PlatformBlockState.class));
-        when(platform.registries()).thenReturn(registries);
-        IrisPlatforms.bind(platform);
     }
 
     @AfterClass
     public static void unbindPlatform() {
-        IrisPlatforms.unbind();
         IrisSettings.settings = previousSettings;
     }
 

core/src/test/java/art/arcane/iris/engine/framework/HintedLocatorTest.java

@@ -17,6 +17,7 @@ import art.arcane.iris.engine.hydrology.runtime.IrisHydrologyRuntime;
 import art.arcane.iris.engine.history.GenerationSemanticIndex;
 import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.iris.util.project.stream.ProceduralStream;
 import art.arcane.iris.util.project.stream.interpolation.Interpolated;
 import art.arcane.volmlib.util.collection.KList;
@@ -24,6 +25,7 @@ import art.arcane.volmlib.util.math.Position2;
 import org.junit.AfterClass;
 import org.junit.Before;
 import org.junit.BeforeClass;
+import org.junit.ClassRule;
 import org.junit.Test;
 
 import java.io.File;
@@ -50,6 +52,9 @@ import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 public class HintedLocatorTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     private static boolean boundPlatform;
 
     @BeforeClass

core/src/test/java/art/arcane/iris/engine/framework/StructureAssemblerCompatTest.java

@@ -34,13 +34,9 @@ import art.arcane.iris.engine.object.IrisObject;
 import art.arcane.iris.engine.object.IrisPosition;
 import art.arcane.iris.engine.object.IrisStructure;
 import art.arcane.iris.engine.object.JigsawJoint;
-import art.arcane.iris.spi.IrisPlatform;
+import art.arcane.iris.testsupport.PlatformBinding;
-import art.arcane.iris.spi.IrisPlatforms;
-import art.arcane.iris.spi.PlatformBlockState;
-import art.arcane.iris.spi.PlatformRegistries;
 import art.arcane.volmlib.util.math.RNG;
-import org.junit.AfterClass;
+import org.junit.ClassRule;
-import org.junit.BeforeClass;
 import org.junit.Test;
 
 import java.util.List;
@@ -48,26 +44,12 @@ import java.util.List;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
-import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 public class StructureAssemblerCompatTest {
-    @BeforeClass
+    @ClassRule
-    public static void bindPlatform() {
+    public static final PlatformBinding PLATFORM = PlatformBinding.mockPlatform();
-        IrisPlatforms.unbind();
-        PlatformBlockState block = mock(PlatformBlockState.class);
-        PlatformRegistries registries = mock(PlatformRegistries.class);
-        when(registries.block(anyString())).thenReturn(block);
-        IrisPlatform platform = mock(IrisPlatform.class);
-        when(platform.registries()).thenReturn(registries);
-        IrisPlatforms.bind(platform);
-    }
-
-    @AfterClass
-    public static void unbindPlatform() {
-        IrisPlatforms.unbind();
-    }
 
     @Test
     public void anExcludedPieceIsNeverDrawnFromItsPool() {

core/src/test/java/art/arcane/iris/engine/framework/StructureAssemblerTest.java

@@ -34,13 +34,9 @@ import art.arcane.iris.engine.object.IrisObject;
 import art.arcane.iris.engine.object.IrisPosition;
 import art.arcane.iris.engine.object.IrisStructure;
 import art.arcane.iris.engine.object.JigsawJoint;
-import art.arcane.iris.spi.IrisPlatform;
+import art.arcane.iris.testsupport.PlatformBinding;
-import art.arcane.iris.spi.IrisPlatforms;
-import art.arcane.iris.spi.PlatformBlockState;
-import art.arcane.iris.spi.PlatformRegistries;
 import art.arcane.volmlib.util.math.RNG;
-import org.junit.AfterClass;
+import org.junit.ClassRule;
-import org.junit.BeforeClass;
 import org.junit.Test;
 
 import java.util.List;
@@ -50,26 +46,12 @@ import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertSame;
 import static org.junit.Assert.assertThrows;
 import static org.junit.Assert.assertTrue;
-import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 public class StructureAssemblerTest {
-    @BeforeClass
+    @ClassRule
-    public static void bindPlatform() {
+    public static final PlatformBinding PLATFORM = PlatformBinding.mockPlatform();
-        IrisPlatforms.unbind();
-        PlatformBlockState block = mock(PlatformBlockState.class);
-        PlatformRegistries registries = mock(PlatformRegistries.class);
-        when(registries.block(anyString())).thenReturn(block);
-        IrisPlatform platform = mock(IrisPlatform.class);
-        when(platform.registries()).thenReturn(registries);
-        IrisPlatforms.bind(platform);
-    }
-
-    @AfterClass
-    public static void unbindPlatform() {
-        IrisPlatforms.unbind();
-    }
 
     @Test
     public void attachedNonRotatablePieceKeepsItsAuthoredFacing() {

core/src/test/java/art/arcane/iris/engine/framework/StructureCaveAnchorResolverTest.java

@@ -5,14 +5,10 @@ import art.arcane.iris.engine.object.IrisStructureAnchorMode;
 import art.arcane.iris.engine.object.IrisStructurePlacement;
 import art.arcane.iris.engine.hydrology.cave.HydrologyCaveAction;
 import art.arcane.iris.engine.hydrology.cave.HydrologyCaveCell;
-import art.arcane.iris.spi.IrisPlatform;
+import art.arcane.iris.testsupport.PlatformBinding;
-import art.arcane.iris.spi.IrisPlatforms;
-import art.arcane.iris.spi.PlatformBlockState;
-import art.arcane.iris.spi.PlatformRegistries;
 import art.arcane.volmlib.util.math.RNG;
 import art.arcane.volmlib.util.matter.MatterCavern;
-import org.junit.After;
+import org.junit.Rule;
-import org.junit.Before;
 import org.junit.Test;
 
 import java.util.Arrays;
@@ -27,7 +23,6 @@ import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.ArgumentMatchers.anyInt;
-import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.RETURNS_DEEP_STUBS;
 import static org.mockito.Mockito.mock;
@@ -36,21 +31,8 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 public class StructureCaveAnchorResolverTest {
-    @Before
+    @Rule
-    public void bindPlatform() {
+    public final PlatformBinding platform = PlatformBinding.mockPlatform();
-        IrisPlatforms.unbind();
-        PlatformBlockState block = mock(PlatformBlockState.class);
-        PlatformRegistries registries = mock(PlatformRegistries.class);
-        when(registries.block(anyString())).thenReturn(block);
-        IrisPlatform platform = mock(IrisPlatform.class);
-        when(platform.registries()).thenReturn(registries);
-        IrisPlatforms.bind(platform);
-    }
-
-    @After
-    public void unbindPlatform() {
-        IrisPlatforms.unbind();
-    }
 
     @Test
     public void floorRequiresSolidBoundaryAndUpwardClearance() {

core/src/test/java/art/arcane/iris/engine/framework/StructureReachabilityContractTest.java

@@ -24,6 +24,8 @@ import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformStructureHooks;
 import art.arcane.iris.spi.PlatformWorld;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
+import org.junit.ClassRule;
 import org.junit.Test;
 
 import java.util.List;
@@ -35,6 +37,9 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 public class StructureReachabilityContractTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Test
     public void reachableKeysRejectsNullEngine() {
         assertThrows(NullPointerException.class, () -> StructureReachability.reachableKeys(null));

core/src/test/java/art/arcane/iris/engine/framework/structure/StructureGraphCompilerTest.java

@@ -14,13 +14,9 @@ import art.arcane.iris.engine.object.IrisObject;
 import art.arcane.iris.engine.object.IrisPosition;
 import art.arcane.iris.engine.object.IrisStructure;
 import art.arcane.iris.engine.object.JigsawJoint;
-import art.arcane.iris.spi.IrisPlatform;
+import art.arcane.iris.testsupport.PlatformBinding;
-import art.arcane.iris.spi.IrisPlatforms;
-import art.arcane.iris.spi.PlatformBlockState;
-import art.arcane.iris.spi.PlatformRegistries;
 import art.arcane.volmlib.util.collection.KList;
-import org.junit.AfterClass;
+import org.junit.ClassRule;
-import org.junit.BeforeClass;
 import org.junit.Test;
 
 import java.util.ArrayList;
@@ -31,26 +27,10 @@ import java.util.Map;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
-import static org.mockito.ArgumentMatchers.anyString;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.when;
 
 public class StructureGraphCompilerTest {
-    @BeforeClass
+    @ClassRule
-    public static void bindPlatform() {
+    public static final PlatformBinding PLATFORM = PlatformBinding.mockPlatform();
-        IrisPlatforms.unbind();
-        PlatformBlockState block = mock(PlatformBlockState.class);
-        PlatformRegistries registries = mock(PlatformRegistries.class);
-        when(registries.block(anyString())).thenReturn(block);
-        IrisPlatform platform = mock(IrisPlatform.class);
-        when(platform.registries()).thenReturn(registries);
-        IrisPlatforms.bind(platform);
-    }
-
-    @AfterClass
-    public static void unbindPlatform() {
-        IrisPlatforms.unbind();
-    }
 
