Initial work on using Minecraft gametests to test component hashing

bootstrap/mod/fabric/src/gametest/java/org/geysermc/geyser/platform/fabric/gametest/GeyserComponentHashTestInstance.java

@@ -0,0 +1,94 @@
+/*
+ * Copyright (c) 2025 GeyserMC. http://geysermc.org
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @author GeyserMC
+ * @link https://github.com/GeyserMC/Geyser
+ */
+
+package org.geysermc.geyser.platform.fabric.gametest;
+
+import com.google.common.hash.HashCode;
+import com.mojang.serialization.MapCodec;
+import io.netty.buffer.Unpooled;
+import net.minecraft.core.component.DataComponentType;
+import net.minecraft.core.component.TypedDataComponent;
+import net.minecraft.gametest.framework.GameTestHelper;
+import net.minecraft.gametest.framework.GameTestInstance;
+import net.minecraft.network.RegistryFriendlyByteBuf;
+import net.minecraft.network.chat.Component;
+import net.minecraft.network.chat.MutableComponent;
+import net.minecraft.resources.RegistryOps;
+import net.minecraft.util.HashOps;
+import org.geysermc.geyser.item.hashing.DataComponentHashers;
+import org.geysermc.geyser.session.GeyserSession;
+import org.geysermc.mcprotocollib.protocol.codec.MinecraftTypes;
+import org.geysermc.mcprotocollib.protocol.data.game.item.component.DataComponent;
+import org.geysermc.mcprotocollib.protocol.data.game.item.component.DataComponentTypes;
+import org.jetbrains.annotations.NotNull;
+
+public class GeyserComponentHashTestInstance<T> extends GeyserTestInstance {
+
+    private static final MapCodec<TypedDataComponent<?>> TYPED_COMPONENT_CODEC = DataComponentType.PERSISTENT_CODEC
+        .dispatchMap("component", TypedDataComponent::type, GeyserComponentHashTestInstance::typedComponentCodec);
+    public static final MapCodec<GeyserComponentHashTestInstance<?>> CODEC = TYPED_COMPONENT_CODEC.xmap(GeyserComponentHashTestInstance::new,
+        instance -> instance.testValue);
+
+    private final TypedDataComponent<T> testValue;
+
+    protected GeyserComponentHashTestInstance(TypedDataComponent<T> testValue) {
+        this.testValue = testValue;
+    }
+
+    @Override
+    protected void run(@NotNull GameTestHelper helper, GeyserSession session) {
+        // Encode vanilla component to buffer
+        RegistryFriendlyByteBuf buffer = new RegistryFriendlyByteBuf(Unpooled.buffer(), helper.getLevel().registryAccess());
+        TypedDataComponent.STREAM_CODEC.encode(buffer, testValue);
+
+        // Read with MCPL
+        int id = MinecraftTypes.readVarInt(buffer);
+        DataComponent<?, ?> mcplComponent = DataComponentTypes.from(id).readDataComponent(buffer);
+
+        // Hash both and compare
+        RegistryOps<HashCode> ops = RegistryOps.create(HashOps.CRC32C_INSTANCE, helper.getLevel().registryAccess());
+        int expected = testValue.encodeValue(ops).getOrThrow().asInt();
+        int geyser = DataComponentHashers.hash(session, mcplComponent).asInt();
+
+        helper.assertValueEqual(expected, geyser, Component.literal("Hash for component " + testValue));
+
+        // Succeed if nothing was thrown
+        helper.succeed();
+    }
+
+    @Override
+    public @NotNull MapCodec<? extends GameTestInstance> codec() {
+        return CODEC;
+    }
+
+    @Override
+    protected @NotNull MutableComponent typeDescription() {
+        return Component.literal("Geyser Data Component Hash Test");
+    }
+
+    private static <T> MapCodec<TypedDataComponent<T>> typedComponentCodec(DataComponentType<T> component) {
+        return component.codecOrThrow().fieldOf("value").xmap(value -> new TypedDataComponent<>(component, value), TypedDataComponent::value);
+    }
+}

