Clean up & enforce unused variable checkstyle rules

build-logic/src/main/kotlin/buildlogic.adapter-reobf.gradle.kts

@@ -1,3 +1,4 @@
+import buildlogic.primaryJavaReleaseVersion
 import io.papermc.paperweight.userdev.ReobfArtifactConfiguration
 
 plugins {
@@ -15,15 +16,13 @@ tasks.named("assemble") {
     dependsOn("reobfJar")
 }
 
+crankcaseJava {
+    // We use Java 21 for most of the pre-existing adapters.
+    javaRelease = 21
+}
+
 java {
     // Required when we de-sync release option and declared Java versions.
     disableAutoTargetJvm()
+    toolchain.languageVersion = JavaLanguageVersion.of(primaryJavaReleaseVersion)
 }
-
-tasks
-    .withType<JavaCompile>()
-    .matching { it.name == "compileJava" || it.name == "compileTestJava" }
-    .configureEach {
-        // We use Java 21 for most of the pre-existing adapters.
-        options.release.set(21)
-    }

build-logic/src/main/kotlin/buildlogic.common-java.gradle.kts

@@ -1,5 +1,6 @@
 import buildlogic.stringyLibs
 import buildlogic.getLibrary
+import buildlogic.primaryJavaReleaseVersion
 
 plugins {
     id("eclipse")
@@ -10,7 +11,7 @@ plugins {
 }
 
 crankcaseJava {
-    javaRelease = 25
+    javaRelease = primaryJavaReleaseVersion
     disabledLints = listOf("processing", "path", "fallthrough", "serial", "overloads")
     disabledErrorprone = listOf(
         // We use reference equality intentionally in several places

build-logic/src/main/kotlin/buildlogic/GradleExtras.kt

@@ -19,6 +19,9 @@ val Project.ext: ExtraPropertiesExtension
 val Project.stringyLibs: VersionCatalog
     get() = extensions.getByType<VersionCatalogsExtension>().named("libs")
 
+val Project.primaryJavaReleaseVersion: Int
+    get() = stringyLibs.getVersion("primaryJavaRelease").requiredVersion.toInt()
+
 val Project.internalVersion: Provider<String>
     get() {
         val version = version.toString()

config/checkstyle/checkstyle-suppression.xml

@@ -3,8 +3,6 @@
         "https://checkstyle.org/dtds/suppressions_1_2.dtd">
 
 <suppressions>
-    <!-- TODO: Apply these Checkstyle rules -->
-    <suppress files=".*" checks="UnusedLocalVariable|UnusedCatchParameterShouldBeUnnamed|UnusedLambdaParameterShouldBeUnnamed|UnusedTryResourceShouldBeUnnamed"/>
     <suppress files=".*DataFixer\.java" checks="MethodName|FallThrough|EmptyStatement|UseEnhancedSwitch"/>
     <suppress files=".*DataConverters\.java"
               checks="MethodName|FallThrough|EmptyStatement|UseEnhancedSwitch|DefaultComesLast|JavadocParagraph"/>

gradle/libs.versions.toml

@@ -5,6 +5,8 @@ sponge-vanillagradle = { id = "org.spongepowered.gradle.vanilla", version.ref =
 fabric-loom = "net.fabricmc.fabric-loom:1.18.2"
 
 [versions]
+primaryJavaRelease = "25"
+
 kyoriText = "3.0.4"
 piston = "0.6.0"
 autoValue = "1.10.4"

worldedit-bukkit/adapters/adapter-1.21.11/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/v1_21_11/PaperweightAdapter.java

@@ -222,8 +222,7 @@ public final class PaperweightAdapter implements BukkitImplAdapter {
 
     public PaperweightAdapter() throws NoSuchFieldException, NoSuchMethodException {
         // A simple test
-        @SuppressWarnings({"ReturnValueIgnored", "unused"})
-        var unused = CraftServer.class.cast(Bukkit.getServer());
+        checkState(Bukkit.getServer() instanceof CraftServer, "Bukkit Server isn't a CraftServer");
 
         int dataVersion = SharedConstants.getCurrentVersion().dataVersion().version();
         if (dataVersion != Constants.DATA_VERSION_MC_1_21_11) {

worldedit-bukkit/adapters/adapter-1.21.11/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/v1_21_11/PaperweightDataConverters.java

@@ -2438,8 +2438,6 @@ public int getDataVersion() {
         }
 
         public net.minecraft.nbt.CompoundTag convert(net.minecraft.nbt.CompoundTag cmp) {
-            boolean flag = true;
-
             try {
                 net.minecraft.nbt.CompoundTag nbttagcompound1 = cmp.getCompoundOrEmpty("Level");
                 int i = nbttagcompound1.getIntOr("xPos", 0);

worldedit-bukkit/adapters/adapter-1.21.4/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/v1_21_4/PaperweightAdapter.java