     @Test
     public void compilesACompleteTerminalGraphAndSamplesDeterministically() {

core/src/test/java/art/arcane/iris/engine/history/ArchivedRegistryCompilerTest.java

@@ -9,7 +9,9 @@ import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformGenerationRegistry;
 import art.arcane.iris.spi.PlatformRegistries;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.volmlib.util.collection.KList;
+import org.junit.ClassRule;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
@@ -27,6 +29,9 @@ import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 public class ArchivedRegistryCompilerTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Rule
     public final TemporaryFolder temporary = new TemporaryFolder();
 

core/src/test/java/art/arcane/iris/engine/hydrology/HydrologyPlannerCrossTileCaveAdmissionIntegrationTest.java

@@ -9,6 +9,8 @@ import art.arcane.iris.core.IrisSettings;
 import art.arcane.iris.engine.hydrology.cave.HydrologyCavePlan;
 import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
+import org.junit.ClassRule;
 import org.junit.Test;
 
 import java.util.ArrayList;
@@ -23,6 +25,9 @@ import static org.junit.Assert.assertTrue;
 import static org.mockito.Mockito.mock;
 
 public class HydrologyPlannerCrossTileCaveAdmissionIntegrationTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     private static final long SEED = 77L;
     private static final List<TilePair> ADJACENT_PAIRS = List.of(
             new TilePair(new HydrologyTileKey(0, -2), new HydrologyTileKey(0, -1)),

core/src/test/java/art/arcane/iris/engine/mantle/EngineMantleCleanupTest.java

@@ -3,10 +3,8 @@ package art.arcane.iris.engine.mantle;
 import art.arcane.iris.core.link.Identifier;
 import art.arcane.iris.engine.framework.TreeBlockMaterial;
 import art.arcane.iris.engine.hydrology.cave.HydrologyCaveCell;
-import art.arcane.iris.spi.IrisPlatform;
-import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformBlockState;
-import art.arcane.iris.spi.PlatformRegistries;
+import art.arcane.iris.testsupport.PlatformBinding;
 import art.arcane.iris.util.project.matter.PreObjectMatterCell;
 import art.arcane.iris.util.project.matter.TileWrapper;
 import art.arcane.volmlib.util.mantle.flag.MantleFlag;
@@ -15,7 +13,7 @@ import art.arcane.volmlib.util.mantle.runtime.MantleChunk;
 import art.arcane.volmlib.util.matter.Matter;
 import art.arcane.volmlib.util.matter.MatterCavern;
 import org.junit.After;
-import org.junit.Before;
+import org.junit.Rule;
 import org.junit.Test;
 import org.mockito.InOrder;
 
@@ -27,7 +25,6 @@ import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.Answers.CALLS_REAL_METHODS;
 import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.doReturn;
@@ -38,20 +35,11 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 public class EngineMantleCleanupTest {
-    @Before
+    @Rule
-    public void bindPlatform() {
+    public final PlatformBinding platform = PlatformBinding.mockPlatform();
-        IrisPlatforms.unbind();
-        PlatformBlockState block = mock(PlatformBlockState.class);
-        PlatformRegistries registries = mock(PlatformRegistries.class);
-        when(registries.block(anyString())).thenReturn(block);
-        IrisPlatform platform = mock(IrisPlatform.class);
-        when(platform.registries()).thenReturn(registries);
-        IrisPlatforms.bind(platform);
-    }
 
     @After
     public void unbindPlatform() {
-        IrisPlatforms.unbind();
         MantleSliceRetention.clearForTesting();
     }
 

core/src/test/java/art/arcane/iris/engine/mantle/EngineMantleCoverageTest.java

@@ -5,12 +5,14 @@ import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformBlockState;
 import art.arcane.iris.spi.PlatformRegistries;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.volmlib.util.mantle.flag.MantleFlag;
 import art.arcane.volmlib.util.mantle.runtime.Mantle;
 import art.arcane.volmlib.util.mantle.runtime.MantleChunk;
 import art.arcane.volmlib.util.matter.Matter;
 import org.junit.After;
 import org.junit.Before;
+import org.junit.ClassRule;
 import org.junit.Test;
 
 import java.util.ArrayList;
@@ -34,6 +36,9 @@ import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 public class EngineMantleCoverageTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Before
     public void bindPlatform() {
         IrisPlatforms.unbind();

core/src/test/java/art/arcane/iris/engine/mantle/EngineMantleMarkerTest.java

@@ -3,24 +3,19 @@ package art.arcane.iris.engine.mantle;
 import art.arcane.iris.engine.framework.Engine;
 import art.arcane.iris.engine.framework.EnginePlatformHooks;
 import art.arcane.iris.engine.object.IrisPosition;
-import art.arcane.iris.spi.IrisPlatform;
+import art.arcane.iris.testsupport.PlatformBinding;
-import art.arcane.iris.spi.IrisPlatforms;
-import art.arcane.iris.spi.PlatformBlockState;
-import art.arcane.iris.spi.PlatformRegistries;
 import art.arcane.volmlib.util.collection.KList;
 import art.arcane.volmlib.util.function.Consumer4;
 import art.arcane.volmlib.util.mantle.runtime.Mantle;
 import art.arcane.volmlib.util.matter.Matter;
 import art.arcane.volmlib.util.matter.MatterMarker;
-import org.junit.After;
+import org.junit.Rule;
-import org.junit.Before;
 import org.junit.Test;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.Answers.CALLS_REAL_METHODS;
 import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.mock;
@@ -28,21 +23,8 @@ import static org.mockito.Mockito.verifyNoInteractions;
 import static org.mockito.Mockito.when;
 
 public class EngineMantleMarkerTest {
-    @Before
+    @Rule
-    public void bindPlatform() {
+    public final PlatformBinding platform = PlatformBinding.mockPlatform();
-        IrisPlatforms.unbind();
-        PlatformBlockState block = mock(PlatformBlockState.class);
-        PlatformRegistries registries = mock(PlatformRegistries.class);
-        when(registries.block(anyString())).thenReturn(block);
-        IrisPlatform platform = mock(IrisPlatform.class);
-        when(platform.registries()).thenReturn(registries);
-        IrisPlatforms.bind(platform);
-    }
-
-    @After
-    public void unbindPlatform() {
-        IrisPlatforms.unbind();
-    }
 
     @Test
     @SuppressWarnings("unchecked")

core/src/test/java/art/arcane/iris/engine/mantle/MantleWriterOverlayTest.java

@@ -7,17 +7,15 @@ import art.arcane.iris.engine.history.TransitionGenerationPlan;
 import art.arcane.iris.engine.hydrology.cave.HydrologyCaveAction;
 import art.arcane.iris.engine.hydrology.cave.HydrologyCaveCell;
 import art.arcane.iris.engine.object.IrisDimension;
-import art.arcane.iris.spi.IrisPlatform;
-import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformBlockState;
-import art.arcane.iris.spi.PlatformRegistries;
+import art.arcane.iris.testsupport.PlatformBinding;
 import art.arcane.volmlib.util.mantle.runtime.Mantle;
 import art.arcane.volmlib.util.mantle.runtime.MantleChunk;
 import art.arcane.volmlib.util.matter.Matter;
 import art.arcane.volmlib.util.matter.MatterCavern;
 import art.arcane.volmlib.util.matter.MatterSlice;
-import org.junit.After;
 import org.junit.Before;
+import org.junit.Rule;
 import org.junit.Test;
 
 import static org.junit.Assert.assertFalse;
@@ -26,13 +24,15 @@ import static org.junit.Assert.assertTrue;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyInt;
 import static org.mockito.Mockito.doReturn;
-import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 public class MantleWriterOverlayTest {
+    @Rule
+    public final PlatformBinding platform = PlatformBinding.mockPlatform();
+
     private static final int X = 1;
     private static final int Y = 2;
     private static final int Z = 3;
@@ -51,14 +51,6 @@ public class MantleWriterOverlayTest {
     @Before
     @SuppressWarnings("unchecked")
     public void setUp() {
-        IrisPlatforms.unbind();
-        PlatformBlockState defaultBlock = mock(PlatformBlockState.class);
-        PlatformRegistries registries = mock(PlatformRegistries.class);
-        IrisPlatform platform = mock(IrisPlatform.class);
-        when(registries.block(anyString())).thenReturn(defaultBlock);
-        when(platform.registries()).thenReturn(registries);
-        IrisPlatforms.bind(platform);
-
         engineMantle = mock(EngineMantle.class);
         Engine engine = mock(Engine.class);
         dimension = mock(IrisDimension.class);
@@ -92,11 +84,6 @@ public class MantleWriterOverlayTest {
         writer = new MantleWriter(engineMantle, mantle, 0, 0, 0, false);
     }
 
-    @After
-    public void tearDown() {
-        IrisPlatforms.unbind();
-    }
-
     @Test
     public void existingCavernStillClearsBlockAndDeferredPlacement() {
         MatterCavern existing = new MatterCavern(true, "", (byte) 3);

core/src/test/java/art/arcane/iris/engine/mantle/MantleWriterPreObjectJournalTest.java

