Bump CC:T to 1.108.2

- Update to Rollup 4.x
 - Replace terser and postcss with swc and lightningcss. This is
   definitely more code for us to write (maybe I should turn them into
   proper plugins we can depend on), but both speedier and fewer
   dependencies.
 - Drop dependency on glob - we can get away with fs.readdir for what we
   needed it for.

.pre-commit-config.yaml

@@ -44,7 +44,7 @@ repos:
     name: Check Java codestyle
     files: ".*\\.java$"
     language: system
-    entry: ./gradlew checkstyleMain checkstyleTest
+    entry: ./gradlew checkstyle
     pass_filenames: false
     require_serial: true
   - id: illuaminate

.reuse/dep5

@@ -10,8 +10,8 @@ Files:
   projects/common/src/testMod/resources/data/cctest/structures/*
   projects/fabric/src/generated/*
   projects/forge/src/generated/*
-  projects/web/src/export/index.json
+  projects/web/src/htmlTransform/export/index.json
-  projects/web/src/export/items/minecraft/*
+  projects/web/src/htmlTransform/export/items/minecraft/*
 Comment: Generated/data files are CC0.
 Copyright: The CC: Tweaked Developers
 License: CC0-1.0
@@ -37,10 +37,10 @@ Files:
   projects/fabric/src/testMod/resources/computercraft-gametest.fabric.mixins.json
   projects/fabric/src/testMod/resources/fabric.mod.json
   projects/forge/src/client/resources/computercraft-client.forge.mixins.json
-  projects/web/src/mount/.settings
+  projects/web/src/frontend/mount/.settings
-  projects/web/src/mount/example.nfp
+  projects/web/src/frontend/mount/example.nfp
-  projects/web/src/mount/example.nft
+  projects/web/src/frontend/mount/example.nft
-  projects/web/src/mount/expr_template.lua
+  projects/web/src/frontend/mount/expr_template.lua
   projects/web/tsconfig.json
 Comment: Several assets where it's inconvenient to create a .license file.
 Copyright: The CC: Tweaked Developers
@@ -56,7 +56,7 @@ Files:
   projects/core/src/main/resources/data/computercraft/lua/rom/autorun/.ignoreme
   projects/core/src/main/resources/data/computercraft/lua/rom/help/*
   projects/core/src/main/resources/data/computercraft/lua/rom/programs/fun/advanced/levels/*
-  projects/web/src/export/items/computercraft/*
+  projects/web/src/htmlTransform/export/items/computercraft/*
 Comment: Bulk-license original assets as CCPL.
 Copyright: 2011 Daniel Ratcliffe
 License: LicenseRef-CCPL

CONTRIBUTING.md

@@ -100,7 +100,6 @@ about how you can build on that until you've covered everything!
 [new-issue]: https://github.com/cc-tweaked/CC-Tweaked/issues/new/choose "Create a new issue"
 [community]: README.md#community "Get in touch with the community."
 [Adoptium]: https://adoptium.net/temurin/releases?version=17 "Download OpenJDK 17"
-[checkstyle]: https://checkstyle.org/
 [illuaminate]: https://github.com/SquidDev/illuaminate/ "Illuaminate on GitHub"
 [weblate]: https://i18n.tweaked.cc/projects/cc-tweaked/minecraft/ "CC: Tweaked weblate instance"
 [docs]: https://tweaked.cc/ "CC: Tweaked documentation"

buildSrc/src/main/kotlin/cc-tweaked.java-convention.gradle.kts

@@ -66,6 +66,7 @@ repositories {
             includeGroup("me.shedaniel.cloth")
             includeGroup("me.shedaniel")
             includeGroup("mezz.jei")
+            includeGroup("org.teavm")
             includeModule("com.terraformersmc", "modmenu")
             includeModule("me.lucko", "fabric-permissions-api")
         }
@@ -99,7 +100,10 @@ sourceSets.all {
             check("FutureReturnValueIgnored", CheckSeverity.OFF) // Too many false positives with Netty
 
             check("NullAway", CheckSeverity.ERROR)
-            option("NullAway:AnnotatedPackages", listOf("dan200.computercraft", "net.fabricmc.fabric.api").joinToString(","))
+            option(
+                "NullAway:AnnotatedPackages",
+                listOf("dan200.computercraft", "cc.tweaked", "net.fabricmc.fabric.api").joinToString(","),
+            )
             option("NullAway:ExcludedFieldAnnotations", listOf("org.spongepowered.asm.mixin.Shadow").joinToString(","))
             option("NullAway:CastToNonNullMethod", "dan200.computercraft.core.util.Nullability.assertNonNull")
             option("NullAway:CheckOptionalEmptiness")
@@ -174,6 +178,12 @@ project.plugins.withType(CCTweakedPlugin::class.java) {
     }
 }
 
+tasks.register("checkstyle") {
+    description = "Run Checkstyle on all sources"
+    group = LifecycleBasePlugin.VERIFICATION_GROUP
+    dependsOn(tasks.withType(Checkstyle::class.java))
+}
+
 spotless {
     encoding = StandardCharsets.UTF_8
     lineEndings = LineEnding.UNIX

buildSrc/src/main/kotlin/cc/tweaked/gradle/ExecTasks.kt

@@ -4,6 +4,7 @@
 
 package cc.tweaked.gradle
 
+import org.gradle.api.file.DirectoryProperty
 import org.gradle.api.provider.Property
 import org.gradle.api.tasks.AbstractExecTask
 import org.gradle.api.tasks.OutputDirectory
@@ -11,5 +12,5 @@ import java.io.File
 
 abstract class ExecToDir : AbstractExecTask<ExecToDir>(ExecToDir::class.java) {
     @get:OutputDirectory
-    abstract val output: Property<File>
+    abstract val output: DirectoryProperty
 }

buildSrc/src/main/kotlin/cc/tweaked/gradle/Extensions.kt

@@ -5,6 +5,8 @@
 package cc.tweaked.gradle
 
 import org.gradle.api.artifacts.dsl.DependencyHandler
+import org.gradle.api.file.FileSystemLocation
+import org.gradle.api.file.FileSystemLocationProperty
 import org.gradle.api.provider.Property
 import org.gradle.api.provider.Provider
 import org.gradle.api.tasks.JavaExec
@@ -124,3 +126,6 @@ class CloseScope : AutoCloseable {
 
 /** Proxy method to avoid overload ambiguity. */
 fun <T> Property<T>.setProvider(provider: Provider<out T>) = set(provider)
+
+/** Short-cut method to get the absolute path of a [FileSystemLocation] provider. */
+fun Provider<out FileSystemLocation>.getAbsolutePath(): String = get().asFile.absolutePath

config/checkstyle/suppressions.xml

@@ -16,4 +16,10 @@ SPDX-License-Identifier: MPL-2.0
 
     <!-- The commands API is documented in Lua. -->
     <suppress checks="SummaryJavadocCheck" files=".*[\\/]CommandAPI.java" />
+
+    <!-- Allow putting files in other packages if they look like our TeaVM stubs. -->
+    <suppress checks="PackageName" files=".*[\\/]T[A-Za-z]+.java" />
+
+    <!-- Allow underscores in our test classes. -->
+    <suppress checks="MethodName" files=".*Contract.java" />
 </suppressions>

doc/events/file_transfer.md

@@ -29,7 +29,7 @@ for _, file in ipairs(files.getFiles()) do
   local size = file.seek("end")
   file.seek("set", 0)
 
