Bump CC:T to 1.109.6

We've been out-of-date for a while now, as we needed to update
lua_menhir to work with lrgrep 3.

 - Better handling of standalone names/expressions - we now correctly
   handle lists of names.

 - Handle missing commas in tables in a few more places.

.gitignore

@@ -7,6 +7,7 @@
 /logs
 /build
 /projects/*/logs
+/projects/fabric/fabricloader.log
 /projects/*/build
 /buildSrc/build
 /out

README.md

@@ -75,8 +75,8 @@ minecraft {
 ```
 
 You should also be careful to only use classes within the `dan200.computercraft.api` package. Non-API classes are
-subject to change at any point. If you depend on functionality outside the API, file an issue, and we can look into
-exposing more features.
+subject to change at any point. If you depend on functionality outside the API (or need to mixin to CC:T), please file
+an issue to let me know!
 
 We bundle the API sources with the jar, so documentation should be easily viewable within your editor. Alternatively,
 the generated documentation [can be browsed online](https://tweaked.cc/javadoc/).

buildSrc/build.gradle.kts

@@ -29,19 +29,19 @@ repositories {
         }
     }
 
-    maven("https://repo.spongepowered.org/repository/maven-public/") {
-        name = "Sponge"
-        content {
-            includeGroup("org.spongepowered")
-        }
-    }
-
     maven("https://maven.fabricmc.net/") {
         name = "Fabric"
         content {
             includeGroup("net.fabricmc")
         }
     }
+
+    maven("https://squiddev.cc/maven") {
+        name = "SquidDev"
+        content {
+            includeGroup("cc.tweaked.vanilla-extract")
+        }
+    }
 }
 
 dependencies {
@@ -55,8 +55,7 @@ dependencies {
     implementation(libs.ideaExt)
     implementation(libs.librarian)
     implementation(libs.minotaur)
-    implementation(libs.vanillaGradle)
-    implementation(libs.vineflower)
+    implementation(libs.vanillaExtract)
 }
 
 gradlePlugin {

buildSrc/src/main/kotlin/cc-tweaked.fabric.gradle.kts

@@ -12,7 +12,6 @@ import cc.tweaked.gradle.MinecraftConfigurations
 plugins {
     `java-library`
     id("fabric-loom")
-    id("io.github.juuxel.loom-vineflower")
     id("cc-tweaked.java-convention")
 }
 

buildSrc/src/main/kotlin/cc-tweaked.vanilla.gradle.kts

@@ -10,25 +10,31 @@ import cc.tweaked.gradle.MinecraftConfigurations
 
 plugins {
     id("cc-tweaked.java-convention")
-    id("org.spongepowered.gradle.vanilla")
+    id("cc.tweaked.vanilla-extract")
 }
 
 plugins.apply(CCTweakedPlugin::class.java)
 
 val mcVersion: String by extra
 
+val libs = project.extensions.getByType<VersionCatalogsExtension>().named("libs")
+
 minecraft {
     version(mcVersion)
+
+    mappings {
+        parchment(libs.findVersion("parchmentMc").get().toString(), libs.findVersion("parchment").get().toString())
+    }
+
+    unpick(libs.findLibrary("yarn").get())
 }
 
 dependencies {
-    val libs = project.extensions.getByType<VersionCatalogsExtension>().named("libs")
-
     // Depend on error prone annotations to silence a lot of compile warnings.
-    compileOnlyApi(libs.findLibrary("errorProne.annotations").get())
+    compileOnly(libs.findLibrary("errorProne.annotations").get())
 }
 
-MinecraftConfigurations.setup(project)
+MinecraftConfigurations.setupBasic(project)
 
 extensions.configure(CCTweakedExtension::class.java) {
     linters(minecraft = true, loader = null)

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

@@ -255,7 +255,7 @@ abstract class CCTweakedExtension(
     }
 
     /**
-     * Exclude a dependency from being publisehd in Maven.
+     * Exclude a dependency from being published in Maven.
      */
     fun exclude(dep: Dependency) {
         excludedDeps.add(dep)

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

@@ -7,12 +7,15 @@ package cc.tweaked.gradle
 import org.gradle.api.DefaultTask
 import org.gradle.api.GradleException
 import org.gradle.api.artifacts.Configuration
+import org.gradle.api.artifacts.MinimalExternalModuleDependency
 import org.gradle.api.artifacts.component.ModuleComponentIdentifier
 import org.gradle.api.artifacts.component.ModuleComponentSelector
 import org.gradle.api.artifacts.component.ProjectComponentIdentifier
 import org.gradle.api.artifacts.result.DependencyResult
 import org.gradle.api.artifacts.result.ResolvedDependencyResult
 import org.gradle.api.provider.ListProperty
+import org.gradle.api.provider.MapProperty
+import org.gradle.api.provider.Provider
 import org.gradle.api.tasks.Input
 import org.gradle.api.tasks.TaskAction
 import org.gradle.language.base.plugins.LifecycleBasePlugin
@@ -21,9 +24,25 @@ abstract class DependencyCheck : DefaultTask() {
     @get:Input
     abstract val configuration: ListProperty<Configuration>
 
+    /**
+     * A mapping of module coordinates (`group:module`) to versions, overriding the requested version.
+     */
+    @get:Input
+    abstract val overrides: MapProperty<String, String>
+
     init {
         description = "Check :core's dependencies are consistent with Minecraft's."
         group = LifecycleBasePlugin.VERIFICATION_GROUP
+
+        configuration.finalizeValueOnRead()
+        overrides.finalizeValueOnRead()
+    }
+
+    /**
+     * Override a module with a different version.
+     */
+    fun override(module: Provider<MinimalExternalModuleDependency>, version: String) {
+        overrides.putAll(project.provider { mutableMapOf(module.get().module.toString() to version) })
     }
 
     @TaskAction
@@ -60,7 +79,8 @@ abstract class DependencyCheck : DefaultTask() {
         ) {
             // If the version is different between the requested and selected version, report an error.
             val selected = dependency.selected.moduleVersion!!.version
-            if (requested.version != selected) {
+            val requestedVersion = overrides.get()["${requested.group}:${requested.module}"] ?: requested.version
+            if (requestedVersion != selected) {
                 logger.error("Requested dependency {} (via {}) but got version {}", requested, from, selected)
                 return false
             }

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

@@ -4,23 +4,17 @@
 
 package cc.tweaked.gradle
 
+import cc.tweaked.vanillaextract.configurations.Capabilities
+import cc.tweaked.vanillaextract.configurations.MinecraftSetup
 import org.gradle.api.Project
-import org.gradle.api.artifacts.Configuration
 import org.gradle.api.artifacts.ModuleDependency
 import org.gradle.api.artifacts.dsl.DependencyHandler
-import org.gradle.api.attributes.Bundling
-import org.gradle.api.attributes.Category
-import org.gradle.api.attributes.LibraryElements
-import org.gradle.api.attributes.Usage
-import org.gradle.api.attributes.java.TargetJvmVersion
-import org.gradle.api.capabilities.Capability
 import org.gradle.api.plugins.BasePlugin
 import org.gradle.api.plugins.JavaPluginExtension
 import org.gradle.api.tasks.SourceSet
 import org.gradle.api.tasks.bundling.Jar
 import org.gradle.api.tasks.javadoc.Javadoc
 import org.gradle.kotlin.dsl.get
-import org.gradle.kotlin.dsl.named
 
 /**
  * This sets up a separate client-only source set, and extends that and the main/common source set with additional
@@ -59,31 +53,13 @@ class MinecraftConfigurations private constructor(private val project: Project)
         }
         configurations.named(client.implementationConfigurationName) { extendsFrom(clientApi) }
 
-        /*
-          Now add outgoing variants for the main and common source sets that we can consume downstream. This is possibly
-          the worst way to do things, but unfortunately the alternatives don't actually work very well:
-
-           - Just using source set outputs: This means dependencies don't propagate, which means when :fabric depends
-             on :fabric-api, we don't inherit the fake :common-api in IDEA.
-
-           - Having separate common/main jars: Nice in principle, but unfortunately Forge needs a separate deobf jar
-             task (as the original jar is obfuscated), and IDEA is not able to map its output back to a source set.
-
-          This works for now, but is incredibly brittle. It's part of the reason we can't use testFixtures inside our
-          MC projects, as that adds a project(self) -> test dependency, which would pull in the jar instead.
-
-          Note we register a fake client jar here. It's not actually needed, but is there to make sure IDEA has
-          a way to tell that client classes are needed at runtime.
-
-          I'm so sorry, deeply aware how cursed this is.
-        */
-        setupOutgoing(main, "CommonOnly")
         project.tasks.register(client.jarTaskName, Jar::class.java) {
             description = "An empty jar standing in for the client classes."
             group = BasePlugin.BUILD_GROUP
             archiveClassifier.set("client")
         }
-        setupOutgoing(client)
+
+        MinecraftSetup(project).setupOutgoingConfigurations()
 
         // Reset the client classpath (Loom configures it slightly differently to this) and add a main -> client
         // dependency. Here we /can/ use source set outputs as we add transitive deps by patching the classpath. Nasty,
@@ -106,6 +82,12 @@ class MinecraftConfigurations private constructor(private val project: Project)
         project.tasks.named("jar", Jar::class.java) { from(client.output) }
         project.tasks.named("sourcesJar", Jar::class.java) { from(client.allSource) }
 
+        setupBasic()
+    }
+
+    private fun setupBasic() {
+        val client = sourceSets["client"]
+
         project.extensions.configure(CCTweakedExtension::class.java) {
             sourceDirectories.add(SourceSetReference.internal(client))
         }
@@ -120,83 +102,19 @@ class MinecraftConfigurations private constructor(private val project: Project)
         project.tasks.named("check") { dependsOn(checkDependencyConsistency) }
     }
 
-    private fun setupOutgoing(sourceSet: SourceSet, suffix: String = "") {
-        setupOutgoing("${sourceSet.apiElementsConfigurationName}$suffix", sourceSet, objects.named(Usage.JAVA_API)) {
-            description = "API elements for ${sourceSet.name}"
-            extendsFrom(configurations[sourceSet.apiConfigurationName])
-        }
-
-        setupOutgoing("${sourceSet.runtimeElementsConfigurationName}$suffix", sourceSet, objects.named(Usage.JAVA_RUNTIME)) {
-            description = "Runtime elements for ${sourceSet.name}"
-            extendsFrom(configurations[sourceSet.implementationConfigurationName], configurations[sourceSet.runtimeOnlyConfigurationName])
-        }
-    }
-
-    /**
-     * Set up an outgoing configuration for a specific source set. We set an additional "main" or "client" capability
-     * (depending on the source set name) which allows downstream projects to consume them separately (see
-     * [DependencyHandler.commonClasses] and [DependencyHandler.clientClasses]).
-     */
-    private fun setupOutgoing(name: String, sourceSet: SourceSet, usage: Usage, configure: Configuration.() -> Unit) {
-        configurations.register(name) {
-            isVisible = false
-            isCanBeConsumed = true
-            isCanBeResolved = false
-
-            configure(this)
-
-            attributes {
-                attribute(Category.CATEGORY_ATTRIBUTE, objects.named(Category.LIBRARY))
-                attribute(Usage.USAGE_ATTRIBUTE, usage)
-                attribute(Bundling.BUNDLING_ATTRIBUTE, objects.named(Bundling.EXTERNAL))
-                attributeProvider(
-                    TargetJvmVersion.TARGET_JVM_VERSION_ATTRIBUTE,
-                    java.toolchain.languageVersion.map { it.asInt() },
-                )
-                attribute(LibraryElements.LIBRARY_ELEMENTS_ATTRIBUTE, objects.named(LibraryElements.JAR))
-            }
-
-            outgoing {
-                capability(BasicOutgoingCapability(project, sourceSet.name))
-
-                // We have two outgoing variants here: the original jar and the classes.
-                artifact(project.tasks.named(sourceSet.jarTaskName))
-
-                variants.create("classes") {
-                    attributes.attribute(LibraryElements.LIBRARY_ELEMENTS_ATTRIBUTE, objects.named(LibraryElements.CLASSES))
-                    sourceSet.output.classesDirs.forEach { artifact(it) { builtBy(sourceSet.output) } }
-                }
-            }
-        }
-    }
-
     companion object {
+        fun setupBasic(project: Project) {
+            MinecraftConfigurations(project).setupBasic()
+        }
+
         fun setup(project: Project) {
             MinecraftConfigurations(project).setup()
         }
     }
 }
 
-private class BasicIncomingCapability(private val module: ModuleDependency, private val name: String) : Capability {
-    override fun getGroup(): String = module.group!!
-    override fun getName(): String = "${module.name}-$name"
-    override fun getVersion(): String? = null
-}
+fun DependencyHandler.clientClasses(notation: Any): ModuleDependency =
+    Capabilities.clientClasses(create(notation) as ModuleDependency)
 
-private class BasicOutgoingCapability(private val project: Project, private val name: String) : Capability {
-    override fun getGroup(): String = project.group.toString()
-    override fun getName(): String = "${project.name}-$name"
-    override fun getVersion(): String = project.version.toString()
-}
-
-fun DependencyHandler.clientClasses(notation: Any): ModuleDependency {
-    val dep = create(notation) as ModuleDependency
-    dep.capabilities { requireCapability(BasicIncomingCapability(dep, "client")) }
-    return dep
-}
-
-fun DependencyHandler.commonClasses(notation: Any): ModuleDependency {
-    val dep = create(notation) as ModuleDependency
-    dep.capabilities { requireCapability(BasicIncomingCapability(dep, "main")) }
-    return dep
-}
+fun DependencyHandler.commonClasses(notation: Any): ModuleDependency =
+    Capabilities.commonClasses(create(notation) as ModuleDependency)

doc/reference/breaking_changes.md

@@ -21,7 +21,7 @@ of the mod should run fine on later versions.
 However, some changes to the underlying game, or CC: Tweaked's own internals may break some programs. This page serves
 as documentation for breaking changes and "gotchas" one should look out for between versions.
 
-## CC: Tweaked 1.109.0 to 1.109.2 {#cct-1.109}
+## CC: Tweaked 1.109.0 to 1.109.3 {#cct-1.109}
 
  - Update to Lua 5.2:
    - Support for Lua 5.0's pseudo-argument `arg` has been removed. You should always use `...` for varargs.
@@ -76,6 +76,6 @@ as documentation for breaking changes and "gotchas" one should look out for betw
  - Programs containing `/` are looked up in the current directory and are no longer looked up on the path. For instance,
    you can no longer type `turtle/excavate` to run `/rom/programs/turtle/excavate.lua`.
 
-[flattening]: https://minecraft.wiki.com/w/Java_Edition_1.13/Flattening
+[flattening]: https://minecraft.wiki/w/Java_Edition_1.13/Flattening
 [legal_data_pack]: https://minecraft.gamepedia.com/Tutorials/Creating_a_data_pack#Legal_characters
 [datapack-example]: https://github.com/cc-tweaked/datapack-example "An example datapack for CC: Tweaked"

gradle.properties

@@ -10,7 +10,7 @@ kotlin.jvm.target.validation.mode=error
 
 # Mod properties
 isUnstable=false
-modVersion=1.109.3
+modVersion=1.109.6
 
 # Minecraft properties: We want to configure this here so we can read it in settings.gradle
 mcVersion=1.20.1

gradle/libs.versions.toml

@@ -14,6 +14,7 @@ forgeSpi = "7.0.1"
 mixin = "0.8.5"
 parchment = "2023.08.20"
 parchmentMc = "1.20.1"
+yarn = "1.20.1+build.10"
 
 # Core dependencies (these versions are tied to the version Minecraft uses)
 fastutil = "8.5.9"
@@ -25,7 +26,7 @@ slf4j = "2.0.1"
 asm = "9.6"
 autoService = "1.1.1"
 checkerFramework = "3.42.0"
-cobalt = "0.8.2"
+cobalt = "0.9.1"
 commonsCli = "1.6.0"
 jetbrainsAnnotations = "24.1.0"
 jsr305 = "3.0.2"
@@ -57,8 +58,8 @@ checkstyle = "10.12.6"
 curseForgeGradle = "1.0.14"
 errorProne-core = "2.23.0"
 errorProne-plugin = "3.1.0"
-fabric-loom = "1.3.9"
-forgeGradle = "6.0.8"
+fabric-loom = "1.5.7"
+forgeGradle = "6.0.20"
 githubRelease = "2.5.2"
 gradleVersions = "0.50.0"
 ideaExt = "1.1.7"
@@ -71,9 +72,8 @@ nullAway = "0.9.9"
 spotless = "6.23.3"
 taskTree = "2.1.1"
 teavm = "0.10.0-SQUID.2"
-vanillaGradle = "0.2.1-SNAPSHOT"
+vanillaExtract = "0.1.1"
 versionCatalogUpdate = "0.8.1"
-vineflower = "1.11.0"
 
 [libraries]
 # Normal dependencies
@@ -159,8 +159,8 @@ teavm-metaprogramming-api = { module = "org.teavm:teavm-metaprogramming-api", ve
 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" }
+vanillaExtract = { module = "cc.tweaked.vanilla-extract:plugin", version.ref = "vanillaExtract" }
+yarn = { module = "net.fabricmc:yarn", version.ref = "yarn" }
 
 [plugins]
 forgeGradle = { id = "net.minecraftforge.gradle", version.ref = "forgeGradle" }
@@ -180,7 +180,6 @@ kotlin = ["kotlin-stdlib", "kotlin-coroutines"]
 externalMods-common = ["jei-api", "nightConfig-core", "nightConfig-toml"]
 externalMods-forge-compile = ["moreRed", "oculus", "jei-api"]
 externalMods-forge-runtime = ["jei-forge"]
-externalMods-fabric = ["nightConfig-core", "nightConfig-toml"]
 externalMods-fabric-compile = ["fabricPermissions", "iris", "jei-api", "rei-api", "rei-builtin"]
 externalMods-fabric-runtime = ["jei-fabric", "modmenu"]
 

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,7 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.1.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.5-bin.zip
 networkTimeout=10000
+validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists

gradlew

@@ -83,7 +83,8 @@ done
 # This is normally unused
 # shellcheck disable=SC2034
 APP_BASE_NAME=${0##*/}
-APP_HOME=$( cd "${APP_HOME:-./}" && pwd -P ) || exit
+# Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036)
+APP_HOME=$( cd "${APP_HOME:-./}" > /dev/null && pwd -P ) || exit
 
 # Use the maximum available, or set MAX_FD != -1 to use that value.
 MAX_FD=maximum
@@ -130,10 +131,13 @@ location of your Java installation."
     fi
 else
     JAVACMD=java
-    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+    if ! command -v java >/dev/null 2>&1
+    then
+        die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
 
 Please set the JAVA_HOME variable in your environment to match the
 location of your Java installation."