@@ -7,6 +7,7 @@ import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformBlockState;
 import art.arcane.iris.spi.PlatformRegistries;
 import art.arcane.iris.testsupport.BukkitTestServer;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.iris.util.project.matter.IrisMatterSupport;
 import art.arcane.iris.util.project.matter.PreObjectMatterCell;
 import art.arcane.volmlib.util.mantle.runtime.Mantle;
@@ -18,6 +19,7 @@ import art.arcane.volmlib.util.matter.MatterSlice;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.BeforeClass;
+import org.junit.ClassRule;
 import org.junit.Test;
 
 import java.util.concurrent.CountDownLatch;
@@ -37,6 +39,9 @@ import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 public class MantleWriterPreObjectJournalTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     private static final int X = 2;
     private static final int Y = 5;
     private static final int Z = 4;

core/src/test/java/art/arcane/iris/engine/mantle/MatterGeneratorCarvePassRadiusTest.java

@@ -3,18 +3,14 @@ package art.arcane.iris.engine.mantle;
 import art.arcane.iris.engine.framework.Engine;
 import art.arcane.iris.engine.framework.EnginePlatformHooks;
 import art.arcane.iris.engine.object.IrisDimension;
-import art.arcane.iris.spi.IrisPlatform;
+import art.arcane.iris.testsupport.PlatformBinding;
-import art.arcane.iris.spi.IrisPlatforms;
-import art.arcane.iris.spi.PlatformBlockState;
-import art.arcane.iris.spi.PlatformRegistries;
 import art.arcane.iris.util.project.context.ChunkContext;
 import art.arcane.volmlib.util.mantle.flag.MantleFlag;
 import art.arcane.volmlib.util.mantle.flag.ReservedFlag;
 import art.arcane.volmlib.util.mantle.runtime.Mantle;
 import art.arcane.volmlib.util.mantle.runtime.MantleChunk;
 import art.arcane.volmlib.util.matter.Matter;
-import org.junit.AfterClass;
+import org.junit.ClassRule;
-import org.junit.BeforeClass;
 import org.junit.Test;
 
 import java.util.LinkedHashSet;
@@ -25,33 +21,14 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyInt;
-import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 public class MatterGeneratorCarvePassRadiusTest {
-    private static IrisPlatform previousPlatform;
+    @ClassRule
+    public static final PlatformBinding PLATFORM = PlatformBinding.mockPlatform();
 
-    @BeforeClass
-    public static void bindPlatform() {
-        previousPlatform = IrisPlatforms.isBound() ? IrisPlatforms.get() : null;
-        IrisPlatforms.unbind();
-        PlatformBlockState air = mock(PlatformBlockState.class);
-        PlatformRegistries registries = mock(PlatformRegistries.class);
-        IrisPlatform platform = mock(IrisPlatform.class);
-        when(registries.block(anyString())).thenReturn(air);
-        when(platform.registries()).thenReturn(registries);
-        IrisPlatforms.bind(platform);
-    }
-
-    @AfterClass
-    public static void restorePlatform() {
-        IrisPlatforms.unbind();
-        if (previousPlatform != null) {
-            IrisPlatforms.bind(previousPlatform);
-        }
-    }
 
     @Test
     @SuppressWarnings("unchecked")

core/src/test/java/art/arcane/iris/engine/mantle/ResolvedTerrainPlacementTest.java

@@ -8,6 +8,7 @@ import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformBlockState;
 import art.arcane.iris.spi.PlatformRegistries;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.iris.util.project.matter.IrisMatterSupport;
 import art.arcane.iris.util.project.matter.PreObjectMatterCell;
 import art.arcane.iris.util.project.matter.slices.PreObjectMatterTest;
@@ -17,6 +18,7 @@ import art.arcane.volmlib.util.matter.IrisMatter;
 import art.arcane.volmlib.util.matter.Matter;
 import org.junit.After;
 import org.junit.Before;
+import org.junit.ClassRule;
 import org.junit.Test;
 
 import java.util.List;
@@ -39,6 +41,9 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 public class ResolvedTerrainPlacementTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     private EngineMantle engineMantle;
     private Mantle<Matter> mantle;
     private PlatformBlockState stone;

core/src/test/java/art/arcane/iris/engine/mantle/components/MantleCarvingComponentBoundaryRadiusTest.java

@@ -7,17 +7,13 @@ import art.arcane.iris.engine.mantle.MantlePass;
 import art.arcane.iris.engine.mantle.EngineMantle;
 import art.arcane.iris.engine.mantle.MatterGenerator;
 import art.arcane.iris.engine.object.IrisDimension;
-import art.arcane.iris.spi.IrisPlatform;
+import art.arcane.iris.testsupport.PlatformBinding;
-import art.arcane.iris.spi.IrisPlatforms;
-import art.arcane.iris.spi.PlatformBlockState;
-import art.arcane.iris.spi.PlatformRegistries;
 import art.arcane.iris.util.project.context.ChunkContext;
 import art.arcane.iris.util.project.stream.ProceduralStream;
 import art.arcane.volmlib.util.mantle.runtime.Mantle;
 import art.arcane.volmlib.util.mantle.runtime.MantleChunk;
 import art.arcane.volmlib.util.matter.Matter;
-import org.junit.After;
+import org.junit.Rule;
-import org.junit.Before;
 import org.junit.Test;
 
 import java.util.ArrayList;
@@ -27,7 +23,6 @@ import static org.junit.Assert.assertEquals;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyDouble;
 import static org.mockito.ArgumentMatchers.anyInt;
-import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.never;
@@ -36,21 +31,8 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 public class MantleCarvingComponentBoundaryRadiusTest {
-    @Before
+    @Rule
-    public void bindPlatform() {
+    public final PlatformBinding platform = PlatformBinding.mockPlatform();
-        IrisPlatforms.unbind();
-        PlatformBlockState block = mock(PlatformBlockState.class);
-        PlatformRegistries registries = mock(PlatformRegistries.class);
-        when(registries.block(anyString())).thenReturn(block);
-        IrisPlatform platform = mock(IrisPlatform.class);
-        when(platform.registries()).thenReturn(registries);
-        IrisPlatforms.bind(platform);
-    }
-
-    @After
-    public void unbindPlatform() {
-        IrisPlatforms.unbind();
-    }
 
     @Test
     public void boundaryWallResolutionSchedulesAdjacentCarvingChunks() {

core/src/test/java/art/arcane/iris/engine/mantle/components/MantleFloatingObjectComponentBoundaryRadiusTest.java

@@ -28,13 +28,8 @@ import art.arcane.iris.engine.object.IrisFloatingChildBiomes;
 import art.arcane.iris.engine.object.IrisObject;
 import art.arcane.iris.engine.object.IrisObjectPlacement;
 import art.arcane.iris.engine.object.IrisObjectTranslate;
-import art.arcane.iris.spi.IrisPlatform;
+import art.arcane.iris.testsupport.PlatformBinding;
-import art.arcane.iris.spi.IrisPlatforms;
-import art.arcane.iris.spi.PlatformBlockState;
-import art.arcane.iris.spi.PlatformRegistries;
 import art.arcane.volmlib.util.collection.KList;
-import org.junit.After;
-import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
@@ -44,30 +39,16 @@ import java.io.File;
 import java.io.FileOutputStream;
 
 import static org.junit.Assert.assertEquals;
-import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 public class MantleFloatingObjectComponentBoundaryRadiusTest {
+    @Rule
+    public final PlatformBinding platform = PlatformBinding.mockPlatform();
+
     @Rule
     public TemporaryFolder temporaryFolder = new TemporaryFolder();
 
-    @Before
-    public void bindPlatform() {
-        IrisPlatforms.unbind();
-        PlatformBlockState block = mock(PlatformBlockState.class);
-        PlatformRegistries registries = mock(PlatformRegistries.class);
-        when(registries.block(anyString())).thenReturn(block);
-        IrisPlatform platform = mock(IrisPlatform.class);
-        when(platform.registries()).thenReturn(registries);
-        IrisPlatforms.bind(platform);
-    }
-
-    @After
-    public void unbindPlatform() {
-        IrisPlatforms.unbind();
-    }
-
     @Test
     @SuppressWarnings("unchecked")
     public void transformedFloatingPlacementExpandsOwnerRadius() throws Exception {

core/src/test/java/art/arcane/iris/engine/mantle/components/MantleObjectComponentBoundaryRadiusTest.java

@@ -28,6 +28,7 @@ import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformBlockState;
 import art.arcane.iris.spi.PlatformRegistries;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.iris.util.common.math.IrisBlockVector;
 import art.arcane.iris.util.project.context.ChunkContext;
 import art.arcane.volmlib.util.collection.KList;
@@ -36,6 +37,7 @@ import art.arcane.volmlib.util.mantle.runtime.MantleChunk;
 import art.arcane.volmlib.util.matter.Matter;
 import org.junit.After;
 import org.junit.Before;
+import org.junit.ClassRule;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
@@ -59,6 +61,9 @@ import static org.mockito.Mockito.when;
 import static org.mockito.Mockito.verify;
 
 public class MantleObjectComponentBoundaryRadiusTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Rule
     public TemporaryFolder temporaryFolder = new TemporaryFolder();
 

core/src/test/java/art/arcane/iris/engine/modifier/IrisCarveModifierInferenceIsolationTest.java