-  print(file.getName() .. " " .. file.getSize())
+  print(file.getName() .. " " .. size)
 end
 ```
 

gradle.properties

@@ -10,7 +10,7 @@ kotlin.jvm.target.validation.mode=error
 
 # Mod properties
 isUnstable=false
-modVersion=1.108.1
+modVersion=1.108.2
 
 # Minecraft properties: We want to configure this here so we can read it in settings.gradle
 mcVersion=1.20.1

gradle/libs.versions.toml

@@ -30,7 +30,7 @@ kotlin = "1.8.10"
 kotlin-coroutines = "1.6.4"
 netty = "4.1.82.Final"
 nightConfig = "3.6.7"
-slf4j = "1.7.36"
+slf4j = "2.0.1"
 
 # Minecraft mods
 emi = "1.0.8+1.20.1"
@@ -60,7 +60,7 @@ fabric-loom = "1.3.7"
 forgeGradle = "6.0.8"
 githubRelease = "2.4.1"
 ideaExt = "1.1.7"
-illuaminate = "0.1.0-40-g975cbc3"
+illuaminate = "0.1.0-44-g9ee0055"
 librarian = "1.+"
 minotaur = "2.+"
 mixinGradle = "0.7.+"
@@ -69,10 +69,12 @@ spotless = "6.21.0"
 taskTree = "2.1.1"
 vanillaGradle = "0.2.1-SNAPSHOT"
 vineflower = "1.11.0"
+teavm = "0.9.0-SQUID.1"
 
 [libraries]
 # Normal dependencies
 asm = { module = "org.ow2.asm:asm", version.ref = "asm" }
+asm-commons = { module = "org.ow2.asm:asm-commons", version.ref = "asm" }
 autoService = { module = "com.google.auto.service:auto-service", version.ref = "autoService" }
 checkerFramework = { module = "org.checkerframework:checker-qual", version.ref = "checkerFramework" }
 cobalt = { module = "org.squiddev:Cobalt", version.ref = "cobalt" }
@@ -138,6 +140,14 @@ librarian = { module = "org.parchmentmc:librarian", version.ref = "librarian" }
 minotaur = { module = "com.modrinth.minotaur:Minotaur", version.ref = "minotaur" }
 nullAway = { module = "com.uber.nullaway:nullaway", version.ref = "nullAway" }
 spotless = { module = "com.diffplug.spotless:spotless-plugin-gradle", version.ref = "spotless" }
+teavm-classlib = { module = "org.teavm:teavm-classlib", version.ref = "teavm" }
+teavm-jso = { module = "org.teavm:teavm-jso", version.ref = "teavm" }
+teavm-jso-apis = { module = "org.teavm:teavm-jso-apis", version.ref = "teavm" }
+teavm-jso-impl = { module = "org.teavm:teavm-jso-impl", version.ref = "teavm" }
+teavm-metaprogramming-api = { module = "org.teavm:teavm-metaprogramming-api", version.ref = "teavm" }
+teavm-metaprogramming-impl = { module = "org.teavm:teavm-metaprogramming-impl", version.ref = "teavm" }
+teavm-platform = { module = "org.teavm:teavm-platform", version.ref = "teavm" }
+teavm-tooling = { module = "org.teavm:teavm-tooling", version.ref = "teavm" }
 vanillaGradle = { module = "org.spongepowered:vanillagradle", version.ref = "vanillaGradle" }
 vineflower = { module = "io.github.juuxel:loom-vineflower", version.ref = "vineflower" }
 
@@ -151,6 +161,7 @@ mixinGradle = { id = "org.spongepowered.mixin", version.ref = "mixinGradle" }
 taskTree = { id = "com.dorongold.task-tree", version.ref = "taskTree" }
 
 [bundles]
+annotations = ["jsr305", "checkerFramework", "jetbrainsAnnotations"]
 kotlin = ["kotlin-stdlib", "kotlin-coroutines"]
 
 # Minecraft
@@ -164,3 +175,7 @@ externalMods-fabric-runtime = ["jei-fabric", "modmenu"]
 # Testing
 test = ["junit-jupiter-api", "junit-jupiter-params", "hamcrest", "jqwik-api"]
 testRuntime = ["junit-jupiter-engine", "jqwik-engine"]
+
+# Build tools
+teavm-api = [ "teavm-jso", "teavm-jso-apis", "teavm-platform", "teavm-classlib", "teavm-metaprogramming-api" ]
+teavm-tooling = [ "teavm-tooling", "teavm-metaprogramming-impl", "teavm-jso-impl" ]

illuaminate.sexp

@@ -10,7 +10,7 @@
   /projects/core/src/main/resources/data/computercraft/lua/bios.lua
   /projects/core/src/main/resources/data/computercraft/lua/rom/
   /projects/core/src/test/resources/test-rom
-  /projects/web/src/mount)
+  /projects/web/src/frontend/mount)
 
 (doc
   ; Also defined in projects/web/build.gradle.kts
@@ -23,7 +23,7 @@
     (url https://tweaked.cc/)
     (source-link https://github.com/cc-tweaked/CC-Tweaked/blob/${commit}/${path}#L${line})
 
-    (styles /projects/web/src/styles.css)
+    (styles  /projects/web/build/rollup/index.css)
     (scripts /projects/web/build/rollup/index.js)
     (head doc/head.html))
 
@@ -115,4 +115,4 @@
       :max sleep write
       cct_test describe expect howlci fail it pending stub before_each)))
 
-(at /projects/web/src/mount/expr_template.lua (lint (globals :max __expr__)))
+(at /projects/web/src/frontend/mount/expr_template.lua (lint (globals :max __expr__)))

package.json

@@ -6,24 +6,24 @@
   "license": "BSD-3-Clause",
   "type": "module",
   "dependencies": {
+    "@squid-dev/cc-web-term": "^2.0.0",
     "preact": "^10.5.5",
+    "setimmediate": "^1.0.5",
     "tslib": "^2.0.3"
   },
   "devDependencies": {
-    "@rollup/plugin-terser": "^0.4.0",
+    "@rollup/plugin-node-resolve": "^15.2.1",
     "@rollup/plugin-typescript": "^11.0.0",
     "@rollup/plugin-url": "^8.0.1",
-    "@types/glob": "^8.1.0",
+    "@swc/core": "^1.3.92",
-    "@types/react-dom": "^18.0.5",
+    "@types/node": "^20.8.3",
-    "glob": "^10.3.4",
+    "lightningcss": "^1.22.0",
-    "react-dom": "^18.1.0",
+    "preact-render-to-string": "^6.2.1",
-    "react": "^18.1.0",
+    "rehype": "^13.0.0",
-    "rehype-highlight": "^6.0.0",
+    "rehype-highlight": "^7.0.0",
-    "rehype-react": "^7.1.1",
+    "rehype-react": "^8.0.0",
-    "rehype": "^12.0.0",
+    "rollup": "^4.0.0",
-    "requirejs": "^2.3.6",
+    "tsx": "^3.12.10",
-    "rollup": "^3.19.1",
-    "ts-node": "^10.8.0",
     "typescript": "^5.2.2"
   }
 }

projects/common-api/src/main/java/dan200/computercraft/api/ComputerCraftTags.java

@@ -46,6 +46,14 @@ public class ComputerCraftTags {
         public static final TagKey<Block> WIRED_MODEM = make("wired_modem");
         public static final TagKey<Block> MONITOR = make("monitor");
 
+        /**
+         * Blocks which should be ignored by a {@code peripheral_hub} peripheral.
+         * <p>
+         * This should include blocks which themselves expose a peripheral hub (such as {@linkplain #WIRED_MODEM wired
+         * modems}).
+         */
+        public static final TagKey<Block> PERIPHERAL_HUB_IGNORE = make("peripheral_hub_ignore");
+
         /**
          * Blocks which can be broken by any turtle tool.
          */

projects/common/src/main/java/dan200/computercraft/data/RecipeProvider.java

@@ -5,6 +5,7 @@
 package dan200.computercraft.data;
 
 import com.google.gson.JsonObject;
+import com.mojang.authlib.GameProfile;
 import dan200.computercraft.api.ComputerCraftAPI;
 import dan200.computercraft.api.pocket.PocketUpgradeDataProvider;
 import dan200.computercraft.api.turtle.TurtleUpgradeDataProvider;
@@ -25,15 +26,12 @@ import net.minecraft.core.registries.Registries;
 import net.minecraft.data.PackOutput;
 import net.minecraft.data.recipes.*;
 import net.minecraft.nbt.CompoundTag;
+import net.minecraft.nbt.NbtUtils;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.tags.TagKey;
 import net.minecraft.util.GsonHelper;
-import net.minecraft.world.item.DyeColor;
+import net.minecraft.world.item.*;
-import net.minecraft.world.item.DyeItem;
-import net.minecraft.world.item.Item;
-import net.minecraft.world.item.Items;
 import net.minecraft.world.item.crafting.Ingredient;
-import net.minecraft.world.item.crafting.RecipeSerializer;
 import net.minecraft.world.item.crafting.ShapedRecipe;
 import net.minecraft.world.item.crafting.SimpleCraftingRecipeSerializer;
 import net.minecraft.world.level.ItemLike;
@@ -41,6 +39,7 @@ import net.minecraft.world.level.block.Blocks;
 
 import java.util.List;
 import java.util.Locale;
+import java.util.UUID;
 import java.util.function.Consumer;
 
 import static dan200.computercraft.api.ComputerCraftTags.Items.COMPUTER;
@@ -443,7 +442,7 @@ class RecipeProvider extends net.minecraft.data.recipes.RecipeProvider {
             .requires(ModRegistry.Items.MONITOR_NORMAL.get())
             .unlockedBy("has_monitor", inventoryChange(ModRegistry.Items.MONITOR_NORMAL.get()))
             .save(
-                RecipeWrapper.wrap(RecipeSerializer.SHAPELESS_RECIPE, add)
+                RecipeWrapper.wrap(ModRegistry.RecipeSerializers.SHAPELESS.get(), add)
                     .withResultTag(playerHead("Cloudhunter", "6d074736-b1e9-4378-a99b-bd8777821c9c")),
                 new ResourceLocation(ComputerCraftAPI.MOD_ID, "skull_cloudy")
             );
@@ -454,7 +453,7 @@ class RecipeProvider extends net.minecraft.data.recipes.RecipeProvider {
             .requires(ModRegistry.Items.COMPUTER_ADVANCED.get())
             .unlockedBy("has_computer", inventoryChange(ModRegistry.Items.COMPUTER_ADVANCED.get()))
             .save(
-                RecipeWrapper.wrap(RecipeSerializer.SHAPELESS_RECIPE, add)
+                RecipeWrapper.wrap(ModRegistry.RecipeSerializers.SHAPELESS.get(), add)
                     .withResultTag(playerHead("dan200", "f3c8d69b-0776-4512-8434-d1b2165909eb")),
                 new ResourceLocation(ComputerCraftAPI.MOD_ID, "skull_dan200")
             );
@@ -513,17 +512,15 @@ class RecipeProvider extends net.minecraft.data.recipes.RecipeProvider {
     }
 
     private static CompoundTag playerHead(String name, String uuid) {
-        var owner = new CompoundTag();
+        var owner = NbtUtils.writeGameProfile(new CompoundTag(), new GameProfile(UUID.fromString(uuid), name));
-        owner.putString("Name", name);
-        owner.putString("Id", uuid);
 
         var tag = new CompoundTag();
-        tag.put("SkullOwner", owner);
+        tag.put(PlayerHeadItem.TAG_SKULL_OWNER, owner);
         return tag;
     }
 
     private static Consumer<JsonObject> family(ComputerFamily family) {
-        return json -> json.addProperty("family", family.toString());
+        return json -> json.addProperty("family", family.getSerializedName());
     }
 
     private static void addSpecial(Consumer<FinishedRecipe> add, SimpleCraftingRecipeSerializer<?> special) {

projects/common/src/main/java/dan200/computercraft/data/TagProvider.java

@@ -35,6 +35,8 @@ class TagProvider {
         tags.tag(ComputerCraftTags.Blocks.WIRED_MODEM).add(ModRegistry.Blocks.CABLE.get(), ModRegistry.Blocks.WIRED_MODEM_FULL.get());
         tags.tag(ComputerCraftTags.Blocks.MONITOR).add(ModRegistry.Blocks.MONITOR_NORMAL.get(), ModRegistry.Blocks.MONITOR_ADVANCED.get());
 
+        tags.tag(ComputerCraftTags.Blocks.PERIPHERAL_HUB_IGNORE).addTag(ComputerCraftTags.Blocks.WIRED_MODEM);
+
         tags.tag(ComputerCraftTags.Blocks.TURTLE_ALWAYS_BREAKABLE).addTag(BlockTags.LEAVES).add(
             Blocks.BAMBOO, Blocks.BAMBOO_SAPLING // Bamboo isn't instabreak for some odd reason.
         );

projects/common/src/main/java/dan200/computercraft/shared/ModRegistry.java

@@ -70,6 +70,10 @@ import dan200.computercraft.shared.pocket.items.PocketComputerItem;
 import dan200.computercraft.shared.pocket.peripherals.PocketModem;
 import dan200.computercraft.shared.pocket.peripherals.PocketSpeaker;
 import dan200.computercraft.shared.pocket.recipes.PocketComputerUpgradeRecipe;
+import dan200.computercraft.shared.recipe.CustomShapedRecipe;
+import dan200.computercraft.shared.recipe.CustomShapelessRecipe;
+import dan200.computercraft.shared.recipe.ImpostorShapedRecipe;
+import dan200.computercraft.shared.recipe.ImpostorShapelessRecipe;
 import dan200.computercraft.shared.turtle.FurnaceRefuelHandler;
 import dan200.computercraft.shared.turtle.blocks.TurtleBlock;
 import dan200.computercraft.shared.turtle.blocks.TurtleBlockEntity;
@@ -79,8 +83,6 @@ import dan200.computercraft.shared.turtle.recipes.TurtleOverlayRecipe;
 import dan200.computercraft.shared.turtle.recipes.TurtleRecipe;
 import dan200.computercraft.shared.turtle.recipes.TurtleUpgradeRecipe;
 import dan200.computercraft.shared.turtle.upgrades.*;
-import dan200.computercraft.shared.util.ImpostorRecipe;
-import dan200.computercraft.shared.util.ImpostorShapelessRecipe;
 import net.minecraft.commands.CommandSourceStack;
 import net.minecraft.commands.synchronization.ArgumentTypeInfo;
 import net.minecraft.commands.synchronization.SingletonArgumentInfo;
@@ -359,17 +361,21 @@ public final class ModRegistry {
             return REGISTRY.register(name, () -> new SimpleCraftingRecipeSerializer<>(factory));
         }
 
+        public static final RegistryEntry<RecipeSerializer<CustomShapedRecipe>> SHAPED = REGISTRY.register("shaped", () -> CustomShapedRecipe.serialiser(CustomShapedRecipe::new));
+        public static final RegistryEntry<RecipeSerializer<CustomShapelessRecipe>> SHAPELESS = REGISTRY.register("shapeless", () -> CustomShapelessRecipe.serialiser(CustomShapelessRecipe::new));
+
+        public static final RegistryEntry<RecipeSerializer<ImpostorShapedRecipe>> IMPOSTOR_SHAPED = REGISTRY.register("impostor_shaped", () -> CustomShapedRecipe.serialiser(ImpostorShapedRecipe::new));
+        public static final RegistryEntry<RecipeSerializer<ImpostorShapelessRecipe>> IMPOSTOR_SHAPELESS = REGISTRY.register("impostor_shapeless", () -> CustomShapelessRecipe.serialiser(ImpostorShapelessRecipe::new));
+
         public static final RegistryEntry<SimpleCraftingRecipeSerializer<ColourableRecipe>> DYEABLE_ITEM = simple("colour", ColourableRecipe::new);
         public static final RegistryEntry<SimpleCraftingRecipeSerializer<ClearColourRecipe>> DYEABLE_ITEM_CLEAR = simple("clear_colour", ClearColourRecipe::new);
-        public static final RegistryEntry<TurtleRecipe.Serializer> TURTLE = REGISTRY.register("turtle", TurtleRecipe.Serializer::new);
+        public static final RegistryEntry<RecipeSerializer<TurtleRecipe>> TURTLE = REGISTRY.register("turtle", () -> TurtleRecipe.validatingSerialiser(TurtleRecipe::of));
         public static final RegistryEntry<SimpleCraftingRecipeSerializer<TurtleUpgradeRecipe>> TURTLE_UPGRADE = simple("turtle_upgrade", TurtleUpgradeRecipe::new);
-        public static final RegistryEntry<TurtleOverlayRecipe.Serializer> TURTLE_OVERLAY = REGISTRY.register("turtle_overlay", TurtleOverlayRecipe.Serializer::new);
+        public static final RegistryEntry<RecipeSerializer<TurtleOverlayRecipe>> TURTLE_OVERLAY = REGISTRY.register("turtle_overlay", TurtleOverlayRecipe.Serializer::new);
         public static final RegistryEntry<SimpleCraftingRecipeSerializer<PocketComputerUpgradeRecipe>> POCKET_COMPUTER_UPGRADE = simple("pocket_computer_upgrade", PocketComputerUpgradeRecipe::new);
         public static final RegistryEntry<SimpleCraftingRecipeSerializer<PrintoutRecipe>> PRINTOUT = simple("printout", PrintoutRecipe::new);
         public static final RegistryEntry<SimpleCraftingRecipeSerializer<DiskRecipe>> DISK = simple("disk", DiskRecipe::new);
-        public static final RegistryEntry<ComputerUpgradeRecipe.Serializer> COMPUTER_UPGRADE = REGISTRY.register("computer_upgrade", ComputerUpgradeRecipe.Serializer::new);
+        public static final RegistryEntry<RecipeSerializer<ComputerUpgradeRecipe>> COMPUTER_UPGRADE = REGISTRY.register("computer_upgrade", ComputerUpgradeRecipe.Serializer::new);
-        public static final RegistryEntry<ImpostorRecipe.Serializer> IMPOSTOR_SHAPED = REGISTRY.register("impostor_shaped", ImpostorRecipe.Serializer::new);
-        public static final RegistryEntry<ImpostorShapelessRecipe.Serializer> IMPOSTOR_SHAPELESS = REGISTRY.register("impostor_shapeless", ImpostorShapelessRecipe.Serializer::new);
     }
 
     public static class Permissions {

projects/common/src/main/java/dan200/computercraft/shared/computer/core/ComputerFamily.java

@@ -4,8 +4,33 @@
 
 package dan200.computercraft.shared.computer.core;
 
-public enum ComputerFamily {
+import com.google.gson.JsonObject;
-    NORMAL,
+import com.google.gson.JsonSyntaxException;
-    ADVANCED,
+import net.minecraft.util.GsonHelper;
-    COMMAND
+import net.minecraft.util.StringRepresentable;
+
+public enum ComputerFamily implements StringRepresentable {
+    NORMAL("normal"),
+    ADVANCED("advanced"),
+    COMMAND("command");
+
+    private final String name;
+
+    ComputerFamily(String name) {
+        this.name = name;
+    }
+
+    public static ComputerFamily getFamily(JsonObject json, String name) {
+        var familyName = GsonHelper.getAsString(json, name);
+        for (var family : values()) {
+            if (family.getSerializedName().equalsIgnoreCase(familyName)) return family;
+        }
+
+        throw new JsonSyntaxException("Unknown computer family '" + familyName + "' for field " + name);
+    }
+
+    @Override
+    public String getSerializedName() {
+        return name;
+    }
 }

projects/common/src/main/java/dan200/computercraft/shared/computer/core/ResourceMount.java

@@ -29,8 +29,6 @@ import java.util.Map;
 public final class ResourceMount extends ArchiveMount<ResourceMount.FileEntry> {
     private static final Logger LOG = LoggerFactory.getLogger(ResourceMount.class);
 
-    private static final byte[] TEMP_BUFFER = new byte[8192];
-
     /**
      * Maintain a cache of currently loaded resource mounts. This cache is invalidated when currentManager changes.
      */
@@ -60,7 +58,7 @@ public final class ResourceMount extends ArchiveMount<ResourceMount.FileEntry> {
         var hasAny = false;
         String existingNamespace = null;
 
-        var newRoot = new FileEntry("", new ResourceLocation(namespace, subPath));
+        var newRoot = new FileEntry(new ResourceLocation(namespace, subPath));
         for (var file : manager.listResources(subPath, s -> true).keySet()) {
             existingNamespace = file.getNamespace();
 
@@ -68,7 +66,11 @@ public final class ResourceMount extends ArchiveMount<ResourceMount.FileEntry> {
             if (!FileSystem.contains(subPath, file.getPath())) continue; // Some packs seem to include the parent?
 
             var localPath = FileSystem.toLocal(file.getPath(), subPath);
-            create(newRoot, localPath);
+            try {
+                getOrCreateChild(newRoot, localPath, this::createEntry);
+            } catch (ResourceLocationException e) {
+                LOG.warn("Cannot create resource location for {} ({})", localPath, e.getMessage());
+            }
             hasAny = true;
         }
 
@@ -83,65 +85,24 @@ public final class ResourceMount extends ArchiveMount<ResourceMount.FileEntry> {
         }
     }
 
-    private void create(FileEntry lastEntry, String path) {
+    private FileEntry createEntry(String path) {
-        var lastIndex = 0;
+        return new FileEntry(new ResourceLocation(namespace, subPath + "/" + path));
-        while (lastIndex < path.length()) {
-            var nextIndex = path.indexOf('/', lastIndex);
-            if (nextIndex < 0) nextIndex = path.length();
-
-            var part = path.substring(lastIndex, nextIndex);
-            if (lastEntry.children == null) lastEntry.children = new HashMap<>();
-
-            var nextEntry = lastEntry.children.get(part);
-            if (nextEntry == null) {
-                ResourceLocation childPath;
-                try {
-                    childPath = new ResourceLocation(namespace, subPath + "/" + path);
-                } catch (ResourceLocationException e) {
-                    LOG.warn("Cannot create resource location for {} ({})", part, e.getMessage());
-                    return;
-                }
-                lastEntry.children.put(part, nextEntry = new FileEntry(path, childPath));
-            }
-
-            lastEntry = nextEntry;
-            lastIndex = nextIndex + 1;
-        }
     }
 
     @Override
-    public long getSize(FileEntry file) {
+    protected byte[] getFileContents(String path, FileEntry file) throws IOException {
         var resource = manager.getResource(file.identifier).orElse(null);
-        if (resource == null) return 0;
+        if (resource == null) throw new FileOperationException(path, NO_SUCH_FILE);
-
-        try (var stream = resource.open()) {
-            int total = 0, read = 0;
-            do {
-                total += read;
-                read = stream.read(TEMP_BUFFER);
-            } while (read > 0);
-
-            return total;
-        } catch (IOException e) {
-            return 0;
-        }
-    }
-
-    @Override
-    public byte[] getContents(FileEntry file) throws IOException {
-        var resource = manager.getResource(file.identifier).orElse(null);
-        if (resource == null) throw new FileOperationException(file.path, NO_SUCH_FILE);
 
         try (var stream = resource.open()) {
             return stream.readAllBytes();
         }
     }
 
-    protected static class FileEntry extends ArchiveMount.FileEntry<FileEntry> {
+    protected static final class FileEntry extends ArchiveMount.FileEntry<FileEntry> {
         final ResourceLocation identifier;
 
-        FileEntry(String path, ResourceLocation identifier) {
+        FileEntry(ResourceLocation identifier) {
-            super(path);
             this.identifier = identifier;
         }
     }

projects/common/src/main/java/dan200/computercraft/shared/computer/menu/ServerInputState.java

@@ -4,7 +4,12 @@
 
 package dan200.computercraft.shared.computer.menu;
 
-import dan200.computercraft.shared.computer.upload.*;
+import dan200.computercraft.core.apis.handles.ByteBufferChannel;
+import dan200.computercraft.core.apis.transfer.TransferredFile;
+import dan200.computercraft.core.apis.transfer.TransferredFiles;
+import dan200.computercraft.shared.computer.upload.FileSlice;
+import dan200.computercraft.shared.computer.upload.FileUpload;
+import dan200.computercraft.shared.computer.upload.UploadResult;
 import dan200.computercraft.shared.network.client.UploadResultMessage;
 import dan200.computercraft.shared.platform.PlatformHelper;
 import it.unimi.dsi.fastutil.ints.IntOpenHashSet;
@@ -18,7 +23,6 @@ import org.slf4j.LoggerFactory;
 import javax.annotation.Nullable;
 import java.util.List;
 import java.util.UUID;
-import java.util.stream.Collectors;
 
 /**
  * The default concrete implementation of {@link ServerInputHandler}.
@@ -150,8 +154,14 @@ public class ServerInputState<T extends AbstractContainerMenu & ComputerMenu> im
             }
         }
 
-        computer.queueEvent("file_transfer", new Object[]{
+        computer.queueEvent(TransferredFiles.EVENT, new Object[]{
-            new TransferredFiles(player, owner, toUpload.stream().map(x -> new TransferredFile(x.getName(), x.getBytes())).collect(Collectors.toList())),
+            new TransferredFiles(
+                toUpload.stream().map(x -> new TransferredFile(x.getName(), new ByteBufferChannel(x.getBytes()))).toList(),
+                () -> {
+                    if (player.isAlive() && player.containerMenu == owner) {
+                        PlatformHelper.get().sendToPlayer(UploadResultMessage.consumed(owner), player);
+                    }
+                }),
         });
         return UploadResultMessage.queued(owner);
     }

projects/common/src/main/java/dan200/computercraft/shared/computer/recipe/ComputerConvertRecipe.java

@@ -5,31 +5,20 @@
 package dan200.computercraft.shared.computer.recipe;
 
 import dan200.computercraft.shared.computer.items.IComputerItem;
-import net.minecraft.core.NonNullList;
+import dan200.computercraft.shared.recipe.CustomShapedRecipe;
+import dan200.computercraft.shared.recipe.ShapedRecipeSpec;
 import net.minecraft.core.RegistryAccess;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.world.inventory.CraftingContainer;
 import net.minecraft.world.item.ItemStack;
-import net.minecraft.world.item.crafting.CraftingBookCategory;
-import net.minecraft.world.item.crafting.Ingredient;
-import net.minecraft.world.item.crafting.ShapedRecipe;
 import net.minecraft.world.level.Level;
 
 /**
- * Represents a recipe which converts a computer from one form into another.
+ * A recipe which converts a computer from one form into another.
  */
-public abstract class ComputerConvertRecipe extends ShapedRecipe {
+public abstract class ComputerConvertRecipe extends CustomShapedRecipe {
-    private final String group;
+    public ComputerConvertRecipe(ResourceLocation identifier, ShapedRecipeSpec recipe) {
-    private final ItemStack result;
+        super(identifier, recipe);
-
-    public ComputerConvertRecipe(ResourceLocation identifier, String group, CraftingBookCategory category, int width, int height, NonNullList<Ingredient> ingredients, ItemStack result) {
-        super(identifier, group, category, width, height, ingredients, result);
-        this.group = group;
-        this.result = result;
-    }
-
-    public ItemStack getResultItem() {
-        return result;
     }
 
     protected abstract ItemStack convert(IComputerItem item, ItemStack stack);
@@ -55,9 +44,4 @@ public abstract class ComputerConvertRecipe extends ShapedRecipe {
 
         return ItemStack.EMPTY;
     }
-
-    @Override
-    public String getGroup() {
-        return group;
-    }
 }

projects/common/src/main/java/dan200/computercraft/shared/computer/recipe/ComputerFamilyRecipe.java

@@ -1,72 +0,0 @@
-// SPDX-FileCopyrightText: 2018 The CC: Tweaked Developers
-//
-// SPDX-License-Identifier: MPL-2.0
-
-package dan200.computercraft.shared.computer.recipe;
-
-import com.google.gson.JsonObject;
-import dan200.computercraft.shared.computer.core.ComputerFamily;
-import dan200.computercraft.shared.util.RecipeUtil;
-import net.minecraft.core.NonNullList;
-import net.minecraft.network.FriendlyByteBuf;
-import net.minecraft.resources.ResourceLocation;
-import net.minecraft.util.GsonHelper;
-import net.minecraft.world.item.ItemStack;
-import net.minecraft.world.item.crafting.CraftingBookCategory;
-import net.minecraft.world.item.crafting.Ingredient;
-import net.minecraft.world.item.crafting.RecipeSerializer;