+    fi
 fi
 
 # Increase the maximum file descriptors if we can.
@@ -141,7 +145,7 @@ if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
     case $MAX_FD in #(
       max*)
         # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
-        # shellcheck disable=SC3045
+        # shellcheck disable=SC2039,SC3045
         MAX_FD=$( ulimit -H -n ) ||
             warn "Could not query maximum file descriptor limit"
     esac
@@ -149,7 +153,7 @@ if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
       '' | soft) :;; #(
       *)
         # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
-        # shellcheck disable=SC3045
+        # shellcheck disable=SC2039,SC3045
         ulimit -n "$MAX_FD" ||
             warn "Could not set maximum file descriptor limit to $MAX_FD"
     esac
@@ -198,11 +202,11 @@ fi
 # Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
 DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
 
-# Collect all arguments for the java command;
-#   * $DEFAULT_JVM_OPTS, $JAVA_OPTS, and $GRADLE_OPTS can contain fragments of
-#     shell script including quotes and variable substitutions, so put them in
-#     double quotes to make sure that they get re-expanded; and
-#   * put everything else in single quotes, so that it's not re-expanded.
+# Collect all arguments for the java command:
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments,
+#     and any embedded shellness will be escaped.
+#   * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be
+#     treated as '${Hostname}' itself on the command line.
 
 set -- \
         "-Dorg.gradle.appname=$APP_BASE_NAME" \

illuaminate.sexp

@@ -105,6 +105,10 @@
    /projects/core/src/main/resources/data/computercraft/lua/rom/apis/turtle/turtle.lua)
   (linters -var:deprecated))
 
+;; Suppress unused variable warnings in the parser.
+(at /projects/core/src/main/resources/data/computercraft/lua/rom/modules/main/cc/internal/syntax/parser.lua
+  (linters -var:unused))
+
 (at /projects/core/src/test/resources/test-rom
   ; We should still be able to test deprecated members.
   (linters -var:deprecated)

package.json

@@ -23,7 +23,7 @@
     "rehype-highlight": "^7.0.0",
     "rehype-react": "^8.0.0",
     "rollup": "^4.0.0",
-    "tsx": "^3.12.10",
+    "tsx": "^4.7.0",
     "typescript": "^5.2.2"
   }
 }

projects/common-api/src/client/java/dan200/computercraft/api/client/ComputerCraftAPIClient.java

@@ -27,8 +27,13 @@ public final class ComputerCraftAPIClient {
      * @param serialiser The turtle upgrade serialiser.
      * @param modeller   The upgrade modeller.
      * @param <T>        The type of the turtle upgrade.
+     * @deprecated This method can lead to confusing load behaviour on Forge. Use
+     * {@code dan200.computercraft.api.client.FabricComputerCraftAPIClient#registerTurtleUpgradeModeller} on Fabric, or
+     * {@code dan200.computercraft.api.client.turtle.RegisterTurtleModellersEvent} on Forge.
      */
+    @Deprecated(forRemoval = true)
     public static <T extends ITurtleUpgrade> void registerTurtleUpgradeModeller(TurtleUpgradeSerialiser<T> serialiser, TurtleUpgradeModeller<T> modeller) {
+        // TODO(1.20.4): Remove this
         getInstance().registerTurtleUpgradeModeller(serialiser, modeller);
     }
 

projects/common-api/src/client/java/dan200/computercraft/api/client/turtle/RegisterTurtleUpgradeModeller.java

@@ -0,0 +1,26 @@
+// SPDX-FileCopyrightText: 2023 The CC: Tweaked Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+
+package dan200.computercraft.api.client.turtle;
+
+import dan200.computercraft.api.turtle.ITurtleUpgrade;
+import dan200.computercraft.api.turtle.TurtleUpgradeSerialiser;
+
+/**
+ * A functional interface to register a {@link TurtleUpgradeModeller} for a class of turtle upgrades.
+ * <p>
+ * This interface is largely intended to be used from multi-loader code, to allow sharing registration code between
+ * multiple loaders.
+ */
+@FunctionalInterface
+public interface RegisterTurtleUpgradeModeller {
+    /**
+     * Register a {@link TurtleUpgradeModeller}.
+     *
+     * @param serialiser The turtle upgrade serialiser.
+     * @param modeller   The upgrade modeller.
+     * @param <T>        The type of the turtle upgrade.
+     */
+    <T extends ITurtleUpgrade> void register(TurtleUpgradeSerialiser<T> serialiser, TurtleUpgradeModeller<T> modeller);
+}

projects/common-api/src/client/java/dan200/computercraft/api/client/turtle/TurtleUpgradeModeller.java

@@ -4,12 +4,10 @@
 
 package dan200.computercraft.api.client.turtle;
 
-import dan200.computercraft.api.client.ComputerCraftAPIClient;
 import dan200.computercraft.api.client.TransformedModel;
 import dan200.computercraft.api.turtle.ITurtleAccess;
 import dan200.computercraft.api.turtle.ITurtleUpgrade;
 import dan200.computercraft.api.turtle.TurtleSide;
-import dan200.computercraft.api.turtle.TurtleUpgradeSerialiser;
 import net.minecraft.client.resources.model.ModelResourceLocation;
 import net.minecraft.client.resources.model.UnbakedModel;
 import net.minecraft.nbt.CompoundTag;
@@ -21,9 +19,13 @@ import java.util.List;
 
 /**
  * Provides models for a {@link ITurtleUpgrade}.
+ * <p>
+ * Use {@code dan200.computercraft.api.client.FabricComputerCraftAPIClient#registerTurtleUpgradeModeller} to register a
+ * modeller on Fabric and {@code dan200.computercraft.api.client.turtle.RegisterTurtleModellersEvent} to register one
+ * on Forge
  *
  * @param <T> The type of turtle upgrade this modeller applies to.
- * @see ComputerCraftAPIClient#registerTurtleUpgradeModeller(TurtleUpgradeSerialiser, TurtleUpgradeModeller) To register a modeller.
+ * @see RegisterTurtleUpgradeModeller For multi-loader registration support.
  */
 public interface TurtleUpgradeModeller<T extends ITurtleUpgrade> {
     /**

projects/common-api/src/main/java/dan200/computercraft/api/turtle/TurtleUpgradeSerialiser.java

@@ -48,13 +48,8 @@ import java.util.function.Function;
  * }
  * }</pre>
  * <p>
- * Finally, we need to register a model for our upgrade. This is done with
- * {@link dan200.computercraft.api.client.ComputerCraftAPIClient#registerTurtleUpgradeModeller}:
- *
- * <pre>{@code
- * // Register our model inside FMLClientSetupEvent
- * ComputerCraftAPIClient.registerTurtleUpgradeModeller(MY_UPGRADE.get(), TurtleUpgradeModeller.flatItem())
- * }</pre>
+ * Finally, we need to register a model for our upgrade. The way to do this varies on mod loader, see
+ * {@link dan200.computercraft.api.client.turtle.TurtleUpgradeModeller} for more information.
  * <p>
  * {@link TurtleUpgradeDataProvider} provides a data provider to aid with generating these JSON files.
  *

projects/common/build.gradle.kts

@@ -22,6 +22,14 @@ configurations {
     register("cctJavadoc")
 }
 
+repositories {
+    maven("https://maven.minecraftforge.net/") {
+        content {
+            includeModule("org.spongepowered", "mixin")
+        }
+    }
+}
+
 dependencies {
     // Pull in our other projects. See comments in MinecraftConfigurations on this nastiness.
     implementation(project(":core"))
@@ -31,7 +39,6 @@ dependencies {
     compileOnly(libs.bundles.externalMods.common)
     clientCompileOnly(variantOf(libs.emi) { classifier("api") })
 
-    compileOnly(libs.mixin)
     annotationProcessorEverywhere(libs.autoService)
     testFixturesAnnotationProcessor(libs.autoService)
 
@@ -39,6 +46,7 @@ dependencies {
     testImplementation(libs.bundles.test)
     testRuntimeOnly(libs.bundles.testRuntime)
 
+    testModCompileOnly(libs.mixin)
     testModImplementation(testFixtures(project(":core")))
     testModImplementation(testFixtures(project(":common")))
     testModImplementation(libs.bundles.kotlin)
@@ -72,7 +80,7 @@ val luaJavadoc by tasks.registering(Javadoc::class) {
 
     javadocTool.set(
         javaToolchains.javadocToolFor {
-            languageVersion.set(cc.tweaked.gradle.CCTweakedPlugin.JAVA_VERSION)
+            languageVersion.set(CCTweakedPlugin.JAVA_VERSION)
         },
     )
 }

projects/common/src/client/java/dan200/computercraft/client/ClientHooks.java

@@ -17,8 +17,6 @@ import dan200.computercraft.client.render.monitor.MonitorRenderState;
 import dan200.computercraft.client.sound.SpeakerManager;
 import dan200.computercraft.shared.CommonHooks;
 import dan200.computercraft.shared.ModRegistry;
-import dan200.computercraft.shared.command.CommandComputerCraft;
-import dan200.computercraft.shared.computer.core.ServerContext;
 import dan200.computercraft.shared.media.items.PrintoutItem;
 import dan200.computercraft.shared.peripheral.modem.wired.CableBlock;
 import dan200.computercraft.shared.peripheral.modem.wired.CableModemVariant;
@@ -28,7 +26,6 @@ import dan200.computercraft.shared.pocket.items.PocketComputerItem;
 import dan200.computercraft.shared.turtle.blocks.TurtleBlockEntity;
 import dan200.computercraft.shared.util.PauseAwareTimer;
 import dan200.computercraft.shared.util.WorldUtil;
-import net.minecraft.Util;
 import net.minecraft.client.Camera;
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.renderer.MultiBufferSource;
@@ -43,7 +40,6 @@ import net.minecraft.world.phys.BlockHitResult;
 import net.minecraft.world.phys.HitResult;
 
 import javax.annotation.Nullable;
-import java.io.File;
 import java.util.function.Consumer;
 
 /**
@@ -71,10 +67,6 @@ public final class ClientHooks {
         ClientPocketComputers.reset();
     }
 
-    public static boolean onChatMessage(String message) {
-        return handleOpenComputerCommand(message);
-    }
-
     public static boolean drawHighlight(PoseStack transform, MultiBufferSource bufferSource, Camera camera, BlockHitResult hit) {
         return CableHighlightRenderer.drawHighlight(transform, bufferSource, camera, hit)
             || MonitorHighlightRenderer.drawHighlight(transform, bufferSource, camera, hit);
@@ -109,34 +101,6 @@ public final class ClientHooks {
         SpeakerManager.onPlayStreaming(engine, channel, stream);
     }
 
-    /**
-     * Handle the {@link CommandComputerCraft#OPEN_COMPUTER} "clientside command". This isn't a true command, as we
-     * don't want it to actually be visible to the user.
-     *
-     * @param message The current chat message.
-     * @return Whether to cancel sending this message.
-     */
-    private static boolean handleOpenComputerCommand(String message) {
-        if (!message.startsWith(CommandComputerCraft.OPEN_COMPUTER)) return false;
-
-        var server = Minecraft.getInstance().getSingleplayerServer();
-        if (server == null) return false;
-
-        var idStr = message.substring(CommandComputerCraft.OPEN_COMPUTER.length()).trim();
-        int id;
-        try {
-            id = Integer.parseInt(idStr);
-        } catch (NumberFormatException ignore) {
-            return false;
-        }
-
-        var file = new File(ServerContext.get(server).storageDir().toFile(), "computer/" + id);
-        if (!file.isDirectory()) return false;
-
-        Util.getPlatform().openFile(file);
-        return true;
-    }
-
     /**
      * Add additional information about the currently targeted block to the debug screen.
      *

projects/common/src/client/java/dan200/computercraft/client/ClientRegistry.java

@@ -4,8 +4,12 @@
 
 package dan200.computercraft.client;
 
+import com.mojang.brigadier.CommandDispatcher;
+import com.mojang.brigadier.arguments.IntegerArgumentType;
+import com.mojang.brigadier.builder.LiteralArgumentBuilder;
+import com.mojang.brigadier.builder.RequiredArgumentBuilder;
 import dan200.computercraft.api.ComputerCraftAPI;
-import dan200.computercraft.api.client.ComputerCraftAPIClient;
+import dan200.computercraft.api.client.turtle.RegisterTurtleUpgradeModeller;
 import dan200.computercraft.api.client.turtle.TurtleUpgradeModeller;
 import dan200.computercraft.client.gui.*;
 import dan200.computercraft.client.pocket.ClientPocketComputers;
@@ -16,11 +20,14 @@ import dan200.computercraft.client.turtle.TurtleModemModeller;
 import dan200.computercraft.client.turtle.TurtleUpgradeModellers;
 import dan200.computercraft.core.util.Colour;
 import dan200.computercraft.shared.ModRegistry;
+import dan200.computercraft.shared.command.CommandComputerCraft;
 import dan200.computercraft.shared.common.IColouredItem;
+import dan200.computercraft.shared.computer.core.ServerContext;
 import dan200.computercraft.shared.computer.inventory.AbstractComputerMenu;
 import dan200.computercraft.shared.computer.inventory.ViewComputerMenu;
 import dan200.computercraft.shared.media.items.DiskItem;
 import dan200.computercraft.shared.media.items.TreasureDiskItem;
+import net.minecraft.Util;
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.color.item.ItemColor;
 import net.minecraft.client.gui.screens.MenuScreens;
@@ -30,6 +37,7 @@ import net.minecraft.client.renderer.blockentity.BlockEntityRendererProvider;
 import net.minecraft.client.renderer.blockentity.BlockEntityRenderers;
 import net.minecraft.client.renderer.item.ClampedItemPropertyFunction;
 import net.minecraft.client.renderer.item.ItemProperties;
+import net.minecraft.network.chat.Component;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.server.packs.resources.PreparableReloadListener;
 import net.minecraft.server.packs.resources.ResourceProvider;
@@ -39,6 +47,7 @@ import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.level.ItemLike;
 
 import javax.annotation.Nullable;
+import java.io.File;
 import java.io.IOException;
 import java.util.function.BiConsumer;
 import java.util.function.Consumer;
@@ -60,18 +69,6 @@ public final class ClientRegistry {
      * Register any client-side objects which don't have to be done on the main thread.
      */
     public static void register() {
-        ComputerCraftAPIClient.registerTurtleUpgradeModeller(ModRegistry.TurtleSerialisers.SPEAKER.get(), TurtleUpgradeModeller.sided(
-            new ResourceLocation(ComputerCraftAPI.MOD_ID, "block/turtle_speaker_left"),
-            new ResourceLocation(ComputerCraftAPI.MOD_ID, "block/turtle_speaker_right")
-        ));
-        ComputerCraftAPIClient.registerTurtleUpgradeModeller(ModRegistry.TurtleSerialisers.WORKBENCH.get(), TurtleUpgradeModeller.sided(
-            new ResourceLocation(ComputerCraftAPI.MOD_ID, "block/turtle_crafting_table_left"),
-            new ResourceLocation(ComputerCraftAPI.MOD_ID, "block/turtle_crafting_table_right")
-        ));
-        ComputerCraftAPIClient.registerTurtleUpgradeModeller(ModRegistry.TurtleSerialisers.WIRELESS_MODEM_NORMAL.get(), new TurtleModemModeller(false));
-        ComputerCraftAPIClient.registerTurtleUpgradeModeller(ModRegistry.TurtleSerialisers.WIRELESS_MODEM_ADVANCED.get(), new TurtleModemModeller(true));
-        ComputerCraftAPIClient.registerTurtleUpgradeModeller(ModRegistry.TurtleSerialisers.TOOL.get(), TurtleUpgradeModeller.flatItem());
-
         BlockEntityRenderers.register(ModRegistry.BlockEntities.MONITOR_NORMAL.get(), MonitorBlockEntityRenderer::new);
         BlockEntityRenderers.register(ModRegistry.BlockEntities.MONITOR_ADVANCED.get(), MonitorBlockEntityRenderer::new);
         BlockEntityRenderers.register(ModRegistry.BlockEntities.TURTLE_NORMAL.get(), TurtleBlockEntityRenderer::new);
@@ -103,6 +100,20 @@ public final class ClientRegistry {
         );
     }
 
+    public static void registerTurtleModellers(RegisterTurtleUpgradeModeller register) {
+        register.register(ModRegistry.TurtleSerialisers.SPEAKER.get(), TurtleUpgradeModeller.sided(
+            new ResourceLocation(ComputerCraftAPI.MOD_ID, "block/turtle_speaker_left"),
+            new ResourceLocation(ComputerCraftAPI.MOD_ID, "block/turtle_speaker_right")
+        ));
+        register.register(ModRegistry.TurtleSerialisers.WORKBENCH.get(), TurtleUpgradeModeller.sided(
+            new ResourceLocation(ComputerCraftAPI.MOD_ID, "block/turtle_crafting_table_left"),
+            new ResourceLocation(ComputerCraftAPI.MOD_ID, "block/turtle_crafting_table_right")
+        ));
+        register.register(ModRegistry.TurtleSerialisers.WIRELESS_MODEM_NORMAL.get(), new TurtleModemModeller(false));
+        register.register(ModRegistry.TurtleSerialisers.WIRELESS_MODEM_ADVANCED.get(), new TurtleModemModeller(true));
+        register.register(ModRegistry.TurtleSerialisers.TOOL.get(), TurtleUpgradeModeller.flatItem());
+    }
+
     @SafeVarargs
     private static void registerItemProperty(String name, ClampedItemPropertyFunction getter, Supplier<? extends Item>... items) {
         var id = new ResourceLocation(ComputerCraftAPI.MOD_ID, name);
@@ -179,4 +190,45 @@ public final class ClientRegistry {
             return function.unclampedCall(stack, level, entity, layer);
         }
     }
+
+    /**
+     * Register client-side commands.
+     *
+     * @param dispatcher The dispatcher to register the commands to.
+     * @param sendError  A function to send an error message.
+     * @param <T>        The type of the client-side command context.
+     */
+    public static <T> void registerClientCommands(CommandDispatcher<T> dispatcher, BiConsumer<T, Component> sendError) {
+        dispatcher.register(LiteralArgumentBuilder.<T>literal(CommandComputerCraft.CLIENT_OPEN_FOLDER)
+            .requires(x -> Minecraft.getInstance().getSingleplayerServer() != null)
+            .then(RequiredArgumentBuilder.<T, Integer>argument("computer_id", IntegerArgumentType.integer(0))
+                .executes(c -> handleOpenComputerCommand(c.getSource(), sendError, c.getArgument("computer_id", Integer.class)))
+            ));
+    }
+
+    /**
+     * Handle the {@link CommandComputerCraft#CLIENT_OPEN_FOLDER} command.
+     *
+     * @param context   The command context.
+     * @param sendError A function to send an error message.
+     * @param id        The computer's id.
+     * @param <T>       The type of the client-side command context.
+     * @return {@code 1} if a folder was opened, {@code 0} otherwise.