@@ -9,17 +9,13 @@ import art.arcane.iris.engine.object.IrisDimension;
 import art.arcane.iris.engine.object.IrisDimensionCarvingResolver;
 import art.arcane.iris.engine.object.IrisRegion;
 import art.arcane.iris.engine.object.IrisWorld;
-import art.arcane.iris.spi.IrisPlatform;
+import art.arcane.iris.testsupport.PlatformBinding;
-import art.arcane.iris.spi.IrisPlatforms;
-import art.arcane.iris.spi.PlatformBlockState;
-import art.arcane.iris.spi.PlatformRegistries;
 import art.arcane.iris.util.project.hunk.Hunk;
 import art.arcane.iris.util.project.stream.ProceduralStream;
 import art.arcane.volmlib.util.mantle.runtime.MantleChunk;
 import art.arcane.volmlib.util.matter.MatterCavern;
 import it.unimi.dsi.fastutil.longs.Long2ObjectOpenHashMap;
-import org.junit.AfterClass;
+import org.junit.ClassRule;
-import org.junit.BeforeClass;
 import org.junit.Test;
 
 import java.lang.reflect.Field;
@@ -30,27 +26,13 @@ import java.util.Map;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertSame;
 import static org.mockito.ArgumentMatchers.anyDouble;
-import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.Mockito.CALLS_REAL_METHODS;
 import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.mock;
 
 public class IrisCarveModifierInferenceIsolationTest {
-    @BeforeClass
+    @ClassRule
-    public static void bindPlatform() {
+    public static final PlatformBinding PLATFORM = PlatformBinding.mockPlatform();
-        IrisPlatforms.unbind();
-        PlatformBlockState block = mock(PlatformBlockState.class);
-        PlatformRegistries registries = mock(PlatformRegistries.class);
-        doReturn(block).when(registries).block(anyString());
-        IrisPlatform platform = mock(IrisPlatform.class);
-        doReturn(registries).when(platform).registries();
-        IrisPlatforms.bind(platform);
-    }
-
-    @AfterClass
-    public static void unbindPlatform() {
-        IrisPlatforms.unbind();
-    }
 
     @Test
     @SuppressWarnings("unchecked")

core/src/test/java/art/arcane/iris/engine/modifier/IrisDepositModifierContextTest.java

@@ -6,10 +6,8 @@ import art.arcane.iris.engine.object.IrisDepositGenerator;
 import art.arcane.iris.engine.object.IrisDepositHeightDistribution;
 import art.arcane.iris.engine.object.IrisDepositPlacementScope;
 import art.arcane.iris.engine.object.IrisObject;
-import art.arcane.iris.spi.IrisPlatform;
-import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformBlockState;
-import art.arcane.iris.spi.PlatformRegistries;
+import art.arcane.iris.testsupport.PlatformBinding;
 import art.arcane.iris.util.common.parallel.BurstExecutor;
 import art.arcane.iris.util.common.parallel.MultiBurst;
 import art.arcane.iris.util.project.context.ChunkContext;
@@ -20,9 +18,8 @@ import art.arcane.volmlib.util.mantle.runtime.Mantle;
 import art.arcane.volmlib.util.mantle.runtime.MantleChunk;
 import art.arcane.volmlib.util.matter.Matter;
 import art.arcane.volmlib.util.math.RNG;
+import org.junit.ClassRule;
 import org.junit.Test;
-import org.junit.AfterClass;
-import org.junit.BeforeClass;
 
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
@@ -37,7 +34,6 @@ import static org.junit.Assert.assertSame;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.assertThrows;
 import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.Mockito.RETURNS_DEEP_STUBS;
 import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.doReturn;
@@ -49,21 +45,8 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 public class IrisDepositModifierContextTest {
-    @BeforeClass
+    @ClassRule
-    public static void bindPlatform() {
+    public static final PlatformBinding PLATFORM = PlatformBinding.mockPlatform();
-        IrisPlatforms.unbind();
-        PlatformBlockState block = mock(PlatformBlockState.class);
-        PlatformRegistries registries = mock(PlatformRegistries.class);
-        when(registries.block(anyString())).thenReturn(block);
-        IrisPlatform platform = mock(IrisPlatform.class);
-        when(platform.registries()).thenReturn(registries);
-        IrisPlatforms.bind(platform);
-    }
-
-    @AfterClass
-    public static void unbindPlatform() {
-        IrisPlatforms.unbind();
-    }
 
     @Test
     public void workerDepositsRetainRuntimeAndChunkContextUntilCompletion() throws Exception {

core/src/test/java/art/arcane/iris/engine/modifier/IrisDepositModifierOrderingTest.java

@@ -9,6 +9,7 @@ import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformBlockState;
 import art.arcane.iris.spi.PlatformRegistries;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.iris.util.common.data.B;
 import art.arcane.iris.util.common.math.IrisBlockVector;
 import art.arcane.iris.util.common.parallel.BurstExecutor;
@@ -22,6 +23,7 @@ import art.arcane.volmlib.util.matter.Matter;
 import art.arcane.volmlib.util.math.RNG;
 import org.junit.After;
 import org.junit.Before;
+import org.junit.ClassRule;
 import org.junit.Test;
 import org.mockito.MockedStatic;
 
@@ -48,6 +50,9 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 public class IrisDepositModifierOrderingTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Before
     public void bindPlatform() {
         IrisPlatforms.unbind();

core/src/test/java/art/arcane/iris/engine/modifier/IrisDepositModifierParityTest.java

@@ -13,6 +13,7 @@ import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformBlockState;
 import art.arcane.iris.spi.PlatformRegistries;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.iris.util.common.data.B;
 import art.arcane.iris.util.common.parallel.MultiBurst;
 import art.arcane.iris.util.project.context.ChunkContext;
@@ -24,6 +25,7 @@ import art.arcane.volmlib.util.matter.Matter;
 import art.arcane.volmlib.util.matter.MatterCavern;
 import org.junit.After;
 import org.junit.Before;
+import org.junit.ClassRule;
 import org.junit.Test;
 import org.mockito.MockedStatic;
 
@@ -44,6 +46,9 @@ import static org.mockito.Mockito.mockStatic;
 import static org.mockito.Mockito.when;
 
 public class IrisDepositModifierParityTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     private final Map<String, PlatformBlockState> states = new HashMap<>();
 
     @Before

core/src/test/java/art/arcane/iris/engine/object/IrisBiomeCompatChildrenTest.java

@@ -8,10 +8,10 @@ import art.arcane.iris.core.loader.ResourceLoader;
 import art.arcane.volmlib.util.collection.KList;
 import org.junit.Test;
 
-import static art.arcane.iris.engine.object.CompatFixtures.MISSING_BLOCK;
+import static art.arcane.iris.engine.object.PackCompatFixtures.MISSING_BLOCK;
-import static art.arcane.iris.engine.object.CompatFixtures.biome;
+import static art.arcane.iris.engine.object.PackCompatFixtures.biome;
-import static art.arcane.iris.engine.object.CompatFixtures.excludeBlock;
+import static art.arcane.iris.engine.object.PackCompatFixtures.excludeBlock;
-import static art.arcane.iris.engine.object.CompatFixtures.find;
+import static art.arcane.iris.engine.object.PackCompatFixtures.find;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
@@ -23,7 +23,7 @@ import static org.mockito.Mockito.when;
 public class IrisBiomeCompatChildrenTest {
     @SuppressWarnings("unchecked")
     private static IrisData dataWith(PackCompatReport report, IrisBiome... biomes) {
-        IrisData data = CompatFixtures.data(report);
+        IrisData data = PackCompatFixtures.data(report);
         ResourceLoader<IrisBiome> biomeLoader = mock(ResourceLoader.class);
         when(data.getBiomeLoader()).thenReturn(biomeLoader);
         for (IrisBiome biome : biomes) {

core/src/test/java/art/arcane/iris/engine/object/IrisBiomeDerivativeCompatTest.java

@@ -12,7 +12,7 @@ import static org.junit.Assert.assertEquals;
 public class IrisBiomeDerivativeCompatTest {
     @Test
     public void droppedVanillaDerivativeFallsBackToDerivative() {
-        IrisBiome biome = CompatFixtures.biome("cave/sulfur-grotto");
+        IrisBiome biome = PackCompatFixtures.biome("cave/sulfur-grotto");
         biome.setDerivative("minecraft:dripstone_caves");
         biome.setVanillaDerivative("minecraft:sulfur_caves");
 
@@ -25,7 +25,7 @@ public class IrisBiomeDerivativeCompatTest {
 
     @Test
     public void blankVanillaDerivativeFallsBackToDerivative() {
-        IrisBiome biome = CompatFixtures.biome("cave/sulfur-grotto");
+        IrisBiome biome = PackCompatFixtures.biome("cave/sulfur-grotto");
         biome.setDerivative("minecraft:dripstone_caves");
         biome.setVanillaDerivative("");
 

core/src/test/java/art/arcane/iris/engine/object/IrisDimensionCompatRegionTest.java