-
-public abstract class ComputerFamilyRecipe extends ComputerConvertRecipe {
-    private final ComputerFamily family;
-
-    public ComputerFamilyRecipe(ResourceLocation identifier, String group, CraftingBookCategory category, int width, int height, NonNullList<Ingredient> ingredients, ItemStack result, ComputerFamily family) {
-        super(identifier, group, category, width, height, ingredients, result);
-        this.family = family;
-    }
-
-    public ComputerFamily getFamily() {
-        return family;
-    }
-
-    public abstract static class Serializer<T extends ComputerFamilyRecipe> implements RecipeSerializer<T> {
-        protected abstract T create(ResourceLocation identifier, String group, CraftingBookCategory category, int width, int height, NonNullList<Ingredient> ingredients, ItemStack result, ComputerFamily family);
-
-        @Override
-        public T fromJson(ResourceLocation identifier, JsonObject json) {
-            var group = GsonHelper.getAsString(json, "group", "");
-            var category = CraftingBookCategory.CODEC.byName(GsonHelper.getAsString(json, "category", null), CraftingBookCategory.MISC);
-            var family = RecipeUtil.getFamily(json, "family");
-
-            var template = RecipeUtil.getTemplate(json);
-            var result = itemStackFromJson(GsonHelper.getAsJsonObject(json, "result"));
-
-            return create(identifier, group, category, template.width(), template.height(), template.ingredients(), result, family);
-        }
-
-        @Override
-        public T fromNetwork(ResourceLocation identifier, FriendlyByteBuf buf) {
-            var width = buf.readVarInt();
-            var height = buf.readVarInt();
-            var group = buf.readUtf();
-            var category = buf.readEnum(CraftingBookCategory.class);
-
-            var ingredients = NonNullList.withSize(width * height, Ingredient.EMPTY);
-            for (var i = 0; i < ingredients.size(); i++) ingredients.set(i, Ingredient.fromNetwork(buf));
-
-            var result = buf.readItem();
-            var family = buf.readEnum(ComputerFamily.class);
-            return create(identifier, group, category, width, height, ingredients, result, family);
-        }
-
-        @Override
-        public void toNetwork(FriendlyByteBuf buf, T recipe) {
-            buf.writeVarInt(recipe.getWidth());
-            buf.writeVarInt(recipe.getHeight());
-            buf.writeUtf(recipe.getGroup());
-            buf.writeEnum(recipe.category());
-            for (var ingredient : recipe.getIngredients()) ingredient.toNetwork(buf);
-            buf.writeItem(recipe.getResultItem());
-            buf.writeEnum(recipe.getFamily());
-        }
-    }
-}

projects/common/src/main/java/dan200/computercraft/shared/computer/recipe/ComputerUpgradeRecipe.java

@@ -4,35 +4,57 @@
 
 package dan200.computercraft.shared.computer.recipe;
 
+import com.google.gson.JsonObject;
 import dan200.computercraft.shared.ModRegistry;
 import dan200.computercraft.shared.computer.core.ComputerFamily;
 import dan200.computercraft.shared.computer.items.IComputerItem;
-import net.minecraft.core.NonNullList;
+import dan200.computercraft.shared.recipe.ShapedRecipeSpec;
+import net.minecraft.network.FriendlyByteBuf;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.world.item.ItemStack;
-import net.minecraft.world.item.crafting.CraftingBookCategory;
-import net.minecraft.world.item.crafting.Ingredient;
 import net.minecraft.world.item.crafting.RecipeSerializer;
 
-public final class ComputerUpgradeRecipe extends ComputerFamilyRecipe {
+/**
-    private ComputerUpgradeRecipe(ResourceLocation identifier, String group, CraftingBookCategory category, int width, int height, NonNullList<Ingredient> ingredients, ItemStack result, ComputerFamily family) {
+ * A recipe which "upgrades" a {@linkplain IComputerItem computer}, converting it from one {@linkplain ComputerFamily
-        super(identifier, group, category, width, height, ingredients, result, family);
+ * family} to another.
+ */
+public final class ComputerUpgradeRecipe extends ComputerConvertRecipe {
+    private final ComputerFamily family;
+
+    private ComputerUpgradeRecipe(ResourceLocation identifier, ShapedRecipeSpec recipe, ComputerFamily family) {
+        super(identifier, recipe);
+        this.family = family;
     }
 
     @Override
     protected ItemStack convert(IComputerItem item, ItemStack stack) {
-        return item.withFamily(stack, getFamily());
+        return item.withFamily(stack, family);
     }
 
     @Override
-    public RecipeSerializer<?> getSerializer() {
+    public RecipeSerializer<ComputerUpgradeRecipe> getSerializer() {
         return ModRegistry.RecipeSerializers.COMPUTER_UPGRADE.get();
     }
 
-    public static class Serializer extends ComputerFamilyRecipe.Serializer<ComputerUpgradeRecipe> {
+    public static class Serializer implements RecipeSerializer<ComputerUpgradeRecipe> {
         @Override
-        protected ComputerUpgradeRecipe create(ResourceLocation identifier, String group, CraftingBookCategory category, int width, int height, NonNullList<Ingredient> ingredients, ItemStack result, ComputerFamily family) {
+        public ComputerUpgradeRecipe fromJson(ResourceLocation identifier, JsonObject json) {
-            return new ComputerUpgradeRecipe(identifier, group, category, width, height, ingredients, result, family);
+            var recipe = ShapedRecipeSpec.fromJson(json);
+            var family = ComputerFamily.getFamily(json, "family");
+            return new ComputerUpgradeRecipe(identifier, recipe, family);
+        }
+
+        @Override
+        public ComputerUpgradeRecipe fromNetwork(ResourceLocation identifier, FriendlyByteBuf buf) {
+            var recipe = ShapedRecipeSpec.fromNetwork(buf);
+            var family = buf.readEnum(ComputerFamily.class);
+            return new ComputerUpgradeRecipe(identifier, recipe, family);
+        }
+
+        @Override
+        public void toNetwork(FriendlyByteBuf buf, ComputerUpgradeRecipe recipe) {
+            recipe.toSpec().toNetwork(buf);
+            buf.writeEnum(recipe.family);
         }
     }
 }

projects/common/src/main/java/dan200/computercraft/shared/details/ItemDetails.java

@@ -61,7 +61,7 @@ public class ItemDetails {
 
         /*
          * Used to hide some data from ItemStack tooltip.
-         * @see https://minecraft.gamepedia.com/Tutorials/Command_NBT_tags
+         * @see https://minecraft.wiki/w/Tutorials/Command_NBT_tags
          * @see ItemStack#getTooltip
          */
         var hideFlags = tag != null ? tag.getInt("HideFlags") : 0;

projects/common/src/main/java/dan200/computercraft/shared/peripheral/modem/wired/WiredModemLocalPeripheral.java

@@ -4,8 +4,8 @@
 
 package dan200.computercraft.shared.peripheral.modem.wired;
 
+import dan200.computercraft.api.ComputerCraftTags;
 import dan200.computercraft.api.peripheral.IPeripheral;
-import dan200.computercraft.shared.ModRegistry;
 import dan200.computercraft.shared.computer.core.ServerContext;
 import dan200.computercraft.shared.platform.ComponentAccess;
 import dan200.computercraft.shared.platform.PlatformHelper;
@@ -124,8 +124,7 @@ public final class WiredModemLocalPeripheral {
     private IPeripheral getPeripheralFrom(Level world, BlockPos pos, Direction direction) {
         var offset = pos.relative(direction);
 
-        var block = world.getBlockState(offset).getBlock();
+        if (world.getBlockState(offset).is(ComputerCraftTags.Blocks.PERIPHERAL_HUB_IGNORE)) return null;
-        if (block == ModRegistry.Blocks.WIRED_MODEM_FULL.get() || block == ModRegistry.Blocks.CABLE.get()) return null;
 
         var peripheral = peripherals.get((ServerLevel) world, pos, direction);
         return peripheral instanceof WiredModemPeripheral ? null : peripheral;

projects/common/src/main/java/dan200/computercraft/shared/peripheral/monitor/MonitorBlockEntity.java

@@ -349,13 +349,15 @@ public class MonitorBlockEntity extends BlockEntity {
         // Either delete the current monitor or sync a new one.
         if (needsTerminal) {
             if (serverMonitor == null) serverMonitor = new ServerMonitor(advanced, this);
-        } else {
-            serverMonitor = null;
-        }
 
-        // Update the terminal's width and height and rebuild it. This ensures the monitor
+            // Update the terminal's width and height and rebuild it. This ensures the monitor
-        // is consistent when syncing it to other monitors.
+            // is consistent when syncing it to other monitors.
-        if (serverMonitor != null) serverMonitor.rebuild();
+            serverMonitor.rebuild();
+        } else {
+            // Remove the terminal from the serverMonitor, but keep it around - this ensures that we sync
+            // the (now blank) monitor to the client.
+            if (serverMonitor != null) serverMonitor.reset();
+        }
 
         // Update the other monitors, setting coordinates, dimensions and the server terminal
         var pos = getBlockPos();

projects/common/src/main/java/dan200/computercraft/shared/peripheral/monitor/ServerMonitor.java

@@ -55,6 +55,12 @@ public class ServerMonitor {
         }
     }
 
+    synchronized void reset() {
+        if (terminal == null) return;
+        terminal = null;
+        markChanged();
+    }
+
     private void markChanged() {
         if (!changed.getAndSet(true)) TickScheduler.schedule(origin.tickToken);
     }

projects/common/src/main/java/dan200/computercraft/shared/peripheral/speaker/SpeakerPeripheral.java

@@ -188,7 +188,7 @@ public abstract class SpeakerPeripheral implements IPeripheral {
      * {@literal false}.
      * <p>
      * ### Valid instruments
-     * The speaker supports [all of Minecraft's noteblock instruments](https://minecraft.fandom.com/wiki/Note_Block#Instruments).
+     * The speaker supports [all of Minecraft's noteblock instruments](https://minecraft.wiki/w/Note_Block#Instruments).
      * These are:
      * <p>
      * {@code "harp"}, {@code "basedrum"}, {@code "snare"}, {@code "hat"}, {@code "bass"}, {@code "flute"},
@@ -228,7 +228,7 @@ public abstract class SpeakerPeripheral implements IPeripheral {
     /**
      * Plays a Minecraft sound through the speaker.
      * <p>
-     * This takes the [name of a Minecraft sound](https://minecraft.fandom.com/wiki/Sounds.json), such as
+     * This takes the [name of a Minecraft sound](https://minecraft.wiki/w/Sounds.json), such as
      * {@code "minecraft:block.note_block.harp"}, as well as an optional volume and pitch.
      * <p>
      * Only one sound can be played at once. This function will return {@literal false} if another sound was started

projects/common/src/main/java/dan200/computercraft/shared/recipe/CustomShapedRecipe.java

@@ -0,0 +1,86 @@
+// SPDX-FileCopyrightText: 2023 The CC: Tweaked Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+
+package dan200.computercraft.shared.recipe;
+
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParseException;
+import com.mojang.serialization.DataResult;
+import dan200.computercraft.shared.ModRegistry;
+import net.minecraft.Util;
+import net.minecraft.network.FriendlyByteBuf;
+import net.minecraft.resources.ResourceLocation;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.crafting.RecipeSerializer;
+import net.minecraft.world.item.crafting.ShapedRecipe;
+
+/**
+ * A custom version of {@link ShapedRecipe}, which can be converted to and from a {@link ShapedRecipeSpec}.
+ * <p>
+ * This recipe may both be used as a normal recipe (behaving mostly the same as {@link ShapedRecipe}, with
+ * {@linkplain RecipeUtil#itemStackFromJson(JsonObject) support for putting nbt on the result}), or subclassed to
+ * customise the crafting behaviour.
+ */
+public class CustomShapedRecipe extends ShapedRecipe {
+    private final ItemStack result;
+
+    public CustomShapedRecipe(ResourceLocation id, ShapedRecipeSpec recipe) {
+        super(
+            id,
+            recipe.properties().group(), recipe.properties().category(),
+            recipe.template().width(), recipe.template().height(), recipe.template().ingredients(),
+            recipe.result()
+        );
+        this.result = recipe.result();
+    }
+
+    public final ShapedRecipeSpec toSpec() {
+        return new ShapedRecipeSpec(RecipeProperties.of(this), ShapedTemplate.of(this), result);
+    }
+
+    @Override
+    public RecipeSerializer<? extends CustomShapedRecipe> getSerializer() {
+        return ModRegistry.RecipeSerializers.SHAPED.get();
+    }
+
+    public interface Factory<R> {
+        R create(ResourceLocation id, ShapedRecipeSpec recipe);
+    }
+
+    public static <T extends CustomShapedRecipe> RecipeSerializer<T> serialiser(CustomShapedRecipe.Factory<T> factory) {
+        return new Serialiser<>((id, r) -> DataResult.success(factory.create(id, r)));
+    }
+
+    public static <T extends CustomShapedRecipe> RecipeSerializer<T> validatingSerialiser(CustomShapedRecipe.Factory<DataResult<T>> factory) {
+        return new Serialiser<>(factory);
+    }
+
+    private record Serialiser<T extends CustomShapedRecipe>(
+        Factory<DataResult<T>> factory
+    ) implements RecipeSerializer<T> {
+        private Serialiser(Factory<DataResult<T>> factory) {
+            this.factory = (id, r) -> factory.create(id, r).flatMap(x -> {
+                if (x.getSerializer() != this) {
+                    return DataResult.error(() -> "Expected serialiser to be " + this + ", but was " + x.getSerializer());
+                }
+                return DataResult.success(x);
+            });
+        }
+
+        @Override
+        public T fromJson(ResourceLocation id, JsonObject json) {
+            return Util.getOrThrow(factory.create(id, ShapedRecipeSpec.fromJson(json)), JsonParseException::new);
+        }
+
+        @Override
+        public T fromNetwork(ResourceLocation id, FriendlyByteBuf buffer) {
+            return Util.getOrThrow(factory.create(id, ShapedRecipeSpec.fromNetwork(buffer)), IllegalStateException::new);
+        }
+
+        @Override
+        public void toNetwork(FriendlyByteBuf buffer, T recipe) {
+            recipe.toSpec().toNetwork(buffer);
+        }
+    }
+}

projects/common/src/main/java/dan200/computercraft/shared/recipe/CustomShapelessRecipe.java

@@ -0,0 +1,81 @@
+// SPDX-FileCopyrightText: 2023 The CC: Tweaked Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+
+package dan200.computercraft.shared.recipe;
+
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParseException;
+import com.mojang.serialization.DataResult;
+import dan200.computercraft.shared.ModRegistry;
+import net.minecraft.Util;
+import net.minecraft.network.FriendlyByteBuf;
+import net.minecraft.resources.ResourceLocation;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.crafting.RecipeSerializer;
+import net.minecraft.world.item.crafting.ShapelessRecipe;
+
+/**
+ * A custom version of {@link ShapelessRecipe}, which can be converted to and from a {@link ShapelessRecipeSpec}.
+ * <p>
+ * This recipe may both be used as a normal recipe (behaving mostly the same as {@link ShapelessRecipe}, with
+ * {@linkplain RecipeUtil#itemStackFromJson(JsonObject) support for putting nbt on the result}), or subclassed to
+ * customise the crafting behaviour.
+ */
+public class CustomShapelessRecipe extends ShapelessRecipe {
+    private final ItemStack result;
+
+    public CustomShapelessRecipe(ResourceLocation id, ShapelessRecipeSpec recipe) {
+        super(id, recipe.properties().group(), recipe.properties().category(), recipe.result(), recipe.ingredients());
+        this.result = recipe.result();
+    }
+
+    public final ShapelessRecipeSpec toSpec() {
+        return new ShapelessRecipeSpec(RecipeProperties.of(this), getIngredients(), result);
+    }
+
+    @Override
+    public RecipeSerializer<? extends CustomShapelessRecipe> getSerializer() {
+        return ModRegistry.RecipeSerializers.SHAPELESS.get();
+    }
+
+    public interface Factory<R> {
+        R create(ResourceLocation id, ShapelessRecipeSpec recipe);
+    }
+
+    public static <T extends CustomShapelessRecipe> RecipeSerializer<T> serialiser(Factory<T> factory) {
+        return new CustomShapelessRecipe.Serialiser<>((id, r) -> DataResult.success(factory.create(id, r)));
+    }
+
+    public static <T extends CustomShapelessRecipe> RecipeSerializer<T> validatingSerialiser(Factory<DataResult<T>> factory) {
+        return new CustomShapelessRecipe.Serialiser<>(factory);
+    }
+
+    private record Serialiser<T extends CustomShapelessRecipe>(
+        Factory<DataResult<T>> factory
+    ) implements RecipeSerializer<T> {
+        private Serialiser(Factory<DataResult<T>> factory) {
+            this.factory = (id, r) -> factory.create(id, r).flatMap(x -> {
+                if (x.getSerializer() != this) {
+                    return DataResult.error(() -> "Expected serialiser to be " + this + ", but was " + x.getSerializer());
+                }
+                return DataResult.success(x);
+            });
+        }
+
+        @Override
+        public T fromJson(ResourceLocation id, JsonObject json) {
+            return Util.getOrThrow(factory.create(id, ShapelessRecipeSpec.fromJson(json)), JsonParseException::new);
+        }
+
+        @Override
+        public T fromNetwork(ResourceLocation id, FriendlyByteBuf buffer) {
+            return Util.getOrThrow(factory.create(id, ShapelessRecipeSpec.fromNetwork(buffer)), IllegalStateException::new);
+        }
+
+        @Override
+        public void toNetwork(FriendlyByteBuf buffer, T recipe) {
+            recipe.toSpec().toNetwork(buffer);
+        }
+    }
+}

projects/common/src/main/java/dan200/computercraft/shared/recipe/ImpostorShapedRecipe.java

@@ -0,0 +1,41 @@
+// Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
+//
+// SPDX-License-Identifier: LicenseRef-CCPL
+
+package dan200.computercraft.shared.recipe;
+
+import dan200.computercraft.shared.ModRegistry;
+import net.minecraft.core.RegistryAccess;
+import net.minecraft.resources.ResourceLocation;
+import net.minecraft.world.inventory.CraftingContainer;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.crafting.CustomRecipe;
+import net.minecraft.world.item.crafting.RecipeSerializer;
+import net.minecraft.world.item.crafting.ShapedRecipe;
+import net.minecraft.world.level.Level;
+
+/**
+ * A fake {@link ShapedRecipe}, which appears in the recipe book (and other recipe mods), but cannot be crafted.
+ * <p>
+ * This is used to represent examples for our {@link CustomRecipe}s.
+ */
+public final class ImpostorShapedRecipe extends CustomShapedRecipe {
+    public ImpostorShapedRecipe(ResourceLocation id, ShapedRecipeSpec recipe) {
+        super(id, recipe);
+    }
+
+    @Override
+    public boolean matches(CraftingContainer inv, Level world) {
+        return false;
+    }
+
+    @Override
+    public ItemStack assemble(CraftingContainer inventory, RegistryAccess registryAccess) {
+        return ItemStack.EMPTY;
+    }
+
+    @Override
+    public RecipeSerializer<ImpostorShapedRecipe> getSerializer() {
+        return ModRegistry.RecipeSerializers.IMPOSTOR_SHAPED.get();
+    }
+}

projects/common/src/main/java/dan200/computercraft/shared/recipe/ImpostorShapelessRecipe.java

@@ -0,0 +1,41 @@
+// Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
+//
+// SPDX-License-Identifier: LicenseRef-CCPL
+
+package dan200.computercraft.shared.recipe;
+
+import dan200.computercraft.shared.ModRegistry;
+import net.minecraft.core.RegistryAccess;
+import net.minecraft.resources.ResourceLocation;
+import net.minecraft.world.inventory.CraftingContainer;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.crafting.CustomRecipe;
+import net.minecraft.world.item.crafting.RecipeSerializer;
+import net.minecraft.world.item.crafting.ShapelessRecipe;
+import net.minecraft.world.level.Level;
+
+/**
+ * A fake {@link ShapelessRecipe}, which appears in the recipe book (and other recipe mods), but cannot be crafted.
+ * <p>
+ * This is used to represent examples for our {@link CustomRecipe}s.
+ */
+public final class ImpostorShapelessRecipe extends CustomShapelessRecipe {
+    public ImpostorShapelessRecipe(ResourceLocation id, ShapelessRecipeSpec recipe) {
+        super(id, recipe);
+    }
+
+    @Override
+    public boolean matches(CraftingContainer inv, Level world) {
+        return false;
+    }
+
+    @Override
+    public ItemStack assemble(CraftingContainer inventory, RegistryAccess access) {
+        return ItemStack.EMPTY;
+    }
+
+    @Override
+    public RecipeSerializer<ImpostorShapelessRecipe> getSerializer() {
+        return ModRegistry.RecipeSerializers.IMPOSTOR_SHAPELESS.get();
+    }
+}

projects/common/src/main/java/dan200/computercraft/shared/recipe/MoreCodecs.java

@@ -0,0 +1,33 @@
+// SPDX-FileCopyrightText: 2023 The CC: Tweaked Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+
+package dan200.computercraft.shared.recipe;
+
+import com.mojang.brigadier.exceptions.CommandSyntaxException;
+import com.mojang.datafixers.util.Either;
+import com.mojang.serialization.Codec;
+import com.mojang.serialization.DataResult;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.nbt.TagParser;
+
+/**
+ * Additional codecs for working with recipes.
+ */
+public class MoreCodecs {
+    /**
+     * A codec for {@link CompoundTag}s, which either accepts a NBT-string or a JSON object.
+     */
+    public static final Codec<CompoundTag> TAG = Codec.either(Codec.STRING, CompoundTag.CODEC).flatXmap(
+        either -> either.map(MoreCodecs::parseTag, DataResult::success),
+        nbtCompound -> DataResult.success(Either.left(nbtCompound.getAsString()))
+    );
+
+    private static DataResult<CompoundTag> parseTag(String contents) {
+        try {
+            return DataResult.success(TagParser.parseTag(contents));
+        } catch (CommandSyntaxException e) {
+            return DataResult.error(e::getMessage);
+        }
+    }
+}

projects/common/src/main/java/dan200/computercraft/shared/recipe/RecipeProperties.java

@@ -0,0 +1,40 @@
+// SPDX-FileCopyrightText: 2023 The CC: Tweaked Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+
+package dan200.computercraft.shared.recipe;
+
+import com.google.gson.JsonObject;
+import net.minecraft.network.FriendlyByteBuf;
+import net.minecraft.util.GsonHelper;
+import net.minecraft.world.item.crafting.CraftingBookCategory;
+import net.minecraft.world.item.crafting.CraftingRecipe;
+
+/**
+ * Common properties that appear in all {@link CraftingRecipe}s.
+ *
+ * @param group    The (optional) group of the recipe, see {@link CraftingRecipe#getGroup()}.
+ * @param category The category the recipe appears in, see {@link CraftingRecipe#category()}.
+ */
+public record RecipeProperties(String group, CraftingBookCategory category) {
+    public static RecipeProperties of(CraftingRecipe recipe) {
+        return new RecipeProperties(recipe.getGroup(), recipe.category());
+    }
+
+    public static RecipeProperties fromJson(JsonObject json) {
+        var group = GsonHelper.getAsString(json, "group", "");
+        var category = CraftingBookCategory.CODEC.byName(GsonHelper.getAsString(json, "category", null), CraftingBookCategory.MISC);
+        return new RecipeProperties(group, category);
+    }
+
+    public static RecipeProperties fromNetwork(FriendlyByteBuf buffer) {
+        var group = buffer.readUtf();
+        var category = buffer.readEnum(CraftingBookCategory.class);
+        return new RecipeProperties(group, category);
+    }
+
+    public void toNetwork(FriendlyByteBuf buffer) {
+        buffer.writeUtf(group());
+        buffer.writeEnum(category());
+    }
+}

projects/common/src/main/java/dan200/computercraft/shared/recipe/RecipeUtil.java

@@ -0,0 +1,70 @@
+// SPDX-FileCopyrightText: 2017 The CC: Tweaked Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+
+package dan200.computercraft.shared.recipe;
+
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParseException;
+import com.google.gson.JsonSyntaxException;
+import com.mojang.serialization.JsonOps;
+import net.minecraft.Util;
+import net.minecraft.core.NonNullList;
+import net.minecraft.network.FriendlyByteBuf;
+import net.minecraft.util.GsonHelper;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.crafting.Ingredient;
+import net.minecraft.world.item.crafting.ShapedRecipe;
+
+public final class RecipeUtil {
+    private RecipeUtil() {
+    }
+
+    public static NonNullList<Ingredient> readIngredients(FriendlyByteBuf buffer) {
+        return buffer.readCollection(x -> NonNullList.withSize(x, Ingredient.EMPTY), Ingredient::fromNetwork);
+    }
+
+    public static void writeIngredients(FriendlyByteBuf buffer, NonNullList<Ingredient> ingredients) {
+        buffer.writeCollection(ingredients, (a, b) -> b.toNetwork(a));
+    }
+
+    public static NonNullList<Ingredient> readShapelessIngredients(JsonObject json) {
+        NonNullList<Ingredient> ingredients = NonNullList.create();
+
+        var ingredientsList = GsonHelper.getAsJsonArray(json, "ingredients");
+        for (var i = 0; i < ingredientsList.size(); ++i) {
+            var ingredient = Ingredient.fromJson(ingredientsList.get(i));
+            if (!ingredient.isEmpty()) ingredients.add(ingredient);
+        }
+
+        if (ingredients.isEmpty()) throw new JsonParseException("No ingredients for shapeless recipe");
+        if (ingredients.size() > 9) {