bootstrap/mod/fabric/src/gametest/java/org/geysermc/geyser/platform/fabric/gametest/GeyserFabricGametestBootstrap.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2025 GeyserMC. http://geysermc.org
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @author GeyserMC
+ * @link https://github.com/GeyserMC/Geyser
+ */
+
+package org.geysermc.geyser.platform.fabric.gametest;
+
+import net.fabricmc.api.ModInitializer;
+import net.minecraft.core.Registry;
+import net.minecraft.core.registries.BuiltInRegistries;
+import net.minecraft.resources.ResourceLocation;
+
+public class GeyserFabricGametestBootstrap implements ModInitializer {
+
+    @Override
+    public void onInitialize() {
+        Registry.register(BuiltInRegistries.TEST_INSTANCE_TYPE, ResourceLocation.fromNamespaceAndPath("geyser", "component_hash"), GeyserComponentHashTestInstance.CODEC);
+    }
+}

bootstrap/mod/fabric/src/gametest/java/org/geysermc/geyser/platform/fabric/gametest/GeyserTestInstance.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) 2025 GeyserMC. http://geysermc.org
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @author GeyserMC
+ * @link https://github.com/GeyserMC/Geyser
+ */
+
+package org.geysermc.geyser.platform.fabric.gametest;
+
+import net.minecraft.core.Holder;
+import net.minecraft.gametest.framework.GameTestHelper;
+import net.minecraft.gametest.framework.GameTestInstance;
+import net.minecraft.gametest.framework.TestData;
+import net.minecraft.gametest.framework.TestEnvironmentDefinition;
+import net.minecraft.resources.ResourceLocation;
+import org.geysermc.geyser.session.GeyserSession;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.List;
+
+public abstract class GeyserTestInstance extends GameTestInstance {
+
+    protected GeyserTestInstance() {
+        // TODO use default vanilla test environment
+        super(new TestData<>(Holder.direct(new TestEnvironmentDefinition.AllOf(List.of())),
+            ResourceLocation.withDefaultNamespace("empty"), 1, 1, true));
+    }
+
+    @Override
+    public void run(@NotNull GameTestHelper helper) {
+        /*Map<UUID, GeyserSession> sessions = GeyserImpl.getInstance().getSessionManager().getSessions();
+        while (sessions.isEmpty()) {
+            try {
+                Thread.sleep(100L);
+            } catch (InterruptedException ignored) {}
+        }
+        GeyserSession session = sessions.values().stream().findAny().orElseThrow();*/
+        run(helper, null);
+    }
+
+    protected abstract void run(@NotNull GameTestHelper helper, GeyserSession session);
+}

bootstrap/mod/fabric/src/gametest/java/org/geysermc/geyser/platform/fabric/gametest/mixin/GameTestServerMixin.java

@@ -0,0 +1,85 @@
+/*
+ * Copyright (c) 2025 GeyserMC. http://geysermc.org
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @author GeyserMC
+ * @link https://github.com/GeyserMC/Geyser
+ */
+
+package org.geysermc.geyser.platform.fabric.gametest.mixin;
+
+import com.mojang.datafixers.DataFixer;
+import net.minecraft.gametest.framework.GameTestServer;
+import net.minecraft.server.MinecraftServer;
+import net.minecraft.server.Services;
+import net.minecraft.server.WorldStem;
+import net.minecraft.server.level.progress.ChunkProgressListenerFactory;
+import net.minecraft.server.packs.repository.PackRepository;
+import net.minecraft.world.level.storage.LevelStorageSource;
+import org.geysermc.geyser.platform.mod.GeyserServerPortGetter;
+import org.slf4j.Logger;
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
+
+import java.io.IOException;
+import java.net.InetAddress;
+import java.net.Proxy;
+
+@Mixin(GameTestServer.class)
+public abstract class GameTestServerMixin extends MinecraftServer implements GeyserServerPortGetter {
+
+    @Shadow
+    @Final
+    private static Logger LOGGER;
+
+    public GameTestServerMixin(Thread thread, LevelStorageSource.LevelStorageAccess levelStorageAccess, PackRepository packRepository, WorldStem worldStem,
+                               Proxy proxy, DataFixer dataFixer, Services services, ChunkProgressListenerFactory chunkProgressListenerFactory) {
+        super(thread, levelStorageAccess, packRepository, worldStem, proxy, dataFixer, services, chunkProgressListenerFactory);
+    }
+
+    @Override
+    public int geyser$getServerPort() {
+        return this.getPort();
+    }
+
+    @Inject(method = "initServer", at = @At("HEAD"), cancellable = true)
+    public void startTcpServer(CallbackInfoReturnable<Boolean> callbackInfoReturnable) {
+        // A bit of copying from dedicated server code
+        InetAddress address = InetAddress.getLoopbackAddress();
+        if (getPort() < 0) {
+            setPort(25565);
+        }
+        LOGGER.info("Starting gametest server on {}:{}", address, getPort());
+        LOGGER.info("Geyser's tests will start once a bedrock player connects!");
+
+        try {
+            this.getConnection().startTcpServerListener(address, getPort());
+        } catch (IOException exception) {
+            LOGGER.warn("**** FAILED TO BIND TO PORT!");
+            LOGGER.warn("The exception was: {}", exception.toString());
+            LOGGER.warn("Perhaps a server is already running on that port?");
+            callbackInfoReturnable.setReturnValue(false);
+        }
+    }
+}