@@ -12,10 +12,10 @@ import org.junit.Test;
 
 import java.util.Map;
 
-import static art.arcane.iris.engine.object.CompatFixtures.MISSING_BLOCK;
+import static art.arcane.iris.engine.object.PackCompatFixtures.MISSING_BLOCK;
-import static art.arcane.iris.engine.object.CompatFixtures.excludeBlock;
+import static art.arcane.iris.engine.object.PackCompatFixtures.excludeBlock;
-import static art.arcane.iris.engine.object.CompatFixtures.find;
+import static art.arcane.iris.engine.object.PackCompatFixtures.find;
-import static art.arcane.iris.engine.object.CompatFixtures.region;
+import static art.arcane.iris.engine.object.PackCompatFixtures.region;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
@@ -26,7 +26,7 @@ import static org.mockito.Mockito.when;
 public class IrisDimensionCompatRegionTest {
     @SuppressWarnings("unchecked")
     private static IrisData dataWith(PackCompatReport report, IrisRegion... regions) {
-        IrisData data = CompatFixtures.data(report);
+        IrisData data = PackCompatFixtures.data(report);
         ResourceLoader<IrisRegion> regionLoader = mock(ResourceLoader.class);
         when(data.getRegionLoader()).thenReturn(regionLoader);
         for (IrisRegion region : regions) {

core/src/test/java/art/arcane/iris/engine/object/IrisDimensionReachableBiomesTest.java

@@ -176,7 +176,7 @@ public class IrisDimensionReachableBiomesTest {
                 .setLandBiomes(new KList<>("plains"))
                 .setCaveBiomes(new KList<>("carving/sulfur"));
         IrisBiome plains = biome("plains");
-        IrisBiome sulfur = CompatFixtures.excludeBlock(biome("carving/sulfur"))
+        IrisBiome sulfur = PackCompatFixtures.excludeBlock(biome("carving/sulfur"))
                 .setChildren(new KList<>("carving/sulfur-hollows"));
 
         IrisData data = mock(IrisData.class);

core/src/test/java/art/arcane/iris/engine/object/IrisLootTableCompatTest.java

@@ -14,8 +14,8 @@ import org.junit.Test;
 import java.util.List;
 import java.util.Map;
 
-import static art.arcane.iris.engine.object.CompatFixtures.find;
+import static art.arcane.iris.engine.object.PackCompatFixtures.find;
-import static art.arcane.iris.engine.object.CompatFixtures.lootTable;
+import static art.arcane.iris.engine.object.PackCompatFixtures.lootTable;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
@@ -26,7 +26,7 @@ import static org.mockito.Mockito.when;
 public class IrisLootTableCompatTest {
     @SuppressWarnings("unchecked")
     private static IrisData dataWith(PackCompatReport report, IrisLootTable... tables) {
-        IrisData data = CompatFixtures.data(report);
+        IrisData data = PackCompatFixtures.data(report);
         ResourceLoader<IrisLootTable> lootLoader = mock(ResourceLoader.class);
         when(data.getLootLoader()).thenReturn(lootLoader);
         for (IrisLootTable table : tables) {
@@ -43,7 +43,7 @@ public class IrisLootTableCompatTest {
     public void evaluateCompatExcludesTableWhoseEntriesWereAllDropped() {
         PackCompatReport report = new PackCompatReport();
         IrisLootTable table = lootTable("chest/sulfur-cache");
-        table.setLoader(CompatFixtures.data(report));
+        table.setLoader(PackCompatFixtures.data(report));
         // The gate walker drops every entry with a missing item and hands the cascade its reasons.
         CompatStatus walked = new CompatStatus(false, List.of(new CompatFinding(CompatRegistry.ITEM,
                 "minecraft:sulfur_dust", CompatAction.DROPPED, "loot", "chest/sulfur-cache", "loot[0]")));
@@ -62,7 +62,7 @@ public class IrisLootTableCompatTest {
     public void evaluateCompatKeepsTableWithSurvivingEntries() {
         PackCompatReport report = new PackCompatReport();
         IrisLootTable table = lootTable("chest/mixed");
-        table.setLoader(CompatFixtures.data(report));
+        table.setLoader(PackCompatFixtures.data(report));
         table.setLoot(new KList<>(new IrisLoot()));
         CompatStatus walked = new CompatStatus(false, List.of(new CompatFinding(CompatRegistry.ITEM,
                 "minecraft:sulfur_dust", CompatAction.DROPPED, "loot", "chest/mixed", "loot[1]")));
@@ -74,7 +74,7 @@ public class IrisLootTableCompatTest {
     public void evaluateCompatKeepsTableThatNeverDeclaredLoot() {
         PackCompatReport report = new PackCompatReport();
         IrisLootTable table = lootTable("chest/empty");
-        table.setLoader(CompatFixtures.data(report));
+        table.setLoader(PackCompatFixtures.data(report));
 
         assertFalse(table.evaluateCompat(gate(report)).excluded());
         assertTrue(report.isEmpty());
@@ -84,7 +84,7 @@ public class IrisLootTableCompatTest {
     public void lootReferenceSkipsExcludedAndUnloadableTables() {
         PackCompatReport report = new PackCompatReport();
         IrisLootTable kept = lootTable("chest/common");
-        IrisLootTable excluded = CompatFixtures.exclude(lootTable("chest/sulfur-cache"),
+        IrisLootTable excluded = PackCompatFixtures.exclude(lootTable("chest/sulfur-cache"),
                 CompatRegistry.ITEM, "minecraft:sulfur_dust");
         IrisData data = dataWith(report, kept, excluded);
         IrisLootReference reference = new IrisLootReference()

core/src/test/java/art/arcane/iris/engine/object/IrisObjectPlacementRunnerRegressionTest.java

@@ -7,6 +7,7 @@ import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformBlockState;
 import art.arcane.iris.spi.PlatformRegistries;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.volmlib.util.collection.KList;
 import art.arcane.volmlib.util.collection.KMap;
 import art.arcane.volmlib.util.math.RNG;
@@ -15,6 +16,7 @@ import org.bukkit.block.BlockFace;
 import org.bukkit.block.data.Directional;
 import org.junit.After;
 import org.junit.Before;
+import org.junit.ClassRule;
 import org.junit.Test;
 
 import java.util.ArrayList;
@@ -40,6 +42,9 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 public class IrisObjectPlacementRunnerRegressionTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     private static final int ANCHOR_Y = 80;
 
     private IrisData data;

core/src/test/java/art/arcane/iris/engine/object/IrisObjectShapingTest.java

@@ -4,9 +4,11 @@ import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformBlockState;
 import art.arcane.iris.spi.PlatformRegistries;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.iris.util.common.math.IrisBlockVector;
 import org.junit.After;
 import org.junit.Before;
+import org.junit.ClassRule;
 import org.junit.Test;
 
 import java.util.ArrayList;
@@ -23,6 +25,9 @@ import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 public class IrisObjectShapingTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Before
     public void bindPlatform() {
         IrisPlatforms.unbind();

core/src/test/java/art/arcane/iris/engine/object/IrisObjectSurfaceSupportPlacementTest.java

@@ -3,14 +3,12 @@ package art.arcane.iris.engine.object;
 import art.arcane.iris.core.loader.IrisData;
 import art.arcane.iris.engine.IrisComplex;
 import art.arcane.iris.engine.framework.Engine;
-import art.arcane.iris.spi.IrisPlatform;
-import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformBlockState;
-import art.arcane.iris.spi.PlatformRegistries;
+import art.arcane.iris.testsupport.PlatformBinding;
 import art.arcane.iris.util.project.stream.ProceduralStream;
 import art.arcane.volmlib.util.math.RNG;
-import org.junit.After;
 import org.junit.Before;
+import org.junit.Rule;
 import org.junit.Test;
 
 import java.util.HashMap;
@@ -23,13 +21,15 @@ import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertThrows;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.ArgumentMatchers.anyDouble;
-import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 public class IrisObjectSurfaceSupportPlacementTest {
+    @Rule
+    public final PlatformBinding platform = PlatformBinding.mockPlatform();
+
     private static final int SURFACE_Y = 80;
 
     private IrisData data;
@@ -38,14 +38,6 @@ public class IrisObjectSurfaceSupportPlacementTest {
 
     @Before
     public void bindPlatform() {
-        IrisPlatforms.unbind();
-        PlatformBlockState block = mock(PlatformBlockState.class);
-        PlatformRegistries registries = mock(PlatformRegistries.class);
-        when(registries.block(anyString())).thenReturn(block);
-        IrisPlatform platform = mock(IrisPlatform.class);
-        when(platform.registries()).thenReturn(registries);
-        IrisPlatforms.bind(platform);
-
         @SuppressWarnings("unchecked")
         ProceduralStream<Double> heightStream = mock(ProceduralStream.class);
         when(heightStream.get(anyDouble(), anyDouble())).thenReturn((double) SURFACE_Y);
@@ -59,11 +51,6 @@ public class IrisObjectSurfaceSupportPlacementTest {
         when(data.getEngine()).thenReturn(engine);
     }
 