+            throw new JsonParseException("Too many ingredients for shapeless recipe the max is 9");
+        }
+
+        return ingredients;
+    }
+
+    /**
+     * Extends {@link ShapedRecipe#itemStackFromJson(JsonObject)} with support for the {@code nbt} field.
+     *
+     * @param json The json to extract the item from.
+     * @return The parsed item stack.
+     */
+    public static ItemStack itemStackFromJson(JsonObject json) {
+        var item = ShapedRecipe.itemFromJson(json);
+        if (json.has("data")) throw new JsonParseException("Disallowed data tag found");
+
+        var count = GsonHelper.getAsInt(json, "count", 1);
+        if (count < 1) throw new JsonSyntaxException("Invalid output count: " + count);
+
+        var stack = new ItemStack(item, count);
+
+        var nbt = json.get("nbt");
+        if (nbt != null) {
+            stack.setTag(Util.getOrThrow(MoreCodecs.TAG.parse(JsonOps.INSTANCE, nbt), JsonParseException::new));
+        }
+        return stack;
+    }
+
+}

projects/common/src/main/java/dan200/computercraft/shared/recipe/ShapedRecipeSpec.java

@@ -0,0 +1,43 @@
+// SPDX-FileCopyrightText: 2023 The CC: Tweaked Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+
+package dan200.computercraft.shared.recipe;
+
+import com.google.gson.JsonObject;
+import net.minecraft.network.FriendlyByteBuf;
+import net.minecraft.util.GsonHelper;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.crafting.ShapedRecipe;
+
+/**
+ * A description of a {@link ShapedRecipe}.
+ * <p>
+ * This is meant to be used in conjunction with {@link CustomShapedRecipe} for more reusable serialisation and
+ * deserialisation of {@link ShapedRecipe}-like recipes.
+ *
+ * @param properties The common properties of this recipe.
+ * @param template   The shaped template of the recipe.
+ * @param result     The result of the recipe.
+ */
+public record ShapedRecipeSpec(RecipeProperties properties, ShapedTemplate template, ItemStack result) {
+    public static ShapedRecipeSpec fromJson(JsonObject json) {
+        var properties = RecipeProperties.fromJson(json);
+        var template = ShapedTemplate.fromJson(json);
+        var result = RecipeUtil.itemStackFromJson(GsonHelper.getAsJsonObject(json, "result"));
+        return new ShapedRecipeSpec(properties, template, result);
+    }
+
+    public static ShapedRecipeSpec fromNetwork(FriendlyByteBuf buffer) {
+        var properties = RecipeProperties.fromNetwork(buffer);
+        var template = ShapedTemplate.fromNetwork(buffer);
+        var result = buffer.readItem();
+        return new ShapedRecipeSpec(properties, template, result);
+    }
+
+    public void toNetwork(FriendlyByteBuf buffer) {
+        properties().toNetwork(buffer);
+        template().toNetwork(buffer);
+        buffer.writeItem(result());
+    }
+}

projects/common/src/main/java/dan200/computercraft/shared/recipe/ShapedTemplate.java

@@ -0,0 +1,99 @@
+// SPDX-FileCopyrightText: 2023 The CC: Tweaked Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+
+package dan200.computercraft.shared.recipe;
+
+import com.google.gson.JsonObject;
+import com.google.gson.JsonSyntaxException;
+import net.minecraft.core.NonNullList;
+import net.minecraft.network.FriendlyByteBuf;
+import net.minecraft.util.GsonHelper;
+import net.minecraft.world.item.crafting.Ingredient;
+import net.minecraft.world.item.crafting.ShapedRecipe;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * The template for {@linkplain ShapedRecipe shaped recipes}. This largely exists for parsing shaped recipes from JSON.
+ *
+ * @param width       The width of the recipe, see {@link ShapedRecipe#getWidth()}.
+ * @param height      The height of the recipe, see {@link ShapedRecipe#getHeight()}.
+ * @param ingredients The ingredients in the recipe, see {@link ShapedRecipe#getIngredients()}
+ */
+public record ShapedTemplate(int width, int height, NonNullList<Ingredient> ingredients) {
+    public static ShapedTemplate of(ShapedRecipe recipe) {
+        return new ShapedTemplate(recipe.getWidth(), recipe.getHeight(), recipe.getIngredients());
+    }
+
+    public static ShapedTemplate fromJson(JsonObject json) {
+        Map<Character, Ingredient> key = new HashMap<>();
+        for (var entry : GsonHelper.getAsJsonObject(json, "key").entrySet()) {
+            if (entry.getKey().length() != 1) {
+                throw new JsonSyntaxException("Invalid key entry: '" + entry.getKey() + "' is an invalid symbol (must be 1 character only).");
+            }
+            if (" ".equals(entry.getKey())) {
+                throw new JsonSyntaxException("Invalid key entry: ' ' is a reserved symbol.");
+            }
+
+            key.put(entry.getKey().charAt(0), Ingredient.fromJson(entry.getValue()));
+        }
+
+        var patternList = GsonHelper.getAsJsonArray(json, "pattern");
+        if (patternList.size() == 0) {
+            throw new JsonSyntaxException("Invalid pattern: empty pattern not allowed");
+        }
+
+        var pattern = new String[patternList.size()];
+        for (var x = 0; x < pattern.length; x++) {
+            var line = GsonHelper.convertToString(patternList.get(x), "pattern[" + x + "]");
+            if (x > 0 && pattern[0].length() != line.length()) {
+                throw new JsonSyntaxException("Invalid pattern: each row must  be the same width");
+            }
+            pattern[x] = line;
+        }
+
+        var width = pattern[0].length();
+        var height = pattern.length;
+        var ingredients = NonNullList.withSize(width * height, Ingredient.EMPTY);
+
+        Set<Character> missingKeys = new HashSet<>(key.keySet());
+
+        var ingredientIdx = 0;
+        for (var line : pattern) {
+            for (var x = 0; x < line.length(); x++) {
+                var chr = line.charAt(x);
+                var ing = chr == ' ' ? Ingredient.EMPTY : key.get(chr);
+                if (ing == null) {
+                    throw new JsonSyntaxException("Pattern references symbol '" + chr + "' but it's not defined in the key");
+                }
+                ingredients.set(ingredientIdx++, ing);
+                missingKeys.remove(chr);
+            }
+        }
+
+        if (!missingKeys.isEmpty()) {
+            throw new JsonSyntaxException("Key defines symbols that aren't used in pattern: " + missingKeys);
+        }
+
+        return new ShapedTemplate(width, height, ingredients);
+    }
+
+    public static ShapedTemplate fromNetwork(FriendlyByteBuf buffer) {
+        var width = buffer.readVarInt();
+        var height = buffer.readVarInt();
+        var ingredients = NonNullList.withSize(width * height, Ingredient.EMPTY);
+        for (var i = 0; i < ingredients.size(); ++i) ingredients.set(i, Ingredient.fromNetwork(buffer));
+        return new ShapedTemplate(width, height, ingredients);
+    }
+
+    public void toNetwork(FriendlyByteBuf buffer) {
+        buffer.writeVarInt(width());
+        buffer.writeVarInt(height());
+        for (var ingredient : ingredients) ingredient.toNetwork(buffer);
+    }
+
+}

projects/common/src/main/java/dan200/computercraft/shared/recipe/ShapelessRecipeSpec.java

@@ -0,0 +1,46 @@
+// SPDX-FileCopyrightText: 2023 The CC: Tweaked Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+
+package dan200.computercraft.shared.recipe;
+
+import com.google.gson.JsonObject;
+import net.minecraft.core.NonNullList;
+import net.minecraft.network.FriendlyByteBuf;
+import net.minecraft.util.GsonHelper;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.crafting.Ingredient;
+import net.minecraft.world.item.crafting.ShapelessRecipe;
+
+/**
+ * A description of a {@link ShapelessRecipe}.
+ * <p>
+ * This is meant to be used in conjunction with {@link CustomShapelessRecipe} for more reusable serialisation and
+ * deserialisation of {@link ShapelessRecipe}-like recipes.
+ *
+ * @param properties  The common properties of this recipe.
+ * @param ingredients The ingredients of the recipe.
+ * @param result      The result of the recipe.
+ */
+public record ShapelessRecipeSpec(RecipeProperties properties, NonNullList<Ingredient> ingredients, ItemStack result) {
+    public static ShapelessRecipeSpec fromJson(JsonObject json) {
+        var properties = RecipeProperties.fromJson(json);
+        var ingredients = RecipeUtil.readShapelessIngredients(json);
+        var result = RecipeUtil.itemStackFromJson(GsonHelper.getAsJsonObject(json, "result"));
+        return new ShapelessRecipeSpec(properties, ingredients, result);
+    }
+
+    public static ShapelessRecipeSpec fromNetwork(FriendlyByteBuf buffer) {
+        var properties = RecipeProperties.fromNetwork(buffer);
+        var ingredients = RecipeUtil.readIngredients(buffer);
+        var result = buffer.readItem();
+
+        return new ShapelessRecipeSpec(properties, ingredients, result);
+    }
+
+    public void toNetwork(FriendlyByteBuf buffer) {
+        properties().toNetwork(buffer);
+        RecipeUtil.writeIngredients(buffer, ingredients());
+        buffer.writeItem(result());
+    }
+}

projects/common/src/main/java/dan200/computercraft/shared/turtle/recipes/TurtleOverlayRecipe.java

@@ -4,32 +4,30 @@
 
 package dan200.computercraft.shared.turtle.recipes;
 
-import com.google.gson.JsonArray;
 import com.google.gson.JsonObject;
-import com.google.gson.JsonParseException;
 import dan200.computercraft.api.turtle.TurtleSide;
 import dan200.computercraft.shared.ModRegistry;
+import dan200.computercraft.shared.recipe.CustomShapelessRecipe;
+import dan200.computercraft.shared.recipe.ShapelessRecipeSpec;
 import dan200.computercraft.shared.turtle.items.TurtleItem;
-import net.minecraft.core.NonNullList;
 import net.minecraft.core.RegistryAccess;
 import net.minecraft.network.FriendlyByteBuf;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.util.GsonHelper;
 import net.minecraft.world.inventory.CraftingContainer;
 import net.minecraft.world.item.ItemStack;
-import net.minecraft.world.item.crafting.*;
+import net.minecraft.world.item.crafting.RecipeSerializer;
+import net.minecraft.world.item.crafting.ShapelessRecipe;
 
 /**
  * A {@link ShapelessRecipe} which sets the {@linkplain TurtleItem#getOverlay(ItemStack)} turtle's overlay} instead.
  */
-public class TurtleOverlayRecipe extends ShapelessRecipe {
+public class TurtleOverlayRecipe extends CustomShapelessRecipe {
     private final ResourceLocation overlay;
-    private final ItemStack result;
 
-    public TurtleOverlayRecipe(ResourceLocation id, String group, CraftingBookCategory category, ItemStack result, NonNullList<Ingredient> ingredients, ResourceLocation overlay) {
+    public TurtleOverlayRecipe(ResourceLocation id, ShapelessRecipeSpec spec, ResourceLocation overlay) {
-        super(id, group, category, result, ingredients);
+        super(id, spec);
         this.overlay = overlay;
-        this.result = result;
     }
 
     private static ItemStack make(ItemStack stack, ResourceLocation overlay) {
@@ -56,63 +54,29 @@ public class TurtleOverlayRecipe extends ShapelessRecipe {
     }
 
     @Override
-    public RecipeSerializer<?> getSerializer() {
+    public RecipeSerializer<TurtleOverlayRecipe> getSerializer() {
         return ModRegistry.RecipeSerializers.TURTLE_OVERLAY.get();
     }
 
     public static class Serializer implements RecipeSerializer<TurtleOverlayRecipe> {
         @Override
         public TurtleOverlayRecipe fromJson(ResourceLocation id, JsonObject json) {
-            var group = GsonHelper.getAsString(json, "group", "");
+            var recipe = ShapelessRecipeSpec.fromJson(json);
-            var category = CraftingBookCategory.CODEC.byName(GsonHelper.getAsString(json, "category", null), CraftingBookCategory.MISC);
-            var ingredients = readIngredients(GsonHelper.getAsJsonArray(json, "ingredients"));
-
-            if (ingredients.isEmpty()) throw new JsonParseException("No ingredients for shapeless recipe");
-            if (ingredients.size() > 9) {
-                throw new JsonParseException("Too many ingredients for shapeless recipe the max is 9");
-            }
-
             var overlay = new ResourceLocation(GsonHelper.getAsString(json, "overlay"));
 
-            // We could derive this from the ingredients, but we want to avoid evaluating the ingredients too early, so
+            return new TurtleOverlayRecipe(id, recipe, overlay);
-            // it's easier to do this.
-            var result = make(ShapedRecipe.itemStackFromJson(GsonHelper.getAsJsonObject(json, "result")), overlay);
-
-            return new TurtleOverlayRecipe(id, group, category, result, ingredients, overlay);
-        }
-
-        private NonNullList<Ingredient> readIngredients(JsonArray arrays) {
-            NonNullList<Ingredient> items = NonNullList.create();
-            for (var i = 0; i < arrays.size(); ++i) {
-                var ingredient = Ingredient.fromJson(arrays.get(i));
-                if (!ingredient.isEmpty()) items.add(ingredient);
-            }
-
-            return items;
         }
 
         @Override
         public TurtleOverlayRecipe fromNetwork(ResourceLocation id, FriendlyByteBuf buffer) {
-            var group = buffer.readUtf();
+            var recipe = ShapelessRecipeSpec.fromNetwork(buffer);
-            var category = buffer.readEnum(CraftingBookCategory.class);
-            var count = buffer.readVarInt();
-            var items = NonNullList.withSize(count, Ingredient.EMPTY);
-
-            for (var j = 0; j < items.size(); j++) items.set(j, Ingredient.fromNetwork(buffer));
-            var result = buffer.readItem();
             var overlay = buffer.readResourceLocation();
-
+            return new TurtleOverlayRecipe(id, recipe, overlay);
-            return new TurtleOverlayRecipe(id, group, category, result, items, overlay);
         }
 
         @Override
         public void toNetwork(FriendlyByteBuf buffer, TurtleOverlayRecipe recipe) {
-            buffer.writeUtf(recipe.getGroup());
+            recipe.toSpec().toNetwork(buffer);
-            buffer.writeEnum(recipe.category());
-            buffer.writeVarInt(recipe.getIngredients().size());
-
-            for (var ingredient : recipe.getIngredients()) ingredient.toNetwork(buffer);
-            buffer.writeItem(recipe.result);
             buffer.writeResourceLocation(recipe.overlay);
         }
     }

projects/common/src/main/java/dan200/computercraft/shared/turtle/recipes/TurtleRecipe.java

@@ -4,26 +4,33 @@
 
 package dan200.computercraft.shared.turtle.recipes;
 
+import com.mojang.serialization.DataResult;
 import dan200.computercraft.shared.ModRegistry;
-import dan200.computercraft.shared.computer.core.ComputerFamily;
 import dan200.computercraft.shared.computer.items.IComputerItem;
-import dan200.computercraft.shared.computer.recipe.ComputerFamilyRecipe;
+import dan200.computercraft.shared.computer.recipe.ComputerConvertRecipe;
+import dan200.computercraft.shared.recipe.ShapedRecipeSpec;
 import dan200.computercraft.shared.turtle.items.TurtleItem;
-import net.minecraft.core.NonNullList;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.world.item.ItemStack;
-import net.minecraft.world.item.crafting.CraftingBookCategory;
-import net.minecraft.world.item.crafting.Ingredient;
 import net.minecraft.world.item.crafting.RecipeSerializer;
 
-public final class TurtleRecipe extends ComputerFamilyRecipe {
+/**
-    public TurtleRecipe(ResourceLocation identifier, String group, CraftingBookCategory category, int width, int height, NonNullList<Ingredient> ingredients, ItemStack result, ComputerFamily family) {
+ * The recipe which crafts a turtle from an existing computer item.
-        super(identifier, group, category, width, height, ingredients, result, family);
+ */
+public final class TurtleRecipe extends ComputerConvertRecipe {
+    private final TurtleItem turtle;
+
+    private TurtleRecipe(ResourceLocation id, ShapedRecipeSpec recipe, TurtleItem turtle) {
+        super(id, recipe);
+        this.turtle = turtle;
     }
 
-    @Override
+    public static DataResult<TurtleRecipe> of(ResourceLocation id, ShapedRecipeSpec recipe) {
-    public RecipeSerializer<?> getSerializer() {
+        if (!(recipe.result().getItem() instanceof TurtleItem turtle)) {
-        return ModRegistry.RecipeSerializers.TURTLE.get();
+            return DataResult.error(() -> recipe.result().getItem() + " is not a turtle item");
+        }
+
+        return DataResult.success(new TurtleRecipe(id, recipe, turtle));
     }
 
     @Override
@@ -31,13 +38,11 @@ public final class TurtleRecipe extends ComputerFamilyRecipe {
         var computerID = item.getComputerID(stack);
         var label = item.getLabel(stack);
 
-        return TurtleItem.create(computerID, label, -1, getFamily(), null, null, 0, null);
+        return turtle.create(computerID, label, -1, null, null, 0, null);
     }
 
-    public static class Serializer extends ComputerFamilyRecipe.Serializer<TurtleRecipe> {
+    @Override
-        @Override
+    public RecipeSerializer<TurtleRecipe> getSerializer() {
-        protected TurtleRecipe create(ResourceLocation identifier, String group, CraftingBookCategory category, int width, int height, NonNullList<Ingredient> ingredients, ItemStack result, ComputerFamily family) {
+        return ModRegistry.RecipeSerializers.TURTLE.get();
-            return new TurtleRecipe(identifier, group, category, width, height, ingredients, result, family);
-        }
     }
 }

projects/common/src/main/java/dan200/computercraft/shared/util/ImpostorRecipe.java

@@ -1,88 +0,0 @@
-// Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
-//
-// SPDX-License-Identifier: LicenseRef-CCPL
-
-package dan200.computercraft.shared.util;
-
-import com.google.gson.JsonObject;
-import dan200.computercraft.shared.ModRegistry;
-import net.minecraft.core.NonNullList;
-import net.minecraft.core.RegistryAccess;
-import net.minecraft.network.FriendlyByteBuf;
-import net.minecraft.resources.ResourceLocation;
-import net.minecraft.util.GsonHelper;
-import net.minecraft.world.inventory.CraftingContainer;
-import net.minecraft.world.item.ItemStack;
-import net.minecraft.world.item.crafting.CraftingBookCategory;
-import net.minecraft.world.item.crafting.Ingredient;
-import net.minecraft.world.item.crafting.RecipeSerializer;
-import net.minecraft.world.item.crafting.ShapedRecipe;
-import net.minecraft.world.level.Level;
-
-public final class ImpostorRecipe extends ShapedRecipe {
-    private final String group;
-    private final ItemStack result;
-
-    private ImpostorRecipe(ResourceLocation id, String group, CraftingBookCategory category, int width, int height, NonNullList<Ingredient> ingredients, ItemStack result) {
-        super(id, group, category, width, height, ingredients, result);
-        this.group = group;
-        this.result = result;
-    }
-
-    @Override
-    public String getGroup() {
-        return group;
-    }
-
-    ItemStack getResultItem() {
-        return result;
-    }
-
-    @Override
-    public boolean matches(CraftingContainer inv, Level world) {
-        return false;
-    }
-
-    @Override
-    public ItemStack assemble(CraftingContainer inventory, RegistryAccess registryAccess) {
-        return ItemStack.EMPTY;
-    }
-
-    @Override
-    public RecipeSerializer<?> getSerializer() {
-        return ModRegistry.RecipeSerializers.IMPOSTOR_SHAPED.get();
-    }
-
-    public static class Serializer implements RecipeSerializer<ImpostorRecipe> {
-        @Override
-        public ImpostorRecipe fromJson(ResourceLocation identifier, JsonObject json) {
-            var group = GsonHelper.getAsString(json, "group", "");
-            var category = CraftingBookCategory.CODEC.byName(GsonHelper.getAsString(json, "category", null), CraftingBookCategory.MISC);
-            var recipe = RecipeSerializer.SHAPED_RECIPE.fromJson(identifier, json);
-            var result = ShapedRecipe.itemStackFromJson(GsonHelper.getAsJsonObject(json, "result"));
-            return new ImpostorRecipe(identifier, group, category, recipe.getWidth(), recipe.getHeight(), recipe.getIngredients(), result);
-        }
-
-        @Override
-        public ImpostorRecipe fromNetwork(ResourceLocation identifier, FriendlyByteBuf buf) {
-            var width = buf.readVarInt();
-            var height = buf.readVarInt();
-            var group = buf.readUtf(Short.MAX_VALUE);
-            var category = buf.readEnum(CraftingBookCategory.class);
-            var items = NonNullList.withSize(width * height, Ingredient.EMPTY);
-            for (var k = 0; k < items.size(); k++) items.set(k, Ingredient.fromNetwork(buf));
-            var result = buf.readItem();
-            return new ImpostorRecipe(identifier, group, category, width, height, items, result);
-        }
-
-        @Override
-        public void toNetwork(FriendlyByteBuf buf, ImpostorRecipe recipe) {
-            buf.writeVarInt(recipe.getWidth());
-            buf.writeVarInt(recipe.getHeight());
-            buf.writeUtf(recipe.getGroup());
-            buf.writeEnum(recipe.category());
-            for (var ingredient : recipe.getIngredients()) ingredient.toNetwork(buf);
-            buf.writeItem(recipe.getResultItem());
-        }
-    }
-}

projects/common/src/main/java/dan200/computercraft/shared/util/ImpostorShapelessRecipe.java

@@ -1,104 +0,0 @@
-// Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
-//
-// SPDX-License-Identifier: LicenseRef-CCPL
-
-package dan200.computercraft.shared.util;
-
-import com.google.gson.JsonArray;
-import com.google.gson.JsonObject;
-import com.google.gson.JsonParseException;
-import dan200.computercraft.shared.ModRegistry;
-import net.minecraft.core.NonNullList;
-import net.minecraft.core.RegistryAccess;
-import net.minecraft.network.FriendlyByteBuf;
-import net.minecraft.resources.ResourceLocation;
-import net.minecraft.util.GsonHelper;
-import net.minecraft.world.inventory.CraftingContainer;
-import net.minecraft.world.item.ItemStack;
-import net.minecraft.world.item.crafting.*;
-import net.minecraft.world.level.Level;
-
-public final class ImpostorShapelessRecipe extends ShapelessRecipe {
-    private final String group;
-    private final ItemStack result;
-
-    private ImpostorShapelessRecipe(ResourceLocation id, String group, CraftingBookCategory category, ItemStack result, NonNullList<Ingredient> ingredients) {
-        super(id, group, category, result, ingredients);
-        this.group = group;
-        this.result = result;
-    }
-
-    @Override
-    public String getGroup() {
-        return group;
-    }
-
-    ItemStack getResultItem() {
-        return result;
-    }
-
-    @Override
-    public boolean matches(CraftingContainer inv, Level world) {
-        return false;
-    }
-
-    @Override
-    public ItemStack assemble(CraftingContainer inventory, RegistryAccess access) {
-        return ItemStack.EMPTY;
-    }
-
-    @Override
-    public RecipeSerializer<?> getSerializer() {
-        return ModRegistry.RecipeSerializers.IMPOSTOR_SHAPELESS.get();
-    }
-
-    public static final class Serializer implements RecipeSerializer<ImpostorShapelessRecipe> {
-        @Override
-        public ImpostorShapelessRecipe fromJson(ResourceLocation id, JsonObject json) {
-            var group = GsonHelper.getAsString(json, "group", "");
-            var category = CraftingBookCategory.CODEC.byName(GsonHelper.getAsString(json, "category", null), CraftingBookCategory.MISC);
-            var ingredients = readIngredients(GsonHelper.getAsJsonArray(json, "ingredients"));
-
-            if (ingredients.isEmpty()) throw new JsonParseException("No ingredients for shapeless recipe");
-            if (ingredients.size() > 9) {
-                throw new JsonParseException("Too many ingredients for shapeless recipe the max is 9");
-            }
-
-            var result = ShapedRecipe.itemStackFromJson(GsonHelper.getAsJsonObject(json, "result"));
-            return new ImpostorShapelessRecipe(id, group, category, result, ingredients);
-        }
-
-        private NonNullList<Ingredient> readIngredients(JsonArray arrays) {
-            NonNullList<Ingredient> items = NonNullList.create();
-            for (var i = 0; i < arrays.size(); ++i) {
-                var ingredient = Ingredient.fromJson(arrays.get(i));
-                if (!ingredient.isEmpty()) items.add(ingredient);
-            }
-
-            return items;
-        }
-
-        @Override
-        public ImpostorShapelessRecipe fromNetwork(ResourceLocation id, FriendlyByteBuf buffer) {
-            var group = buffer.readUtf();
-            var category = buffer.readEnum(CraftingBookCategory.class);
-            var count = buffer.readVarInt();
-            var items = NonNullList.withSize(count, Ingredient.EMPTY);
-
-            for (var j = 0; j < items.size(); j++) items.set(j, Ingredient.fromNetwork(buffer));
-            var result = buffer.readItem();
-
-            return new ImpostorShapelessRecipe(id, group, category, result, items);
-        }
-
-        @Override
-        public void toNetwork(FriendlyByteBuf buffer, ImpostorShapelessRecipe recipe) {
-            buffer.writeUtf(recipe.getGroup());
-            buffer.writeEnum(recipe.category());
-            buffer.writeVarInt(recipe.getIngredients().size());
-
-            for (var ingredient : recipe.getIngredients()) ingredient.toNetwork(buffer);
-            buffer.writeItem(recipe.getResultItem());
-        }
-    }