+     */
+    private static <T> int handleOpenComputerCommand(T context, BiConsumer<T, Component> sendError, int id) {
+        var server = Minecraft.getInstance().getSingleplayerServer();
+        if (server == null) {
+            sendError.accept(context, Component.literal("Not on a single-player server"));
+            return 0;
+        }
+
+        var file = new File(ServerContext.get(server).storageDir().toFile(), "computer/" + id);
+        if (!file.isDirectory()) {
+            sendError.accept(context, Component.literal("Computer's folder does not exist"));
+            return 0;
+        }
+
+        Util.getPlatform().openFile(file);
+        return 1;
+    }
 }

projects/common/src/client/java/dan200/computercraft/client/gui/AbstractComputerScreen.java

@@ -7,7 +7,7 @@ package dan200.computercraft.client.gui;
 import dan200.computercraft.client.gui.widgets.ComputerSidebar;
 import dan200.computercraft.client.gui.widgets.DynamicImageButton;
 import dan200.computercraft.client.gui.widgets.TerminalWidget;
-import dan200.computercraft.client.platform.ClientPlatformHelper;
+import dan200.computercraft.client.network.ClientNetworking;
 import dan200.computercraft.core.terminal.Terminal;
 import dan200.computercraft.shared.computer.core.ComputerFamily;
 import dan200.computercraft.shared.computer.core.InputHandler;
@@ -207,7 +207,7 @@ public abstract class AbstractComputerScreen<T extends AbstractComputerMenu> ext
             return;
         }
 
-        if (toUpload.size() > 0) UploadFileMessage.send(menu, toUpload, ClientPlatformHelper.get()::sendToServer);
+        if (toUpload.size() > 0) UploadFileMessage.send(menu, toUpload, ClientNetworking::sendToServer);
     }
 
     public void uploadResult(UploadResult result, @Nullable Component message) {

projects/common/src/client/java/dan200/computercraft/client/gui/ClientInputHandler.java

@@ -4,7 +4,7 @@
 
 package dan200.computercraft.client.gui;
 
-import dan200.computercraft.client.platform.ClientPlatformHelper;
+import dan200.computercraft.client.network.ClientNetworking;
 import dan200.computercraft.shared.computer.core.InputHandler;
 import dan200.computercraft.shared.computer.menu.ComputerMenu;
 import dan200.computercraft.shared.network.server.ComputerActionServerMessage;
@@ -29,51 +29,51 @@ public final class ClientInputHandler implements InputHandler {
 
     @Override
     public void turnOn() {
-        ClientPlatformHelper.get().sendToServer(new ComputerActionServerMessage(menu, ComputerActionServerMessage.Action.TURN_ON));
+        ClientNetworking.sendToServer(new ComputerActionServerMessage(menu, ComputerActionServerMessage.Action.TURN_ON));
     }
 
     @Override
     public void shutdown() {
-        ClientPlatformHelper.get().sendToServer(new ComputerActionServerMessage(menu, ComputerActionServerMessage.Action.SHUTDOWN));
+        ClientNetworking.sendToServer(new ComputerActionServerMessage(menu, ComputerActionServerMessage.Action.SHUTDOWN));
     }
 
     @Override
     public void reboot() {
-        ClientPlatformHelper.get().sendToServer(new ComputerActionServerMessage(menu, ComputerActionServerMessage.Action.REBOOT));
+        ClientNetworking.sendToServer(new ComputerActionServerMessage(menu, ComputerActionServerMessage.Action.REBOOT));
     }
 
     @Override
     public void queueEvent(String event, @Nullable Object[] arguments) {
-        ClientPlatformHelper.get().sendToServer(new QueueEventServerMessage(menu, event, arguments));
+        ClientNetworking.sendToServer(new QueueEventServerMessage(menu, event, arguments));
     }
 
     @Override
     public void keyDown(int key, boolean repeat) {
-        ClientPlatformHelper.get().sendToServer(new KeyEventServerMessage(menu, repeat ? KeyEventServerMessage.TYPE_REPEAT : KeyEventServerMessage.TYPE_DOWN, key));
+        ClientNetworking.sendToServer(new KeyEventServerMessage(menu, repeat ? KeyEventServerMessage.TYPE_REPEAT : KeyEventServerMessage.TYPE_DOWN, key));
     }
 
     @Override
     public void keyUp(int key) {
-        ClientPlatformHelper.get().sendToServer(new KeyEventServerMessage(menu, KeyEventServerMessage.TYPE_UP, key));
+        ClientNetworking.sendToServer(new KeyEventServerMessage(menu, KeyEventServerMessage.TYPE_UP, key));
     }
 
     @Override
     public void mouseClick(int button, int x, int y) {
-        ClientPlatformHelper.get().sendToServer(new MouseEventServerMessage(menu, MouseEventServerMessage.TYPE_CLICK, button, x, y));
+        ClientNetworking.sendToServer(new MouseEventServerMessage(menu, MouseEventServerMessage.TYPE_CLICK, button, x, y));
     }
 
     @Override
     public void mouseUp(int button, int x, int y) {
-        ClientPlatformHelper.get().sendToServer(new MouseEventServerMessage(menu, MouseEventServerMessage.TYPE_UP, button, x, y));
+        ClientNetworking.sendToServer(new MouseEventServerMessage(menu, MouseEventServerMessage.TYPE_UP, button, x, y));
     }
 
     @Override
     public void mouseDrag(int button, int x, int y) {
-        ClientPlatformHelper.get().sendToServer(new MouseEventServerMessage(menu, MouseEventServerMessage.TYPE_DRAG, button, x, y));
+        ClientNetworking.sendToServer(new MouseEventServerMessage(menu, MouseEventServerMessage.TYPE_DRAG, button, x, y));
     }
 
     @Override
     public void mouseScroll(int direction, int x, int y) {
-        ClientPlatformHelper.get().sendToServer(new MouseEventServerMessage(menu, MouseEventServerMessage.TYPE_SCROLL, direction, x, y));
+        ClientNetworking.sendToServer(new MouseEventServerMessage(menu, MouseEventServerMessage.TYPE_SCROLL, direction, x, y));
     }
 }

projects/common/src/client/java/dan200/computercraft/client/network/ClientNetworking.java

@@ -0,0 +1,28 @@
+// SPDX-FileCopyrightText: 2024 The CC: Tweaked Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+
+package dan200.computercraft.client.network;
+
+import dan200.computercraft.client.platform.ClientPlatformHelper;
+import dan200.computercraft.shared.network.NetworkMessage;
+import dan200.computercraft.shared.network.server.ServerNetworkContext;
+import net.minecraft.client.Minecraft;
+
+/**
+ * Methods for sending packets from clients to the server.
+ */
+public final class ClientNetworking {
+    private ClientNetworking() {
+    }
+
+    /**
+     * Send a network message to the server.
+     *
+     * @param message The message to send.
+     */
+    public static void sendToServer(NetworkMessage<ServerNetworkContext> message) {
+        var connection = Minecraft.getInstance().getConnection();
+        if (connection != null) connection.send(ClientPlatformHelper.get().createPacket(message));
+    }
+}

projects/common/src/client/java/dan200/computercraft/client/platform/ClientNetworkContextImpl.java

@@ -4,6 +4,7 @@
 
 package dan200.computercraft.client.platform;
 
+import com.google.auto.service.AutoService;
 import dan200.computercraft.client.ClientTableFormatter;
 import dan200.computercraft.client.gui.AbstractComputerScreen;
 import dan200.computercraft.client.gui.OptionScreen;
@@ -17,30 +18,30 @@ import dan200.computercraft.shared.computer.upload.UploadResult;
 import dan200.computercraft.shared.network.client.ClientNetworkContext;
 import dan200.computercraft.shared.peripheral.monitor.MonitorBlockEntity;
 import dan200.computercraft.shared.peripheral.speaker.SpeakerPosition;
-import io.netty.buffer.ByteBuf;
 import net.minecraft.client.Minecraft;
 import net.minecraft.core.BlockPos;
 import net.minecraft.network.chat.Component;
 import net.minecraft.resources.ResourceLocation;
+import net.minecraft.sounds.SoundEvent;
 import net.minecraft.world.entity.player.Player;
 import net.minecraft.world.level.Level;
 
 import javax.annotation.Nullable;
+import java.nio.ByteBuffer;
 import java.util.UUID;
 
 /**
- * The base implementation of {@link ClientNetworkContext}.
- * <p>
- * This should be extended by mod loader specific modules with the remaining abstract methods.
+ * The client-side implementation of {@link ClientNetworkContext}.
  */
-public abstract class AbstractClientNetworkContext implements ClientNetworkContext {
+@AutoService(ClientNetworkContext.class)
+public final class ClientNetworkContextImpl implements ClientNetworkContext {
     @Override
-    public final void handleChatTable(TableBuilder table) {
+    public void handleChatTable(TableBuilder table) {
         ClientTableFormatter.INSTANCE.display(table);
     }
 
     @Override
-    public final void handleComputerTerminal(int containerId, TerminalState terminal) {
+    public void handleComputerTerminal(int containerId, TerminalState terminal) {
         Player player = Minecraft.getInstance().player;
         if (player != null && player.containerMenu.containerId == containerId && player.containerMenu instanceof ComputerMenu menu) {
             menu.updateTerminal(terminal);
@@ -48,7 +49,7 @@ public abstract class AbstractClientNetworkContext implements ClientNetworkConte
     }
 
     @Override
-    public final void handleMonitorData(BlockPos pos, TerminalState terminal) {
+    public void handleMonitorData(BlockPos pos, TerminalState terminal) {
         var player = Minecraft.getInstance().player;
         if (player == null) return;
 
@@ -59,44 +60,46 @@ public abstract class AbstractClientNetworkContext implements ClientNetworkConte
     }
 
     @Override
-    public final void handlePocketComputerData(int instanceId, ComputerState state, int lightState, TerminalState terminal) {
+    public void handlePlayRecord(BlockPos pos, @Nullable SoundEvent sound, @Nullable String name) {
+        var mc = Minecraft.getInstance();
+        ClientPlatformHelper.get().playStreamingMusic(pos, sound);
+        if (name != null) mc.gui.setNowPlaying(Component.literal(name));
+    }
+
+    @Override
+    public void handlePocketComputerData(int instanceId, ComputerState state, int lightState, TerminalState terminal) {
         var computer = ClientPocketComputers.get(instanceId, terminal.colour);
         computer.setState(state, lightState);
         if (terminal.hasTerminal()) computer.setTerminal(terminal);
     }
 
     @Override
-    public final void handlePocketComputerDeleted(int instanceId) {
+    public void handlePocketComputerDeleted(int instanceId) {
         ClientPocketComputers.remove(instanceId);
     }
 
     @Override
-    public final void handleSpeakerAudio(UUID source, SpeakerPosition.Message position, float volume) {
-        SpeakerManager.getSound(source).playAudio(reifyPosition(position), volume);
+    public void handleSpeakerAudio(UUID source, SpeakerPosition.Message position, float volume, ByteBuffer buffer) {
+        SpeakerManager.getSound(source).playAudio(reifyPosition(position), volume, buffer);
     }
 
     @Override
-    public final void handleSpeakerAudioPush(UUID source, ByteBuf buffer) {
-        SpeakerManager.getSound(source).pushAudio(buffer);
-    }
-
-    @Override
-    public final void handleSpeakerMove(UUID source, SpeakerPosition.Message position) {
+    public void handleSpeakerMove(UUID source, SpeakerPosition.Message position) {
         SpeakerManager.moveSound(source, reifyPosition(position));
     }
 
     @Override
-    public final void handleSpeakerPlay(UUID source, SpeakerPosition.Message position, ResourceLocation sound, float volume, float pitch) {
+    public void handleSpeakerPlay(UUID source, SpeakerPosition.Message position, ResourceLocation sound, float volume, float pitch) {
         SpeakerManager.getSound(source).playSound(reifyPosition(position), sound, volume, pitch);
     }
 
     @Override
-    public final void handleSpeakerStop(UUID source) {
+    public void handleSpeakerStop(UUID source) {
         SpeakerManager.stopSound(source);
     }
 
     @Override
-    public final void handleUploadResult(int containerId, UploadResult result, @Nullable Component errorMessage) {
+    public void handleUploadResult(int containerId, UploadResult result, @Nullable Component errorMessage) {
         var minecraft = Minecraft.getInstance();
 
         var screen = OptionScreen.unwrap(minecraft.screen);

projects/common/src/client/java/dan200/computercraft/client/platform/ClientPlatformHelper.java

@@ -9,6 +9,10 @@ import dan200.computercraft.shared.network.NetworkMessage;
 import dan200.computercraft.shared.network.server.ServerNetworkContext;
 import net.minecraft.client.renderer.MultiBufferSource;
 import net.minecraft.client.resources.model.BakedModel;
+import net.minecraft.core.BlockPos;
+import net.minecraft.network.protocol.Packet;
+import net.minecraft.network.protocol.game.ServerGamePacketListener;
+import net.minecraft.sounds.SoundEvent;
 
 import javax.annotation.Nullable;
 
@@ -18,11 +22,12 @@ public interface ClientPlatformHelper extends dan200.computercraft.impl.client.C
     }
 
     /**
-     * Send a network message to the server.
+     * Convert a serverbound {@link NetworkMessage} to a Minecraft {@link Packet}.
      *
-     * @param message The message to send.
+     * @param message The messsge to convert.
+     * @return The converted message.
      */
-    void sendToServer(NetworkMessage<ServerNetworkContext> message);
+    Packet<ServerGamePacketListener> createPacket(NetworkMessage<ServerNetworkContext> message);
 
     /**
      * Render a {@link BakedModel}, using any loader-specific hooks.
@@ -35,4 +40,13 @@ public interface ClientPlatformHelper extends dan200.computercraft.impl.client.C
      * @param tints         Block colour tints to apply to the model.
      */
     void renderBakedModel(PoseStack transform, MultiBufferSource buffers, BakedModel model, int lightmapCoord, int overlayLight, @Nullable int[] tints);
+
+    /**
+     * Play a record at a particular position.
+     *
+     * @param pos   The position to play this record.
+     * @param sound The record to play, or {@code null} to stop it.
+     * @see net.minecraft.client.renderer.LevelRenderer#playStreamingMusic(SoundEvent, BlockPos)
+     */
+    void playStreamingMusic(BlockPos pos, @Nullable SoundEvent sound);
 }

projects/common/src/client/java/dan200/computercraft/client/sound/DfpwmStream.java

@@ -6,7 +6,7 @@ package dan200.computercraft.client.sound;
 
 import com.mojang.blaze3d.audio.Channel;
 import dan200.computercraft.shared.peripheral.speaker.SpeakerPeripheral;
-import io.netty.buffer.ByteBuf;
+import dan200.computercraft.shared.peripheral.speaker.SpeakerPosition;
 import net.minecraft.client.sounds.AudioStream;
 import net.minecraft.client.sounds.SoundEngine;
 import org.lwjgl.BufferUtils;
@@ -36,7 +36,7 @@ class DfpwmStream implements AudioStream {
     /**
      * The {@link Channel} which this sound is playing on.
      *
-     * @see SpeakerInstance#pushAudio(ByteBuf)
+     * @see SpeakerInstance#playAudio(SpeakerPosition, float, ByteBuffer)
      */
     @Nullable
     Channel channel;
@@ -44,7 +44,7 @@ class DfpwmStream implements AudioStream {
     /**
      * The underlying {@link SoundEngine} executor.
      *
-     * @see SpeakerInstance#pushAudio(ByteBuf)
+     * @see SpeakerInstance#playAudio(SpeakerPosition, float, ByteBuffer)
      * @see SoundEngine#executor
      */
     @Nullable
@@ -58,12 +58,12 @@ class DfpwmStream implements AudioStream {
     DfpwmStream() {
     }
 
-    void push(ByteBuf input) {
-        var readable = input.readableBytes();
+    void push(ByteBuffer input) {
+        var readable = input.remaining();
         var output = ByteBuffer.allocate(readable * 8).order(ByteOrder.nativeOrder());
 
         for (var i = 0; i < readable; i++) {
-            var inputByte = input.readByte();
+            var inputByte = input.get();
             for (var j = 0; j < 8; j++) {
                 var currentBit = (inputByte & 1) != 0;
                 var target = currentBit ? 127 : -128;

projects/common/src/client/java/dan200/computercraft/client/sound/SpeakerInstance.java

@@ -7,11 +7,11 @@ package dan200.computercraft.client.sound;
 import dan200.computercraft.api.ComputerCraftAPI;
 import dan200.computercraft.core.util.Nullability;
 import dan200.computercraft.shared.peripheral.speaker.SpeakerPosition;
-import io.netty.buffer.ByteBuf;
 import net.minecraft.client.Minecraft;
 import net.minecraft.resources.ResourceLocation;
 
 import javax.annotation.Nullable;
+import java.nio.ByteBuffer;
 
 /**
  * An instance of a speaker, which is either playing a {@link DfpwmStream} stream or a normal sound.
@@ -25,7 +25,7 @@ public class SpeakerInstance {
     SpeakerInstance() {
     }
 
-    public synchronized void pushAudio(ByteBuf buffer) {
+    private void pushAudio(ByteBuffer buffer) {
         var sound = this.sound;
 
         var stream = currentStream;
@@ -43,7 +43,9 @@ public class SpeakerInstance {
         }
     }
 
-    public void playAudio(SpeakerPosition position, float volume) {
+    public void playAudio(SpeakerPosition position, float volume, ByteBuffer buffer) {
+        pushAudio(buffer);
+
         var soundManager = Minecraft.getInstance().getSoundManager();
 
         if (sound != null && sound.stream != currentStream) {

projects/common/src/client/java/dan200/computercraft/client/turtle/TurtleUpgradeModellers.java

@@ -11,11 +11,14 @@ import dan200.computercraft.api.turtle.ITurtleAccess;
 import dan200.computercraft.api.turtle.ITurtleUpgrade;
 import dan200.computercraft.api.turtle.TurtleSide;
 import dan200.computercraft.api.turtle.TurtleUpgradeSerialiser;
+import dan200.computercraft.impl.PlatformHelper;
 import dan200.computercraft.impl.TurtleUpgrades;
 import dan200.computercraft.impl.UpgradeManager;
 import net.minecraft.client.Minecraft;
 import net.minecraft.nbt.CompoundTag;
 import net.minecraft.resources.ResourceLocation;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import java.util.Map;
 import java.util.WeakHashMap;
@@ -24,14 +27,15 @@ import java.util.stream.Stream;
 
 /**
  * A registry of {@link TurtleUpgradeModeller}s.