@@ -220,8 +220,7 @@ public final class PaperweightAdapter implements BukkitImplAdapter {
 
     public PaperweightAdapter() throws NoSuchFieldException, NoSuchMethodException {
         // A simple test
-        @SuppressWarnings({"ReturnValueIgnored", "unused"})
-        var unused = CraftServer.class.cast(Bukkit.getServer());
+        checkState(Bukkit.getServer() instanceof CraftServer, "Bukkit Server isn't a CraftServer");
 
         int dataVersion = SharedConstants.getCurrentVersion().getDataVersion().getVersion();
         if (dataVersion != Constants.DATA_VERSION_MC_1_21_4) {

worldedit-bukkit/adapters/adapter-1.21.5/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/v1_21_5/PaperweightAdapter.java

@@ -220,8 +220,7 @@ public final class PaperweightAdapter implements BukkitImplAdapter {
 
     public PaperweightAdapter() throws NoSuchFieldException, NoSuchMethodException {
         // A simple test
-        @SuppressWarnings({"ReturnValueIgnored", "unused"})
-        var unused = CraftServer.class.cast(Bukkit.getServer());
+        checkState(Bukkit.getServer() instanceof CraftServer, "Bukkit Server isn't a CraftServer");
 
         int dataVersion = SharedConstants.getCurrentVersion().getDataVersion().getVersion();
         if (dataVersion != Constants.DATA_VERSION_MC_1_21_5) {

worldedit-bukkit/adapters/adapter-1.21.5/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/v1_21_5/PaperweightDataConverters.java

@@ -2438,8 +2438,6 @@ public int getDataVersion() {
         }
 
         public net.minecraft.nbt.CompoundTag convert(net.minecraft.nbt.CompoundTag cmp) {
-            boolean flag = true;
-
             try {
                 net.minecraft.nbt.CompoundTag nbttagcompound1 = cmp.getCompoundOrEmpty("Level");
                 int i = nbttagcompound1.getIntOr("xPos", 0);

worldedit-bukkit/adapters/adapter-1.21.6/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/v1_21_6/PaperweightAdapter.java

@@ -223,8 +223,7 @@ public final class PaperweightAdapter implements BukkitImplAdapter {
 
     public PaperweightAdapter() throws NoSuchFieldException, NoSuchMethodException {
         // A simple test
-        @SuppressWarnings({"ReturnValueIgnored", "unused"})
-        var unused = CraftServer.class.cast(Bukkit.getServer());
+        checkState(Bukkit.getServer() instanceof CraftServer, "Bukkit Server isn't a CraftServer");
 
         int dataVersion = SharedConstants.getCurrentVersion().dataVersion().version();
         if (dataVersion < Constants.DATA_VERSION_MC_1_21_6 || dataVersion > Constants.DATA_VERSION_MC_1_21_8) {

worldedit-bukkit/adapters/adapter-1.21.6/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/v1_21_6/PaperweightDataConverters.java

@@ -2438,8 +2438,6 @@ public int getDataVersion() {
         }
 
         public net.minecraft.nbt.CompoundTag convert(net.minecraft.nbt.CompoundTag cmp) {
-            boolean flag = true;
-
             try {
                 net.minecraft.nbt.CompoundTag nbttagcompound1 = cmp.getCompoundOrEmpty("Level");
                 int i = nbttagcompound1.getIntOr("xPos", 0);

worldedit-bukkit/adapters/adapter-1.21.9/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/v1_21_9/PaperweightAdapter.java

@@ -222,8 +222,7 @@ public final class PaperweightAdapter implements BukkitImplAdapter {
 
     public PaperweightAdapter() throws NoSuchFieldException, NoSuchMethodException {
         // A simple test
-        @SuppressWarnings({"ReturnValueIgnored", "unused"})
-        var unused = CraftServer.class.cast(Bukkit.getServer());
+        checkState(Bukkit.getServer() instanceof CraftServer, "Bukkit Server isn't a CraftServer");
 
         int dataVersion = SharedConstants.getCurrentVersion().dataVersion().version();
         if (dataVersion != Constants.DATA_VERSION_MC_1_21_9 && dataVersion != Constants.DATA_VERSION_MC_1_21_10) {

worldedit-bukkit/adapters/adapter-1.21.9/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/v1_21_9/PaperweightDataConverters.java

@@ -2438,8 +2438,6 @@ public int getDataVersion() {
         }
 
         public net.minecraft.nbt.CompoundTag convert(net.minecraft.nbt.CompoundTag cmp) {
-            boolean flag = true;
-
             try {
                 net.minecraft.nbt.CompoundTag nbttagcompound1 = cmp.getCompoundOrEmpty("Level");
                 int i = nbttagcompound1.getIntOr("xPos", 0);

worldedit-bukkit/adapters/adapter-26.1/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/v26_1/PaperweightAdapter.java