-}

projects/common/src/main/java/dan200/computercraft/shared/util/RecipeUtil.java

@@ -1,94 +0,0 @@
-// SPDX-FileCopyrightText: 2017 The CC: Tweaked Developers
-//
-// SPDX-License-Identifier: MPL-2.0
-
-package dan200.computercraft.shared.util;
-
-import com.google.common.collect.Maps;
-import com.google.common.collect.Sets;
-import com.google.gson.JsonObject;
-import com.google.gson.JsonSyntaxException;
-import dan200.computercraft.shared.computer.core.ComputerFamily;
-import net.minecraft.core.NonNullList;
-import net.minecraft.util.GsonHelper;
-import net.minecraft.world.item.crafting.Ingredient;
-
-import java.util.Map;
-import java.util.Set;
-
-// TODO: Replace some things with Forge??
-
-public final class RecipeUtil {
-    private RecipeUtil() {
-    }
-
-    public record ShapedTemplate(int width, int height, NonNullList<Ingredient> ingredients) {
-    }
-
-    public static ShapedTemplate getTemplate(JsonObject json) {
-        Map<Character, Ingredient> ingMap = Maps.newHashMap();
-        for (var entry : GsonHelper.getAsJsonObject(json, "key").entrySet()) {
-            if (entry.getKey().length() != 1) {
-                throw new JsonSyntaxException("Invalid key entry: '" + entry.getKey() + "' is an invalid symbol (must be 1 character only).");
-            }
-            if (" ".equals(entry.getKey())) {
-                throw new JsonSyntaxException("Invalid key entry: ' ' is a reserved symbol.");
-            }
-
-            ingMap.put(entry.getKey().charAt(0), Ingredient.fromJson(entry.getValue()));
-        }
-
-        ingMap.put(' ', Ingredient.EMPTY);
-
-        var patternJ = GsonHelper.getAsJsonArray(json, "pattern");
-
-        if (patternJ.size() == 0) {
-            throw new JsonSyntaxException("Invalid pattern: empty pattern not allowed");
-        }
-
-        var pattern = new String[patternJ.size()];
-        for (var x = 0; x < pattern.length; x++) {
-            var line = GsonHelper.convertToString(patternJ.get(x), "pattern[" + x + "]");
-            if (x > 0 && pattern[0].length() != line.length()) {
-                throw new JsonSyntaxException("Invalid pattern: each row must  be the same width");
-            }
-            pattern[x] = line;
-        }
-
-        var width = pattern[0].length();
-        var height = pattern.length;
-        var ingredients = NonNullList.withSize(width * height, Ingredient.EMPTY);
-
-        Set<Character> missingKeys = Sets.newHashSet(ingMap.keySet());
-        missingKeys.remove(' ');
-
-        var ingredientIdx = 0;
-        for (var line : pattern) {
-            for (var i = 0; i < line.length(); i++) {
-                var chr = line.charAt(i);
-
-                var ing = ingMap.get(chr);
-                if (ing == null) {
-                    throw new JsonSyntaxException("Pattern references symbol '" + chr + "' but it's not defined in the key");
-                }
-                ingredients.set(ingredientIdx++, ing);
-                missingKeys.remove(chr);
-            }
-        }
-
-        if (!missingKeys.isEmpty()) {
-            throw new JsonSyntaxException("Key defines symbols that aren't used in pattern: " + missingKeys);
-        }
-
-        return new ShapedTemplate(width, height, ingredients);
-    }
-
-    public static ComputerFamily getFamily(JsonObject json, String name) {
-        var familyName = GsonHelper.getAsString(json, name);
-        for (var family : ComputerFamily.values()) {
-            if (family.name().equalsIgnoreCase(familyName)) return family;
-        }
-
-        throw new JsonSyntaxException("Unknown computer family '" + familyName + "' for field " + name);
-    }
-}

projects/common/src/testMod/kotlin/dan200/computercraft/gametest/Recipe_Test.kt

@@ -4,6 +4,7 @@
 
 package dan200.computercraft.gametest
 
+import com.mojang.authlib.GameProfile
 import dan200.computercraft.gametest.api.Structures
 import dan200.computercraft.gametest.api.sequence
 import dan200.computercraft.shared.ModRegistry
@@ -11,6 +12,7 @@ import net.minecraft.gametest.framework.GameTest
 import net.minecraft.gametest.framework.GameTestAssertException
 import net.minecraft.gametest.framework.GameTestHelper
 import net.minecraft.nbt.CompoundTag
+import net.minecraft.nbt.NbtUtils
 import net.minecraft.world.entity.player.Player
 import net.minecraft.world.inventory.AbstractContainerMenu
 import net.minecraft.world.inventory.MenuType
@@ -41,11 +43,10 @@ class Recipe_Test {
 
             val result = recipe.get().assemble(container, context.level.registryAccess())
 
-            val owner = CompoundTag()
+            val profile = GameProfile(UUID.fromString("f3c8d69b-0776-4512-8434-d1b2165909eb"), "dan200")
-            owner.putString("Name", "dan200")
+
-            owner.putString("Id", "f3c8d69b-0776-4512-8434-d1b2165909eb")
             val tag = CompoundTag()
-            tag.put("SkullOwner", owner)
+            tag.put("SkullOwner", NbtUtils.writeGameProfile(CompoundTag(), profile))
 
             assertEquals(tag, result.tag, "Expected NBT tags to be the same")
         }

projects/core-api/build.gradle.kts

@@ -18,9 +18,7 @@ val docApi by configurations.registering {
 }
 
 dependencies {
-    compileOnlyApi(libs.jsr305)
+    compileOnlyApi(libs.bundles.annotations)
-    compileOnlyApi(libs.checkerFramework)
-    compileOnlyApi(libs.jetbrainsAnnotations)
 
     "docApi"(project(":common-api"))
 }

projects/core-api/src/main/java/dan200/computercraft/api/filesystem/FileAttributes.java

@@ -12,25 +12,30 @@ import java.time.Instant;
 /**
  * A simple version of {@link BasicFileAttributes}, which provides what information a {@link Mount} already exposes.
  *
- * @param isDirectory Whether this filesystem entry is a directory.
+ * @param isDirectory      Whether this filesystem entry is a directory.
- * @param size        The size of the file.
+ * @param size             The size of the file.
+ * @param creationTime     The time the file was created.
+ * @param lastModifiedTime The time the file was last modified.
  */
-public record FileAttributes(boolean isDirectory, long size) implements BasicFileAttributes {
+public record FileAttributes(
+    boolean isDirectory, long size, FileTime creationTime, FileTime lastModifiedTime
+) implements BasicFileAttributes {
     private static final FileTime EPOCH = FileTime.from(Instant.EPOCH);
 
-    @Override
+    /**
-    public FileTime lastModifiedTime() {
+     * Create a new {@link FileAttributes} instance with the {@linkplain #creationTime() creation time} and
-        return EPOCH;
+     * {@linkplain #lastModifiedTime() last modified time} set to the Unix epoch.
+     *
+     * @param isDirectory Whether the filesystem entry is a directory.
+     * @param size        The size of the file.
+     */
+    public FileAttributes(boolean isDirectory, long size) {
+        this(isDirectory, size, EPOCH, EPOCH);
     }
 
     @Override
     public FileTime lastAccessTime() {
-        return EPOCH;
+        return lastModifiedTime();
-    }
-
-    @Override
-    public FileTime creationTime() {
-        return EPOCH;
     }
 
     @Override

projects/core/src/main/java/dan200/computercraft/core/apis/FSAPI.java

@@ -17,7 +17,6 @@ import dan200.computercraft.core.filesystem.FileSystemException;
 import dan200.computercraft.core.metrics.Metrics;
 
 import javax.annotation.Nullable;
-import java.nio.file.attribute.FileTime;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.function.Function;
@@ -488,9 +487,9 @@ public class FSAPI implements ILuaAPI {
         try (var ignored = environment.time(Metrics.FS_OPS)) {
             var attributes = getFileSystem().getAttributes(path);
             Map<String, Object> result = new HashMap<>();
-            result.put("modification", getFileTime(attributes.lastModifiedTime()));
+            result.put("modification", attributes.lastModifiedTime().toMillis());
-            result.put("modified", getFileTime(attributes.lastModifiedTime()));
+            result.put("modified", attributes.lastModifiedTime().toMillis());
-            result.put("created", getFileTime(attributes.creationTime()));
+            result.put("created", attributes.creationTime().toMillis());
             result.put("size", attributes.isDirectory() ? 0 : attributes.size());
             result.put("isDir", attributes.isDirectory());
             result.put("isReadOnly", getFileSystem().isReadOnly(path));
@@ -499,8 +498,4 @@ public class FSAPI implements ILuaAPI {
             throw new LuaException(e.getMessage());
         }
     }
-
-    private static long getFileTime(@Nullable FileTime time) {
-        return time == null ? 0 : time.toMillis();
-    }
 }

projects/core/src/main/java/dan200/computercraft/core/apis/HTTPAPI.java

@@ -12,6 +12,7 @@ import dan200.computercraft.core.CoreConfig;
 import dan200.computercraft.core.apis.http.*;
 import dan200.computercraft.core.apis.http.request.HttpRequest;
 import dan200.computercraft.core.apis.http.websocket.Websocket;
+import dan200.computercraft.core.apis.http.websocket.WebsocketClient;
 import io.netty.handler.codec.http.DefaultHttpHeaders;
 import io.netty.handler.codec.http.HttpHeaderNames;
 import io.netty.handler.codec.http.HttpHeaders;
@@ -165,7 +166,7 @@ public class HTTPAPI implements ILuaAPI {
         var timeout = getTimeout(timeoutArg);
 
         try {
-            var uri = Websocket.checkUri(address);
+            var uri = WebsocketClient.parseUri(address);
             if (!new Websocket(websockets, apiEnvironment, uri, address, headers, timeout).queue(Websocket::connect)) {
                 throw new LuaException("Too many websockets already open");
             }

projects/core/src/main/java/dan200/computercraft/core/apis/RedstoneAPI.java

@@ -49,7 +49,7 @@ import java.util.List;
  * end
  * }</pre>
  * <p>
- * [comparator]: https://minecraft.gamepedia.com/Redstone_Comparator#Subtract_signal_strength "Redstone Comparator on
+ * [comparator]: https://minecraft.wiki/w/Redstone_Comparator#Subtract_signal_strength "Redstone Comparator on
  * the Minecraft wiki."
  * @cc.module redstone
  */

projects/core/src/main/java/dan200/computercraft/core/apis/handles/BinaryReadableHandle.java

@@ -77,12 +77,10 @@ public class BinaryReadableHandle extends HandleGeneric {
                     var buffer = ByteBuffer.allocate(BUFFER_SIZE);
                     var read = channel.read(buffer);
                     if (read < 0) return null;
+                    buffer.flip();
 
                     // If we failed to read "enough" here, let's just abort
-                    if (read >= count || read < BUFFER_SIZE) {
+                    if (read >= count || read < BUFFER_SIZE) return new Object[]{ buffer };
-                        buffer.flip();
-                        return new Object[]{ buffer };
-                    }
 
                     // Build up an array of ByteBuffers. Hopefully this means we can perform less allocation
                     // than doubling up the buffer each time.
@@ -90,11 +88,13 @@ public class BinaryReadableHandle extends HandleGeneric {
                     List<ByteBuffer> parts = new ArrayList<>(4);
                     parts.add(buffer);
                     while (read >= BUFFER_SIZE && totalRead < count) {
-                        buffer = ByteBuffer.allocate(Math.min(BUFFER_SIZE, count - totalRead));
+                        buffer = ByteBuffer.allocateDirect(Math.min(BUFFER_SIZE, count - totalRead));
                         read = channel.read(buffer);
                         if (read < 0) break;
+                        buffer.flip();
 
                         totalRead += read;
+                        assert read == buffer.remaining();
                         parts.add(buffer);
                     }
 
@@ -102,9 +102,11 @@ public class BinaryReadableHandle extends HandleGeneric {
                     var bytes = new byte[totalRead];
                     var pos = 0;
                     for (var part : parts) {
-                        System.arraycopy(part.array(), 0, bytes, pos, part.position());
+                        int length = part.remaining();
-                        pos += part.position();
+                        part.get(bytes, pos, length);
+                        pos += length;
                     }
+                    assert pos == totalRead;
                     return new Object[]{ bytes };
                 }
             } else {

projects/core/src/main/java/dan200/computercraft/core/apis/http/NetworkUtils.java

@@ -134,7 +134,7 @@ public final class NetworkUtils {
      */
     public static Options getOptions(String host, InetSocketAddress address) throws HTTPRequestException {
         var options = AddressRule.apply(CoreConfig.httpRules, host, address);
-        if (options.action == Action.DENY) throw new HTTPRequestException("Domain not permitted");
+        if (options.action() == Action.DENY) throw new HTTPRequestException("Domain not permitted");
         return options;
     }
 
@@ -150,7 +150,7 @@ public final class NetworkUtils {
      * @throws HTTPRequestException If a proxy is required but not configured correctly.
      */
     public static @Nullable Consumer<SocketChannel> getProxyHandler(Options options, int timeout) throws HTTPRequestException {
-        if (!options.useProxy) return null;
+        if (!options.useProxy()) return null;
 
         var type = CoreConfig.httpProxyType;
         var host = CoreConfig.httpProxyHost;

projects/core/src/main/java/dan200/computercraft/core/apis/http/options/Options.java

@@ -6,20 +6,13 @@ package dan200.computercraft.core.apis.http.options;
 
 
 /**
- * Options about a specific domain.
+ * Options for a given HTTP request or websocket, which control its resource constraints.
+ *
+ * @param action           Whether to {@link Action#ALLOW} or {@link Action#DENY} this request.
+ * @param maxUpload        The maximum size of the HTTP request.
+ * @param maxDownload      The maximum size of the HTTP response.
+ * @param websocketMessage The maximum size of a websocket message (outgoing and incoming).
+ * @param useProxy         Whether to use the configured proxy.
  */
-public final class Options {
+public record Options(Action action, long maxUpload, long maxDownload, int websocketMessage, boolean useProxy) {
-    public final Action action;
-    public final long maxUpload;
-    public final long maxDownload;
-    public final int websocketMessage;
-    public final boolean useProxy;
-
-    Options(Action action, long maxUpload, long maxDownload, int websocketMessage, boolean useProxy) {
-        this.action = action;
-        this.maxUpload = maxUpload;
-        this.maxDownload = maxDownload;
-        this.websocketMessage = websocketMessage;
-        this.useProxy = useProxy;
-    }
 }

projects/core/src/main/java/dan200/computercraft/core/apis/http/options/PartialOptions.java

@@ -34,7 +34,7 @@ public final class PartialOptions {
         this.useProxy = useProxy;
     }
 
-    Options toOptions() {
+    public Options toOptions() {
         if (options != null) return options;
 
         return options = new Options(

projects/core/src/main/java/dan200/computercraft/core/apis/http/request/HttpRequest.java

@@ -130,7 +130,7 @@ public class HttpRequest extends Resource<HttpRequest> {
             if (isClosed()) return;
 
             var requestBody = getHeaderSize(headers) + postBuffer.capacity();
-            if (options.maxUpload != 0 && requestBody > options.maxUpload) {
+            if (options.maxUpload() != 0 && requestBody > options.maxUpload()) {
                 failure("Request body is too large");
                 return;
             }

projects/core/src/main/java/dan200/computercraft/core/apis/http/request/HttpRequestHandler.java

@@ -136,7 +136,7 @@ public final class HttpRequestHandler extends SimpleChannelInboundHandler<HttpOb
             var partial = content.content();
             if (partial.isReadable()) {
                 // If we've read more than we're allowed to handle, abort as soon as possible.
-                if (options.maxDownload != 0 && responseBody.readableBytes() + partial.readableBytes() > options.maxDownload) {
+                if (options.maxDownload() != 0 && responseBody.readableBytes() + partial.readableBytes() > options.maxDownload()) {
                     closed = true;
                     ctx.close();
 

projects/core/src/main/java/dan200/computercraft/core/apis/http/websocket/NoOriginWebSocketHandshaker.java

@@ -16,8 +16,8 @@ import java.net.URI;
  * A version of {@link WebSocketClientHandshaker13} which doesn't add the {@link HttpHeaderNames#ORIGIN} header to the
  * original HTTP request.
  */
-public class NoOriginWebSocketHandshaker extends WebSocketClientHandshaker13 {
+class NoOriginWebSocketHandshaker extends WebSocketClientHandshaker13 {
-    public NoOriginWebSocketHandshaker(URI webSocketURL, WebSocketVersion version, String subprotocol, boolean allowExtensions, HttpHeaders customHeaders, int maxFramePayloadLength) {
+    NoOriginWebSocketHandshaker(URI webSocketURL, WebSocketVersion version, String subprotocol, boolean allowExtensions, HttpHeaders customHeaders, int maxFramePayloadLength) {
         super(webSocketURL, version, subprotocol, allowExtensions, customHeaders, maxFramePayloadLength);
     }
 

projects/core/src/main/java/dan200/computercraft/core/apis/http/websocket/Websocket.java

@@ -12,8 +12,9 @@ import dan200.computercraft.core.apis.http.NetworkUtils;
 import dan200.computercraft.core.apis.http.Resource;
 import dan200.computercraft.core.apis.http.ResourceGroup;
 import dan200.computercraft.core.apis.http.options.Options;
-import dan200.computercraft.core.util.IoUtil;
+import dan200.computercraft.core.metrics.Metrics;
 import io.netty.bootstrap.Bootstrap;
+import io.netty.buffer.Unpooled;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelInitializer;
@@ -23,21 +24,22 @@ import io.netty.handler.codec.http.HttpClientCodec;
 import io.netty.handler.codec.http.HttpHeaderNames;
 import io.netty.handler.codec.http.HttpHeaders;
 import io.netty.handler.codec.http.HttpObjectAggregator;
+import io.netty.handler.codec.http.websocketx.BinaryWebSocketFrame;
+import io.netty.handler.codec.http.websocketx.TextWebSocketFrame;
 import io.netty.handler.codec.http.websocketx.WebSocketClientProtocolHandler;
 import io.netty.handler.codec.http.websocketx.WebSocketVersion;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import javax.annotation.Nullable;
-import java.lang.ref.WeakReference;
 import java.net.URI;
-import java.net.URISyntaxException;
+import java.nio.ByteBuffer;
 import java.util.concurrent.Future;
 
 /**
  * Provides functionality to verify and connect to a remote websocket.
  */
-public class Websocket extends Resource<Websocket> {
+public class Websocket extends Resource<Websocket> implements WebsocketClient {
     private static final Logger LOG = LoggerFactory.getLogger(Websocket.class);
 
     /**
@@ -46,14 +48,8 @@ public class Websocket extends Resource<Websocket> {
      */
     public static final int MAX_MESSAGE_SIZE = 1 << 30;
 
-    static final String SUCCESS_EVENT = "websocket_success";
-    static final String FAILURE_EVENT = "websocket_failure";
-    static final String CLOSE_EVENT = "websocket_closed";
-    static final String MESSAGE_EVENT = "websocket_message";
-
     private @Nullable Future<?> executorFuture;
-    private @Nullable ChannelFuture connectFuture;
+    private @Nullable ChannelFuture channelFuture;
-    private @Nullable WeakReference<WebsocketHandle> websocketHandle;
 
     private final IAPIEnvironment environment;
     private final URI uri;
@@ -70,38 +66,6 @@ public class Websocket extends Resource<Websocket> {
         this.timeout = timeout;
     }
 
-    public static URI checkUri(String address) throws HTTPRequestException {
-        URI uri = null;
-        try {
-            uri = new URI(address);
-        } catch (URISyntaxException ignored) {
-            // Fall through to the case below
-        }
-
-        if (uri == null || uri.getHost() == null) {
-            try {
-                uri = new URI("ws://" + address);
-            } catch (URISyntaxException ignored) {
-                // Fall through to the case below
-            }
-        }
-
-        if (uri == null || uri.getHost() == null) throw new HTTPRequestException("URL malformed");
-
-        var scheme = uri.getScheme();
-        if (scheme == null) {
-            try {
-                uri = new URI("ws://" + uri);
-            } catch (URISyntaxException e) {
-                throw new HTTPRequestException("URL malformed");
-            }
-        } else if (!scheme.equalsIgnoreCase("wss") && !scheme.equalsIgnoreCase("ws")) {
-            throw new HTTPRequestException("Invalid scheme '" + scheme + "'");
-        }
-
-        return uri;
-    }
-
     public void connect() {
         if (isClosed()) return;
         executorFuture = NetworkUtils.EXECUTOR.submit(this::doConnect);
@@ -122,7 +86,7 @@ public class Websocket extends Resource<Websocket> {
             // getAddress may have a slight delay, so let's perform another cancellation check.
             if (isClosed()) return;
 
-            connectFuture = new Bootstrap()
+            channelFuture = new Bootstrap()
                 .group(NetworkUtils.LOOP_GROUP)
                 .channel(NioSocketChannel.class)
                 .handler(new ChannelInitializer<SocketChannel>() {
@@ -133,7 +97,7 @@ public class Websocket extends Resource<Websocket> {
                         var subprotocol = headers.get(HttpHeaderNames.SEC_WEBSOCKET_PROTOCOL);
                         var handshaker = new NoOriginWebSocketHandshaker(
                             uri, WebSocketVersion.V13, subprotocol, true, headers,
-                            options.websocketMessage <= 0 ? MAX_MESSAGE_SIZE : options.websocketMessage
+                            options.websocketMessage() <= 0 ? MAX_MESSAGE_SIZE : options.websocketMessage()
                         );
 
                         var p = ch.pipeline();
@@ -162,12 +126,12 @@ public class Websocket extends Resource<Websocket> {
         }
     }
 
-    void success(Channel channel, Options options) {
+    void success(Options options) {
         if (isClosed()) return;
 
-        var handle = new WebsocketHandle(this, options, channel);
+        var handle = new WebsocketHandle(environment, address, this, options);
         environment().queueEvent(SUCCESS_EVENT, address, handle);
-        websocketHandle = createOwnerReference(handle);
+        createOwnerReference(handle);
 
         checkClosed();
     }
@@ -189,19 +153,35 @@ public class Websocket extends Resource<Websocket> {
         super.dispose();
 
         executorFuture = closeFuture(executorFuture);
-        connectFuture = closeChannel(connectFuture);
+        channelFuture = closeChannel(channelFuture);
-
-        var websocketHandleRef = websocketHandle;
-        var websocketHandle = websocketHandleRef == null ? null : websocketHandleRef.get();
-        IoUtil.closeQuietly(websocketHandle);
-        this.websocketHandle = null;
     }
 
-    public IAPIEnvironment environment() {
+    IAPIEnvironment environment() {
         return environment;
     }
 
-    public String address() {
+    String address() {
         return address;
     }
+
+    private @Nullable Channel channel() {
+        var channel = channelFuture;
+        return channel == null ? null : channel.channel();
+    }
+
+    @Override
+    public void sendText(String message) {
+        environment.observe(Metrics.WEBSOCKET_OUTGOING, message.length());
+
+        var channel = channel();
+        if (channel != null) channel.writeAndFlush(new TextWebSocketFrame(message));
+    }
+
+    @Override
+    public void sendBinary(ByteBuffer message) {
+        environment.observe(Metrics.WEBSOCKET_OUTGOING, message.remaining());
+
+        var channel = channel();
+        if (channel != null) channel.writeAndFlush(new BinaryWebSocketFrame(Unpooled.wrappedBuffer(message)));
+    }
 }

projects/core/src/main/java/dan200/computercraft/core/apis/http/websocket/WebsocketClient.java

@@ -0,0 +1,90 @@
+// SPDX-FileCopyrightText: 2023 The CC: Tweaked Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+
+package dan200.computercraft.core.apis.http.websocket;
+
+import dan200.computercraft.core.apis.http.HTTPRequestException;
+
+import java.io.Closeable;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.nio.ByteBuffer;
+
+/**
+ * A client-side websocket, which can be used to send messages to a remote server.
+ * <p>
+ * {@link WebsocketHandle} wraps this into a Lua-compatible interface.
+ */
+public interface WebsocketClient extends Closeable {
+    String SUCCESS_EVENT = "websocket_success";
+    String FAILURE_EVENT = "websocket_failure";
+    String CLOSE_EVENT = "websocket_closed";
+    String MESSAGE_EVENT = "websocket_message";
+
+    /**
+     * Determine whether this websocket is closed.
+     *
+     * @return Whether this websocket is closed.
+     */
+    boolean isClosed();
+
+    /**
+     * Close this websocket.
+     */
+    @Override
+    void close();
+
+    /**
+     * Send a text websocket frame.
+     *
+     * @param message The message to send.
+     */
+    void sendText(String message);
+
+    /**
+     * Send a binary websocket frame.
+     *
+     * @param message The message to send.
+     */
+    void sendBinary(ByteBuffer message);