-    @After
-    public void unbindPlatform() {
-        IrisPlatforms.unbind();
-    }
-
     @Test
     public void carvedAnchorColumnSkipsEverySurfaceAnchoredMode() {
         for (ObjectPlaceMode mode : new ObjectPlaceMode[]{

core/src/test/java/art/arcane/iris/engine/object/IrisObjectTransformsTileTest.java

@@ -4,11 +4,13 @@ import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformBlockState;
 import art.arcane.iris.spi.PlatformRegistries;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.iris.util.common.math.IrisBlockVector;
 import art.arcane.iris.util.common.math.Vector3i;
 import art.arcane.volmlib.util.collection.KMap;
 import org.junit.After;
 import org.junit.Before;
+import org.junit.ClassRule;
 import org.junit.Test;
 
 import java.util.Collections;
@@ -30,6 +32,9 @@ import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 public class IrisObjectTransformsTileTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Before
     public void bindPlatform() {
         IrisPlatforms.unbind();

core/src/test/java/art/arcane/iris/engine/object/IrisRegionCompatPoolTest.java

@@ -13,10 +13,10 @@ import org.junit.Test;
 
 import java.util.Map;
 
-import static art.arcane.iris.engine.object.CompatFixtures.MISSING_BLOCK;
+import static art.arcane.iris.engine.object.PackCompatFixtures.MISSING_BLOCK;
-import static art.arcane.iris.engine.object.CompatFixtures.biome;
+import static art.arcane.iris.engine.object.PackCompatFixtures.biome;
-import static art.arcane.iris.engine.object.CompatFixtures.excludeBlock;
+import static art.arcane.iris.engine.object.PackCompatFixtures.excludeBlock;
-import static art.arcane.iris.engine.object.CompatFixtures.find;
+import static art.arcane.iris.engine.object.PackCompatFixtures.find;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
@@ -27,7 +27,7 @@ import static org.mockito.Mockito.when;
 public class IrisRegionCompatPoolTest {
     @SuppressWarnings("unchecked")
     private static IrisData dataWith(PackCompatReport report, IrisBiome... biomes) {
-        IrisData data = CompatFixtures.data(report);
+        IrisData data = PackCompatFixtures.data(report);
         ResourceLoader<IrisBiome> biomeLoader = mock(ResourceLoader.class);
         when(data.getBiomeLoader()).thenReturn(biomeLoader);
         for (IrisBiome biome : biomes) {
@@ -46,7 +46,7 @@ public class IrisRegionCompatPoolTest {
         IrisBiome plains = biome("land/plains");
         IrisBiome sulfur = excludeBlock(biome("cave/sulfur-grotto"));
         IrisData data = dataWith(report, plains, sulfur);
-        IrisRegion region = CompatFixtures.region("overworld");
+        IrisRegion region = PackCompatFixtures.region("overworld");
         region.setLoader(data);
         region.setLandBiomes(new KList<>("land/plains", "cave/sulfur-grotto"));
 
@@ -66,7 +66,7 @@ public class IrisRegionCompatPoolTest {
         PackCompatReport report = new PackCompatReport();
         IrisBiome shore = biome("shore/sand");
         IrisData data = dataWith(report, shore);
-        IrisRegion region = CompatFixtures.region("overworld");
+        IrisRegion region = PackCompatFixtures.region("overworld");
         region.setLoader(data);
         region.setSeaBiomes(new KList<>("sea/gone"));
         region.setShoreBiomes(new KList<>("shore/sand"));
@@ -86,7 +86,7 @@ public class IrisRegionCompatPoolTest {
         sulfur.setChildren(new KList<>("cave/sulfur-deep"));
         IrisBiome sulfurDeep = biome("cave/sulfur-deep");
         IrisData data = dataWith(report, plains, sulfur, sulfurDeep);
-        IrisRegion region = CompatFixtures.region("overworld");
+        IrisRegion region = PackCompatFixtures.region("overworld");
         region.setLoader(data);
         region.setLandBiomes(new KList<>("land/plains"));
         region.setCaveBiomes(new KList<>("cave/sulfur-grotto"));
@@ -102,7 +102,7 @@ public class IrisRegionCompatPoolTest {
         PackCompatReport report = new PackCompatReport();
         IrisBiome sulfur = excludeBlock(biome("cave/sulfur-flats"));
         IrisData data = dataWith(report, sulfur);
-        IrisRegion region = CompatFixtures.region("sulfur-lands");
+        IrisRegion region = PackCompatFixtures.region("sulfur-lands");
         region.setLoader(data);
         region.setLandBiomes(new KList<>("cave/sulfur-flats"));
 
@@ -122,7 +122,7 @@ public class IrisRegionCompatPoolTest {
         IrisBiome plains = biome("land/plains");
         IrisBiome sulfur = excludeBlock(biome("cave/sulfur-flats"));
         IrisData data = dataWith(report, plains, sulfur);
-        IrisRegion region = CompatFixtures.region("overworld");
+        IrisRegion region = PackCompatFixtures.region("overworld");
         region.setLoader(data);
         region.setLandBiomes(new KList<>("land/plains", "cave/sulfur-flats"));
 
@@ -133,7 +133,7 @@ public class IrisRegionCompatPoolTest {
     public void evaluateCompatDoesNotExcludeRegionThatNeverDeclaredLandBiomes() {
         PackCompatReport report = new PackCompatReport();
         IrisData data = dataWith(report);
-        IrisRegion region = CompatFixtures.region("empty");
+        IrisRegion region = PackCompatFixtures.region("empty");
         region.setLoader(data);
 
         assertFalse(region.evaluateCompat(gate(report)).excluded());

core/src/test/java/art/arcane/iris/engine/object/IrisSpawnerCompatTest.java

@@ -14,10 +14,10 @@ import org.junit.Test;
 
 import java.util.Map;
 
-import static art.arcane.iris.engine.object.CompatFixtures.MISSING_ENTITY;
+import static art.arcane.iris.engine.object.PackCompatFixtures.MISSING_ENTITY;
-import static art.arcane.iris.engine.object.CompatFixtures.entity;
+import static art.arcane.iris.engine.object.PackCompatFixtures.entity;
-import static art.arcane.iris.engine.object.CompatFixtures.excludeEntity;
+import static art.arcane.iris.engine.object.PackCompatFixtures.excludeEntity;
-import static art.arcane.iris.engine.object.CompatFixtures.find;
+import static art.arcane.iris.engine.object.PackCompatFixtures.find;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
@@ -30,7 +30,7 @@ import static org.mockito.Mockito.when;
 public class IrisSpawnerCompatTest {
     @SuppressWarnings("unchecked")
     private static IrisData dataWith(PackCompatReport report, IrisEntity... entities) {
-        IrisData data = CompatFixtures.data(report);
+        IrisData data = PackCompatFixtures.data(report);
         ResourceLoader<IrisEntity> entityLoader = mock(ResourceLoader.class);
         when(data.getEntityLoader()).thenReturn(entityLoader);
         for (IrisEntity entity : entities) {

core/src/test/java/art/arcane/iris/engine/object/IrisStaticObjectLayerTest.java

@@ -8,6 +8,7 @@ import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformBlockState;
 import art.arcane.iris.spi.PlatformRegistries;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.iris.util.common.math.IrisBlockVector;
 import art.arcane.iris.util.project.hunk.Hunk;
 import art.arcane.iris.util.project.matter.TileWrapper;
@@ -19,6 +20,7 @@ import art.arcane.volmlib.util.matter.Matter;
 import art.arcane.volmlib.util.matter.MatterSlice;
 import org.junit.After;
 import org.junit.Before;
+import org.junit.ClassRule;
 import org.junit.Test;
 
 import java.util.HashMap;
@@ -40,6 +42,9 @@ import static org.mockito.Mockito.verifyNoInteractions;
 import static org.mockito.Mockito.when;
 
 public class IrisStaticObjectLayerTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     private final Map<String, PlatformBlockState> states = new HashMap<>();
     private IrisData data;
     private ResourceLoader<IrisObject> loader;

core/src/test/java/art/arcane/iris/engine/object/NativeStructureObjectVetoTest.java

@@ -4,16 +4,14 @@ import art.arcane.iris.core.loader.IrisData;
 import art.arcane.iris.engine.IrisComplex;
 import art.arcane.iris.engine.framework.Engine;
 import art.arcane.iris.engine.framework.NativeStructureVolume;
-import art.arcane.iris.spi.IrisPlatform;
-import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformBlockState;
-import art.arcane.iris.spi.PlatformRegistries;
+import art.arcane.iris.testsupport.PlatformBinding;
 import art.arcane.iris.util.common.math.Vector3i;
 import art.arcane.iris.util.project.stream.ProceduralStream;
 import art.arcane.volmlib.util.collection.KList;
 import art.arcane.volmlib.util.math.RNG;
-import org.junit.After;
 import org.junit.Before;
+import org.junit.Rule;
 import org.junit.Test;
 
 import java.util.ArrayList;
@@ -23,11 +21,13 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.ArgumentMatchers.anyInt;
-import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 public class NativeStructureObjectVetoTest {
+    @Rule
+    public final PlatformBinding platform = PlatformBinding.mockPlatform();
+
     private static final int SURFACE_Y = 80;
 
     private IrisData data;
@@ -36,14 +36,6 @@ public class NativeStructureObjectVetoTest {
 