@@ -261,10 +261,10 @@ public PaperweightAdapter() throws NoSuchFieldException, NoSuchMethodException {
         try {
             Class.forName("org.spigotmc.WatchdogThread");
             watchdog = new SpigotWatchdog();
-        } catch (ClassNotFoundException | NoSuchFieldException e) {
+        } catch (ClassNotFoundException | NoSuchFieldException _) {
             try {
                 watchdog = new MojangWatchdog(((CraftServer) Bukkit.getServer()).getServer());
-            } catch (NoSuchFieldException ex) {
+            } catch (NoSuchFieldException _) {
                 watchdog = null;
             }
         }
@@ -273,7 +273,7 @@ public PaperweightAdapter() throws NoSuchFieldException, NoSuchMethodException {
         try {
             Class.forName("org.spigotmc.SpigotConfig");
             SpigotConfig.config.set("world-settings.worldeditregentempworld.verbose", false);
-        } catch (ClassNotFoundException ignored) {
+        } catch (ClassNotFoundException _) {
             // It's fine if we couldn't set it
         }
     }
@@ -608,17 +608,17 @@ public BlockMaterial getBlockMaterial(BlockType blockType) {
         @Override
         public Property<?> load(net.minecraft.world.level.block.state.properties.Property state) {
             return switch (state) {
-                case net.minecraft.world.level.block.state.properties.BooleanProperty ignored ->
+                case net.minecraft.world.level.block.state.properties.BooleanProperty _ ->
                         new BooleanProperty(state.getName(), ImmutableList.copyOf(state.getPossibleValues()));
-                case net.minecraft.world.level.block.state.properties.EnumProperty ignored -> {
+                case net.minecraft.world.level.block.state.properties.EnumProperty _ -> {
                     if (state.getValueClass() == net.minecraft.core.Direction.class) {
                         yield new DirectionalProperty(state.getName(),
                                 (List<Direction>) state.getPossibleValues().stream().map(e -> Direction.valueOf(((StringRepresentable) e).getSerializedName().toUpperCase(Locale.ROOT))).toList());
                     }
                     yield new EnumProperty(state.getName(),
                             (List<String>) state.getPossibleValues().stream().map(e -> ((StringRepresentable) e).getSerializedName()).toList());
                 }
-                case net.minecraft.world.level.block.state.properties.IntegerProperty ignored ->
+                case net.minecraft.world.level.block.state.properties.IntegerProperty _ ->
                         new IntegerProperty(state.getName(), ImmutableList.copyOf(state.getPossibleValues()));
                 default ->
                         throw new IllegalArgumentException("WorldEdit needs an update to support " + state.getClass().getSimpleName());
@@ -649,7 +649,7 @@ public void sendFakeNBT(Player player, BlockVector3 pos, LinCompoundTag nbtData)
         structureBlock.setLevel(((CraftPlayer) player).getHandle().level());
         ((CraftPlayer) player).getHandle().connection.send(ClientboundBlockEntityDataPacket.create(
                 structureBlock,
-                (blockEntity, registryAccess) -> (net.minecraft.nbt.CompoundTag) fromNative(nbtData)
+                (_, _) -> (net.minecraft.nbt.CompoundTag) fromNative(nbtData)
         ));
     }
 
@@ -715,7 +715,7 @@ public boolean simulateItemUse(World world, BlockVector3 position, BaseItem item
         PaperweightFakePlayer fakePlayer;
         try {
             fakePlayer = fakePlayers.get(worldServer);
-        } catch (ExecutionException ignored) {
+        } catch (ExecutionException _) {
             return false;
         }
         fakePlayer.setItemInHand(InteractionHand.MAIN_HAND, stack);
@@ -809,7 +809,7 @@ private void doRegen(World bukkitWorld, Region region, Extent extent, RegenOptio
                 @SuppressWarnings("unchecked")
                 Map<String, World> map = (Map<String, World>) serverWorldsField.get(Bukkit.getServer());
                 map.remove("worldeditregentempworld");
-            } catch (IllegalAccessException ignored) {
+            } catch (IllegalAccessException _) {
                 // It's fine if we couldn't remove it
             }
             SafeFiles.tryHardToDeleteDir(tempDir);
@@ -1030,7 +1030,7 @@ public boolean generateStructure(StructureType type, World world, EditSession se
                     structureRegistry.wrapAsHolder(structure), originalWorld.dimension(), originalWorld.registryAccess(),
                     chunkManager.getGenerator(), chunkManager.getGenerator().getBiomeSource(), chunkManager.randomState(),
                     originalWorld.getStructureManager(), originalWorld.getSeed(), chunkPos, 0,
-                    proxyLevel.level(), biome -> true
+                    proxyLevel.level(), _ -> true
             );
 
             if (!structureStart.isValid()) {
@@ -1273,7 +1273,7 @@ private static class MojangWatchdog implements Watchdog {
         public void tick() {
             try {
                 tickField.set(server, Util.getMillis());
-            } catch (IllegalAccessException ignored) {
+            } catch (IllegalAccessException _) {
                 // It's fine if we couldn't set it
             }
         }

worldedit-bukkit/adapters/adapter-26.1/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/v26_1/PaperweightDataConverters.java