- *
- * @see dan200.computercraft.api.client.ComputerCraftAPIClient#registerTurtleUpgradeModeller(TurtleUpgradeSerialiser, TurtleUpgradeModeller)
  */
 public final class TurtleUpgradeModellers {
+    private static final Logger LOG = LoggerFactory.getLogger(TurtleUpgradeModellers.class);
+
     private static final TurtleUpgradeModeller<ITurtleUpgrade> NULL_TURTLE_MODELLER = (upgrade, turtle, side) ->
         new TransformedModel(Minecraft.getInstance().getModelManager().getMissingModel(), Transformation.identity());
 
     private static final Map<TurtleUpgradeSerialiser<?>, TurtleUpgradeModeller<?>> turtleModels = new ConcurrentHashMap<>();
+    private static volatile boolean fetchedModels;
 
     /**
      * In order to avoid a double lookup of {@link ITurtleUpgrade} to {@link UpgradeManager.UpgradeWrapper} to
@@ -45,12 +49,18 @@ public final class TurtleUpgradeModellers {
     }
 
     public static <T extends ITurtleUpgrade> void register(TurtleUpgradeSerialiser<T> serialiser, TurtleUpgradeModeller<T> modeller) {
-        synchronized (turtleModels) {
-            if (turtleModels.containsKey(serialiser)) {
-                throw new IllegalStateException("Modeller already registered for serialiser");
+        if (fetchedModels) {
+            // TODO(1.20.4): Replace with an error.
+            LOG.warn(
+                "Turtle upgrade serialiser {} was registered too late, its models may not be loaded correctly. If you are " +
+                    "the mod author, you may be using a deprecated API - see https://github.com/cc-tweaked/CC-Tweaked/pull/1684 " +
+                    "for further information.",
+                PlatformHelper.get().getRegistryKey(TurtleUpgradeSerialiser.registryId(), serialiser)
+            );
         }
 
-            turtleModels.put(serialiser, modeller);
+        if (turtleModels.putIfAbsent(serialiser, modeller) != null) {
+            throw new IllegalStateException("Modeller already registered for serialiser");
         }
     }
 
@@ -75,6 +85,7 @@ public final class TurtleUpgradeModellers {
     }
 
     public static Stream<ResourceLocation> getDependencies() {
+        fetchedModels = true;
         return turtleModels.values().stream().flatMap(x -> x.getDependencies().stream());
     }
 }

projects/common/src/client/resources/computercraft-client.mixins.json

@@ -1,13 +0,0 @@
-{
-    "required": true,
-    "package": "dan200.computercraft.mixin.client",
-    "minVersion": "0.8",
-    "compatibilityLevel": "JAVA_17",
-    "injectors": {
-        "defaultRequire": 1
-    },
-    "client": [
-        "ClientPacketListenerMixin"
-    ],
-    "refmap": "client-computercraft.refmap.json"
-}

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

@@ -0,0 +1,48 @@
+// SPDX-FileCopyrightText: 2024 The CC: Tweaked Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+
+package dan200.computercraft.data;
+
+import com.google.common.hash.HashCode;
+import com.google.common.hash.HashFunction;
+import com.google.common.hash.Hashing;
+import net.minecraft.data.CachedOutput;
+import net.minecraft.data.DataProvider;
+
+import java.io.IOException;
+import java.nio.file.Path;
+import java.util.concurrent.CompletableFuture;
+
+/**
+ * Wraps an existing {@link DataProvider}, passing generated JSON through {@link PrettyJsonWriter}.
+ *
+ * @param provider The provider to wrap.
+ * @param <T>      The type of the provider to wrap.
+ */
+public record PrettyDataProvider<T extends DataProvider>(T provider) implements DataProvider {
+    @Override
+    public CompletableFuture<?> run(CachedOutput cachedOutput) {
+        return provider.run(new Output(cachedOutput));
+    }
+
+    @Override
+    public String getName() {
+        return provider.getName();
+    }
+
+    private record Output(CachedOutput output) implements CachedOutput {
+        @SuppressWarnings("deprecation")
+        private static final HashFunction HASH_FUNCTION = Hashing.sha1();
+
+        @Override
+        public void writeIfNeeded(Path path, byte[] bytes, HashCode hashCode) throws IOException {
+            if (path.getFileName().toString().endsWith(".json")) {
+                bytes = PrettyJsonWriter.reformat(bytes);
+                hashCode = HASH_FUNCTION.hashBytes(bytes);
+            }
+
+            output.writeIfNeeded(path, bytes, hashCode);
+        }
+    }
+}

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

@@ -22,11 +22,10 @@ import java.util.List;
 
 /**
  * Alternative version of {@link JsonWriter} which attempts to lay out the JSON in a more compact format.
- * <p>
- * Yes, this is at least a little deranged.
+ *
+ * @see PrettyDataProvider
  */
 public class PrettyJsonWriter extends JsonWriter {
-    public static final boolean ENABLED = System.getProperty("cct.pretty-json") != null;
     private static final Gson GSON = new GsonBuilder().setPrettyPrinting().disableHtmlEscaping().create();
 
     private static final int MAX_WIDTH = 120;
@@ -44,17 +43,6 @@ public class PrettyJsonWriter extends JsonWriter {
         this.out = out;
     }
 
-    /**
-     * Create a JSON writer. This will either be a pretty or normal version, depending on whether the global flag is
-     * set.
-     *
-     * @param out The writer to emit to.
-     * @return The constructed JSON writer.
-     */
-    public static JsonWriter createWriter(Writer out) {
-        return ENABLED ? new PrettyJsonWriter(out) : new JsonWriter(out);
-    }
-
     /**
      * Reformat a JSON string with our pretty printer.
      *
@@ -62,8 +50,6 @@ public class PrettyJsonWriter extends JsonWriter {
      * @return The reformatted string.
      */
     public static byte[] reformat(byte[] contents) {
-        if (!ENABLED) return contents;
-
         JsonElement object;
         try (var reader = new InputStreamReader(new ByteArrayInputStream(contents), StandardCharsets.UTF_8)) {
             object = GSON.fromJson(reader, JsonElement.class);

projects/common/src/main/java/dan200/computercraft/impl/UpgradeManager.java

@@ -123,7 +123,7 @@ public class UpgradeManager<R extends UpgradeSerialiser<? extends T>, T extends
         // TODO: Can we track which mod this resource came from and use that instead? It's theoretically possible,
         //  but maybe not ideal for datapacks.
         var modId = id.getNamespace();
-        if (modId.equals("minecraft") || modId.equals("")) modId = ComputerCraftAPI.MOD_ID;
+        if (modId.equals("minecraft") || modId.isEmpty()) modId = ComputerCraftAPI.MOD_ID;
 
         var upgrade = serialiser.fromJson(id, root);
         if (!upgrade.getUpgradeID().equals(id)) {

projects/common/src/main/java/dan200/computercraft/mixin/CacheUpdaterMixin.java

@@ -1,25 +0,0 @@
-// SPDX-FileCopyrightText: 2022 The CC: Tweaked Developers
-//
-// SPDX-License-Identifier: MPL-2.0
-
-package dan200.computercraft.mixin;
-
-import dan200.computercraft.data.PrettyJsonWriter;
-import org.spongepowered.asm.mixin.Mixin;
-import org.spongepowered.asm.mixin.injection.At;
-import org.spongepowered.asm.mixin.injection.ModifyArg;
-
-@Mixin(targets = "net/minecraft/data/HashCache$CacheUpdater")
-public class CacheUpdaterMixin {
-    @SuppressWarnings("UnusedMethod")
-    @ModifyArg(
-        method = "writeIfNeeded",
-        at = @At(value = "INVOKE", target = "Ljava/nio/file/Files;write(Ljava/nio/file/Path;[B[Ljava/nio/file/OpenOption;)Ljava/nio/file/Path;"),
-        require = 0
-    )
-    private byte[] reformatJson(byte[] contents) {
-        // It would be cleaner to do this inside DataProvider.saveStable, but Forge's version of Mixin doesn't allow us
-        // to inject into interfaces.
-        return PrettyJsonWriter.reformat(contents);
-    }
-}

projects/common/src/main/java/dan200/computercraft/shared/command/CommandComputerCraft.java

@@ -54,7 +54,12 @@ import static net.minecraft.commands.Commands.literal;
 
 public final class CommandComputerCraft {
     public static final UUID SYSTEM_UUID = new UUID(0, 0);
-    public static final String OPEN_COMPUTER = "computercraft open-computer ";
+
+    /**
+     * The client-side command to open the folder. Ideally this would live under the main {@code computercraft}
+     * namespace, but unfortunately that overrides commands, rather than merging them.
+     */
+    public static final String CLIENT_OPEN_FOLDER = "computercraft-computer-folder";
 
     private CommandComputerCraft() {
     }
@@ -389,7 +394,7 @@ public final class CommandComputerCraft {
 
         return link(
             text("\u270E"),
-            "/" + OPEN_COMPUTER + id,
+            "/" + CLIENT_OPEN_FOLDER + " " + id,
             Component.translatable("commands.computercraft.dump.open_path")
         );
     }

projects/common/src/main/java/dan200/computercraft/shared/command/text/TableBuilder.java

@@ -7,7 +7,7 @@ package dan200.computercraft.shared.command.text;
 import dan200.computercraft.core.util.Nullability;
 import dan200.computercraft.shared.command.CommandUtils;
 import dan200.computercraft.shared.network.client.ChatTableClientMessage;
-import dan200.computercraft.shared.platform.PlatformHelper;
+import dan200.computercraft.shared.network.server.ServerNetworking;
 import net.minecraft.commands.CommandSourceStack;
 import net.minecraft.network.chat.Component;
 import net.minecraft.server.level.ServerPlayer;
@@ -105,7 +105,7 @@ public class TableBuilder {
         if (CommandUtils.isPlayer(source)) {
             trim(18);
             var player = (ServerPlayer) Nullability.assertNonNull(source.getEntity());
-            PlatformHelper.get().sendToPlayer(new ChatTableClientMessage(this), player);
+            ServerNetworking.sendToPlayer(new ChatTableClientMessage(this), player);
         } else {
             trim(100);
             new ServerTableFormatter(source).display(this);

projects/common/src/main/java/dan200/computercraft/shared/computer/blocks/AbstractComputerBlockEntity.java

@@ -25,7 +25,6 @@ import net.minecraft.core.Direction;
 import net.minecraft.nbt.CompoundTag;
 import net.minecraft.network.chat.Component;
 import net.minecraft.network.protocol.game.ClientboundBlockEntityDataPacket;
-import net.minecraft.server.level.ServerLevel;
 import net.minecraft.world.*;
 import net.minecraft.world.entity.player.Player;
 import net.minecraft.world.item.ItemStack;
@@ -51,7 +50,7 @@ public abstract class AbstractComputerBlockEntity extends BlockEntity implements
     private boolean fresh = false;
 
     private int invalidSides = 0;
-    private final ComponentAccess<IPeripheral> peripherals = PlatformHelper.get().createPeripheralAccess(d -> invalidSides |= 1 << d.ordinal());
+    private final ComponentAccess<IPeripheral> peripherals = PlatformHelper.get().createPeripheralAccess(this, d -> invalidSides |= 1 << d.ordinal());
 
     private LockCode lockCode = LockCode.NO_LOCK;
 
@@ -218,7 +217,7 @@ public abstract class AbstractComputerBlockEntity extends BlockEntity implements
         var localDir = remapToLocalSide(dir);
         if (isPeripheralBlockedOnSide(localDir)) return;
 
-        var peripheral = peripherals.get((ServerLevel) getLevel(), getBlockPos(), dir);
+        var peripheral = peripherals.get(dir);
         computer.setPeripheral(localDir, peripheral);
     }
 

projects/common/src/main/java/dan200/computercraft/shared/computer/blocks/CommandComputerBlockEntity.java

@@ -20,28 +20,24 @@ import net.minecraft.world.level.block.state.BlockState;
 import net.minecraft.world.phys.Vec2;
 import net.minecraft.world.phys.Vec3;
 
-import java.util.HashMap;
-import java.util.Map;
+import java.util.ArrayList;
+import java.util.List;
 
 public class CommandComputerBlockEntity extends ComputerBlockEntity {
     public class CommandReceiver implements CommandSource {
-        private final Map<Integer, String> output = new HashMap<>();
+        private final List<String> output = new ArrayList<>();
 
         public void clearOutput() {
             output.clear();
         }
 
-        public Map<Integer, String> getOutput() {
-            return output;
-        }
-
-        public Map<Integer, String> copyOutput() {
-            return new HashMap<>(output);
+        public List<String> copyOutput() {
+            return new ArrayList<>(output);
         }
 
         @Override
         public void sendSystemMessage(Component textComponent) {
-            output.put(output.size() + 1, textComponent.getString());
+            output.add(textComponent.getString());
         }
 
         @Override

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

@@ -20,7 +20,7 @@ import dan200.computercraft.shared.config.Config;
 import dan200.computercraft.shared.network.NetworkMessage;
 import dan200.computercraft.shared.network.client.ClientNetworkContext;
 import dan200.computercraft.shared.network.client.ComputerTerminalClientMessage;
-import dan200.computercraft.shared.platform.PlatformHelper;
+import dan200.computercraft.shared.network.server.ServerNetworking;
 import net.minecraft.core.BlockPos;
 import net.minecraft.server.level.ServerLevel;
 import net.minecraft.world.inventory.AbstractContainerMenu;
@@ -142,7 +142,7 @@ public class ServerComputer implements InputHandler, ComputerEnvironment {
 
         for (var player : server.getPlayerList().getPlayers()) {
             if (player.containerMenu instanceof ComputerMenu && ((ComputerMenu) player.containerMenu).getComputer() == this) {
-                PlatformHelper.get().sendToPlayer(createPacket.apply(player.containerMenu), player);
+                ServerNetworking.sendToPlayer(createPacket.apply(player.containerMenu), player);
             }
         }
     }

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

@@ -11,7 +11,7 @@ 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 dan200.computercraft.shared.network.server.ServerNetworking;
 import it.unimi.dsi.fastutil.ints.IntOpenHashSet;
 import it.unimi.dsi.fastutil.ints.IntSet;
 import net.minecraft.network.chat.Component;
@@ -138,7 +138,7 @@ public class ServerInputState<T extends AbstractContainerMenu & ComputerMenu> im
             return;
         }
 
-        PlatformHelper.get().sendToPlayer(finishUpload(uploader), uploader);
+        ServerNetworking.sendToPlayer(finishUpload(uploader), uploader);
     }
 
     private UploadResultMessage finishUpload(ServerPlayer player) {
@@ -159,7 +159,7 @@ public class ServerInputState<T extends AbstractContainerMenu & ComputerMenu> im
                 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);
+                        ServerNetworking.sendToPlayer(UploadResultMessage.consumed(owner), player);
                     }
                 }),
         });

projects/common/src/main/java/dan200/computercraft/shared/config/ConfigSpec.java

@@ -224,7 +224,7 @@ public final class ConfigSpec {
                 .defineInRange("max_requests", CoreConfig.httpMaxRequests, 0, Integer.MAX_VALUE);
 
             httpMaxWebsockets = builder
-                .comment("The number of websockets a computer can have open at one time. Set to 0 for unlimited.")
+                .comment("The number of websockets a computer can have open at one time.")
                 .defineInRange("max_websockets", CoreConfig.httpMaxWebsockets, 1, Integer.MAX_VALUE);
 
             builder

projects/common/src/main/java/dan200/computercraft/shared/network/client/ClientNetworkContext.java

@@ -4,30 +4,24 @@
 
 package dan200.computercraft.shared.network.client;
 
-import dan200.computercraft.impl.Services;
 import dan200.computercraft.shared.command.text.TableBuilder;
 import dan200.computercraft.shared.computer.core.ComputerState;
 import dan200.computercraft.shared.computer.terminal.TerminalState;
 import dan200.computercraft.shared.computer.upload.UploadResult;
 import dan200.computercraft.shared.peripheral.speaker.SpeakerPosition;
-import io.netty.buffer.ByteBuf;
 import net.minecraft.core.BlockPos;
 import net.minecraft.network.chat.Component;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.sounds.SoundEvent;
 
 import javax.annotation.Nullable;
+import java.nio.ByteBuffer;
 import java.util.UUID;
 
 /**
  * The context under which clientbound packets are evaluated.
  */
 public interface ClientNetworkContext {
-    static ClientNetworkContext get() {
-        var instance = Instance.INSTANCE;
-        return instance == null ? Services.raise(ClientNetworkContext.class, Instance.ERROR) : instance;
-    }
-
     void handleChatTable(TableBuilder table);
 
     void handleComputerTerminal(int containerId, TerminalState terminal);
@@ -40,9 +34,7 @@ public interface ClientNetworkContext {
 
     void handlePocketComputerDeleted(int instanceId);
 
-    void handleSpeakerAudio(UUID source, SpeakerPosition.Message position, float volume);
-
-    void handleSpeakerAudioPush(UUID source, ByteBuf buffer);
+    void handleSpeakerAudio(UUID source, SpeakerPosition.Message position, float volume, ByteBuffer audio);
 
     void handleSpeakerMove(UUID source, SpeakerPosition.Message position);
 
@@ -51,18 +43,4 @@ public interface ClientNetworkContext {
     void handleSpeakerStop(UUID source);
 
     void handleUploadResult(int containerId, UploadResult result, @Nullable Component errorMessage);
-
-    final class Instance {
-        static final @Nullable ClientNetworkContext INSTANCE;
-        static final @Nullable Throwable ERROR;
-
-        static {
-            var helper = Services.tryLoad(ClientNetworkContext.class);
-            INSTANCE = helper.instance();
-            ERROR = helper.error();
-        }
-
-        private Instance() {
-        }
-    }
 }

projects/common/src/main/java/dan200/computercraft/shared/network/client/SpeakerAudioClientMessage.java

@@ -11,12 +11,9 @@ import dan200.computercraft.shared.peripheral.speaker.SpeakerBlockEntity;
 import dan200.computercraft.shared.peripheral.speaker.SpeakerPosition;
 import net.minecraft.network.FriendlyByteBuf;
 
-import javax.annotation.Nullable;
 import java.nio.ByteBuffer;
 import java.util.UUID;
 
-import static dan200.computercraft.core.util.Nullability.assertNonNull;
-
 /**
  * Starts a sound on the client.
  * <p>
@@ -27,7 +24,7 @@ import static dan200.computercraft.core.util.Nullability.assertNonNull;
 public class SpeakerAudioClientMessage implements NetworkMessage<ClientNetworkContext> {
     private final UUID source;
     private final SpeakerPosition.Message pos;
-    private final @Nullable ByteBuffer content;
+    private final ByteBuffer content;
     private final float volume;
 
     public SpeakerAudioClientMessage(UUID source, SpeakerPosition pos, float volume, ByteBuffer content) {
@@ -42,10 +39,9 @@ public class SpeakerAudioClientMessage implements NetworkMessage<ClientNetworkCo
         pos = SpeakerPosition.Message.read(buf);
         volume = buf.readFloat();
 
-        // TODO: Remove this, so we no longer need a getter for ClientNetworkContext. However, doing so without
-        //  leaking or redundantly copying the buffer is hard.