     @Before
     public void bindPlatform() {
-        IrisPlatforms.unbind();
-        PlatformBlockState block = mock(PlatformBlockState.class);
-        PlatformRegistries registries = mock(PlatformRegistries.class);
-        when(registries.block(anyString())).thenReturn(block);
-        IrisPlatform platform = mock(IrisPlatform.class);
-        when(platform.registries()).thenReturn(registries);
-        IrisPlatforms.bind(platform);
-
         log = state("minecraft:oak_log", true);
         @SuppressWarnings("unchecked")
         ProceduralStream<Double> heightStream = mock(ProceduralStream.class);
@@ -58,11 +50,6 @@ public class NativeStructureObjectVetoTest {
         when(data.getEngine()).thenReturn(engine);
     }
 
-    @After
-    public void unbindPlatform() {
-        IrisPlatforms.unbind();
-    }
-
     @Test
     public void objectPlacesWhenNoNativeStructureIsNear() {
         RecordingPlacer placer = new RecordingPlacer(engine);

core/src/test/java/art/arcane/iris/engine/object/PackCompatFixtures.java

@@ -17,11 +17,11 @@ import static org.mockito.Mockito.when;
  * Shared fixtures for the version-content pool cascade tests. The gate walker (lane L1) is not exercised here: the
  * tests stamp {@code compat} on a registrant directly, which is exactly what the walker stores.
  */
-final class CompatFixtures {
+final class PackCompatFixtures {
     static final String MISSING_BLOCK = "minecraft:sulfur";
     static final String MISSING_ENTITY = "minecraft:camel";
 
-    private CompatFixtures() {
+    private PackCompatFixtures() {
     }
 
     static IrisData data(PackCompatReport report) {

core/src/test/java/art/arcane/iris/engine/platform/EngineBukkitOpsDeferredMaterializationTest.java

@@ -13,6 +13,7 @@ import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.IrisServices;
 import art.arcane.iris.spi.PlatformBlockState;
 import art.arcane.iris.spi.PlatformRegistries;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.iris.util.common.scheduling.J;
 import art.arcane.iris.util.project.matter.TileWrapper;
 import art.arcane.iris.util.project.matter.slices.PreObjectMatterTest;
@@ -30,6 +31,7 @@ import org.bukkit.Material;
 import org.bukkit.World;
 import org.bukkit.block.Block;
 import org.bukkit.block.data.BlockData;
+import org.junit.ClassRule;
 import org.junit.Test;
 import org.mockito.InOrder;
 import org.mockito.MockedStatic;
@@ -59,6 +61,9 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 public class EngineBukkitOpsDeferredMaterializationTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Test
     @SuppressWarnings("unchecked")
     public void savedMantlePlacementUsesCurrentProviderWithoutReadingCurrentMantle() {

core/src/test/java/art/arcane/iris/spi/IrisLoggingTest.java

@@ -1,7 +1,9 @@
 package art.arcane.iris.spi;
 
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import org.junit.After;
 import org.junit.Before;
+import org.junit.ClassRule;
 import org.junit.Test;
 
 import java.util.ArrayList;
@@ -24,6 +26,9 @@ import static org.mockito.Mockito.verify;
  * exactly one warning and would otherwise repeat per block, per sample or per chunk.
  */
 public class IrisLoggingTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     private final List<LogLevel> levels = new ArrayList<>();
     private final List<String> messages = new ArrayList<>();
     private IrisPlatform capturingPlatform;

core/src/test/java/art/arcane/iris/spi/IrisPlatformsBindLifecycleTest.java

@@ -1,7 +1,9 @@
 package art.arcane.iris.spi;
 
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import org.junit.After;
 import org.junit.Before;
+import org.junit.ClassRule;
 import org.junit.Test;
 
 import static org.junit.Assert.assertFalse;
@@ -10,6 +12,9 @@ import static org.junit.Assert.assertTrue;
 import static org.mockito.Mockito.mock;
 
 public class IrisPlatformsBindLifecycleTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Before
     public void resetBinding() {
         IrisPlatforms.unbind();

core/src/test/java/art/arcane/iris/spi/IrisServicesTest.java

@@ -18,12 +18,17 @@
 
 package art.arcane.iris.spi;
 
+import art.arcane.iris.testsupport.PlatformLeakGuard;
+import org.junit.ClassRule;
 import org.junit.Test;
 
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertSame;
 
 public class IrisServicesTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Test
     public void removeThenReregisterRebindsService() {
         Sample first = new Sample();

core/src/test/java/art/arcane/iris/testsupport/BukkitTestServer.java

@@ -5,6 +5,9 @@ import org.bukkit.Material;
 import org.bukkit.Server;
 import org.bukkit.block.data.BlockData;
 import org.bukkit.plugin.PluginManager;
+import org.junit.rules.TestRule;
+import org.junit.runner.Description;
+import org.junit.runners.model.Statement;
 import org.mockito.invocation.InvocationOnMock;
 
 import java.util.Locale;
@@ -18,6 +21,8 @@ import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.mock;
 
 public final class BukkitTestServer {
+    private static final String DEFAULT_NAME = "IrisTestServer";
+    private static final String DEFAULT_VERSION = "1.0";
     private static final Object LOCK = new Object();
     private static volatile Server installed;
 
@@ -46,9 +51,7 @@ public final class BukkitTestServer {
             Server server = mock(Server.class);
             doReturn(Logger.getLogger("IrisTest")).when(server).getLogger();
             doReturn(mock(PluginManager.class)).when(server).getPluginManager();
-            doReturn("IrisTestServer").when(server).getName();
+            applyBranding(server, DEFAULT_NAME, DEFAULT_VERSION);
-            doReturn("1.0").when(server).getVersion();
-            doReturn("1.0").when(server).getBukkitVersion();
             doAnswer((InvocationOnMock invocation) -> blockData(invocation.getArgument(0, Material.class).name().toLowerCase(Locale.ROOT)))
                     .when(server).createBlockData(any(Material.class));
             doAnswer((InvocationOnMock invocation) -> blockData(invocation.getArgument(0, String.class)))
@@ -67,13 +70,51 @@ public final class BukkitTestServer {
         }
     }
 
-    public static void brand(String name, String version) {
+    public static ServerBranding branding() {
-        Server server = install();
+        return new ServerBranding();
+    }
+
+    private static void applyBranding(Server server, String name, String version) {
         doReturn(name).when(server).getName();
         doReturn(version).when(server).getVersion();
         doReturn(version).when(server).getBukkitVersion();
     }
 
+    public static final class ServerBranding implements TestRule {
+        private boolean applied;
+
+        private ServerBranding() {
+        }
+
+        public void set(String name, String version) {
+            applyBranding(install(), name, version);
+            applied = true;
+        }
+
+        @Override
+        public Statement apply(Statement base, Description description) {
+            return new Statement() {
+                @Override
+                public void evaluate() throws Throwable {
+                    try {
+                        base.evaluate();
+                    } finally {
+                        restore();
+                    }
+                }
+            };
+        }
+
+        private void restore() {
+            if (!applied) {
+                return;
+            }
+
+            applied = false;
+            applyBranding(install(), DEFAULT_NAME, DEFAULT_VERSION);
+        }
+    }
+
     public static BlockData blockData(String key) {
         String canonical = key.indexOf(':') >= 0 ? key : "minecraft:" + key;
         BlockData data = mock(BlockData.class);

core/src/test/java/art/arcane/iris/testsupport/IrisRuntimeState.java

@@ -0,0 +1,52 @@
+package art.arcane.iris.testsupport;
+
+import art.arcane.iris.spi.IrisPlatforms;
+import art.arcane.iris.spi.IrisServices;
+
+import java.lang.reflect.Field;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.TreeSet;
+
+public final class IrisRuntimeState {
+    private static final Map<Class<?>, Object> SERVICES = services();
+
+    private IrisRuntimeState() {
+    }
+
+    public static boolean platformBound() {
+        return IrisPlatforms.isBound();
+    }
+
+    public static List<String> registeredServices() {
+        TreeSet<String> names = new TreeSet<>();
+
+        for (Class<?> type : SERVICES.keySet()) {
+            names.add(type.getName());
+        }
+
+        return Collections.unmodifiableList(new ArrayList<>(names));
+    }
+
+    public static void reset() {
+        IrisPlatforms.unbind();
+        IrisServices.clear();
+    }
+
+    private static Map<Class<?>, Object> services() {
+        try {
+            Field field = IrisServices.class.getDeclaredField("SERVICES");
+            field.setAccessible(true);
+            return castServices(field.get(null));
+        } catch (ReflectiveOperationException e) {
+            throw new IllegalStateException("IrisServices no longer exposes its backing map to the test guard", e);
+        }
+    }
+
+    @SuppressWarnings("unchecked")
+    private static Map<Class<?>, Object> castServices(Object value) {
+        return (Map<Class<?>, Object>) value;
+    }
+}