bootstrap/mod/fabric/src/gametest/resources/data/geyser/test_instance/test.json

@@ -0,0 +1,15 @@
+{
+    "type": "geyser:component_hash",
+    "component": "minecraft:custom_data",
+    "value": {
+        "hello": "g'day",
+        "nice?": false,
+        "coolness": 100,
+        "geyser": {
+            "is": "very cool"
+        },
+        "a list": [
+            ["in a list"]
+        ]
+    }
+}

bootstrap/mod/fabric/src/gametest/resources/fabric.mod.json

@@ -1,13 +1,30 @@
 {
     "schemaVersion": 1,
-    "id": "geyser-gametest",
-    "version": "1.0.0",
-    "name": "Geyser-GameTest",
+    "id": "${id}-fabric-tests",
+    "version": "${version}",
+    "name": "${name}-Fabric-gametest",
+    "description": "A bridge/proxy allowing you to connect to Minecraft: Java Edition servers with Minecraft: Bedrock Edition. ",
+    "authors": [
+        "${author}"
+    ],
+    "contact": {
+        "website": "${url}",
+        "repo": "https://github.com/GeyserMC/Geyser"
+    },
+    "license": "MIT",
     "icon": "assets/geyser/icon.png",
     "environment": "*",
     "entrypoints": {
         "fabric-gametest": [
-            "org.geysermc.geyser.gametest.GeyserGameTest"
+            "org.geysermc.geyser.platform.fabric.gametest.GeyserFabricGametestBootstrap"
         ]
+    },
+    "mixins": [
+        "geyser-fabric-tests.mixins.json"
+    ],
+    "depends": {
+        "fabricloader": ">=0.16.7",
+        "fabric-api": "*",
+        "minecraft": ">=1.21.5"
     }
 }

bootstrap/mod/fabric/src/gametest/resources/geyser-fabric-tests.mixins.json

@@ -0,0 +1,14 @@
+{
+    "required": true,
+    "minVersion": "0.8",
+    "package": "org.geysermc.geyser.platform.fabric.gametest.mixin",
+    "compatibilityLevel": "JAVA_17",
+    "mixins": [
+        "GameTestServerMixin"
+    ],
+    "server": [],
+    "client": [],
+    "injectors": {
+        "defaultRequire": 1
+  }
+}

bootstrap/mod/fabric/src/main/java/org/geysermc/geyser/platform/fabric/GeyserFabricPlatform.java

@@ -82,6 +82,9 @@ public class GeyserFabricPlatform implements GeyserModPlatform {
 
     @Override
     public @Nullable InputStream resolveResource(@NonNull String resource) {
+        if (true) {
+            return this.getClass().getClassLoader().getResourceAsStream(resource);
+        }
         // We need to handle this differently, because Fabric shares the classloader across multiple mods
         Path path = this.mod.findPath(resource).orElse(null);
         if (path == null) {

core/src/main/java/org/geysermc/geyser/item/hashing/DataComponentHashers.java

@@ -317,6 +317,10 @@ public class DataComponentHashers {
         }
     }
 
+    public static <V, T extends DataComponentType<V>> HashCode hash(GeyserSession session, DataComponent<V, T> component) {
+        return hash(session, component.getType(), component.getValue());
+    }
+
     public static HashedStack hashStack(GeyserSession session, ItemStack stack) {
         if (stack == null) {
             return null;