-        ClientNetworkContext.get().handleSpeakerAudioPush(source, buf);
-        content = null;
+        var bytes = new byte[buf.readableBytes()];
+        buf.readBytes(bytes);
+        content = ByteBuffer.wrap(bytes);
     }
 
     @Override
@@ -53,12 +49,12 @@ public class SpeakerAudioClientMessage implements NetworkMessage<ClientNetworkCo
         buf.writeUUID(source);
         pos.write(buf);
         buf.writeFloat(volume);
-        buf.writeBytes(assertNonNull(content).duplicate());
+        buf.writeBytes(content.duplicate());
     }
 
     @Override
     public void handle(ClientNetworkContext context) {
-        context.handleSpeakerAudio(source, pos, volume);
+        context.handleSpeakerAudio(source, pos, volume, content);
     }
 
     @Override

projects/common/src/main/java/dan200/computercraft/shared/network/server/ServerNetworking.java

@@ -0,0 +1,82 @@
+// SPDX-FileCopyrightText: 2024 The CC: Tweaked Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+
+package dan200.computercraft.shared.network.server;
+
+import dan200.computercraft.shared.network.NetworkMessage;
+import dan200.computercraft.shared.network.client.ClientNetworkContext;
+import dan200.computercraft.shared.platform.PlatformHelper;
+import net.minecraft.server.MinecraftServer;
+import net.minecraft.server.level.ServerChunkCache;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.world.level.chunk.LevelChunk;
+import net.minecraft.world.phys.Vec3;
+
+import java.util.Collection;
+
+/**
+ * Methods for sending network messages from the server to clients.
+ */
+public final class ServerNetworking {
+    private ServerNetworking() {
+    }
+
+    /**
+     * Send a message to a specific player.
+     *
+     * @param message The message to send.
+     * @param player  The player to send it to.
+     */
+    public static void sendToPlayer(NetworkMessage<ClientNetworkContext> message, ServerPlayer player) {
+        player.connection.send(PlatformHelper.get().createPacket(message));
+    }
+
+    /**
+     * Send a message to a set of players.
+     *
+     * @param message The message to send.
+     * @param players The players to send it to.
+     */
+    public static void sendToPlayers(NetworkMessage<ClientNetworkContext> message, Collection<ServerPlayer> players) {
+        if (players.isEmpty()) return;
+        var packet = PlatformHelper.get().createPacket(message);
+        for (var player : players) player.connection.send(packet);
+    }
+
+    /**
+     * Send a message to all players.
+     *
+     * @param message The message to send.
+     * @param server  The current server.
+     */
+    public static void sendToAllPlayers(NetworkMessage<ClientNetworkContext> message, MinecraftServer server) {
+        server.getPlayerList().broadcastAll(PlatformHelper.get().createPacket(message));
+    }
+
+    /**
+     * Send a message to all players around a point.
+     *
+     * @param message  The message to send.
+     * @param level    The level the point is in.
+     * @param pos      The centre position.
+     * @param distance The distance to the centre players must be within.
+     */
+    public static void sendToAllAround(NetworkMessage<ClientNetworkContext> message, ServerLevel level, Vec3 pos, float distance) {
+        level.getServer().getPlayerList().broadcast(null, pos.x, pos.y, pos.z, distance, level.dimension(), PlatformHelper.get().createPacket(message));
+    }
+
+    /**
+     * Send a message to all players tracking a chunk.
+     *
+     * @param message The message to send.
+     * @param chunk   The chunk players must be tracking.
+     */
+    public static void sendToAllTracking(NetworkMessage<ClientNetworkContext> message, LevelChunk chunk) {
+        var packet = PlatformHelper.get().createPacket(message);
+        for (var player : ((ServerChunkCache) chunk.getLevel().getChunkSource()).chunkMap.getPlayers(chunk.getPos(), false)) {
+            player.connection.send(packet);
+        }
+    }
+}

projects/common/src/main/java/dan200/computercraft/shared/peripheral/diskdrive/DiskDriveBlockEntity.java

@@ -7,11 +7,12 @@ package dan200.computercraft.shared.peripheral.diskdrive;
 import com.google.errorprone.annotations.concurrent.GuardedBy;
 import dan200.computercraft.api.filesystem.Mount;
 import dan200.computercraft.api.filesystem.WritableMount;
+import dan200.computercraft.api.media.IMedia;
 import dan200.computercraft.api.peripheral.IComputerAccess;
 import dan200.computercraft.api.peripheral.IPeripheral;
 import dan200.computercraft.shared.common.AbstractContainerBlockEntity;
 import dan200.computercraft.shared.network.client.PlayRecordClientMessage;
-import dan200.computercraft.shared.platform.PlatformHelper;
+import dan200.computercraft.shared.network.server.ServerNetworking;
 import dan200.computercraft.shared.util.WorldUtil;
 import net.minecraft.core.BlockPos;
 import net.minecraft.core.Direction;
@@ -32,6 +33,28 @@ import java.util.Map;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicReference;
 
+/**
+ * The underlying block entity for disk drives. This holds the main logic for the {@linkplain DiskDrivePeripheral disk
+ * drive peripheral}, such as handling mounts and {@linkplain DiskDrivePeripheral#playAudio() playing audio}.
+ * <p>
+ * Most disk drive peripheral methods execute on the computer thread (largely due to historic reasons). This causes some
+ * problems, as the disk item could be read by both the computer thread (via peripheral calls) and main thread (via
+ * Minecraft inventory interaction).
+ * <p>
+ * To solve this, we use an immutable {@link MediaStack}, which holds an immutable version of the current
+ * {@link ItemStack} (and its corresponding {@link IMedia}). When the {@linkplain #setChanged() inventory is changed},
+ * we {@linkplain #updateMedia() update the media stack} and recompute mounts.
+ * <p>
+ * This is somewhat complicated by {@link #attach(IComputerAccess)}. As that can happen on the computer thread and
+ * may mutate the stack (when {@link IMedia#createDataMount(ItemStack, ServerLevel)} assigns an ID for the first time),
+ * we need a way to safely update the inventory. To solve this, all internal non-inventory interactions with disk drives
+ * treat the media stack as the "primary" stack. This allows us to atomically update it, and then sync it back to the
+ * main inventory ({@link #updateMediaStack(ItemStack, boolean)}) either directly ({@link #updateDiskFromMedia()}) or
+ * on the next block tick ({@link #stackDirty}). This does mean there's a one-tick delay where the inventory may be
+ * out-of-date, but that should happen very rarely.
+ *
+ * @see DiskDrivePeripheral
+ */
 public final class DiskDriveBlockEntity extends AbstractContainerBlockEntity {
     private static final String NBT_ITEM = "Item";
 
@@ -42,11 +65,13 @@ public final class DiskDriveBlockEntity extends AbstractContainerBlockEntity {
 
     private final DiskDrivePeripheral peripheral = new DiskDrivePeripheral(this);
 
-    private final @GuardedBy("this") Map<IComputerAccess, MountInfo> computers = new HashMap<>();
-
     private final NonNullList<ItemStack> inventory = NonNullList.withSize(1, ItemStack.EMPTY);
 
+    @GuardedBy("this")
+    private final Map<IComputerAccess, MountInfo> computers = new HashMap<>();
+    @GuardedBy("this")
     private MediaStack media = MediaStack.EMPTY;
+    @GuardedBy("this")
     private @Nullable Mount mount;
 
     private boolean recordPlaying = false;
@@ -54,7 +79,12 @@ public final class DiskDriveBlockEntity extends AbstractContainerBlockEntity {
     // then read them when ticking.
     private final AtomicReference<RecordCommand> recordQueued = new AtomicReference<>(null);
     private final AtomicBoolean ejectQueued = new AtomicBoolean(false);
-    private final AtomicBoolean mountQueued = new AtomicBoolean(false);
+
+    /**
+     * Whether the stack in {@link #media} has been modified on the computer thread, and needs to be written back to the
+     * inventory on the main thread.
+     */
+    private final AtomicBoolean stackDirty = new AtomicBoolean(false);
 
     public DiskDriveBlockEntity(BlockEntityType<DiskDriveBlockEntity> type, BlockPos pos, BlockState state) {
         super(type, pos, state);
@@ -66,7 +96,7 @@ public final class DiskDriveBlockEntity extends AbstractContainerBlockEntity {
 
     @Override
     public void clearRemoved() {
-        updateItem();
+        updateMedia();
     }
 
     @Override
@@ -93,12 +123,14 @@ public final class DiskDriveBlockEntity extends AbstractContainerBlockEntity {
     }
 
     void serverTick() {
+        if (stackDirty.getAndSet(false)) updateDiskFromMedia();
         if (ejectQueued.getAndSet(false)) ejectContents();
 
         var recordQueued = this.recordQueued.getAndSet(null);
         if (recordQueued != null) {
             switch (recordQueued) {
                 case PLAY -> {
+                    var media = getMedia();
                     var record = media.getAudio();
                     if (record != null) {
                         recordPlaying = true;
@@ -112,12 +144,6 @@ public final class DiskDriveBlockEntity extends AbstractContainerBlockEntity {
                 }
             }
         }
-
-        if (mountQueued.get()) {
-            synchronized (this) {
-                mountAll();
-            }
-        }
     }
 
     @Override
@@ -127,25 +153,27 @@ public final class DiskDriveBlockEntity extends AbstractContainerBlockEntity {
 
     @Override
     public void setChanged() {
-        if (level != null && !level.isClientSide) updateItem();
+        if (level != null && !level.isClientSide) updateMedia();
         super.setChanged();
     }
 
-    private void updateItem() {
-        var newDisk = getDiskStack();
-        if (ItemStack.isSameItemSameTags(newDisk, media.stack)) return;
+    /**
+     * Called on the server after the item has changed. This unmounts the old media and mounts the new one.
+     */
+    private synchronized void updateMedia() {
+        var newStack = getDiskStack();
+        if (ItemStack.isSameItemSameTags(newStack, media.stack())) return;
 
-        var media = MediaStack.of(newDisk);
+        var newMedia = MediaStack.of(newStack);
 
-        if (newDisk.isEmpty()) {
+        if (newStack.isEmpty()) {
             updateBlockState(DiskDriveState.EMPTY);
         } else {
-            updateBlockState(media.media != null ? DiskDriveState.FULL : DiskDriveState.INVALID);
+            updateBlockState(newMedia.media() != null ? DiskDriveState.FULL : DiskDriveState.INVALID);
         }
 
-        synchronized (this) {
         // Unmount old disk
-            if (!this.media.stack.isEmpty()) {
+        if (!media.stack().isEmpty()) {
             for (var computer : computers.entrySet()) unmountDisk(computer.getKey(), computer.getValue());
         }
 
@@ -155,10 +183,16 @@ public final class DiskDriveBlockEntity extends AbstractContainerBlockEntity {
             recordPlaying = false;
         }
 
+        // Use our new media, and (if needed) mount the new disk.
         mount = null;
-            this.media = media;
+        media = newMedia;
+        stackDirty.set(false);
 
-            mountAll();
+        if (!newStack.isEmpty() && !computers.isEmpty()) {
+            var mount = getOrCreateMount(true);
+            for (var entry : computers.entrySet()) {
+                mountDisk(entry.getKey(), entry.getValue(), mount);
+            }
         }
     }
 
@@ -166,7 +200,7 @@ public final class DiskDriveBlockEntity extends AbstractContainerBlockEntity {
         return getItem(0);
     }
 
-    MediaStack getMedia() {
+    synchronized MediaStack getMedia() {
         return media;
     }
 
@@ -181,17 +215,32 @@ public final class DiskDriveBlockEntity extends AbstractContainerBlockEntity {
     }
 
     /**
-     * Update the current disk stack, assuming the underlying item does not change. Unlike
-     * {@link #setDiskStack(ItemStack)} this will not change any mounts.
-     *
-     * @param stack The new disk stack.
+     * Update the inventory's disk stack from the media stack. Unlike {@link #setDiskStack(ItemStack)} this will not
+     * change any mounts.
      */
-    void updateDiskStack(ItemStack stack) {
-        setItem(0, stack);
-        if (!ItemStack.isSameItemSameTags(stack, media.stack)) {
-            media = MediaStack.of(stack);
+    private synchronized void updateDiskFromMedia() {
+        // Write back the item to the main inventory, and then mark it as dirty.
+        setItem(0, media.stack().copy());
         super.setChanged();
     }
+
+    /**
+     * Atomically update {@link #media}'s stack, then sync it back to the main inventory.
+     *
+     * @param stack     The original stack.
+     * @param immediate Whether to do this immediately (when called from the main thread) or asynchronously (when called
+     *                  from the computer thread).
+     */
+    @GuardedBy("this")
+    private void updateMediaStack(ItemStack stack, boolean immediate) {
+        if (ItemStack.isSameItemSameTags(media.stack(), stack)) return;
+        media = new MediaStack(stack, media.media());
+
+        if (immediate) {
+            updateDiskFromMedia();
+        } else {
+            stackDirty.set(true);
+        }
     }
 
     @Nullable
@@ -212,7 +261,9 @@ public final class DiskDriveBlockEntity extends AbstractContainerBlockEntity {
         synchronized (this) {
             var info = new MountInfo();
             computers.put(computer, info);
-            mountQueued.set(true);
+            if (!media.stack().isEmpty()) {
+                mountDisk(computer, info, getOrCreateMount(level instanceof ServerLevel l && l.getServer().isSameThread()));
+            }
         }
     }
 
@@ -234,35 +285,31 @@ public final class DiskDriveBlockEntity extends AbstractContainerBlockEntity {
         ejectQueued.set(true);
     }
 
-    /**
-     * Add our mount to all computers.
-     */
-    @GuardedBy("this")
-    private void mountAll() {
-        doMountAll();
-        mountQueued.set(false);
+    synchronized MountResult setDiskLabel(@Nullable String label) {
+        if (media.media() == null) return MountResult.NO_MEDIA;
+
+        // Set the label, and write it back to the media stack.
+        var stack = media.stack().copy();
+        if (!media.media().setLabel(stack, label)) return MountResult.NOT_ALLOWED;
+        updateMediaStack(stack, true);
+
+        return MountResult.CHANGED;
     }
 
-    /**
-     * The worker for {@link #mountAll()}. This is responsible for creating the mount and placing it on all computers.
-     */
     @GuardedBy("this")
-    private void doMountAll() {
-        if (computers.isEmpty() || media.media == null) return;
+    private @Nullable Mount getOrCreateMount(boolean immediate) {
+        if (media.media() == null) return null;
+        if (mount != null) return mount;
 
-        if (mount == null) {
-            var stack = getDiskStack();
-            mount = media.media.createDataMount(stack, (ServerLevel) level);
-            setDiskStack(stack);
+        // Set the id (if needed) and write it back to the media stack.
+        var stack = media.stack().copy();
+        mount = media.media().createDataMount(stack, (ServerLevel) level);
+        updateMediaStack(stack, immediate);
+
+        return mount;
     }
 
-        if (mount == null) return;
-
-        for (var entry : computers.entrySet()) {
-            var computer = entry.getKey();
-            var info = entry.getValue();
-            if (info.mountPath != null) continue;
-
+    private static void mountDisk(IComputerAccess computer, MountInfo info, @Nullable Mount mount) {
         if (mount instanceof WritableMount writable) {
             // Try mounting at the lowest numbered "disk" name we can
             var n = 1;
@@ -270,18 +317,19 @@ public final class DiskDriveBlockEntity extends AbstractContainerBlockEntity {
                 info.mountPath = computer.mountWritable(n == 1 ? "disk" : "disk" + n, writable);
                 n++;
             }
-            } else {
+        } else if (mount != null) {
             // Try mounting at the lowest numbered "disk" name we can
             var n = 1;
             while (info.mountPath == null) {
                 info.mountPath = computer.mount(n == 1 ? "disk" : "disk" + n, mount);
                 n++;
             }
+        } else {
+            assert info.mountPath == null : "Mount path should be null";
         }
 
         computer.queueEvent("disk", computer.getAttachmentName());
     }
-    }
 
     private static void unmountDisk(IComputerAccess computer, MountInfo info) {
         if (info.mountPath != null) {
@@ -315,7 +363,7 @@ public final class DiskDriveBlockEntity extends AbstractContainerBlockEntity {
     }
 
     private void sendMessage(PlayRecordClientMessage message) {
-        PlatformHelper.get().sendToAllAround(message, (ServerLevel) getLevel(), Vec3.atCenterOf(getBlockPos()), 64);
+        ServerNetworking.sendToAllAround(message, (ServerLevel) getLevel(), Vec3.atCenterOf(getBlockPos()), 64);
     }
 
     @Override
@@ -327,4 +375,10 @@ public final class DiskDriveBlockEntity extends AbstractContainerBlockEntity {
         PLAY,
         STOP,
     }
+
+    enum MountResult {
+        NO_MEDIA,
+        NOT_ALLOWED,
+        CHANGED,
+    }
 }

projects/common/src/main/java/dan200/computercraft/shared/peripheral/diskdrive/DiskDrivePeripheral.java

@@ -51,7 +51,7 @@ public class DiskDrivePeripheral implements IPeripheral {
      */
     @LuaFunction
     public final boolean isDiskPresent() {
-        return !diskDrive.getMedia().stack.isEmpty();
+        return !diskDrive.getMedia().stack().isEmpty();
     }
 
     /**
@@ -64,7 +64,7 @@ public class DiskDrivePeripheral implements IPeripheral {
     @LuaFunction
     public final Object[] getDiskLabel() {
         var media = diskDrive.getMedia();
-        return media.media == null ? null : new Object[]{ media.media.getLabel(media.stack) };
+        return media.media() == null ? null : new Object[]{ media.media().getLabel(media.stack()) };
     }
 
     /**
@@ -80,15 +80,11 @@ public class DiskDrivePeripheral implements IPeripheral {
      */
     @LuaFunction(mainThread = true)
     public final void setDiskLabel(Optional<String> label) throws LuaException {
-        var media = diskDrive.getMedia();
-        if (media.media == null) return;
-
-        // We're on the main thread so the stack and media should be in sync.
-        var stack = diskDrive.getDiskStack();
-        if (!media.media.setLabel(stack, label.map(StringUtil::normaliseLabel).orElse(null))) {
-            throw new LuaException("Disk label cannot be changed");
+        switch (diskDrive.setDiskLabel(label.map(StringUtil::normaliseLabel).orElse(null))) {
+            case NOT_ALLOWED -> throw new LuaException("Disk label cannot be changed");
+            case CHANGED, NO_MEDIA -> {
+            }
         }
-        diskDrive.updateDiskStack(stack);
     }
 
     /**
@@ -172,7 +168,7 @@ public class DiskDrivePeripheral implements IPeripheral {
     @Nullable
     @LuaFunction
     public final Object[] getDiskID() {
-        var disk = diskDrive.getMedia().stack;
+        var disk = diskDrive.getMedia().stack();
         return disk.getItem() instanceof DiskItem ? new Object[]{ DiskItem.getDiskID(disk) } : null;
     }
 

projects/common/src/main/java/dan200/computercraft/shared/peripheral/diskdrive/MediaStack.java

@@ -13,19 +13,14 @@ import javax.annotation.Nullable;
 
 /**
  * An immutable snapshot of the current disk. This allows us to read the stack in a thread-safe manner.
+ *
+ * @param stack An immutable {@link ItemStack}.