core/src/test/java/art/arcane/iris/testsupport/PlatformBinding.java

@@ -0,0 +1,99 @@
+package art.arcane.iris.testsupport;
+
+import art.arcane.iris.spi.IrisPlatform;
+import art.arcane.iris.spi.IrisPlatforms;
+import art.arcane.iris.spi.PlatformBlockState;
+import art.arcane.iris.spi.PlatformRegistries;
+import org.junit.rules.TestRule;
+import org.junit.runner.Description;
+import org.junit.runners.model.Statement;
+
+import java.util.function.Supplier;
+
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+public final class PlatformBinding implements TestRule {
+    private final Supplier<IrisPlatform> factory;
+    private IrisPlatform platform;
+    private PlatformRegistries registries;
+    private PlatformBlockState block;
+
+    private PlatformBinding(Supplier<IrisPlatform> factory) {
+        this.factory = factory;
+    }
+
+    public static PlatformBinding mockPlatform() {
+        return new PlatformBinding(null);
+    }
+
+    public static PlatformBinding of(Supplier<IrisPlatform> factory) {
+        if (factory == null) {
+            throw new IllegalArgumentException("A platform factory is required");
+        }
+
+        return new PlatformBinding(factory);
+    }
+
+    public IrisPlatform platform() {
+        if (platform == null) {
+            throw new IllegalStateException("The platform binding rule is not active");
+        }
+
+        return platform;
+    }
+
+    public PlatformRegistries registries() {
+        if (registries == null) {
+            registries = platform().registries();
+        }
+
+        return registries;
+    }
+
+    public PlatformBlockState block() {
+        if (block == null) {
+            block = registries().block("minecraft:stone");
+        }
+
+        return block;
+    }
+
+    @Override
+    public Statement apply(Statement base, Description description) {
+        String scope = description.getDisplayName();
+
+        return new Statement() {
+            @Override
+            public void evaluate() throws Throwable {
+                PlatformLeakGuard.requireClean(scope, "start");
+                bind();
+
+                try {
+                    base.evaluate();
+                } finally {
+                    IrisPlatforms.unbind();
+                    platform = null;
+                    registries = null;
+                    block = null;
+                    PlatformLeakGuard.requireClean(scope, "end");
+                }
+            }
+        };
+    }
+
+    private void bind() {
+        if (factory == null) {
+            block = mock(PlatformBlockState.class);
+            registries = mock(PlatformRegistries.class);
+            when(registries.block(anyString())).thenReturn(block);
+            platform = mock(IrisPlatform.class);
+            when(platform.registries()).thenReturn(registries);
+        } else {
+            platform = factory.get();
+        }
+
+        IrisPlatforms.bind(platform);
+    }
+}

core/src/test/java/art/arcane/iris/testsupport/PlatformLeakGuard.java

@@ -0,0 +1,64 @@
+package art.arcane.iris.testsupport;
+
+import org.junit.rules.TestRule;
+import org.junit.runner.Description;
+import org.junit.runners.model.Statement;
+
+import java.util.List;
+
+public final class PlatformLeakGuard implements TestRule {
+    private PlatformLeakGuard() {
+    }
+
+    public static PlatformLeakGuard clean() {
+        return new PlatformLeakGuard();
+    }
+
+    public static void requireClean(String scope, String phase) {
+        boolean bound = IrisRuntimeState.platformBound();
+        List<String> services = IrisRuntimeState.registeredServices();
+
+        if (!bound && services.isEmpty()) {
+            return;
+        }
+
+        IrisRuntimeState.reset();
+        throw new AssertionError(describe(scope, phase, bound, services));
+    }
+
+    @Override
+    public Statement apply(Statement base, Description description) {
+        String scope = description.getDisplayName();
+
+        return new Statement() {
+            @Override
+            public void evaluate() throws Throwable {
+                requireClean(scope, "start");
+
+                try {
+                    base.evaluate();
+                } finally {
+                    requireClean(scope, "end");
+                }
+            }
+        };
+    }
+
+    private static String describe(String scope, String phase, boolean bound, List<String> services) {
+        StringBuilder message = new StringBuilder("Iris runtime state is dirty at ")
+                .append(phase)
+                .append(" of ")
+                .append(scope)
+                .append(':');
+
+        if (bound) {
+            message.append(" platform still bound;");
+        }
+
+        if (!services.isEmpty()) {
+            message.append(" services still registered ").append(services).append(';');
+        }
+
+        return message.toString();
+    }
+}

core/src/test/java/art/arcane/iris/util/common/data/PlatformStateRebindTest.java

@@ -5,9 +5,11 @@ import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformBlockState;
 import art.arcane.iris.spi.PlatformRegistries;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.iris.util.project.hunk.view.ChunkDataHunkHolder;
 import org.bukkit.generator.ChunkGenerator;
 import org.junit.After;
+import org.junit.ClassRule;
 import org.junit.Test;
 
 import java.lang.reflect.Field;
@@ -24,6 +26,9 @@ import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 public class PlatformStateRebindTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     private static final List<String> CONVERTED = List.of(
             "art.arcane.iris.engine.actuator.IrisDimensionStackActuator",
             "art.arcane.iris.engine.actuator.IrisTerrainNormalActuator",

core/src/test/java/art/arcane/iris/util/common/director/DirectorAuthoringDataTest.java

@@ -6,6 +6,8 @@ import art.arcane.iris.engine.framework.Engine;
 import art.arcane.iris.engine.object.IrisDimension;
 import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
+import org.junit.ClassRule;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
@@ -28,6 +30,9 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 public class DirectorAuthoringDataTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Rule
     public final TemporaryFolder temporary = new TemporaryFolder();
 

core/src/test/java/art/arcane/iris/util/common/director/specialhandlers/StructureHandlerTest.java

@@ -17,8 +17,10 @@ import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformStructureHooks;
 import art.arcane.iris.spi.PlatformWorld;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.volmlib.util.collection.KList;
 import art.arcane.volmlib.util.director.exceptions.DirectorParsingException;
+import org.junit.ClassRule;
 import org.junit.Test;
 
 import java.util.LinkedHashSet;
@@ -36,6 +38,9 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 public class StructureHandlerTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Test
     public void registeredEligibilityMatchesFindExecutionTruthTable() {
         IrisNativeStructureDecision replacement = decision(NativeStructureGenerationStatus.REPLACED_BY_IRIS);

core/src/test/java/art/arcane/iris/util/common/misc/WebCacheTest.java

@@ -2,11 +2,13 @@ package art.arcane.iris.util.common.misc;
 
 import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.volmlib.util.io.IO;
 import com.sun.net.httpserver.HttpExchange;
 import com.sun.net.httpserver.HttpServer;
 import org.junit.After;
 import org.junit.Before;
+import org.junit.ClassRule;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
@@ -34,6 +36,9 @@ import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 public class WebCacheTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Rule
     public TemporaryFolder temp = new TemporaryFolder();
 

core/src/test/java/art/arcane/iris/util/common/scheduling/JHybridPlatformTest.java

@@ -3,8 +3,10 @@ package art.arcane.iris.util.common.scheduling;
 import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
 import art.arcane.iris.spi.PlatformScheduler;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import org.junit.After;
 import org.junit.Before;
+import org.junit.ClassRule;
 import org.junit.Test;
 
 import static org.junit.Assert.assertNotEquals;
@@ -17,6 +19,9 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 public class JHybridPlatformTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Before
     public void clearPlatform() {
         IrisPlatforms.unbind();

core/src/test/java/art/arcane/iris/util/project/context/ChunkContextPrefillPlanTest.java

@@ -5,8 +5,10 @@ import art.arcane.iris.engine.hydrology.runtime.IrisHydrologyRuntime;
 import art.arcane.iris.engine.object.IrisBiome;
 import art.arcane.iris.engine.object.IrisRegion;
 import art.arcane.iris.spi.IrisPlatforms;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import art.arcane.iris.util.project.stream.ProceduralStream;
 import org.bukkit.block.data.BlockData;
+import org.junit.ClassRule;
 import org.junit.Test;
 import org.mockito.MockedStatic;
 
@@ -29,6 +31,9 @@ import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.verify;
 
 public class ChunkContextPrefillPlanTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Test
     public void noCavePrefillSkipsCaveCacheFill() {
         AtomicInteger caveCalls = new AtomicInteger();

core/src/test/java/art/arcane/iris/util/project/matter/slices/IrisMatterPlatformSelectionTest.java

@@ -2,7 +2,9 @@ package art.arcane.iris.util.project.matter.slices;
 
 import art.arcane.iris.spi.IrisPlatform;
 import art.arcane.iris.spi.IrisPlatforms;
+import art.arcane.iris.testsupport.PlatformLeakGuard;
 import org.bukkit.World;
+import org.junit.ClassRule;
 import org.junit.Test;
 
 import static org.junit.Assert.assertNotNull;
@@ -11,6 +13,9 @@ import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 public class IrisMatterPlatformSelectionTest {
+    @ClassRule
+    public static final PlatformLeakGuard PLATFORM_GUARD = PlatformLeakGuard.clean();
+
     @Test
     public void hybridClasspathDoesNotEnableBukkitMatterIoForModdedPlatform() {
         IrisPlatform platform = mock(IrisPlatform.class);