@@ -323,13 +323,13 @@ public interface DataConverter {
 
 
     private void registerInspector(LegacyType type, DataInspector inspector) {
-        this.inspectors.computeIfAbsent(type, k -> new ArrayList<>()).add(inspector);
+        this.inspectors.computeIfAbsent(type, _ -> new ArrayList<>()).add(inspector);
     }
 
     private void registerConverter(LegacyType type, DataConverter converter) {
         int version = converter.getDataVersion();
 
-        List<DataConverter> list = this.converters.computeIfAbsent(type, k -> new ArrayList<>());
+        List<DataConverter> list = this.converters.computeIfAbsent(type, _ -> new ArrayList<>());
         if (!list.isEmpty() && list.get(list.size() - 1).getDataVersion() > version) {
             for (int j = 0; j < list.size(); ++j) {
                 if (list.get(j).getDataVersion() > version) {
@@ -1894,22 +1894,22 @@ public net.minecraft.nbt.CompoundTag convert(net.minecraft.nbt.CompoundTag cmp)
                                     if (object == null) {
                                         object = Component.literal("");
                                     }
-                                } catch (JsonParseException jsonparseexception) {
+                                } catch (JsonParseException _) {
                                     ;
                                 }
 
                                 if (object == null) {
                                     try {
                                         object = ComponentConverter.Serializer.fromJson(s, MinecraftServer.getServer().registryAccess());
-                                    } catch (JsonParseException jsonparseexception1) {
+                                    } catch (JsonParseException _) {
                                         ;
                                     }
                                 }
 
                                 if (object == null) {
                                     try {
                                         object = ComponentConverter.Serializer.fromJsonLenient(s, MinecraftServer.getServer().registryAccess());
-                                    } catch (JsonParseException jsonparseexception2) {
+                                    } catch (JsonParseException _) {
                                         ;
                                     }
                                 }
@@ -1972,7 +1972,7 @@ public net.minecraft.nbt.CompoundTag convert(net.minecraft.nbt.CompoundTag cmp)
                     i = cmp.getInt("VillagerProfession").flatMap(profession -> {
                         try {
                             return Optional.of(this.convert(profession));
-                        } catch (RuntimeException runtimeexception) {
+                        } catch (RuntimeException _) {
                             return Optional.empty();
                         }
                     }).orElse(i);
@@ -2438,8 +2438,6 @@ public int getDataVersion() {
         }
 
         public net.minecraft.nbt.CompoundTag convert(net.minecraft.nbt.CompoundTag cmp) {
-            boolean flag = true;
-
             try {
                 net.minecraft.nbt.CompoundTag nbttagcompound1 = cmp.getCompoundOrEmpty("Level");
                 int i = nbttagcompound1.getIntOr("xPos", 0);
@@ -2467,7 +2465,7 @@ public net.minecraft.nbt.CompoundTag convert(net.minecraft.nbt.CompoundTag cmp)
                         }
                     }
                 }
-            } catch (Exception exception) {
+            } catch (Exception _) {
                 DataConverterBedBlock.a.warn("Unable to datafix Bed blocks, level format may be missing tags.");
             }
 
@@ -2557,22 +2555,22 @@ private void convert(net.minecraft.nbt.CompoundTag nbttagcompound, String s) {
                         if (object == null) {
                             object = Component.literal("");
                         }
-                    } catch (JsonParseException jsonparseexception) {
+                    } catch (JsonParseException _) {
                         ;
                     }
 
                     if (object == null) {
                         try {
                             object = ComponentConverter.Serializer.fromJson(s1, MinecraftServer.getServer().registryAccess());
-                        } catch (JsonParseException jsonparseexception1) {
+                        } catch (JsonParseException _) {
                             ;
                         }
                     }
 
                     if (object == null) {
                         try {
                             object = ComponentConverter.Serializer.fromJsonLenient(s1, MinecraftServer.getServer().registryAccess());
-                        } catch (JsonParseException jsonparseexception2) {
+                        } catch (JsonParseException _) {
                             ;
                         }
                     }