+ * @param media The associated {@link IMedia} instance for this stack.
  */
-final class MediaStack {
+record MediaStack(ItemStack stack, @Nullable IMedia media) {
     static final MediaStack EMPTY = new MediaStack(ItemStack.EMPTY, null);
 
-    final ItemStack stack;
-    final @Nullable IMedia media;
-
-    private MediaStack(ItemStack stack, @Nullable IMedia media) {
-        this.stack = stack;
-        this.media = media;
-    }
-
-    public static MediaStack of(ItemStack stack) {
+    static MediaStack of(ItemStack stack) {
         if (stack.isEmpty()) return EMPTY;
 
         var freshStack = stack.copy();

projects/common/src/main/java/dan200/computercraft/shared/peripheral/generic/ComponentLookup.java

@@ -6,7 +6,7 @@ package dan200.computercraft.shared.peripheral.generic;
 
 import net.minecraft.core.BlockPos;
 import net.minecraft.core.Direction;
-import net.minecraft.world.level.Level;
+import net.minecraft.server.level.ServerLevel;
 import net.minecraft.world.level.block.entity.BlockEntity;
 import net.minecraft.world.level.block.state.BlockState;
 
@@ -32,5 +32,5 @@ public interface ComponentLookup<C extends Runnable> {
      * @return The found component, or {@code null} if not present.
      */
     @Nullable
-    Object find(Level level, BlockPos pos, BlockState state, BlockEntity blockEntity, Direction side, C invalidate);
+    Object find(ServerLevel level, BlockPos pos, BlockState state, BlockEntity blockEntity, Direction side, C invalidate);
 }

projects/common/src/main/java/dan200/computercraft/shared/peripheral/generic/GenericPeripheralProvider.java

@@ -11,7 +11,7 @@ import dan200.computercraft.core.methods.PeripheralMethod;
 import dan200.computercraft.shared.computer.core.ServerContext;
 import net.minecraft.core.BlockPos;
 import net.minecraft.core.Direction;
-import net.minecraft.world.level.Level;
+import net.minecraft.server.level.ServerLevel;
 import net.minecraft.world.level.block.entity.BlockEntity;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -43,7 +43,7 @@ public final class GenericPeripheralProvider<C extends Runnable> {
         if (!lookups.contains(lookup)) lookups.add(lookup);
     }
 
-    public void forEachMethod(MethodSupplier<PeripheralMethod> methods, Level level, BlockPos pos, Direction side, BlockEntity blockEntity, C invalidate, MethodSupplier.TargetedConsumer<PeripheralMethod> consumer) {
+    public void forEachMethod(MethodSupplier<PeripheralMethod> methods, ServerLevel level, BlockPos pos, Direction side, BlockEntity blockEntity, C invalidate, MethodSupplier.TargetedConsumer<PeripheralMethod> consumer) {
         methods.forEachMethod(blockEntity, consumer);
 
         for (var lookup : lookups) {
@@ -53,17 +53,11 @@ public final class GenericPeripheralProvider<C extends Runnable> {
     }
 
     @Nullable
-    public IPeripheral getPeripheral(Level level, BlockPos pos, Direction side, @Nullable BlockEntity blockEntity, C invalidate) {
+    public IPeripheral getPeripheral(ServerLevel level, BlockPos pos, Direction side, @Nullable BlockEntity blockEntity, C invalidate) {
         if (blockEntity == null) return null;
 
-        var server = level.getServer();
-        if (server == null) {
-            LOG.warn("Fetching peripherals on a non-server level {}.", level, new IllegalStateException("Fetching peripherals on a non-server level."));
-            return null;
-        }
-
         var builder = new GenericPeripheralBuilder();
-        forEachMethod(ServerContext.get(server).peripheralMethods(), level, pos, side, blockEntity, invalidate, builder::addMethod);
+        forEachMethod(ServerContext.get(level.getServer()).peripheralMethods(), level, pos, side, blockEntity, invalidate, builder::addMethod);
         return builder.toPeripheral(blockEntity, side);
     }
 }

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

@@ -18,7 +18,6 @@ import net.minecraft.core.BlockPos;
 import net.minecraft.core.Direction;
 import net.minecraft.nbt.CompoundTag;
 import net.minecraft.network.chat.Component;
-import net.minecraft.server.level.ServerLevel;
 import net.minecraft.world.InteractionResult;
 import net.minecraft.world.entity.player.Player;
 import net.minecraft.world.item.ItemStack;
@@ -60,10 +59,11 @@ public class CableBlockEntity extends BlockEntity {
 
     private boolean invalidPeripheral;
     private boolean peripheralAccessAllowed;
-    private final WiredModemLocalPeripheral peripheral = new WiredModemLocalPeripheral(this::queueRefreshPeripheral);
+    private final WiredModemLocalPeripheral peripheral = new WiredModemLocalPeripheral(PlatformHelper.get().createPeripheralAccess(this, x -> queueRefreshPeripheral()));
     private @Nullable Runnable modemChanged;
 
     private boolean connectionsFormed = false;
+    private boolean connectionsChanged = false;
 
     private final WiredModemElement cable = new CableElement();
     private final WiredNode node = cable.getNode();
@@ -88,7 +88,7 @@ public class CableBlockEntity extends BlockEntity {
         }
     };
 
-    private final ComponentAccess<WiredElement> connectedElements = PlatformHelper.get().createWiredElementAccess(x -> connectionsChanged());
+    private final ComponentAccess<WiredElement> connectedElements = PlatformHelper.get().createWiredElementAccess(this, x -> scheduleConnectionsChanged());
 
     public CableBlockEntity(BlockEntityType<? extends CableBlockEntity> type, BlockPos pos, BlockState state) {
         super(type, pos, state);
@@ -237,10 +237,18 @@ public class CableBlockEntity extends BlockEntity {
                 updateConnectedPeripherals();
             }
         }
+
+        if (connectionsChanged) connectionsChanged();
+    }
+
+    private void scheduleConnectionsChanged() {
+        connectionsChanged = true;
+        TickScheduler.schedule(tickToken);
     }
 
     void connectionsChanged() {
         if (getLevel().isClientSide) return;
+        connectionsChanged = false;
 
         var state = getBlockState();
         var world = getLevel();
@@ -249,7 +257,7 @@ public class CableBlockEntity extends BlockEntity {
             var offset = current.relative(facing);
             if (!world.isLoaded(offset)) continue;
 
-            var element = connectedElements.get((ServerLevel) world, current, facing);
+            var element = connectedElements.get(facing);
             if (element == null) continue;
 
             var node = element.getNode();

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

@@ -17,7 +17,6 @@ import net.minecraft.core.BlockPos;
 import net.minecraft.core.Direction;
 import net.minecraft.nbt.CompoundTag;
 import net.minecraft.network.chat.Component;
-import net.minecraft.server.level.ServerLevel;
 import net.minecraft.world.InteractionResult;
 import net.minecraft.world.entity.player.Player;
 import net.minecraft.world.level.Level;
@@ -75,21 +74,22 @@ public class WiredModemFullBlockEntity extends BlockEntity {
     private final WiredModemLocalPeripheral[] peripherals = new WiredModemLocalPeripheral[6];
 
     private boolean connectionsFormed = false;
+    private boolean connectionsChanged = false;
 
     private final TickScheduler.Token tickToken = new TickScheduler.Token(this);
     private final ModemState modemState = new ModemState(() -> TickScheduler.schedule(tickToken));
     private final WiredModemElement element = new FullElement(this);
     private final WiredNode node = element.getNode();
 
-    private final ComponentAccess<WiredElement> connectedElements = PlatformHelper.get().createWiredElementAccess(x -> connectionsChanged());
+    private final ComponentAccess<WiredElement> connectedElements = PlatformHelper.get().createWiredElementAccess(this, x -> scheduleConnectionsChanged());
 
     private int invalidSides = 0;
 
     public WiredModemFullBlockEntity(BlockEntityType<WiredModemFullBlockEntity> type, BlockPos pos, BlockState state) {
         super(type, pos, state);
+        var peripheralAccess = PlatformHelper.get().createPeripheralAccess(this, this::queueRefreshPeripheral);
         for (var i = 0; i < peripherals.length; i++) {
-            var facing = Direction.from3DDataValue(i);
-            peripherals[i] = new WiredModemLocalPeripheral(() -> queueRefreshPeripheral(facing));
+            peripherals[i] = new WiredModemLocalPeripheral(peripheralAccess);
         }
     }
 
@@ -205,10 +205,18 @@ public class WiredModemFullBlockEntity extends BlockEntity {
                 updateConnectedPeripherals();
             }
         }
+
+        if (connectionsChanged) connectionsChanged();
+    }
+
+    private void scheduleConnectionsChanged() {
+        connectionsChanged = true;
+        TickScheduler.schedule(tickToken);
     }
 
     private void connectionsChanged() {
         if (getLevel().isClientSide) return;
+        connectionsChanged = false;
 
         var world = getLevel();
         var current = getBlockPos();
@@ -216,7 +224,7 @@ public class WiredModemFullBlockEntity extends BlockEntity {
             var offset = current.relative(facing);
             if (!world.isLoaded(offset)) continue;
 
-            var element = connectedElements.get((ServerLevel) getLevel(), getBlockPos(), facing);
+            var element = connectedElements.get(facing);
             if (element == null) continue;
 
             node.connectTo(element.getNode());

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

@@ -8,12 +8,10 @@ import dan200.computercraft.api.ComputerCraftTags;
 import dan200.computercraft.api.peripheral.IPeripheral;
 import dan200.computercraft.shared.computer.core.ServerContext;
 import dan200.computercraft.shared.platform.ComponentAccess;
-import dan200.computercraft.shared.platform.PlatformHelper;
 import net.minecraft.core.BlockPos;
 import net.minecraft.core.Direction;
 import net.minecraft.nbt.CompoundTag;
 import net.minecraft.nbt.Tag;
-import net.minecraft.server.level.ServerLevel;
 import net.minecraft.world.level.Level;
 
 import javax.annotation.Nullable;
@@ -38,8 +36,8 @@ public final class WiredModemLocalPeripheral {
     private @Nullable IPeripheral peripheral;
     private final ComponentAccess<IPeripheral> peripherals;
 
-    public WiredModemLocalPeripheral(Runnable invalidate) {
-        peripherals = PlatformHelper.get().createPeripheralAccess(x -> invalidate.run());
+    public WiredModemLocalPeripheral(ComponentAccess<IPeripheral> peripherals) {
+        this.peripherals = peripherals;
     }
 
     /**
@@ -126,7 +124,7 @@ public final class WiredModemLocalPeripheral {
 
         if (world.getBlockState(offset).is(ComputerCraftTags.Blocks.PERIPHERAL_HUB_IGNORE)) return null;
 
-        var peripheral = peripherals.get((ServerLevel) world, pos, direction);
+        var peripheral = peripherals.get(direction);
         return peripheral instanceof WiredModemPeripheral ? null : peripheral;
     }
 }

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

@@ -7,7 +7,7 @@ package dan200.computercraft.shared.peripheral.monitor;
 import dan200.computercraft.shared.computer.terminal.TerminalState;
 import dan200.computercraft.shared.config.Config;
 import dan200.computercraft.shared.network.client.MonitorClientMessage;
-import dan200.computercraft.shared.platform.PlatformHelper;
+import dan200.computercraft.shared.network.server.ServerNetworking;
 import net.minecraft.server.level.ServerLevel;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.level.chunk.LevelChunk;
@@ -40,7 +40,7 @@ public final class MonitorWatcher {
             if (serverMonitor == null || monitor.enqueued) continue;
 
             var state = getState(monitor, serverMonitor);
-            PlatformHelper.get().sendToPlayer(new MonitorClientMessage(monitor.getBlockPos(), state), player);
+            ServerNetworking.sendToPlayer(new MonitorClientMessage(monitor.getBlockPos(), state), player);
         }
     }
 
@@ -66,7 +66,7 @@ public final class MonitorWatcher {
             }
 
             var state = getState(tile, monitor);
-            PlatformHelper.get().sendToAllTracking(new MonitorClientMessage(pos, state), chunk);
+            ServerNetworking.sendToAllTracking(new MonitorClientMessage(pos, state), chunk);
 
             limit -= state.size();
         }

projects/common/src/main/java/dan200/computercraft/shared/peripheral/printer/PrinterBlockEntity.java

@@ -225,7 +225,9 @@ public final class PrinterBlockEntity extends AbstractContainerBlockEntity imple
         var stack = PrintoutItem.createSingleFromTitleAndText(pageTitle, lines, colours);
         for (var slot : BOTTOM_SLOTS) {
             if (inventory.get(slot).isEmpty()) {
-                setItem(slot, stack);
+                inventory.set(slot, stack);
+                updateBlockState();
+                setChanged();
                 printing = false;
                 return true;
             }

projects/common/src/main/java/dan200/computercraft/shared/peripheral/printer/PrinterPeripheral.java

@@ -15,14 +15,44 @@ import javax.annotation.Nullable;
 import java.util.Optional;
 
 /**
- * The printer peripheral allows pages and books to be printed.
+ * The printer peripheral allows printing text onto pages. These pages can then be crafted together into printed pages
+ * or books.
  * <p>
- * ## Recipe
+ * Printers require ink (one of the coloured dyes) and paper in order to function. Once loaded, a new page can be
+ * started with {@link #newPage()}. Then the printer can be used similarly to a normal terminal; {@linkplain
+ * #write(Coerced) text can be written}, and {@linkplain #setCursorPos(int, int) the cursor moved}. Once all text has
+ * been printed, {@link #endPage()} should be called to finally print the page.
+ * <p>
+ * ## Recipes
  * <div class="recipe-container">
  *     <mc-recipe recipe="computercraft:printer"></mc-recipe>
+ *     <mc-recipe recipe="computercraft:printed_pages"></mc-recipe>
+ *     <mc-recipe recipe="computercraft:printed_book"></mc-recipe>
  * </div>
  *
+ * @cc.usage Print a page titled "Hello" with a small message on it.
+ *
+ * <pre>{@code
+ * local printer = peripheral.find("printer")
+ *
+ * -- Start a new page, or print an error.
+ * if not printer.newPage() then
+ *   error("Cannot start a new page. Do you have ink and paper?")
+ * end
+ *
+ * -- Write to the page
+ * printer.setPageTitle("Hello")
+ * printer.write("This is my first page")
+ * printer.setCursorPos(1, 3)
+ * printer.write("This is two lines below.")
+ *
+ * -- And finally print the page!
+ * if not printer.endPage() then
+ *   error("Cannot end the page. Is there enough space?")
+ * end
+ * }</pre>
  * @cc.module printer
+ * @cc.see cc.strings.wrap To wrap text before printing it.
  */
 public class PrinterPeripheral implements IPeripheral {
     private final PrinterBlockEntity printer;

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

@@ -7,7 +7,7 @@ package dan200.computercraft.shared.peripheral.speaker;
 import dan200.computercraft.api.peripheral.IPeripheral;
 import dan200.computercraft.core.util.Nullability;
 import dan200.computercraft.shared.network.client.SpeakerStopClientMessage;
-import dan200.computercraft.shared.platform.PlatformHelper;
+import dan200.computercraft.shared.network.server.ServerNetworking;
 import net.minecraft.core.BlockPos;
 import net.minecraft.world.level.block.entity.BlockEntity;
 import net.minecraft.world.level.block.entity.BlockEntityType;
@@ -32,7 +32,7 @@ public class SpeakerBlockEntity extends BlockEntity {
     public void setRemoved() {
         super.setRemoved();
         if (level != null && !level.isClientSide) {
-            PlatformHelper.get().sendToAllPlayers(new SpeakerStopClientMessage(peripheral.getSource()), Nullability.assertNonNull(getLevel().getServer()));
+            ServerNetworking.sendToAllPlayers(new SpeakerStopClientMessage(peripheral.getSource()), Nullability.assertNonNull(getLevel().getServer()));
         }
     }
 

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

@@ -17,7 +17,7 @@ import dan200.computercraft.shared.network.client.SpeakerAudioClientMessage;
 import dan200.computercraft.shared.network.client.SpeakerMoveClientMessage;
 import dan200.computercraft.shared.network.client.SpeakerPlayClientMessage;
 import dan200.computercraft.shared.network.client.SpeakerStopClientMessage;
-import dan200.computercraft.shared.platform.PlatformHelper;
+import dan200.computercraft.shared.network.server.ServerNetworking;
 import dan200.computercraft.shared.util.PauseAwareTimer;
 import net.minecraft.ResourceLocationException;
 import net.minecraft.core.BlockPos;
@@ -116,14 +116,14 @@ public abstract class SpeakerPeripheral implements IPeripheral {
         // Stop the speaker and nuke the position, so we don't update it again.
         if (shouldStop && lastPosition != null) {
             lastPosition = null;
-            PlatformHelper.get().sendToAllPlayers(new SpeakerStopClientMessage(getSource()), server);
+            ServerNetworking.sendToAllPlayers(new SpeakerStopClientMessage(getSource()), server);
             return;
         }
 
         var now = PauseAwareTimer.getTime();
         if (sound != null) {
             lastPlayTime = clock;
-            PlatformHelper.get().sendToAllAround(
+            ServerNetworking.sendToAllAround(
                 new SpeakerPlayClientMessage(getSource(), position, sound.sound, sound.volume, sound.pitch),
                 (ServerLevel) level, pos, sound.volume * 16
             );
@@ -131,7 +131,7 @@ public abstract class SpeakerPeripheral implements IPeripheral {
         } else if (dfpwmState != null && dfpwmState.shouldSendPending(now)) {
             // If clients need to receive another batch of audio, send it and then notify computers our internal buffer is
             // free again.
-            PlatformHelper.get().sendToAllTracking(
+            ServerNetworking.sendToAllTracking(
                 new SpeakerAudioClientMessage(getSource(), position, dfpwmState.getVolume(), dfpwmState.pullPending(now)),
                 level.getChunkAt(BlockPos.containing(pos))
             );
@@ -150,7 +150,7 @@ public abstract class SpeakerPeripheral implements IPeripheral {
         // in the last second.
         if (lastPosition != null && (clock - lastPositionTime) >= 20 && !lastPosition.withinDistance(position, 0.1)) {
             // TODO: What to do when entities move away? How do we notify people left behind that they're gone.