+
+    /**
+     * Parse an address, ensuring it is a valid websocket URI.
+     *
+     * @param address The address to parse.
+     * @return The parsed URI.
+     * @throws HTTPRequestException If the address is not valid.
+     */
+    static URI parseUri(String address) throws HTTPRequestException {
+        URI uri = null;
+        try {
+            uri = new URI(address);
+        } catch (URISyntaxException ignored) {
+            // Fall through to the case below
+        }
+
+        if (uri == null || uri.getHost() == null) {
+            try {
+                uri = new URI("ws://" + address);
+            } catch (URISyntaxException ignored) {
+                // Fall through to the case below
+            }
+        }
+
+        if (uri == null || uri.getHost() == null) throw new HTTPRequestException("URL malformed");
+
+        var scheme = uri.getScheme();
+        if (scheme == null) {
+            try {
+                uri = new URI("ws://" + uri);
+            } catch (URISyntaxException e) {
+                throw new HTTPRequestException("URL malformed");
+            }
+        } else if (!scheme.equalsIgnoreCase("wss") && !scheme.equalsIgnoreCase("ws")) {
+            throw new HTTPRequestException("Invalid scheme '" + scheme + "'");
+        }
+
+        return uri;
+    }
+}

projects/core/src/main/java/dan200/computercraft/core/apis/http/websocket/WebsocketHandle.java

@@ -6,40 +6,34 @@ package dan200.computercraft.core.apis.http.websocket;
 
 import com.google.common.base.Objects;
 import dan200.computercraft.api.lua.*;
+import dan200.computercraft.core.apis.IAPIEnvironment;
 import dan200.computercraft.core.apis.http.options.Options;
-import dan200.computercraft.core.metrics.Metrics;
-import io.netty.buffer.Unpooled;
-import io.netty.channel.Channel;
-import io.netty.handler.codec.http.websocketx.BinaryWebSocketFrame;
-import io.netty.handler.codec.http.websocketx.TextWebSocketFrame;
 
-import javax.annotation.Nullable;
-import java.io.Closeable;
 import java.util.Arrays;
 import java.util.Optional;
 
 import static dan200.computercraft.api.lua.LuaValues.checkFinite;
 import static dan200.computercraft.core.apis.IAPIEnvironment.TIMER_EVENT;
-import static dan200.computercraft.core.apis.http.websocket.Websocket.CLOSE_EVENT;
+import static dan200.computercraft.core.apis.http.websocket.WebsocketClient.CLOSE_EVENT;
-import static dan200.computercraft.core.apis.http.websocket.Websocket.MESSAGE_EVENT;
+import static dan200.computercraft.core.apis.http.websocket.WebsocketClient.MESSAGE_EVENT;
 
 /**
- * A websocket, which can be used to send an receive messages with a web server.
+ * A websocket, which can be used to send and receive messages with a web server.
  *
  * @cc.module http.Websocket
  * @see dan200.computercraft.core.apis.HTTPAPI#websocket On how to open a websocket.
  */
-public class WebsocketHandle implements Closeable {
+public class WebsocketHandle {
-    private final Websocket websocket;
+    private final IAPIEnvironment environment;
+    private final String address;
+    private final WebsocketClient websocket;
     private final Options options;
-    private boolean closed = false;
 
-    private @Nullable Channel channel;
+    public WebsocketHandle(IAPIEnvironment environment, String address, WebsocketClient websocket, Options options) {
-
+        this.environment = environment;
-    public WebsocketHandle(Websocket websocket, Options options, Channel channel) {
+        this.address = address;
         this.websocket = websocket;
         this.options = options;
-        this.channel = channel;
     }
 
     /**
@@ -58,7 +52,7 @@ public class WebsocketHandle implements Closeable {
     public final MethodResult receive(Optional<Double> timeout) throws LuaException {
         checkOpen();
         var timeoutId = timeout.isPresent()
-            ? websocket.environment().startTimer(Math.round(checkFinite(0, timeout.get()) / 0.05))
+            ? environment.startTimer(Math.round(checkFinite(0, timeout.get()) / 0.05))
             : -1;
 
         return new ReceiveCallback(timeoutId).pull;
@@ -78,17 +72,14 @@ public class WebsocketHandle implements Closeable {
         checkOpen();
 
         var text = message.value();
-        if (options.websocketMessage != 0 && text.length() > options.websocketMessage) {
+        if (options.websocketMessage() != 0 && text.length() > options.websocketMessage()) {
             throw new LuaException("Message is too large");
         }
 
-        websocket.environment().observe(Metrics.WEBSOCKET_OUTGOING, text.length());
+        if (binary.orElse(false)) {
-
+            websocket.sendBinary(LuaValues.encode(text));
-        var channel = this.channel;
+        } else {
-        if (channel != null) {
+            websocket.sendText(text);
-            channel.writeAndFlush(binary.orElse(false)
-                ? new BinaryWebSocketFrame(Unpooled.wrappedBuffer(LuaValues.encode(text)))
-                : new TextWebSocketFrame(text));
         }
     }
 
@@ -96,25 +87,13 @@ public class WebsocketHandle implements Closeable {
      * Close this websocket. This will terminate the connection, meaning messages can no longer be sent or received
      * along it.
      */
-    @LuaFunction("close")
+    @LuaFunction
-    public final void doClose() {
+    public final void close() {
-        close();
         websocket.close();
     }
 
     private void checkOpen() throws LuaException {
-        if (closed) throw new LuaException("attempt to use a closed file");
+        if (websocket.isClosed()) throw new LuaException("attempt to use a closed file");
-    }
-
-    @Override
-    public void close() {
-        closed = true;
-
-        var channel = this.channel;
-        if (channel != null) {
-            channel.close();
-            this.channel = null;
-        }
     }
 
     private final class ReceiveCallback implements ILuaCallback {
@@ -127,9 +106,9 @@ public class WebsocketHandle implements Closeable {
 
         @Override
         public MethodResult resume(Object[] event) {
-            if (event.length >= 3 && Objects.equal(event[0], MESSAGE_EVENT) && Objects.equal(event[1], websocket.address())) {
+            if (event.length >= 3 && Objects.equal(event[0], MESSAGE_EVENT) && Objects.equal(event[1], address)) {
                 return MethodResult.of(Arrays.copyOfRange(event, 2, event.length));
-            } else if (event.length >= 2 && Objects.equal(event[0], CLOSE_EVENT) && Objects.equal(event[1], websocket.address()) && closed) {
+            } else if (event.length >= 2 && Objects.equal(event[0], CLOSE_EVENT) && Objects.equal(event[1], address) && websocket.isClosed()) {
                 // If the socket is closed abort.
                 return MethodResult.of();
             } else if (event.length >= 2 && timeoutId != -1 && Objects.equal(event[0], TIMER_EVENT)

projects/core/src/main/java/dan200/computercraft/core/apis/http/websocket/WebsocketHandler.java

@@ -13,14 +13,14 @@ import io.netty.handler.codec.http.FullHttpResponse;
 import io.netty.handler.codec.http.websocketx.*;
 import io.netty.util.CharsetUtil;
 
-import static dan200.computercraft.core.apis.http.websocket.Websocket.MESSAGE_EVENT;
+import static dan200.computercraft.core.apis.http.websocket.WebsocketClient.MESSAGE_EVENT;
 
-public class WebsocketHandler extends SimpleChannelInboundHandler<Object> {
+class WebsocketHandler extends SimpleChannelInboundHandler<Object> {
     private final Websocket websocket;
     private final Options options;
     private boolean handshakeComplete = false;
 
-    public WebsocketHandler(Websocket websocket, Options options) {
+    WebsocketHandler(Websocket websocket, Options options) {
         this.websocket = websocket;
         this.options = options;
     }
@@ -32,9 +32,9 @@ public class WebsocketHandler extends SimpleChannelInboundHandler<Object> {
     }
 
     @Override
-    public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
+    public void userEventTriggered(ChannelHandlerContext ctx, Object evt) {
         if (evt == WebSocketClientProtocolHandler.ClientHandshakeStateEvent.HANDSHAKE_COMPLETE) {
-            websocket.success(ctx.channel(), options);
+            websocket.success(options);
             handshakeComplete = true;
         } else if (evt == WebSocketClientProtocolHandler.ClientHandshakeStateEvent.HANDSHAKE_TIMEOUT) {
             websocket.failure("Timed out");

projects/core/src/main/java/dan200/computercraft/core/apis/transfer/TransferredFile.java

@@ -2,14 +2,13 @@
 //
 // SPDX-License-Identifier: MPL-2.0
 
-package dan200.computercraft.shared.computer.upload;
+package dan200.computercraft.core.apis.transfer;
 
 import dan200.computercraft.api.lua.LuaFunction;
 import dan200.computercraft.core.apis.handles.BinaryReadableHandle;
-import dan200.computercraft.core.apis.handles.ByteBufferChannel;
 import dan200.computercraft.core.methods.ObjectSource;
 
-import java.nio.ByteBuffer;
+import java.nio.channels.SeekableByteChannel;
 import java.util.Collections;
 import java.util.Optional;
 
@@ -26,9 +25,9 @@ public class TransferredFile implements ObjectSource {
     private final String name;
     private final BinaryReadableHandle handle;
 
-    public TransferredFile(String name, ByteBuffer contents) {
+    public TransferredFile(String name, SeekableByteChannel contents) {
         this.name = name;
-        handle = BinaryReadableHandle.of(new ByteBufferChannel(contents));
+        handle = BinaryReadableHandle.of(contents);
     }
 
     /**

projects/core/src/main/java/dan200/computercraft/core/apis/transfer/TransferredFiles.java

@@ -2,13 +2,9 @@
 //
 // SPDX-License-Identifier: MPL-2.0
 
-package dan200.computercraft.shared.computer.upload;
+package dan200.computercraft.core.apis.transfer;
 
 import dan200.computercraft.api.lua.LuaFunction;
-import dan200.computercraft.shared.network.client.UploadResultMessage;
-import dan200.computercraft.shared.platform.PlatformHelper;
-import net.minecraft.server.level.ServerPlayer;
-import net.minecraft.world.inventory.AbstractContainerMenu;
 
 import java.util.List;
 import java.util.concurrent.atomic.AtomicBoolean;
@@ -19,16 +15,16 @@ import java.util.concurrent.atomic.AtomicBoolean;
  * @cc.module [kind=event] file_transfer.TransferredFiles
  */
 public class TransferredFiles {
-    private final ServerPlayer player;
+    public static final String EVENT = "file_transfer";
-    private final AbstractContainerMenu container;
+
     private final AtomicBoolean consumed = new AtomicBoolean(false);
+    private final Runnable onConsumed;
 
     private final List<TransferredFile> files;
 
-    public TransferredFiles(ServerPlayer player, AbstractContainerMenu container, List<TransferredFile> files) {
+    public TransferredFiles(List<TransferredFile> files, Runnable onConsumed) {
-        this.player = player;
-        this.container = container;
         this.files = files;
+        this.onConsumed = onConsumed;
     }
 
     /**
@@ -44,9 +40,6 @@ public class TransferredFiles {
 
     private void consumed() {
         if (consumed.getAndSet(true)) return;
-
+        onConsumed.run();
-        if (player.isAlive() && player.containerMenu == container) {
-            PlatformHelper.get().sendToPlayer(UploadResultMessage.consumed(container), player);
-        }
     }
 }

projects/core/src/main/java/dan200/computercraft/core/asm/PeripheralMethodSupplier.java

@@ -20,7 +20,7 @@ import java.util.Objects;
  * This is used by {@link ComputerContext} to construct {@linkplain ComputerContext#peripheralMethods() the context-wide
  * method supplier}. It should not be used directly.
  */
-public class PeripheralMethodSupplier {
+public final class PeripheralMethodSupplier {
     private static final Generator<PeripheralMethod> GENERATOR = new Generator<>(PeripheralMethod.class, List.of(ILuaContext.class, IComputerAccess.class),
         m -> (target, context, computer, args) -> {
             var escArgs = args.escapes();
@@ -31,6 +31,9 @@ public class PeripheralMethodSupplier {
         method -> (instance, context, computer, args) -> ((IDynamicPeripheral) instance).callMethod(computer, context, method, args)
     );
 
+    private PeripheralMethodSupplier() {
+    }
+
     public static MethodSupplier<PeripheralMethod> create(List<GenericMethod> genericMethods) {
         return new MethodSupplierImpl<>(genericMethods, GENERATOR, DYNAMIC, x -> x instanceof IDynamicPeripheral dynamic
             ? Objects.requireNonNull(dynamic.getMethodNames(), "Dynamic methods cannot be null")

projects/core/src/main/java/dan200/computercraft/core/filesystem/AbstractInMemoryMount.java

@@ -0,0 +1,146 @@
+// SPDX-FileCopyrightText: 2022 The CC: Tweaked Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+
+package dan200.computercraft.core.filesystem;
+
+import dan200.computercraft.api.filesystem.FileAttributes;
+import dan200.computercraft.api.filesystem.FileOperationException;
+import dan200.computercraft.api.filesystem.Mount;
+
+import javax.annotation.Nullable;
+import java.io.IOException;
+import java.nio.channels.SeekableByteChannel;
+import java.nio.file.attribute.BasicFileAttributes;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.function.Function;
+
+/**
+ * An abstract mount which stores its file tree in memory.
+ *
+ * @param <T> The type of file.
+ */
+public abstract class AbstractInMemoryMount<T extends AbstractInMemoryMount.FileEntry<T>> implements Mount {
+    protected static final String NO_SUCH_FILE = "No such file";
+
+    @Nullable
+    protected T root;
+
+    protected final @Nullable T get(String path) {
+        var lastEntry = root;
+        var lastIndex = 0;
+
+        while (lastEntry != null && lastIndex < path.length()) {
+            var nextIndex = path.indexOf('/', lastIndex);
+            if (nextIndex < 0) nextIndex = path.length();
+
+            lastEntry = lastEntry.children == null ? null : lastEntry.children.get(path.substring(lastIndex, nextIndex));
+            lastIndex = nextIndex + 1;
+        }
+
+        return lastEntry;
+    }
+
+    @Override
+    public final boolean exists(String path) {
+        return get(path) != null;
+    }
+
+    @Override
+    public final boolean isDirectory(String path) {
+        var file = get(path);
+        return file != null && file.isDirectory();
+    }
+
+    @Override
+    public final void list(String path, List<String> contents) throws IOException {
+        var file = get(path);
+        if (file == null || file.children == null) throw new FileOperationException(path, "Not a directory");
+
+        contents.addAll(file.children.keySet());
+    }
+
+    @Override
+    public final long getSize(String path) throws IOException {
+        var file = get(path);
+        if (file == null) throw new FileOperationException(path, NO_SUCH_FILE);
+        return getSize(path, file);
+    }
+
+    /**
+     * Get the size of a file.
+     *
+     * @param path The file path, for error messages.
+     * @param file The file to get the size of.
+     * @return The size of the file. This should be 0 for directories, and equal to {@code openForRead(_).size()} for files.
+     * @throws IOException If the size could not be read.
+     */
+    protected abstract long getSize(String path, T file) throws IOException;
+
+    @Override
+    public final SeekableByteChannel openForRead(String path) throws IOException {
+        var file = get(path);
+        if (file == null || file.isDirectory()) throw new FileOperationException(path, NO_SUCH_FILE);
+        return openForRead(path, file);
+    }
+
+    /**
+     * Open a file for reading.
+     *
+     * @param path The file path, for error messages.
+     * @param file The file to read. This will not be a directory.
+     * @return The channel for this file.
+     */
+    protected abstract SeekableByteChannel openForRead(String path, T file) throws IOException;
+
+    @Override
+    public final BasicFileAttributes getAttributes(String path) throws IOException {
+        var file = get(path);
+        if (file == null) throw new FileOperationException(path, NO_SUCH_FILE);
+        return getAttributes(path, file);
+    }
+
+    /**
+     * Get all attributes of the file.
+     *
+     * @param path The file path, for error messages.
+     * @param file The file to compute attributes for.
+     * @return The file's attributes.
+     * @throws IOException If the attributes could not be read.
+     */
+    protected BasicFileAttributes getAttributes(String path, T file) throws IOException {
+        return new FileAttributes(file.isDirectory(), getSize(path, file));
+    }
+
+    protected T getOrCreateChild(T lastEntry, String localPath, Function<String, T> factory) {
+        var lastIndex = 0;
+        while (lastIndex < localPath.length()) {
+            var nextIndex = localPath.indexOf('/', lastIndex);
+            if (nextIndex < 0) nextIndex = localPath.length();
+
+            var part = localPath.substring(lastIndex, nextIndex);
+            if (lastEntry.children == null) lastEntry.children = new HashMap<>(0);
+
+            var nextEntry = lastEntry.children.get(part);
+            if (nextEntry == null || !nextEntry.isDirectory()) {
+                lastEntry.children.put(part, nextEntry = factory.apply(localPath.substring(0, nextIndex)));
+            }
+
+            lastEntry = nextEntry;
+            lastIndex = nextIndex + 1;
+        }
+
+        return lastEntry;
+    }
+
+    protected static class FileEntry<T extends FileEntry<T>> {
+        @Nullable
+        public Map<String, T> children;
+
+        public boolean isDirectory() {
+            return children != null;
+        }
+    }
+}

projects/core/src/main/java/dan200/computercraft/core/filesystem/ArchiveMount.java

@@ -6,25 +6,21 @@ package dan200.computercraft.core.filesystem;
 
 import com.google.common.cache.Cache;
 import com.google.common.cache.CacheBuilder;
-import dan200.computercraft.api.filesystem.FileAttributes;
-import dan200.computercraft.api.filesystem.FileOperationException;
-import dan200.computercraft.api.filesystem.Mount;
 import dan200.computercraft.core.apis.handles.ArrayByteChannel;
 
-import javax.annotation.Nullable;
 import java.io.IOException;
 import java.nio.channels.SeekableByteChannel;
-import java.nio.file.attribute.BasicFileAttributes;
-import java.util.List;
-import java.util.Map;
 import java.util.concurrent.TimeUnit;
 
 /**
  * An abstract mount based on some archive of files, such as a Zip or Minecraft's resources.
+ * <p>
+ * We assume that we cannot create {@link SeekableByteChannel}s directly from the archive, and so maintain a (shared)
+ * cache of recently read files and their contents.
  *
  * @param <T> The type of file.
  */
-public abstract class ArchiveMount<T extends ArchiveMount.FileEntry<T>> implements Mount {
+public abstract class ArchiveMount<T extends ArchiveMount.FileEntry<T>> extends AbstractInMemoryMount<T> {
     protected static final String NO_SUCH_FILE = "No such file";
 
     /**
@@ -44,128 +40,51 @@ public abstract class ArchiveMount<T extends ArchiveMount.FileEntry<T>> implemen
         .<FileEntry<?>, byte[]>weigher((k, v) -> v.length)
         .build();
 
-    @Nullable
-    protected T root;
-
-    private @Nullable T get(String path) {
-        var lastEntry = root;
-        var lastIndex = 0;
-
-        while (lastEntry != null && lastIndex < path.length()) {
-            var nextIndex = path.indexOf('/', lastIndex);
-            if (nextIndex < 0) nextIndex = path.length();
-
-            lastEntry = lastEntry.children == null ? null : lastEntry.children.get(path.substring(lastIndex, nextIndex));
-            lastIndex = nextIndex + 1;
-        }
-
-        return lastEntry;
-    }
-
     @Override
-    public final boolean exists(String path) {
+    protected final long getSize(String path, T file) throws IOException {
-        return get(path) != null;
-    }
-
-    @Override
-    public final boolean isDirectory(String path) {
-        var file = get(path);
-        return file != null && file.isDirectory();
-    }
-
-    @Override
-    public final void list(String path, List<String> contents) throws IOException {
-        var file = get(path);
-        if (file == null || !file.isDirectory()) throw new FileOperationException(path, "Not a directory");
-
-        file.list(contents);
-    }
-
-    @Override
-    public final long getSize(String path) throws IOException {
-        var file = get(path);
-        if (file == null) throw new FileOperationException(path, NO_SUCH_FILE);
-        return getCachedSize(file);
-    }
-
-    private long getCachedSize(T file) throws IOException {
         if (file.size != -1) return file.size;
         if (file.isDirectory()) return file.size = 0;
 
         var contents = CONTENTS_CACHE.getIfPresent(file);
-        if (contents != null) return file.size = contents.length;
+        return file.size = contents != null ? contents.length : getFileSize(path, file);
-
-        return file.size = getSize(file);
     }
 
     /**
-     * Get the size of a file.
+     * Get the size of the file by reading it (or its metadata) from disk.
-     * <p>
-     * This should only be called once per file, as the result is cached in {@link #getSize(String)}.
      *
-     * @param file The file to compute the size of. This will not be a directory.
+     * @param path The file path, for error messages.
-     * @return The size of the file.
+     * @param file The file to get the size of.
-     * @throws IOException If the size could not be read.
+     * @return The file's size.
+     * @throws IOException If the size could not be computed.
      */
-    protected abstract long getSize(T file) throws IOException;
+    protected long getFileSize(String path, T file) throws IOException {
+        return getContents(path, file).length;
+    }
 
     @Override
-    public SeekableByteChannel openForRead(String path) throws IOException {
+    protected final SeekableByteChannel openForRead(String path, T file) throws IOException {
-        var file = get(path);
+        return new ArrayByteChannel(getContents(path, file));
-        if (file == null || file.isDirectory()) throw new FileOperationException(path, NO_SUCH_FILE);
+    }
 
+    private byte[] getContents(String path, T file) throws IOException {
         var cachedContents = CONTENTS_CACHE.getIfPresent(file);
-        if (cachedContents != null) return new ArrayByteChannel(cachedContents);
+        if (cachedContents != null) return cachedContents;
 
-        var contents = getContents(file);
+        var contents = getFileContents(path, file);
         CONTENTS_CACHE.put(file, contents);
-        return new ArrayByteChannel(contents);
+        return contents;
     }
 
     /**
      * Read the entirety of a file into memory.
      *
+     * @param path The file path, for error messages.
      * @param file The file to read into memory. This will not be a directory.
      * @return The contents of the file.
      */
-    protected abstract byte[] getContents(T file) throws IOException;
+    protected abstract byte[] getFileContents(String path, T file) throws IOException;
-
-    @Override
-    public final BasicFileAttributes getAttributes(String path) throws IOException {
-        var file = get(path);
-        if (file == null) throw new FileOperationException(path, NO_SUCH_FILE);
-
-        return getAttributes(file);
-    }
-
-    /**
-     * Get all attributes of the file.
-     *
-     * @param file The file to compute attributes for. This will not be a directory.
-     * @return The file's attributes.
-     * @throws IOException If the attributes could not be read.
-     */
-    protected BasicFileAttributes getAttributes(T file) throws IOException {
-        return new FileAttributes(file.isDirectory(), getCachedSize(file));
-    }
-
-    protected static class FileEntry<T extends ArchiveMount.FileEntry<T>> {
-        public final String path;
-        @Nullable
-        public Map<String, T> children;
 
+    protected static class FileEntry<T extends FileEntry<T>> extends AbstractInMemoryMount.FileEntry<T> {
         long size = -1;
-
-        protected FileEntry(String path) {
-            this.path = path;
-        }
-
-        protected boolean isDirectory() {
-            return children != null;
-        }
-
-        protected void list(List<String> contents) {
-            if (children != null) contents.addAll(children.keySet());
-        }
     }
 }

projects/core/src/main/java/dan200/computercraft/core/filesystem/JarMount.java

@@ -4,8 +4,8 @@
 
 package dan200.computercraft.core.filesystem;
 
+import dan200.computercraft.api.filesystem.FileAttributes;
 import dan200.computercraft.api.filesystem.FileOperationException;
-import dan200.computercraft.core.util.Nullability;
 
 import javax.annotation.Nullable;
 import java.io.Closeable;
@@ -22,7 +22,7 @@ import java.util.zip.ZipFile;
 /**
  * A mount which reads zip/jar files.
  */
-public class JarMount extends ArchiveMount<JarMount.FileEntry> implements Closeable {
+public final class JarMount extends ArchiveMount<JarMount.FileEntry> implements Closeable {
     private final ZipFile zip;
 
     public JarMount(File jarFile, String subPath) throws IOException {
@@ -42,7 +42,7 @@ public class JarMount extends ArchiveMount<JarMount.FileEntry> implements Closea
         }
 
         // Read in all the entries
-        root = new FileEntry("");
+        var root = this.root = new FileEntry();
         var zipEntries = zip.entries();
         while (zipEntries.hasMoreElements()) {
             var entry = zipEntries.nextElement();
@@ -51,55 +51,33 @@ public class JarMount extends ArchiveMount<JarMount.FileEntry> implements Closea
             if (!entryPath.startsWith(subPath)) continue;
 
             var localPath = FileSystem.toLocal(entryPath, subPath);
-            create(entry, localPath);
+            getOrCreateChild(root, localPath, x -> new FileEntry()).setup(entry);
         }
     }
 
-    private void create(ZipEntry entry, String localPath) {
-        var lastEntry = Nullability.assertNonNull(root);
-
-        var lastIndex = 0;
-        while (lastIndex < localPath.length()) {
-            var nextIndex = localPath.indexOf('/', lastIndex);
-            if (nextIndex < 0) nextIndex = localPath.length();
-
-            var part = localPath.substring(lastIndex, nextIndex);
-            if (lastEntry.children == null) lastEntry.children = new HashMap<>(0);
-
-            var nextEntry = lastEntry.children.get(part);
-            if (nextEntry == null || !nextEntry.isDirectory()) {
-                lastEntry.children.put(part, nextEntry = new FileEntry(localPath.substring(0, nextIndex)));
-            }
-
-            lastEntry = nextEntry;
-            lastIndex = nextIndex + 1;
-        }
-
-        lastEntry.setup(entry);
-    }
-
     @Override
-    protected long getSize(FileEntry file) throws FileOperationException {
+    protected long getFileSize(String path, FileEntry file) throws FileOperationException {
-        if (file.zipEntry == null) throw new FileOperationException(file.path, NO_SUCH_FILE);
+        if (file.zipEntry == null) throw new FileOperationException(path, NO_SUCH_FILE);
         return file.zipEntry.getSize();
     }
 
     @Override
-    protected byte[] getContents(FileEntry file) throws FileOperationException {
+    protected byte[] getFileContents(String path, FileEntry file) throws FileOperationException {
-        if (file.zipEntry == null) throw new FileOperationException(file.path, NO_SUCH_FILE);
+        if (file.zipEntry == null) throw new FileOperationException(path, NO_SUCH_FILE);
 
         try (var stream = zip.getInputStream(file.zipEntry)) {
             return stream.readAllBytes();
         } catch (IOException e) {
             // Mask other IO exceptions as a non-existent file.
-            throw new FileOperationException(file.path, NO_SUCH_FILE);
+            throw new FileOperationException(path, NO_SUCH_FILE);
         }
     }
 
     @Override
-    public BasicFileAttributes getAttributes(FileEntry file) throws FileOperationException {
+    protected BasicFileAttributes getAttributes(String path, FileEntry file) throws IOException {
-        if (file.zipEntry == null) throw new FileOperationException(file.path, NO_SUCH_FILE);
+        return file.zipEntry == null ? super.getAttributes(path, file) : new FileAttributes(
-        return new ZipEntryAttributes(file.zipEntry);
+            file.isDirectory(), getSize(path, file), orEpoch(file.zipEntry.getCreationTime()), orEpoch(file.zipEntry.getLastModifiedTime())
+        );
     }
 
     @Override
@@ -107,79 +85,19 @@ public class JarMount extends ArchiveMount<JarMount.FileEntry> implements Closea
         zip.close();
     }
 
-    protected static class FileEntry extends ArchiveMount.FileEntry<FileEntry> {
+    protected static final class FileEntry extends ArchiveMount.FileEntry<FileEntry> {
         @Nullable
         ZipEntry zipEntry;
 
-        protected FileEntry(String path) {
-            super(path);
-        }
-
         void setup(ZipEntry entry) {
             zipEntry = entry;
-            size = entry.getSize();
             if (children == null && entry.isDirectory()) children = new HashMap<>(0);
         }
     }
 
-    private static class ZipEntryAttributes implements BasicFileAttributes {
+    private static final FileTime EPOCH = FileTime.from(Instant.EPOCH);
-        private final ZipEntry entry;
 
-        ZipEntryAttributes(ZipEntry entry) {
+    private static FileTime orEpoch(@Nullable FileTime time) {
-            this.entry = entry;
+        return time == null ? EPOCH : time;
-        }
-
-        @Override
-        public FileTime lastModifiedTime() {
-            return orEpoch(entry.getLastModifiedTime());
-        }
-
-        @Override
-        public FileTime lastAccessTime() {
-            return orEpoch(entry.getLastAccessTime());
-        }
-
-        @Override
-        public FileTime creationTime() {
-            var time = entry.getCreationTime();
-            return time == null ? lastModifiedTime() : time;
-        }
-
-        @Override
-        public boolean isRegularFile() {
-            return !entry.isDirectory();
-        }
-
-        @Override
-        public boolean isDirectory() {
-            return entry.isDirectory();
-        }
-
-        @Override
-        public boolean isSymbolicLink() {
-            return false;
-        }
-
-        @Override
-        public boolean isOther() {
-            return false;
-        }
-
-        @Override
-        public long size() {
-            return entry.getSize();
-        }
-
-        @Nullable
-        @Override
-        public Object fileKey() {
-            return null;
-        }
-
-        private static final FileTime EPOCH = FileTime.from(Instant.EPOCH);
-
-        private static FileTime orEpoch(@Nullable FileTime time) {
-            return time == null ? EPOCH : time;
-        }
     }
 }

projects/core/src/main/java/dan200/computercraft/core/filesystem/MemoryMount.java

@@ -0,0 +1,334 @@
+// SPDX-FileCopyrightText: 2019 The CC: Tweaked Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+
+package dan200.computercraft.core.filesystem;
+
+import dan200.computercraft.api.filesystem.FileAttributes;
+import dan200.computercraft.api.filesystem.FileOperationException;
+import dan200.computercraft.api.filesystem.Mount;
+import dan200.computercraft.api.filesystem.WritableMount;
+import dan200.computercraft.core.util.Nullability;
+
+import javax.annotation.Nullable;
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.nio.channels.ClosedChannelException;
+import java.nio.channels.SeekableByteChannel;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.AccessDeniedException;
+import java.nio.file.attribute.BasicFileAttributes;
+import java.nio.file.attribute.FileTime;
+import java.time.Instant;
+import java.util.*;
+
+import static dan200.computercraft.core.filesystem.WritableFileMount.MINIMUM_FILE_SIZE;
+
+/**
+ * A basic {@link Mount} which stores files and directories in-memory.
+ */
+public final class MemoryMount extends AbstractInMemoryMount<MemoryMount.FileEntry> implements WritableMount {
+    private static final byte[] EMPTY = new byte[0];
+    private static final FileTime EPOCH = FileTime.from(Instant.EPOCH);
+
+    private final long capacity;
+
+    /**
+     * Create a memory mount with a 1GB capacity.
+     */
+    public MemoryMount() {
+        this(1000_000_000);
+    }
+
+    /**
+     * Create a memory mount with a custom capacity. Note, this is only used in calculations for {@link #getCapacity()}
+     * and {@link #getRemainingSpace()}, it is not checked when creating or writing files.
+     *
+     * @param capacity The capacity of this mount.
+     */
+    public MemoryMount(long capacity) {
+        this.capacity = capacity;
+        root = new FileEntry();
+        root.children = new HashMap<>();
+    }
+
+    public MemoryMount addFile(String file, byte[] contents, FileTime created, FileTime modified) {
+        var entry = getOrCreateChild(Nullability.assertNonNull(root), file, x -> new FileEntry());
+        entry.contents = contents;
+        entry.length = contents.length;
+        entry.created = created;
+        entry.modified = modified;
+        return this;
+    }
+
+    public MemoryMount addFile(String file, String contents, FileTime created, FileTime modified) {
+        return addFile(file, contents.getBytes(StandardCharsets.UTF_8), created, modified);
+    }
+
+    public MemoryMount addFile(String file, byte[] contents) {
+        return addFile(file, contents, EPOCH, EPOCH);
+    }
+
+    public MemoryMount addFile(String file, String contents) {
+        return addFile(file, contents, EPOCH, EPOCH);
+    }
+
+    @Override
+    protected long getSize(String path, FileEntry file) {
+        return file.length;
+    }
+
+    @Override
+    protected SeekableByteChannel openForRead(String path, FileEntry file) throws IOException {
+        if (file.contents == null) throw new FileOperationException(path, "File is a directory");
+        return new EntryChannel(file, 0);
+    }
+
+    @Override
+    protected BasicFileAttributes getAttributes(String path, FileEntry file) throws IOException {
+        return new FileAttributes(file.isDirectory(), file.length, file.created, file.modified);
+    }
+
+    private @Nullable ParentAndName getParentAndName(String path) {
+        if (path.isEmpty()) throw new IllegalArgumentException("Path is empty");
+        var index = path.lastIndexOf('/');
+        if (index == -1) {
+            return new ParentAndName(Nullability.assertNonNull(Nullability.assertNonNull(root).children), path);
+        }
+
+        var entry = get(path.substring(0, index));
+        return entry == null || entry.children == null
+            ? null
+            : new ParentAndName(entry.children, path.substring(index + 1));
+    }
+
+    @Override
+    public void makeDirectory(String path) throws IOException {
+        if (path.isEmpty()) return;
+
+        var lastEntry = Nullability.assertNonNull(root);
+        var lastIndex = 0;
+        while (lastIndex < path.length()) {
+            if (lastEntry.children == null) throw new NullPointerException("children is null");
+
+            var nextIndex = path.indexOf('/', lastIndex);
+            if (nextIndex < 0) nextIndex = path.length();
+
+            var part = path.substring(lastIndex, nextIndex);
+            var nextEntry = lastEntry.children.get(part);
+            if (nextEntry == null) {
+                lastEntry.children.put(part, nextEntry = FileEntry.newDir());
+            } else if (nextEntry.children == null) {
+                throw new FileOperationException(path, "File exists");
+            }
+
+            lastEntry = nextEntry;
+            lastIndex = nextIndex + 1;
+        }
+    }
+
+    @Override
+    public void delete(String path) throws IOException {
+        if (path.isEmpty()) throw new AccessDeniedException("Access denied");
+        var node = getParentAndName(path);
+        if (node != null) node.parent().remove(node.name());
+    }
+
+    @Override
+    public void rename(String source, String dest) throws IOException {
+        if (dest.startsWith(source)) throw new FileOperationException(source, "Cannot move a directory inside itself");
+
+        var sourceParent = getParentAndName(source);
+        if (sourceParent == null || !sourceParent.exists()) throw new FileOperationException(source, "No such file");
+
+        var destParent = getParentAndName(dest);
+        if (destParent == null) throw new FileOperationException(dest, "Parent directory does not exist");
+        if (destParent.exists()) throw new FileOperationException(dest, "File exists");
+
+        destParent.put(sourceParent.parent().remove(sourceParent.name()));
+    }
+
+    private FileEntry getForWrite(String path) throws FileOperationException {
+        if (path.isEmpty()) throw new FileOperationException(path, "Cannot write to directory");
+
+        var parent = getParentAndName(path);
+        if (parent == null) throw new FileOperationException(path, "Parent directory does not exist");
+
+        var file = parent.get();
+        if (file != null && file.isDirectory()) throw new FileOperationException(path, "Cannot write to directory");
+        if (file == null) parent.put(file = FileEntry.newFile());
+
+        return file;
+    }
+
+    @Override
+    public SeekableByteChannel openForWrite(String path) throws IOException {
+        var file = getForWrite(path);
+
+        // Truncate the file.
+        file.contents = EMPTY;
+        file.length = 0;
+        return new EntryChannel(file, 0);
+    }
+
+    @Override
+    public SeekableByteChannel openForAppend(String path) throws IOException {
+        var file = getForWrite(path);
+        return new EntryChannel(file, file.length);
+    }
+
+    @Override
+    public long getRemainingSpace() {
+        return capacity - computeUsedSpace();
+    }
+
+    @Override
+    public long getCapacity() {
+        return capacity;
+    }
+
+    private long computeUsedSpace() {
+        Queue<FileEntry> queue = new ArrayDeque<>();
+        queue.add(root);
+
+        long size = 0;
+
+        FileEntry entry;
+        while ((entry = queue.poll()) != null) {
+            if (entry.children == null) {
+                size += Math.max(MINIMUM_FILE_SIZE, Nullability.assertNonNull(entry.contents).length);
+            } else {
+                size += MINIMUM_FILE_SIZE;
+                queue.addAll(entry.children.values());
+            }
+        }
+
+        return size - MINIMUM_FILE_SIZE; // Subtract one file for the root.
+    }
+
+    protected static final class FileEntry extends AbstractInMemoryMount.FileEntry<FileEntry> {
+        FileTime created = EPOCH;
+        FileTime modified = EPOCH;
+        @Nullable
+        byte[] contents;
+
+        int length;
+
+        static FileEntry newFile() {
+            var entry = new FileEntry();
+            entry.contents = EMPTY;
+            entry.created = entry.modified = FileTime.from(Instant.now());
+            return entry;
+        }
+
+        static FileEntry newDir() {
+            var entry = new FileEntry();
+            entry.children = new HashMap<>();
+            entry.created = entry.modified = FileTime.from(Instant.now());
+            return entry;
+        }
+    }
+
+    private record ParentAndName(Map<String, FileEntry> parent, String name) {
+        boolean exists() {
+            return parent.containsKey(name);
+        }
+
+        @Nullable
+        FileEntry get() {
+            return parent.get(name);
+        }
+
+        void put(FileEntry entry) {
+            assert !parent.containsKey(name);
+            parent.put(name, entry);
+        }
+    }
+
+    private static final class EntryChannel implements SeekableByteChannel {
+        private final FileEntry entry;
+        private long position;
+        private boolean isOpen = true;
+
+        private void checkClosed() throws ClosedChannelException {
+            if (!isOpen()) throw new ClosedChannelException();
+        }
+
+        private EntryChannel(FileEntry entry, int position) {
+            this.entry = entry;
+            this.position = position;
+        }
+
+        @Override
+        public int read(ByteBuffer destination) throws IOException {
+            checkClosed();
+
+            var backing = Nullability.assertNonNull(entry.contents);
+            if (position >= backing.length) return -1;
+
+            var remaining = Math.min(backing.length - (int) position, destination.remaining());
+            destination.put(backing, (int) position, remaining);
+            position += remaining;
+            return remaining;
+        }
+
+        private byte[] ensureCapacity(int capacity) {
+            var contents = Nullability.assertNonNull(entry.contents);
+            if (capacity >= entry.length) {
+                var newCapacity = Math.max(capacity, contents.length << 1);
+                contents = entry.contents = Arrays.copyOf(contents, newCapacity);
+            }
+
+            return contents;
+        }
+
+        @Override
+        public int write(ByteBuffer src) throws IOException {
+            var toWrite = src.remaining();
+            var endPosition = position + toWrite;
+            if (endPosition > 1 << 30) throw new IOException("File is too large");
+
+            var contents = ensureCapacity((int) endPosition);
+            src.get(contents, (int) position, toWrite);
+            position = endPosition;
+            if (endPosition > entry.length) entry.length = (int) endPosition;
+            return toWrite;
+        }
+
+        @Override
+        public long position() throws IOException {
+            checkClosed();
+            return position;
+        }
+
+        @Override
+        public SeekableByteChannel position(long newPosition) throws IOException {
+            checkClosed();
+            if (newPosition < 0) throw new IllegalArgumentException("Position out of bounds");
+            this.position = newPosition;
+            return this;
+        }
+
+        @Override
+        public long size() throws IOException {
+            checkClosed();
+            return entry.length;
+        }
+
+        @Override
+        public SeekableByteChannel truncate(long size) {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        public boolean isOpen() {
+            return isOpen && entry.contents != null;
+        }
+
+        @Override
+        public void close() throws IOException {
+            checkClosed();
+            isOpen = false;
+        }
+    }
+}

projects/core/src/main/java/dan200/computercraft/core/filesystem/WritableFileMount.java

@@ -27,7 +27,7 @@ import java.util.Set;
 public class WritableFileMount extends FileMount implements WritableMount {
     private static final Logger LOG = LoggerFactory.getLogger(WritableFileMount.class);
 
-    private static final long MINIMUM_FILE_SIZE = 500;
+    static final long MINIMUM_FILE_SIZE = 500;
     private static final Set<OpenOption> WRITE_OPTIONS = Sets.newHashSet(StandardOpenOption.WRITE, StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING);
     private static final Set<OpenOption> APPEND_OPTIONS = Sets.newHashSet(StandardOpenOption.WRITE, StandardOpenOption.CREATE, StandardOpenOption.APPEND);
 

projects/core/src/main/resources/data/computercraft/lua/bios.lua

@@ -687,7 +687,7 @@ settings.define("paint.default_extension", {
 
 settings.define("list.show_hidden", {
     default = false,
-    description = [[Show hidden files (those starting with "." in the Lua REPL).]],
+    description = [[Whether the list program show  hidden files (those starting with ".").]],
     type = "boolean",
 })
 

projects/core/src/main/resources/data/computercraft/lua/rom/apis/command/commands.lua

@@ -17,7 +17,7 @@ instance, `commands.say("Hi!")` is equivalent to `commands.exec("say Hi!")`.
 commands. `commands.async.say("Hi!")` is equivalent to
 `commands.execAsync("say Hi!")`.
 
-[mc]: https://minecraft.gamepedia.com/Commands
+[mc]: https://minecraft.wiki/w/Commands
 
 @module commands
 @usage Set the block above this computer to stone:

projects/core/src/main/resources/data/computercraft/lua/rom/apis/disk.lua

@@ -96,7 +96,7 @@ end
 --
 -- If this returns true, you will can [play][`disk.playAudio`] the record.
 --
--- [disk]: https://minecraft.gamepedia.com/Music_Disc
+-- [disk]: https://minecraft.wiki/w/Music_Disc
 --
 -- @tparam string name The name of the disk drive.
 -- @treturn boolean If the disk is present and has audio saved on it.

projects/core/src/main/resources/data/computercraft/lua/rom/apis/textutils.lua

@@ -722,7 +722,7 @@ do
     - `parse_empty_array`: When false, empty arrays will be parsed as a new table.
        By default (or when this value is true), they are parsed as [`empty_json_array`].
 
-    [nbt]: https://minecraft.gamepedia.com/NBT_format
+    [nbt]: https://minecraft.wiki/w/NBT_format
     @return[1] The deserialised object
     @treturn[2] nil If the object could not be deserialised.
     @treturn string A message describing why the JSON string is invalid.

projects/core/src/main/resources/data/computercraft/lua/rom/help/changelog.md

@@ -1,3 +1,12 @@
+# New features in CC: Tweaked 1.108.2
+
+* Add a tag for which blocks wired modems should ignore.
+
+Several bug fixes:
+* Fix monitors sometimes being warped after resizing.
+* Fix the skull recipes using the wrong UUID format.
+* Fix paint canvas not always being redrawn after a term resize.
+
 # New features in CC: Tweaked 1.108.1
 
 Several bug fixes:

projects/core/src/main/resources/data/computercraft/lua/rom/help/commandsapi.txt

@@ -12,4 +12,4 @@ commands.give( "dan200", "minecraft:diamond", 64 )
 This works with any command. Use "commands.async" instead of "commands" to execute asynchronously.
 
 The commands API is only available on Command Computers.
-Visit http://minecraft.gamepedia.com/Commands for documentation on all commands.
+Visit https://minecraft.wiki/w/Commands for documentation on all commands.

projects/core/src/main/resources/data/computercraft/lua/rom/help/keys.txt

@@ -6,4 +6,4 @@ if sEvent == "key" and nKey == keys.enter then
    -- Do something
 end
 
-See http://www.minecraftwiki.net/wiki/Key_codes, or the source code, for a complete reference.
+See https://www.minecraft.wiki/w/Key_codes, or the source code, for a complete reference.

projects/core/src/main/resources/data/computercraft/lua/rom/help/whatsnew.md

@@ -1,7 +1,10 @@
-New features in CC: Tweaked 1.108.1
+New features in CC: Tweaked 1.108.2
+
+* Add a tag for which blocks wired modems should ignore.
 
 Several bug fixes:
-* Prevent no-opped players breaking or placing command computers.
+* Fix monitors sometimes being warped after resizing.
-* Allow using `@LuaFunction`-annotated methods on classes defined in child classloaders.
+* Fix the skull recipes using the wrong UUID format.
+* Fix paint canvas not always being redrawn after a term resize.
 
 Type "help changelog" to see the full version history.

projects/core/src/main/resources/data/computercraft/lua/rom/programs/fun/advanced/paint.lua

@@ -275,6 +275,12 @@ local function drawCanvas()
     end
 end
 
+local function termResize()
+    w, h = term.getSize()
+    drawCanvas()
+    drawInterface()
+end
+
 local menu_choices = {
     Save = function()
         if bReadOnly then
@@ -376,6 +382,8 @@ local function accessMenu()
                 nMenuPosEnd = nMenuPosEnd + 1
                 nMenuPosStart = nMenuPosEnd
             end
+        elseif id == "term_resize" then
+            termResize()
         end
     end
 end
@@ -434,9 +442,7 @@ local function handleEvents()
                 drawInterface()
             end
         elseif id == "term_resize" then
-            w, h = term.getSize()
+            termResize()
-            drawCanvas()
-            drawInterface()
         end
     end
 end

projects/core/src/test/java/dan200/computercraft/core/apis/http/options/AddressRuleTest.java

@@ -23,8 +23,8 @@ public class AddressRuleTest {
             Action.ALLOW.toPartial()
         ));
 
-        assertEquals(apply(rules, "localhost", 8080).action, Action.ALLOW);
+        assertEquals(apply(rules, "localhost", 8080).action(), Action.ALLOW);
-        assertEquals(apply(rules, "localhost", 8081).action, Action.DENY);
+        assertEquals(apply(rules, "localhost", 8081).action(), Action.DENY);
     }
 
     @ParameterizedTest
@@ -43,7 +43,7 @@ public class AddressRuleTest {
         "169.254.169.254", // AWS, Digital Ocean, GCP, etc..
     })
     public void blocksLocalDomains(String domain) {
-        assertEquals(apply(CoreConfig.httpRules, domain, 80).action, Action.DENY);
+        assertEquals(apply(CoreConfig.httpRules, domain, 80).action(), Action.DENY);
     }
 
     @ParameterizedTest
@@ -52,7 +52,7 @@ public class AddressRuleTest {
         "100.63.255.255", "100.128.0.0"
     })
     public void allowsNonLocalDomains(String domain) {
-        assertEquals(apply(CoreConfig.httpRules, domain, 80).action, Action.ALLOW);
+        assertEquals(apply(CoreConfig.httpRules, domain, 80).action(), Action.ALLOW);
     }
 
     private Options apply(Iterable<AddressRule> rules, String host, int port) {

projects/core/src/test/java/dan200/computercraft/core/computer/ComputerBootstrap.java

@@ -12,10 +12,9 @@ import dan200.computercraft.api.lua.LuaFunction;
 import dan200.computercraft.core.ComputerContext;
 import dan200.computercraft.core.computer.mainthread.MainThread;
 import dan200.computercraft.core.computer.mainthread.MainThreadConfig;
+import dan200.computercraft.core.filesystem.MemoryMount;
 import dan200.computercraft.core.terminal.Terminal;
 import dan200.computercraft.test.core.computer.BasicEnvironment;
-import dan200.computercraft.test.core.filesystem.MemoryMount;
-import dan200.computercraft.test.core.filesystem.ReadOnlyWritableMount;
 import org.junit.jupiter.api.Assertions;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -37,7 +36,7 @@ public class ComputerBootstrap {
             .addFile("test.lua", program)
             .addFile("startup.lua", "assertion.assert(pcall(loadfile('test.lua', nil, _ENV))) os.shutdown()");
 
-        run(new ReadOnlyWritableMount(mount), setup, maxTimes);
+        run(mount, setup, maxTimes);
     }
 
     public static void run(String program, int maxTimes) {

projects/core/src/test/java/dan200/computercraft/core/filesystem/MemoryMountTest.java

@@ -0,0 +1,46 @@
+// SPDX-FileCopyrightText: 2023 The CC: Tweaked Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+
+package dan200.computercraft.core.filesystem;
+
+import dan200.computercraft.api.filesystem.Mount;
+import dan200.computercraft.api.filesystem.WritableMount;