-            PlatformHelper.get().sendToAllTracking(
+            ServerNetworking.sendToAllTracking(
                 new SpeakerMoveClientMessage(getSource(), position),
                 level.getChunkAt(BlockPos.containing(pos))
             );

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

@@ -6,7 +6,7 @@ package dan200.computercraft.shared.peripheral.speaker;
 
 import dan200.computercraft.api.peripheral.IComputerAccess;
 import dan200.computercraft.shared.network.client.SpeakerStopClientMessage;
-import dan200.computercraft.shared.platform.PlatformHelper;
+import dan200.computercraft.shared.network.server.ServerNetworking;
 
 
 /**
@@ -25,6 +25,6 @@ public abstract class UpgradeSpeakerPeripheral extends SpeakerPeripheral {
         var server = level.getServer();
         if (server == null || server.isStopped()) return;
 
-        PlatformHelper.get().sendToAllPlayers(new SpeakerStopClientMessage(getSource()), server);
+        ServerNetworking.sendToAllPlayers(new SpeakerStopClientMessage(getSource()), server);
     }
 }

projects/common/src/main/java/dan200/computercraft/shared/platform/ComponentAccess.java

@@ -4,9 +4,7 @@
 
 package dan200.computercraft.shared.platform;
 
-import net.minecraft.core.BlockPos;
 import net.minecraft.core.Direction;
-import net.minecraft.server.level.ServerLevel;
 
 import javax.annotation.Nullable;
 
@@ -18,15 +16,11 @@ import javax.annotation.Nullable;
 public interface ComponentAccess<T> {
     /**
      * Get a peripheral for the current block.
-     * <p>
-     * Both {@code level} and {@code pos} must be constant for the lifetime of the store.
      *
-     * @param level     The current level.
-     * @param pos       The position of the block fetching the peripheral, for instance the computer or modem.
      * @param direction The direction the peripheral is in.
      * @return The peripheral, or {@literal null} if not found.
      * @throws IllegalStateException If the level or position have changed.
      */
     @Nullable
-    T get(ServerLevel level, BlockPos pos, Direction direction);
+    T get(Direction direction);
 }

projects/common/src/main/java/dan200/computercraft/shared/platform/PlatformHelper.java

@@ -20,9 +20,10 @@ import net.minecraft.core.BlockPos;
 import net.minecraft.core.Direction;
 import net.minecraft.core.Registry;
 import net.minecraft.network.FriendlyByteBuf;
+import net.minecraft.network.protocol.Packet;
+import net.minecraft.network.protocol.game.ClientGamePacketListener;
 import net.minecraft.resources.ResourceKey;
 import net.minecraft.resources.ResourceLocation;
-import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.level.ServerLevel;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.server.level.ServerPlayerGameMode;
@@ -44,12 +45,10 @@ import net.minecraft.world.level.block.Block;
 import net.minecraft.world.level.block.entity.BlockEntity;
 import net.minecraft.world.level.block.entity.BlockEntityType;
 import net.minecraft.world.level.block.state.BlockState;
-import net.minecraft.world.level.chunk.LevelChunk;
 import net.minecraft.world.phys.BlockHitResult;
 import net.minecraft.world.phys.Vec3;
 
 import javax.annotation.Nullable;
-import java.util.Collection;
 import java.util.List;
 import java.util.function.BiFunction;
 import java.util.function.Consumer;
@@ -178,64 +177,32 @@ public interface PlatformHelper extends dan200.computercraft.impl.PlatformHelper
     <T extends NetworkMessage<?>> MessageType<T> createMessageType(int id, ResourceLocation channel, Class<T> klass, FriendlyByteBuf.Reader<T> reader);
 
     /**
-     * Send a message to a specific player.
+     * Convert a clientbound {@link NetworkMessage} to a Minecraft {@link Packet}.
      *
-     * @param message The message to send.
-     * @param player  The player to send it to.
+     * @param message The messsge to convert.
+     * @return The converted message.
      */
-    void sendToPlayer(NetworkMessage<ClientNetworkContext> message, ServerPlayer player);
-
-    /**
-     * Send a message to a set of players.
-     *
-     * @param message The message to send.
-     * @param players The players to send it to.
-     */
-    void sendToPlayers(NetworkMessage<ClientNetworkContext> message, Collection<ServerPlayer> players);
-
-    /**
-     * Send a message to all players.
-     *
-     * @param message The message to send.
-     * @param server  The current server.
-     */
-    void sendToAllPlayers(NetworkMessage<ClientNetworkContext> message, MinecraftServer server);
-
-    /**
-     * Send a message to all players around a point.
-     *
-     * @param message  The message to send.
-     * @param level    The level the point is in.
-     * @param pos      The centre position.
-     * @param distance The distance to the centre players must be within.
-     */
-    void sendToAllAround(NetworkMessage<ClientNetworkContext> message, ServerLevel level, Vec3 pos, float distance);
-
-    /**
-     * Send a message to all players tracking a chunk.
-     *
-     * @param message The message to send.
-     * @param chunk   The chunk players must be tracking.
-     */
-    void sendToAllTracking(NetworkMessage<ClientNetworkContext> message, LevelChunk chunk);
+    Packet<ClientGamePacketListener> createPacket(NetworkMessage<ClientNetworkContext> message);
 
     /**
      * Create a {@link ComponentAccess} for surrounding peripherals.
      *
+     * @param owner      The block entity requesting surrounding peripherals.
      * @param invalidate The function to call when a neighbouring peripheral potentially changes. This <em>MAY NOT</em>
      *                   include all changes, and so block updates should still be listened to.
      * @return The peripheral component access.
      */
-    ComponentAccess<IPeripheral> createPeripheralAccess(Consumer<Direction> invalidate);
+    ComponentAccess<IPeripheral> createPeripheralAccess(BlockEntity owner, Consumer<Direction> invalidate);
 
     /**
      * Create a {@link ComponentAccess} for surrounding wired nodes.
      *
+     * @param owner      The block entity requesting surrounding wired elements.
      * @param invalidate The function to call when a neighbouring wired node potentially changes. This <em>MAY NOT</em>
      *                   include all changes, and so block updates should still be listened to.
      * @return The peripheral component access.
      */
-    ComponentAccess<WiredElement> createWiredElementAccess(Consumer<Direction> invalidate);
+    ComponentAccess<WiredElement> createWiredElementAccess(BlockEntity owner, Consumer<Direction> invalidate);
 
     /**
      * Determine if there is a wired element in the given direction. This is equivalent to

projects/common/src/main/java/dan200/computercraft/shared/pocket/core/PocketServerComputer.java

@@ -15,7 +15,7 @@ import dan200.computercraft.shared.computer.core.ServerComputer;
 import dan200.computercraft.shared.config.Config;
 import dan200.computercraft.shared.network.client.PocketComputerDataMessage;
 import dan200.computercraft.shared.network.client.PocketComputerDeletedClientMessage;
-import dan200.computercraft.shared.platform.PlatformHelper;
+import dan200.computercraft.shared.network.server.ServerNetworking;
 import dan200.computercraft.shared.pocket.items.PocketComputerItem;
 import net.minecraft.core.BlockPos;
 import net.minecraft.nbt.CompoundTag;
@@ -161,7 +161,7 @@ public class PocketServerComputer extends ServerComputer implements IPocketAcces
         if (sendState) {
             // Broadcast the state to all players
             tracking.addAll(getLevel().players());
-            PlatformHelper.get().sendToPlayers(new PocketComputerDataMessage(this, false), tracking);
+            ServerNetworking.sendToPlayers(new PocketComputerDataMessage(this, false), tracking);
         } else {
             // Broadcast the state to new players.
             List<ServerPlayer> added = new ArrayList<>();
@@ -169,7 +169,7 @@ public class PocketServerComputer extends ServerComputer implements IPocketAcces
                 if (tracking.add(player)) added.add(player);
             }
             if (!added.isEmpty()) {
-                PlatformHelper.get().sendToPlayers(new PocketComputerDataMessage(this, false), added);
+                ServerNetworking.sendToPlayers(new PocketComputerDataMessage(this, false), added);
             }
         }
     }
@@ -180,13 +180,13 @@ public class PocketServerComputer extends ServerComputer implements IPocketAcces
 
         if (entity instanceof ServerPlayer player && entity.isAlive()) {
             // Broadcast the terminal to the current player.
-            PlatformHelper.get().sendToPlayer(new PocketComputerDataMessage(this, true), player);
+            ServerNetworking.sendToPlayer(new PocketComputerDataMessage(this, true), player);
         }
     }
 
     @Override
     protected void onRemoved() {
         super.onRemoved();
-        PlatformHelper.get().sendToAllPlayers(new PocketComputerDeletedClientMessage(getInstanceID()), getLevel().getServer());
+        ServerNetworking.sendToAllPlayers(new PocketComputerDeletedClientMessage(getInstanceID()), getLevel().getServer());
     }
 }

projects/common/src/main/java/dan200/computercraft/shared/turtle/core/TurtleBrain.java

@@ -42,7 +42,6 @@ import net.minecraft.world.phys.Vec3;
 import javax.annotation.Nullable;
 import java.util.*;
 import java.util.concurrent.TimeUnit;
-import java.util.function.Predicate;
 
 import static dan200.computercraft.shared.common.IColouredItem.NBT_COLOUR;
 import static dan200.computercraft.shared.util.WaterloggableHelpers.WATERLOGGED;
@@ -59,8 +58,6 @@ public class TurtleBrain implements TurtleAccessInternal {
 
     private static final int ANIM_DURATION = 8;
 
-    public static final Predicate<Entity> PUSHABLE_ENTITY = entity -> !entity.isSpectator() && entity.getPistonPushReaction() != PushReaction.IGNORE;
-
     private TurtleBlockEntity owner;
     private @Nullable GameProfile owningPlayer;
 
@@ -694,7 +691,7 @@ public class TurtleBrain implements TurtleAccessInternal {
                     }
 
                     var aabb = new AABB(minX, minY, minZ, maxX, maxY, maxZ);
-                    var list = world.getEntitiesOfClass(Entity.class, aabb, PUSHABLE_ENTITY);
+                    var list = world.getEntitiesOfClass(Entity.class, aabb, TurtleBrain::canPush);
                     if (!list.isEmpty()) {
                         double pushStep = 1.0f / ANIM_DURATION;
                         var pushStepX = moveDir.getStepX() * pushStep;
@@ -737,6 +734,10 @@ public class TurtleBrain implements TurtleAccessInternal {
         }
     }
 
+    private static boolean canPush(Entity entity) {
+        return !entity.isSpectator() && entity.getPistonPushReaction() != PushReaction.IGNORE;
+    }
+
     private float getAnimationFraction(float f) {
         var next = (float) animationProgress / ANIM_DURATION;
         var previous = (float) lastAnimationProgress / ANIM_DURATION;

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

@@ -19,9 +19,7 @@ import java.io.IOException;
 import java.io.OutputStream;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
-import java.util.Arrays;
-import java.util.HashMap;
-import java.util.Map;
+import java.util.*;
 
 public final class NBTUtil {
     private static final Logger LOG = LoggerFactory.getLogger(NBTUtil.class);
@@ -149,20 +147,20 @@ public final class NBTUtil {
             }
             case Tag.TAG_LIST: {
                 var list = (ListTag) tag;
-                Map<Integer, Object> map = new HashMap<>(list.size());
-                for (var i = 0; i < list.size(); i++) map.put(i, toLua(list.get(i)));
+                List<Object> map = new ArrayList<>(list.size());
+                for (var value : list) map.add(toLua(value));
                 return map;
             }
             case Tag.TAG_BYTE_ARRAY: {
                 var array = ((ByteArrayTag) tag).getAsByteArray();
-                Map<Integer, Byte> map = new HashMap<>(array.length);
-                for (var i = 0; i < array.length; i++) map.put(i + 1, array[i]);
+                List<Byte> map = new ArrayList<>(array.length);
+                for (var b : array) map.add(b);
                 return map;
             }
             case Tag.TAG_INT_ARRAY: {
                 var array = ((IntArrayTag) tag).getAsIntArray();
-                Map<Integer, Integer> map = new HashMap<>(array.length);
-                for (var i = 0; i < array.length; i++) map.put(i + 1, array[i]);
+                List<Integer> map = new ArrayList<>(array.length);
+                for (var j : array) map.add(j);
                 return map;
             }
 

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

@@ -27,12 +27,8 @@ import net.minecraft.world.phys.shapes.CollisionContext;
 import net.minecraft.world.phys.shapes.VoxelShape;
 
 import javax.annotation.Nullable;
-import java.util.function.Predicate;
 
 public final class WorldUtil {
-    @SuppressWarnings("UnnecessaryLambda")
-    private static final Predicate<Entity> CAN_COLLIDE = x -> x != null && x.isAlive() && x.isPickable();
-
     public static boolean isLiquidBlock(Level world, BlockPos pos) {
         if (!world.isInWorldBounds(pos)) return false;
         return world.getBlockState(pos).liquid();
@@ -84,7 +80,7 @@ public final class WorldUtil {
         Entity bestEntity = null;
         Vec3 bestHit = null;
 
-        for (var entity : level.getEntities(source, bounds, WorldUtil.CAN_COLLIDE)) {
+        for (var entity : level.getEntities(source, bounds, WorldUtil::canCollide)) {
             var aabb = entity.getBoundingBox().inflate(entity.getPickRadius());
 
             // clip doesn't work when inside the entity. Just assume we've got a perfect match and break.
@@ -109,6 +105,10 @@ public final class WorldUtil {
         return bestEntity == null ? null : new EntityHitResult(bestEntity, bestHit);
     }
 
+    private static boolean canCollide(Entity entity) {
+        return entity != null && entity.isAlive() && entity.isPickable();
+    }
+
     public static Vec3 getRayStart(Player entity) {
         return entity.getEyePosition();
     }

projects/common/src/main/resources/computercraft.mixins.json

@@ -1,13 +0,0 @@
-{
-    "required": true,
-    "package": "dan200.computercraft.mixin",
-    "minVersion": "0.8",
-    "compatibilityLevel": "JAVA_17",
-    "injectors": {
-        "defaultRequire": 1
-    },
-    "mixins": [
-        "CacheUpdaterMixin"
-    ],
-    "refmap": "computercraft.refmap.json"
-}

projects/common/src/test/java/dan200/computercraft/TestPlatformHelper.java

@@ -18,15 +18,18 @@ import dan200.computercraft.shared.network.NetworkMessage;
 import dan200.computercraft.shared.network.client.ClientNetworkContext;
 import dan200.computercraft.shared.network.container.ContainerData;
 import dan200.computercraft.shared.platform.*;
+import io.netty.buffer.Unpooled;
 import net.minecraft.commands.synchronization.ArgumentTypeInfo;
 import net.minecraft.core.BlockPos;
 import net.minecraft.core.Direction;
 import net.minecraft.core.Registry;
 import net.minecraft.core.registries.BuiltInRegistries;
 import net.minecraft.network.FriendlyByteBuf;
+import net.minecraft.network.protocol.Packet;
+import net.minecraft.network.protocol.game.ClientGamePacketListener;
+import net.minecraft.network.protocol.game.ClientboundCustomPayloadPacket;
 import net.minecraft.resources.ResourceKey;
 import net.minecraft.resources.ResourceLocation;
-import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.level.ServerLevel;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.tags.TagKey;
@@ -47,12 +50,10 @@ import net.minecraft.world.level.block.Block;
 import net.minecraft.world.level.block.entity.BlockEntity;
 import net.minecraft.world.level.block.entity.BlockEntityType;
 import net.minecraft.world.level.block.state.BlockState;
-import net.minecraft.world.level.chunk.LevelChunk;
 import net.minecraft.world.phys.BlockHitResult;
 import net.minecraft.world.phys.Vec3;
 
 import javax.annotation.Nullable;
-import java.util.Collection;
 import java.util.Iterator;
 import java.util.List;
 import java.util.function.BiFunction;
@@ -129,31 +130,6 @@ public class TestPlatformHelper extends AbstractComputerCraftAPI implements Plat
         throw new UnsupportedOperationException("Cannot register ArgumentTypeInfo inside tests");
     }
 
-    @Override
-    public void sendToPlayer(NetworkMessage<ClientNetworkContext> message, ServerPlayer player) {
-        throw new UnsupportedOperationException("Cannot send NetworkMessages inside tests");
-    }
-
-    @Override
-    public void sendToPlayers(NetworkMessage<ClientNetworkContext> message, Collection<ServerPlayer> players) {
-        throw new UnsupportedOperationException("Cannot send NetworkMessages inside tests");
-    }
-
-    @Override
-    public void sendToAllPlayers(NetworkMessage<ClientNetworkContext> message, MinecraftServer server) {
-        throw new UnsupportedOperationException("Cannot send NetworkMessages inside tests");
-    }
-
-    @Override
-    public void sendToAllAround(NetworkMessage<ClientNetworkContext> message, ServerLevel level, Vec3 pos, float distance) {
-        throw new UnsupportedOperationException("Cannot send NetworkMessages inside tests");
-    }
-
-    @Override
-    public void sendToAllTracking(NetworkMessage<ClientNetworkContext> message, LevelChunk chunk) {
-        throw new UnsupportedOperationException("Cannot send NetworkMessages inside tests");
-    }
-
     @Override
     public List<TagKey<Item>> getDyeTags() {
         throw new UnsupportedOperationException("Cannot query tags inside tests");
@@ -169,20 +145,30 @@ public class TestPlatformHelper extends AbstractComputerCraftAPI implements Plat
         throw new UnsupportedOperationException("Cannot open menu inside tests");
     }
 
-    @Override
-    public <T extends NetworkMessage<?>> MessageType<T> createMessageType(int id, ResourceLocation channel, Class<T> klass, FriendlyByteBuf.Reader<T> reader) {
-        record TypeImpl<T extends NetworkMessage<?>>(Function<FriendlyByteBuf, T> reader) implements MessageType<T> {
-        }
-        return new TypeImpl<>(reader);
+    record TypeImpl<T extends NetworkMessage<?>>(
+        ResourceLocation id, Function<FriendlyByteBuf, T> reader
+    ) implements MessageType<T> {
     }
 
     @Override
-    public ComponentAccess<IPeripheral> createPeripheralAccess(Consumer<Direction> invalidate) {
+    public <T extends NetworkMessage<?>> MessageType<T> createMessageType(int id, ResourceLocation channel, Class<T> klass, FriendlyByteBuf.Reader<T> reader) {
+        return new TypeImpl<>(channel, reader);
+    }
+
+    @Override
+    public Packet<ClientGamePacketListener> createPacket(NetworkMessage<ClientNetworkContext> message) {
+        var buf = new FriendlyByteBuf(Unpooled.buffer());
+        message.write(buf);
+        return new ClientboundCustomPayloadPacket(((TypeImpl<?>) message.type()).id(), buf);
+    }
+
+    @Override
+    public ComponentAccess<IPeripheral> createPeripheralAccess(BlockEntity owner, Consumer<Direction> invalidate) {
         throw new UnsupportedOperationException("Cannot interact with the world inside tests");
     }
 
     @Override
-    public ComponentAccess<WiredElement> createWiredElementAccess(Consumer<Direction> invalidate) {
+    public ComponentAccess<WiredElement> createWiredElementAccess(BlockEntity owner, Consumer<Direction> invalidate) {
         throw new UnsupportedOperationException("Cannot interact with the world inside tests");
     }
 

projects/common/src/test/java/dan200/computercraft/client/sound/DfpwmStreamTest.java

@@ -4,9 +4,10 @@
 
 package dan200.computercraft.client.sound;
 
-import io.netty.buffer.ByteBufAllocator;
 import org.junit.jupiter.api.Test;
 
+import java.nio.ByteBuffer;
+
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
 public class DfpwmStreamTest {
@@ -14,8 +15,7 @@ public class DfpwmStreamTest {
     public void testDecodesBytes() {
         var stream = new DfpwmStream();
 
-        var input = ByteBufAllocator.DEFAULT.buffer();
-        input.writeBytes(new byte[]{ 43, -31, 33, 44, 30, -16, -85, 23, -3, -55, 46, -70, 68, -67, 74, -96, -68, 16, 94, -87, -5, 87, 11, -16, 19, 92, 85, -71, 126, 5, -84, 64, 17, -6, 85, -11, -1, -87, -12, 1, 85, -56, 33, -80, 82, 104, -93, 17, 126, 23, 91, -30, 37, -32, 117, -72, -58, 11, -76, 19, -108, 86, -65, -10, -1, -68, -25, 10, -46, 85, 124, -54, 15, -24, 43, -94, 117, 63, -36, 15, -6, 88, 87, -26, -83, 106, 41, 13, -28, -113, -10, -66, 119, -87, -113, 68, -55, 40, -107, 62, 20, 72, 3, -96, 114, -87, -2, 39, -104, 30, 20, 42, 84, 24, 47, 64, 43, 61, -35, 95, -65, 42, 61, 42, -50, 4, -9, 81 });
+        var input = ByteBuffer.wrap(new byte[]{ 43, -31, 33, 44, 30, -16, -85, 23, -3, -55, 46, -70, 68, -67, 74, -96, -68, 16, 94, -87, -5, 87, 11, -16, 19, 92, 85, -71, 126, 5, -84, 64, 17, -6, 85, -11, -1, -87, -12, 1, 85, -56, 33, -80, 82, 104, -93, 17, 126, 23, 91, -30, 37, -32, 117, -72, -58, 11, -76, 19, -108, 86, -65, -10, -1, -68, -25, 10, -46, 85, 124, -54, 15, -24, 43, -94, 117, 63, -36, 15, -6, 88, 87, -26, -83, 106, 41, 13, -28, -113, -10, -66, 119, -87, -113, 68, -55, 40, -107, 62, 20, 72, 3, -96, 114, -87, -2, 39, -104, 30, 20, 42, 84, 24, 47, 64, 43, 61, -35, 95, -65, 42, 61, 42, -50, 4, -9, 81 });
         stream.push(input);
 
         var buffer = stream.read(1024 + 1);

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

@@ -5,6 +5,7 @@
 package dan200.computercraft.gametest
 
 import dan200.computercraft.core.apis.FSAPI
+import dan200.computercraft.core.util.Colour
 import dan200.computercraft.gametest.api.*
 import dan200.computercraft.shared.ModRegistry
 import dan200.computercraft.shared.media.items.DiskItem
@@ -19,6 +20,9 @@ import net.minecraft.network.chat.Component
 import net.minecraft.world.item.ItemStack
 import net.minecraft.world.item.Items
 import net.minecraft.world.level.block.RedStoneWireBlock
+import org.hamcrest.MatcherAssert.assertThat
+import org.hamcrest.Matchers.array
+import org.hamcrest.Matchers.equalTo
 import org.junit.jupiter.api.Assertions.assertEquals
 
 class Disk_Drive_Test {
@@ -45,14 +49,48 @@ class Disk_Drive_Test {
         thenWaitUntil { helper.assertItemEntityPresent(Items.MUSIC_DISC_13, stackAt, 0.0) }
     }
 
+    /**
+     * A mount is initially attached, and then removed when the disk is ejected.