+import dan200.computercraft.test.core.filesystem.MountContract;
+import dan200.computercraft.test.core.filesystem.WritableMountContract;
+import org.opentest4j.TestAbortedException;
+
+public class MemoryMountTest implements MountContract, WritableMountContract {
+    @Override
+    public Mount createSkeleton() {
+        var mount = new MemoryMount();
+        mount.addFile("f.lua", "");
+        mount.addFile("dir/file.lua", "print('testing')", EPOCH, MODIFY_TIME);
+        return mount;
+    }
+
+    @Override
+    public MountAccess createMount(long capacity) {
+        var mount = new MemoryMount(capacity);
+        return new MountAccess() {
+            @Override
+            public WritableMount mount() {
+                return mount;
+            }
+
+            @Override
+            public void makeReadOnly(String path) {
+                throw new TestAbortedException("Not supported for MemoryMount");
+            }
+
+            @Override
+            public void ensuresExist() {
+            }
+
+            @Override
+            public long computeRemainingSpace() {
+                return mount.getRemainingSpace();
+            }
+        };
+    }
+}

projects/core/src/test/kotlin/dan200/computercraft/core/apis/http/HttpServer.kt

@@ -27,7 +27,7 @@ object HttpServer {
     const val URL: String = "http://127.0.0.1:$PORT"
     const val WS_URL: String = "ws://127.0.0.1:$PORT/ws"
 
-    fun runServer(run: () -> Unit) {
+    fun runServer(run: (stop: () -> Unit) -> Unit) {
         val workerGroup: EventLoopGroup = NioEventLoopGroup(2)
         try {
             val ch = ServerBootstrap()
@@ -48,7 +48,7 @@ object HttpServer {
                     },
                 ).bind(PORT).sync().channel()
             try {
-                run()
+                run { workerGroup.shutdownGracefully() }
             } finally {
                 ch.close().sync()
             }

projects/core/src/test/kotlin/dan200/computercraft/core/apis/http/TestHttpApi.kt

@@ -5,6 +5,7 @@
 package dan200.computercraft.core.apis.http
 
 import dan200.computercraft.api.lua.Coerced
+import dan200.computercraft.api.lua.LuaException
 import dan200.computercraft.api.lua.ObjectArguments
 import dan200.computercraft.core.CoreConfig
 import dan200.computercraft.core.apis.HTTPAPI
@@ -22,7 +23,9 @@ import org.hamcrest.Matchers.*
 import org.junit.jupiter.api.AfterAll
 import org.junit.jupiter.api.BeforeAll
 import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.assertThrows
 import java.util.*
+import kotlin.time.Duration.Companion.milliseconds
 
 class TestHttpApi {
     companion object {
@@ -79,12 +82,36 @@ class TestHttpApi {
 
                 websocket.close()
 
+                val closeEvent = pullEventOrTimeout(500.milliseconds, "websocket_closed")
+                assertThat("No event was queued", closeEvent, equalTo(null))
+            }
+        }
+    }
+
+    @Test
+    fun `Queues an event when the socket is externally closed`() {
+        runServer { stop ->
+            LuaTaskRunner.runTest {
+                val httpApi = addApi(HTTPAPI(environment))
+                assertThat("http.websocket succeeded", httpApi.websocket(ObjectArguments(WS_URL)), array(equalTo(true)))
+
+                val connectEvent = pullEvent()
+                assertThat(connectEvent, array(equalTo("websocket_success"), equalTo(WS_URL), isA(WebsocketHandle::class.java)))
+
+                val websocket = connectEvent[2] as WebsocketHandle
+
+                stop()
+
                 val closeEvent = pullEvent("websocket_closed")
                 assertThat(
                     "Websocket was closed",
                     closeEvent,
                     array(equalTo("websocket_closed"), equalTo(WS_URL), equalTo("Connection closed"), equalTo(null)),
                 )
+
+                assertThrows<LuaException>("Throws an exception when sending") {
+                    websocket.send(Coerced("hello"), Optional.of(false))
+                }
             }
         }
     }

projects/core/src/testFixtures/java/dan200/computercraft/test/core/CloseScope.java

@@ -10,10 +10,10 @@ import java.util.Deque;
 import java.util.Objects;
 
 /**
- * An {@link AutoCloseable} implementation which can be used to combine other [AutoCloseable] instances.
+ * An {@link AutoCloseable} implementation which can be used to combine other {@link AutoCloseable} instances.
  * <p>
- * Values which implement {@link AutoCloseable} can be dynamically registered with [CloseScope.add]. When the scope is
+ * Values which implement {@link AutoCloseable} can be dynamically registered with {@link CloseScope#add(AutoCloseable)}.
- * closed, each value is closed in the opposite order.
+ * When the scope is closed, each value is closed in the opposite order.
  * <p>
  * This is largely intended for cases where it's not appropriate to nest try-with-resources blocks, for instance when
  * nested would be too deep or when objects are dynamically created.

projects/core/src/testFixtures/java/dan200/computercraft/test/core/ReplaceUnderscoresDisplayNameGenerator.java

@@ -0,0 +1,23 @@
+// SPDX-FileCopyrightText: 2023 The CC: Tweaked Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+
+package dan200.computercraft.test.core;
+
+import org.junit.jupiter.api.DisplayNameGeneration;
+import org.junit.jupiter.api.DisplayNameGenerator;
+
+import java.lang.reflect.Method;
+
+/**
+ * A {@link DisplayNameGenerator} which replaces underscores with spaces. This is equivalent to
+ * {@link DisplayNameGenerator.ReplaceUnderscores}, but excludes the parameter types.
+ *
+ * @see DisplayNameGeneration
+ */
+public class ReplaceUnderscoresDisplayNameGenerator extends DisplayNameGenerator.ReplaceUnderscores {
+    @Override
+    public String generateDisplayNameForMethod(Class<?> testClass, Method testMethod) {
+        return testMethod.getName().replace('_', ' ');
+    }
+}

projects/core/src/testFixtures/java/dan200/computercraft/test/core/computer/BasicEnvironment.java

@@ -11,10 +11,9 @@ import dan200.computercraft.core.computer.ComputerEnvironment;
 import dan200.computercraft.core.computer.GlobalEnvironment;
 import dan200.computercraft.core.filesystem.FileMount;
 import dan200.computercraft.core.filesystem.JarMount;
+import dan200.computercraft.core.filesystem.MemoryMount;
 import dan200.computercraft.core.metrics.Metric;
 import dan200.computercraft.core.metrics.MetricsObserver;
-import dan200.computercraft.test.core.filesystem.MemoryMount;
-import dan200.computercraft.test.core.filesystem.ReadOnlyWritableMount;
 
 import java.io.File;
 import java.io.IOException;
@@ -32,7 +31,7 @@ public class BasicEnvironment implements ComputerEnvironment, GlobalEnvironment,
     private final WritableMount mount;
 
     public BasicEnvironment() {
-        this(new ReadOnlyWritableMount(new MemoryMount()));
+        this(new MemoryMount());
     }
 
     public BasicEnvironment(WritableMount mount) {

projects/core/src/testFixtures/java/dan200/computercraft/test/core/filesystem/MemoryMount.java

@@ -1,59 +0,0 @@
-// SPDX-FileCopyrightText: 2019 The CC: Tweaked Developers
-//
-// SPDX-License-Identifier: MPL-2.0
-
-package dan200.computercraft.test.core.filesystem;
-
-import dan200.computercraft.api.filesystem.FileOperationException;
-import dan200.computercraft.api.filesystem.Mount;
-import dan200.computercraft.core.apis.handles.ArrayByteChannel;
-
-import java.nio.channels.SeekableByteChannel;
-import java.nio.charset.StandardCharsets;
-import java.util.*;
-
-/**
- * A read-only mount {@link Mount} which provides a list of in-memory set of files.
- */
-public class MemoryMount implements Mount {
-    private final Map<String, byte[]> files = new HashMap<>();
-    private final Set<String> directories = new HashSet<>();
-
-    public MemoryMount() {
-        directories.add("");
-    }
-
-    @Override
-    public boolean exists(String path) {
-        return files.containsKey(path) || directories.contains(path);
-    }
-
-    @Override
-    public boolean isDirectory(String path) {
-        return directories.contains(path);
-    }
-
-    @Override
-    public void list(String path, List<String> files) {
-        for (var file : this.files.keySet()) {
-            if (file.startsWith(path)) files.add(file.substring(path.length() + 1));
-        }
-    }
-
-    @Override
-    public long getSize(String path) {
-        throw new RuntimeException("Not implemented");
-    }
-
-    @Override
-    public SeekableByteChannel openForRead(String path) throws FileOperationException {
-        var file = files.get(path);
-        if (file == null) throw new FileOperationException(path, "File not found");
-        return new ArrayByteChannel(file);
-    }
-
-    public MemoryMount addFile(String file, String contents) {
-        files.put(file, contents.getBytes(StandardCharsets.UTF_8));
-        return this;
-    }
-}

projects/core/src/testFixtures/java/dan200/computercraft/test/core/filesystem/MountContract.java

@@ -34,7 +34,10 @@ public interface MountContract {
      * Create a skeleton mount. This should contain the following files:
      *
      * <ul>
-     *     <li>{@code dir/file.lua}, containing {@code print('testing')}.</li>
+     *     <li>
+     *         {@code dir/file.lua}, containing {@code print('testing')}. If {@linkplain #hasFileTimes() file times are
+     *         supported}, it should have a modification time of {@link #MODIFY_TIME}.
+     *     </li>
      *     <li>{@code f.lua}, containing nothing.</li>
      * </ul>
      *

projects/core/src/testFixtures/java/dan200/computercraft/test/core/filesystem/Mounts.java

@@ -0,0 +1,33 @@
+// SPDX-FileCopyrightText: 2023 The CC: Tweaked Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+
+package dan200.computercraft.test.core.filesystem;
+
+import dan200.computercraft.api.filesystem.WritableMount;
+
+import java.io.IOException;
+import java.nio.channels.Channels;
+import java.nio.charset.StandardCharsets;
+
+/**
+ * Utility functions for working with mounts.
+ */
+public final class Mounts {
+    private Mounts() {
+    }
+
+    /**
+     * Write a file to this mount.
+     *
+     * @param mount    The mount to modify.
+     * @param path     The path to write to.
+     * @param contents The contents of this path.
+     * @throws IOException If writing fails.
+     */
+    public static void writeFile(WritableMount mount, String path, String contents) throws IOException {
+        try (var handle = Channels.newWriter(mount.openForWrite(path), StandardCharsets.UTF_8)) {
+            handle.write(contents);
+        }
+    }
+}

projects/core/src/testFixtures/java/dan200/computercraft/test/core/filesystem/ReadOnlyWritableMount.java

@@ -1,91 +0,0 @@
-// SPDX-FileCopyrightText: 2022 The CC: Tweaked Developers
-//
-// SPDX-License-Identifier: MPL-2.0
-
-package dan200.computercraft.test.core.filesystem;
-
-import dan200.computercraft.api.filesystem.FileOperationException;
-import dan200.computercraft.api.filesystem.Mount;
-import dan200.computercraft.api.filesystem.WritableMount;
-
-import java.io.IOException;
-import java.nio.channels.SeekableByteChannel;
-import java.nio.file.attribute.BasicFileAttributes;
-import java.util.List;
-
-/**
- * Wraps a {@link Mount} into a read-only {@link WritableMount}.
- *
- * @param mount The original read-only mount we're wrapping.
- */
-public record ReadOnlyWritableMount(Mount mount) implements WritableMount {
-    @Override
-    public boolean exists(String path) throws IOException {
-        return mount.exists(path);
-    }
-
-    @Override
-    public boolean isDirectory(String path) throws IOException {
-        return mount.isDirectory(path);
-    }
-
-    @Override
-    public void list(String path, List<String> contents) throws IOException {
-        mount.list(path, contents);
-    }
-
-    @Override
-    public long getSize(String path) throws IOException {
-        return mount.getSize(path);
-    }
-
-    @Override
-    public SeekableByteChannel openForRead(String path) throws IOException {
-        return mount.openForRead(path);
-    }
-
-    @Override
-    public BasicFileAttributes getAttributes(String path) throws IOException {
-        return mount.getAttributes(path);
-    }
-
-    @Override
-    public void makeDirectory(String path) throws IOException {
-        throw new FileOperationException(path, "Access denied");
-    }
-
-    @Override
-    public void delete(String path) throws IOException {
-        throw new FileOperationException(path, "Access denied");
-    }
-
-    @Override
-    public void rename(String source, String dest) throws IOException {
-        throw new FileOperationException(source, "Access denied");
-    }
-
-    @Override
-    public SeekableByteChannel openForWrite(String path) throws IOException {
-        throw new FileOperationException(path, "Access denied");
-    }
-
-    @Override
-    public SeekableByteChannel openForAppend(String path) throws IOException {
-        throw new FileOperationException(path, "Access denied");
-    }
-
-    @Override
-    public long getRemainingSpace() {
-        return Integer.MAX_VALUE;
-    }
-
-    @Override
-    public long getCapacity() {
-        return Integer.MAX_VALUE;
-    }
-
-    @Override
-    public boolean isReadOnly(String path) {
-        return true;
-    }
-}

projects/core/src/testFixtures/java/dan200/computercraft/test/core/filesystem/WritableMountContract.java

@@ -5,10 +5,16 @@
 package dan200.computercraft.test.core.filesystem;
 
 import dan200.computercraft.api.filesystem.WritableMount;
+import dan200.computercraft.api.lua.LuaValues;
+import dan200.computercraft.test.core.ReplaceUnderscoresDisplayNameGenerator;
+import org.junit.jupiter.api.DisplayNameGeneration;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.MethodSource;
 import org.opentest4j.TestAbortedException;
 
 import java.io.IOException;
+import java.util.stream.Stream;
 
 import static org.junit.jupiter.api.Assertions.*;
 
@@ -17,9 +23,16 @@ import static org.junit.jupiter.api.Assertions.*;
  *
  * @see MountContract
  */
+@DisplayNameGeneration(ReplaceUnderscoresDisplayNameGenerator.class)
 public interface WritableMountContract {
     long CAPACITY = 1_000_000;
 
+    String LONG_CONTENTS = "This is some example text.\n".repeat(100);
+
+    static Stream<String> fileContents() {
+        return Stream.of("", LONG_CONTENTS);
+    }
+
     /**
      * Create a new empty mount.
      *
@@ -43,18 +56,30 @@ public interface WritableMountContract {
     }
 
     @Test
-    default void testRootWritable() throws IOException {
+    default void Root_is_writable() throws IOException {
         assertFalse(createExisting(CAPACITY).mount().isReadOnly("/"));
         assertFalse(createMount(CAPACITY).mount().isReadOnly("/"));
     }
 
     @Test
-    default void testMissingDirWritable() throws IOException {
+    default void Missing_dir_is_writable() throws IOException {
         assertFalse(createExisting(CAPACITY).mount().isReadOnly("/foo/bar/baz/qux"));
     }
 
     @Test
-    default void testDirReadOnly() throws IOException {
+    default void Make_directory_recursive() throws IOException {
+        var access = createMount(CAPACITY);
+        var mount = access.mount();
+        mount.makeDirectory("a/b/c");
+
+        assertTrue(mount.isDirectory("a/b/c"));
+
+        assertEquals(CAPACITY - 500 * 3, mount.getRemainingSpace());
+        assertEquals(access.computeRemainingSpace(), access.mount().getRemainingSpace(), "Free space is inconsistent");
+    }
+
+    @Test
+    default void Can_make_read_only() throws IOException {
         var root = createMount(CAPACITY);
         var mount = root.mount();
         mount.makeDirectory("read-only");
@@ -66,18 +91,97 @@ public interface WritableMountContract {
     }
 
     @Test
-    default void testMovePreservesSpace() throws IOException {
+    default void Initial_free_space_and_capacity() throws IOException {
+        var mount = createExisting(CAPACITY).mount();
+        assertEquals(CAPACITY, mount.getCapacity());
+        assertEquals(CAPACITY, mount.getRemainingSpace());
+    }
+
+    @Test
+    default void Write_updates_size_and_free_space() throws IOException {
         var access = createExisting(CAPACITY);
         var mount = access.mount();
-        mount.openForWrite("foo").close();
+
+        Mounts.writeFile(mount, "hello.txt", LONG_CONTENTS);
+        assertEquals(LONG_CONTENTS.length(), mount.getSize("hello.txt"));
+        assertEquals(CAPACITY - LONG_CONTENTS.length(), mount.getRemainingSpace());
+
+        Mounts.writeFile(mount, "hello.txt", "");
+        assertEquals(0, mount.getSize("hello.txt"));
+        assertEquals(CAPACITY - 500, mount.getRemainingSpace());
+        assertEquals(access.computeRemainingSpace(), access.mount().getRemainingSpace(), "Free space is inconsistent");
+    }
+
+    @Test
+    default void Append_jumps_to_file_end() throws IOException {
+        var access = createExisting(CAPACITY);
+        var mount = access.mount();
+
+        Mounts.writeFile(mount, "a.txt", "example");
+
+        try (var handle = mount.openForAppend("a.txt")) {
+            assertEquals(7, handle.position());
+            handle.write(LuaValues.encode(" text"));
+            assertEquals(12, handle.position());
+        }
+
+        assertEquals(12, mount.getSize("a.txt"));
+    }
+
+    @ParameterizedTest(name = "\"{0}\"")
+    @MethodSource("fileContents")
+    default void Move_file(String contents) throws IOException {
+        var access = createExisting(CAPACITY);
+        var mount = access.mount();
+        Mounts.writeFile(mount, "src.txt", contents);
 
         var remainingSpace = mount.getRemainingSpace();
-        mount.rename("foo", "bar");
 
+        mount.rename("src.txt", "dest.txt");
+        assertFalse(mount.exists("src.txt"));
+        assertTrue(mount.exists("dest.txt"));
+
+        assertEquals(contents.length(), mount.getSize("dest.txt"));
         assertEquals(remainingSpace, mount.getRemainingSpace(), "Free space has changed after moving");
         assertEquals(access.computeRemainingSpace(), access.mount().getRemainingSpace(), "Free space is inconsistent");
     }
 
+    @ParameterizedTest(name = "\"{0}\"")
+    @MethodSource("fileContents")
+    default void Move_file_fails_when_destination_exists(String contents) throws IOException {
+        var access = createExisting(CAPACITY);
+        var mount = access.mount();
+        Mounts.writeFile(mount, "src.txt", contents);
+        Mounts.writeFile(mount, "dest.txt", "dest");
+
+        var remainingSpace = mount.getRemainingSpace();
+
+        assertThrows(IOException.class, () -> mount.rename("src.txt", "dest.txt"));
+
+        assertEquals(contents.length(), mount.getSize("src.txt"));
+        assertEquals(4, mount.getSize("dest.txt"));
+
+        assertEquals(remainingSpace, mount.getRemainingSpace(), "Free space has changed despite no move occurred.");
+        assertEquals(access.computeRemainingSpace(), access.mount().getRemainingSpace(), "Free space is inconsistent");
+    }
+
+    @Test
+    default void Move_file_fails_when_source_does_not_exist() throws IOException {
+        var access = createExisting(CAPACITY);
+        var mount = access.mount();
+        Mounts.writeFile(mount, "dest.txt", "dest");
+
+        var remainingSpace = mount.getRemainingSpace();
+
+        assertThrows(IOException.class, () -> mount.rename("src.txt", "dest.txt"));
+
+        assertFalse(mount.exists("src.txt"));
+        assertEquals(4, mount.getSize("dest.txt"));
+
+        assertEquals(remainingSpace, mount.getRemainingSpace(), "Free space has changed despite no move occurred.");
+        assertEquals(access.computeRemainingSpace(), access.mount().getRemainingSpace(), "Free space is inconsistent");
+    }
+
     /**
      * Wraps a {@link WritableMount} with additional operations.
      */
@@ -90,7 +194,7 @@ public interface WritableMountContract {
         WritableMount mount();
 
         /**
-         * Make a path read-only. This may throw a {@link TestAbortedException} if
+         * Make a path read-only. This may throw a {@link TestAbortedException} if this operation is not supported.
          *
          * @param path The mount-relative path.
          */

projects/core/src/testFixtures/kotlin/dan200/computercraft/test/core/computer/LuaTaskContext.kt

@@ -12,6 +12,7 @@ import dan200.computercraft.core.apis.OSAPI
 import dan200.computercraft.core.apis.PeripheralAPI
 import kotlinx.coroutines.CancellableContinuation
 import kotlinx.coroutines.suspendCancellableCoroutine
+import kotlinx.coroutines.withTimeoutOrNull
 import kotlin.time.Duration
 
 /**
@@ -29,6 +30,9 @@ interface LuaTaskContext {
     /** Pull a Lua event */
     suspend fun pullEvent(event: String? = null): Array<out Any?>
 
+    suspend fun pullEventOrTimeout(timeout: Duration, event: String? = null): Array<out Any?>? =
+        withTimeoutOrNull(timeout) { pullEvent(event) }
+
     /** Resolve a [MethodResult] until completion, returning the resulting values. */
     suspend fun MethodResult.await(): Array<out Any?>? {
         var result = this

projects/fabric/src/generated/resources/data/computercraft/recipes/computer_advanced_upgrade.json

@@ -1,7 +1,7 @@
 {
   "type": "computercraft:computer_upgrade",
   "category": "redstone",
-  "family": "ADVANCED",
+  "family": "advanced",
   "key": {"#": {"tag": "c:gold_ingots"}, "C": {"item": "computercraft:computer_normal"}},
   "pattern": ["###", "#C#", "# #"],
   "result": {"item": "computercraft:computer_advanced"},

projects/fabric/src/generated/resources/data/computercraft/recipes/pocket_computer_advanced_upgrade.json

@@ -1,7 +1,7 @@
 {
   "type": "computercraft:computer_upgrade",
   "category": "redstone",
-  "family": "ADVANCED",
+  "family": "advanced",
   "key": {"#": {"tag": "c:gold_ingots"}, "C": {"item": "computercraft:pocket_computer_normal"}},
   "pattern": ["###", "#C#", "# #"],
   "result": {"item": "computercraft:pocket_computer_advanced"},

projects/fabric/src/generated/resources/data/computercraft/recipes/skull_cloudy.json

@@ -1,9 +1,9 @@
 {
-  "type": "minecraft:crafting_shapeless",
+  "type": "computercraft:shapeless",
   "category": "misc",
   "ingredients": [{"tag": "c:skulls"}, {"item": "computercraft:monitor_normal"}],
   "result": {
     "item": "minecraft:player_head",
-    "nbt": "{SkullOwner:{Id:\"6d074736-b1e9-4378-a99b-bd8777821c9c\",Name:\"Cloudhunter\"}}"
+    "nbt": "{SkullOwner:{Id:[I;1829193526,-1310112904,-1449411193,2005015708],Name:\"Cloudhunter\"}}"
   }
 }

projects/fabric/src/generated/resources/data/computercraft/recipes/skull_dan200.json

@@ -1,9 +1,9 @@
 {
-  "type": "minecraft:crafting_shapeless",
+  "type": "computercraft:shapeless",
   "category": "misc",
   "ingredients": [{"tag": "c:skulls"}, {"item": "computercraft:computer_advanced"}],
   "result": {
     "item": "minecraft:player_head",
-    "nbt": "{SkullOwner:{Id:\"f3c8d69b-0776-4512-8434-d1b2165909eb\",Name:\"dan200\"}}"
+    "nbt": "{SkullOwner:{Id:[I;-204941669,125191442,-2076913230,374933995],Name:\"dan200\"}}"
   }
 }

projects/fabric/src/generated/resources/data/computercraft/recipes/turtle_advanced.json

@@ -1,7 +1,7 @@
 {
   "type": "computercraft:turtle",
   "category": "redstone",
-  "family": "ADVANCED",
+  "family": "advanced",
   "key": {
     "#": {"tag": "c:gold_ingots"},
     "C": {"item": "computercraft:computer_advanced"},

projects/fabric/src/generated/resources/data/computercraft/recipes/turtle_advanced_upgrade.json

@@ -1,7 +1,7 @@
 {
   "type": "computercraft:computer_upgrade",
   "category": "redstone",
-  "family": "ADVANCED",
+  "family": "advanced",
   "key": {
     "#": {"tag": "c:gold_ingots"},
     "B": {"item": "minecraft:gold_block"},

projects/fabric/src/generated/resources/data/computercraft/recipes/turtle_normal.json

@@ -1,7 +1,7 @@
 {
   "type": "computercraft:turtle",
   "category": "redstone",
-  "family": "NORMAL",
+  "family": "normal",
   "key": {
     "#": {"tag": "c:iron_ingots"},
     "C": {"item": "computercraft:computer_normal"},

projects/fabric/src/generated/resources/data/computercraft/tags/blocks/peripheral_hub_ignore.json

@@ -0,0 +1 @@
+{"replace": false, "values": ["#computercraft:wired_modem"]}

projects/fabric/src/main/java/dan200/computercraft/mixin/ShapedRecipeMixin.java

@@ -1,25 +0,0 @@
-// SPDX-FileCopyrightText: 2022 The CC: Tweaked Developers
-//
-// SPDX-License-Identifier: MPL-2.0
-
-package dan200.computercraft.mixin;
-
-import com.google.gson.JsonObject;
-import dan200.computercraft.shared.FabricCommonHooks;
-import net.minecraft.world.item.ItemStack;
-import net.minecraft.world.item.crafting.ShapedRecipe;
-import org.spongepowered.asm.mixin.Mixin;
-import org.spongepowered.asm.mixin.injection.At;
-import org.spongepowered.asm.mixin.injection.Inject;
-import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
-
-@Mixin(ShapedRecipe.class)
-class ShapedRecipeMixin {
-    @Inject(method = "itemStackFromJson", at = @At("RETURN"))
-    @SuppressWarnings("UnusedMethod")
-    private static void itemStackFromJson(JsonObject json, CallbackInfoReturnable<ItemStack> cir) {
-        // This is a fairly invasive mixin in the sense that every mod goes through this code path. We might want to
-        // remove this and use custom recipes types in the future.
-        FabricCommonHooks.addRecipeResultTag(cir.getReturnValue(), json);
-    }
-}