+     */
+    @GameTest
+    fun Queues_event(helper: GameTestHelper) = helper.sequence {
+        val pos = BlockPos(1, 2, 2)
+
+        var started = false
+        var disk = false
+        var ejected = false
+        thenStartComputer {
+            // thenOnComputer discards events, so instead we need to track our state transitions.
+            started = true
+
+            val diskEvent = pullEvent("disk")
+            assertThat(diskEvent, array(equalTo("disk"), equalTo("right")))
+
+            disk = true
+
+            val ejectEvent = pullEvent("disk_eject")
+            assertThat(ejectEvent, array(equalTo("disk_eject"), equalTo("right")))
+
+            ejected = true
+        }
+
+        thenWaitUntil { helper.assertTrue(started, "Computer not started") }
+        thenExecute { helper.setContainerItem(pos, 0, ItemStack(Items.DIRT)) }
+        thenWaitUntil { helper.assertTrue(disk, "disk not inserted") }
+        thenExecute { helper.setContainerItem(pos, 0, ItemStack.EMPTY) }
+        thenWaitUntil { helper.assertTrue(ejected, "disk not ejected") }
+    }
+
     /**
      * A mount is initially attached, and then removed when the disk is ejected.
      */
     @GameTest
     fun Adds_removes_mount(helper: GameTestHelper) = helper.sequence {
         thenOnComputer { } // Wait for the computer to start up
-        thenIdle(2) // Let the disk drive tick once to create the mount
-        thenOnComputer { // Then actually assert things!
+        thenExecute {
+            helper.setContainerItem(BlockPos(1, 2, 2), 0, DiskItem.createFromIDAndColour(1, null, Colour.BLACK.hex))
+        }
+        thenOnComputer {
             getApi<FSAPI>().getDrive("disk").assertArrayEquals("right")
             callPeripheral("right", "ejectDisk")
         }

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

@@ -24,7 +24,7 @@ class Inventory_Test {
      *
      * @see <https://github.com/cc-tweaked/cc-restitched/issues/121>
      */
-    @GameTest(required = false)
+    @GameTest
     fun Checks_valid_item(helper: GameTestHelper) = helper.sequence {
         thenOnComputer {
             getApi<PeripheralAPI>().call(

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

@@ -7,7 +7,10 @@ package dan200.computercraft.gametest
 import dan200.computercraft.api.lua.ObjectArguments
 import dan200.computercraft.core.apis.PeripheralAPI
 import dan200.computercraft.core.computer.ComputerSide
-import dan200.computercraft.gametest.api.*
+import dan200.computercraft.gametest.api.getBlockEntity
+import dan200.computercraft.gametest.api.sequence
+import dan200.computercraft.gametest.api.thenOnComputer
+import dan200.computercraft.gametest.api.thenStartComputer
 import dan200.computercraft.shared.ModRegistry
 import dan200.computercraft.shared.peripheral.modem.wired.CableBlock
 import dan200.computercraft.test.core.assertArrayEquals

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

@@ -21,7 +21,6 @@ import net.minecraft.world.entity.EntityType
 import net.minecraft.world.item.ItemStack
 import net.minecraft.world.level.block.Blocks
 import org.junit.jupiter.api.Assertions.*
-import java.util.*
 
 class Monitor_Test {
     @GameTest

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

@@ -19,7 +19,6 @@ import net.minecraft.world.inventory.MenuType
 import net.minecraft.world.inventory.TransientCraftingContainer
 import net.minecraft.world.item.ItemStack
 import net.minecraft.world.item.Items
-import net.minecraft.world.item.crafting.CraftingRecipe
 import net.minecraft.world.item.crafting.RecipeType
 import org.junit.jupiter.api.Assertions.assertEquals
 import java.util.*
@@ -37,11 +36,11 @@ class Recipe_Test {
             container.setItem(0, ItemStack(Items.SKELETON_SKULL))
             container.setItem(1, ItemStack(ModRegistry.Items.COMPUTER_ADVANCED.get()))
 
-            val recipe: Optional<CraftingRecipe> = context.level.server.recipeManager
+            val recipe = context.level.server.recipeManager
                 .getRecipeFor(RecipeType.CRAFTING, container, context.level)
-            if (!recipe.isPresent) throw GameTestAssertException("No recipe matches")
+                .orElseThrow { GameTestAssertException("No recipe matches") }
 
-            val result = recipe.get().assemble(container, context.level.registryAccess())
+            val result = recipe.assemble(container, context.level.registryAccess())
 
             val profile = GameProfile(UUID.fromString("f3c8d69b-0776-4512-8434-d1b2165909eb"), "dan200")
 

projects/common/src/testMod/kotlin/dan200/computercraft/gametest/api/TestExtensions.kt

@@ -4,6 +4,7 @@
 
 package dan200.computercraft.gametest.api
 
+import dan200.computercraft.api.peripheral.IPeripheral
 import dan200.computercraft.gametest.core.ManagedComputers
 import dan200.computercraft.mixin.gametest.GameTestHelperAccessor
 import dan200.computercraft.mixin.gametest.GameTestInfoAccessor
@@ -21,6 +22,8 @@ import net.minecraft.world.Container
 import net.minecraft.world.entity.Entity
 import net.minecraft.world.entity.EntityType
 import net.minecraft.world.item.ItemStack
+import net.minecraft.world.level.block.Blocks
+import net.minecraft.world.level.block.entity.BarrelBlockEntity
 import net.minecraft.world.level.block.entity.BlockEntity
 import net.minecraft.world.level.block.entity.BlockEntityType
 import net.minecraft.world.level.block.state.BlockState
@@ -165,6 +168,16 @@ fun <T : Comparable<T>> GameTestHelper.assertBlockHas(pos: BlockPos, property: P
     }
 }
 
+/**
+ * Get a [Container] at a given position.
+ */
+fun GameTestHelper.getContainerAt(pos: BlockPos): Container =
+    when (val container = getBlockEntity(pos)) {
+        is Container -> container
+        null -> failVerbose("Expected a container at $pos, found nothing", pos)
+        else -> failVerbose("Expected a container at $pos, found ${getName(container.type)}", pos)
+    }
+
 /**
  * Assert a container contains exactly these items and no more.
  *
@@ -173,10 +186,7 @@ fun <T : Comparable<T>> GameTestHelper.assertBlockHas(pos: BlockPos, property: P
  * first `n` slots - the remaining are required to be empty.
  */
 fun GameTestHelper.assertContainerExactly(pos: BlockPos, items: List<ItemStack>) =
-    when (val container = getBlockEntity(pos) ?: failVerbose("Expected a container at $pos, found nothing", pos)) {
-        is Container -> assertContainerExactlyImpl(pos, container, items)
-        else -> failVerbose("Expected a container at $pos, found ${getName(container.type)}", pos)
-    }
+    assertContainerExactlyImpl(pos, getContainerAt(pos), items)
 
 /**
  * Assert an container contains exactly these items and no more.
@@ -206,9 +216,17 @@ private fun GameTestHelper.assertContainerExactlyImpl(pos: BlockPos, container:
     }
 }
 
+/**
+ * A nasty hack to get a peripheral at a given position, by creating a dummy [BlockEntity].
+ */
+private fun GameTestHelper.getPeripheralAt(pos: BlockPos, direction: Direction): IPeripheral? {
+    val be = BarrelBlockEntity(absolutePos(pos).relative(direction), Blocks.BARREL.defaultBlockState())
+    be.setLevel(level)
+    return PlatformHelper.get().createPeripheralAccess(be) { }.get(direction.opposite)
+}
+
 fun GameTestHelper.assertPeripheral(pos: BlockPos, direction: Direction = Direction.UP, type: String) {
-    val peripheral = PlatformHelper.get().createPeripheralAccess { }
-        .get(level, absolutePos(pos).relative(direction), direction.opposite)
+    val peripheral = getPeripheralAt(pos, direction)
     when {
         peripheral == null -> fail("No peripheral at position", pos)
         peripheral.type != type -> fail("Peripheral is of type ${peripheral.type}, expected $type", pos)
@@ -216,8 +234,7 @@ fun GameTestHelper.assertPeripheral(pos: BlockPos, direction: Direction = Direct
 }
 
 fun GameTestHelper.assertNoPeripheral(pos: BlockPos, direction: Direction = Direction.UP) {
-    val peripheral = PlatformHelper.get().createPeripheralAccess { }
-        .get(level, absolutePos(pos).relative(direction), direction.opposite)
+    val peripheral = getPeripheralAt(pos, direction)
     if (peripheral != null) fail("Expected no peripheral, got a ${peripheral.type}", pos)
 }
 
@@ -277,3 +294,13 @@ fun GameTestHelper.setBlock(pos: BlockPos, state: BlockInput) = state.place(leve
 fun GameTestHelper.modifyBlock(pos: BlockPos, modify: (BlockState) -> BlockState) {
     setBlock(pos, modify(getBlockState(pos)))
 }
+
+/**
+ * Update items in the container at [pos], setting the item in the specified [slot] to [item], and then marking it
+ * changed.
+ */
+fun GameTestHelper.setContainerItem(pos: BlockPos, slot: Int, item: ItemStack) {
+    val container = getContainerAt(pos)
+    container.setItem(slot, item)
+    container.setChanged()
+}

projects/common/src/testMod/resources/data/cctest/structures/disk_drive_test.adds_removes_mount.snbt

@@ -34,7 +34,7 @@
         {pos: [0, 1, 4], state: "minecraft:air"},
         {pos: [1, 1, 0], state: "minecraft:air"},
         {pos: [1, 1, 1], state: "minecraft:air"},
-        {pos: [1, 1, 2], state: "computercraft:disk_drive{facing:north,state:full}", nbt: {Item: {Count: 1b, id: "computercraft:disk", tag: {Color: 1118481, DiskId: 0}}, id: "computercraft:disk_drive"}},
+        {pos: [1, 1, 2], state: "computercraft:disk_drive{facing:north,state:full}", nbt: {id: "computercraft:disk_drive"}},
         {pos: [1, 1, 3], state: "minecraft:air"},
         {pos: [1, 1, 4], state: "minecraft:air"},
         {pos: [2, 1, 0], state: "minecraft:air"},

projects/common/src/testMod/resources/data/cctest/structures/disk_drive_test.queues_event.snbt

@@ -0,0 +1,138 @@
+{
+    DataVersion: 2975,
+    size: [5, 5, 5],
+    data: [
+        {pos: [0, 0, 0], state: "minecraft:polished_andesite"},
+        {pos: [0, 0, 1], state: "minecraft:polished_andesite"},
+        {pos: [0, 0, 2], state: "minecraft:polished_andesite"},
+        {pos: [0, 0, 3], state: "minecraft:polished_andesite"},
+        {pos: [0, 0, 4], state: "minecraft:polished_andesite"},
+        {pos: [1, 0, 0], state: "minecraft:polished_andesite"},
+        {pos: [1, 0, 1], state: "minecraft:polished_andesite"},
+        {pos: [1, 0, 2], state: "minecraft:polished_andesite"},
+        {pos: [1, 0, 3], state: "minecraft:polished_andesite"},
+        {pos: [1, 0, 4], state: "minecraft:polished_andesite"},
+        {pos: [2, 0, 0], state: "minecraft:polished_andesite"},
+        {pos: [2, 0, 1], state: "minecraft:polished_andesite"},
+        {pos: [2, 0, 2], state: "minecraft:polished_andesite"},
+        {pos: [2, 0, 3], state: "minecraft:polished_andesite"},
+        {pos: [2, 0, 4], state: "minecraft:polished_andesite"},
+        {pos: [3, 0, 0], state: "minecraft:polished_andesite"},
+        {pos: [3, 0, 1], state: "minecraft:polished_andesite"},
+        {pos: [3, 0, 2], state: "minecraft:polished_andesite"},
+        {pos: [3, 0, 3], state: "minecraft:polished_andesite"},
+        {pos: [3, 0, 4], state: "minecraft:polished_andesite"},
+        {pos: [4, 0, 0], state: "minecraft:polished_andesite"},
+        {pos: [4, 0, 1], state: "minecraft:polished_andesite"},
+        {pos: [4, 0, 2], state: "minecraft:polished_andesite"},
+        {pos: [4, 0, 3], state: "minecraft:polished_andesite"},
+        {pos: [4, 0, 4], state: "minecraft:polished_andesite"},
+        {pos: [0, 1, 0], state: "minecraft:air"},
+        {pos: [0, 1, 1], state: "minecraft:air"},
+        {pos: [0, 1, 2], state: "minecraft:air"},
+        {pos: [0, 1, 3], state: "minecraft:air"},
+        {pos: [0, 1, 4], state: "minecraft:air"},
+        {pos: [1, 1, 0], state: "minecraft:air"},
+        {pos: [1, 1, 1], state: "minecraft:air"},
+        {pos: [1, 1, 2], state: "computercraft:disk_drive{facing:north,state:full}", nbt: {id: "computercraft:disk_drive"}},
+        {pos: [1, 1, 3], state: "minecraft:air"},
+        {pos: [1, 1, 4], state: "minecraft:air"},
+        {pos: [2, 1, 0], state: "minecraft:air"},
+        {pos: [2, 1, 1], state: "minecraft:air"},
+        {pos: [2, 1, 2], state: "computercraft:computer_advanced{facing:north,state:blinking}", nbt: {ComputerId: 1, Label: "disk_drive_test.queues_event", On: 1b, id: "computercraft:computer_advanced"}},
+        {pos: [2, 1, 3], state: "minecraft:air"},
+        {pos: [2, 1, 4], state: "minecraft:air"},
+        {pos: [3, 1, 0], state: "minecraft:air"},
+        {pos: [3, 1, 1], state: "minecraft:air"},
+        {pos: [3, 1, 2], state: "minecraft:air"},
+        {pos: [3, 1, 3], state: "minecraft:air"},
+        {pos: [3, 1, 4], state: "minecraft:air"},
+        {pos: [4, 1, 0], state: "minecraft:air"},
+        {pos: [4, 1, 1], state: "minecraft:air"},
+        {pos: [4, 1, 2], state: "minecraft:air"},
+        {pos: [4, 1, 3], state: "minecraft:air"},
+        {pos: [4, 1, 4], state: "minecraft:air"},
+        {pos: [0, 2, 0], state: "minecraft:air"},
+        {pos: [0, 2, 1], state: "minecraft:air"},
+        {pos: [0, 2, 2], state: "minecraft:air"},
+        {pos: [0, 2, 3], state: "minecraft:air"},
+        {pos: [0, 2, 4], state: "minecraft:air"},
+        {pos: [1, 2, 0], state: "minecraft:air"},
+        {pos: [1, 2, 1], state: "minecraft:air"},
+        {pos: [1, 2, 2], state: "minecraft:air"},
+        {pos: [1, 2, 3], state: "minecraft:air"},
+        {pos: [1, 2, 4], state: "minecraft:air"},
+        {pos: [2, 2, 0], state: "minecraft:air"},
+        {pos: [2, 2, 1], state: "minecraft:air"},
+        {pos: [2, 2, 2], state: "minecraft:air"},
+        {pos: [2, 2, 3], state: "minecraft:air"},
+        {pos: [2, 2, 4], state: "minecraft:air"},
+        {pos: [3, 2, 0], state: "minecraft:air"},
+        {pos: [3, 2, 1], state: "minecraft:air"},
+        {pos: [3, 2, 2], state: "minecraft:air"},
+        {pos: [3, 2, 3], state: "minecraft:air"},
+        {pos: [3, 2, 4], state: "minecraft:air"},
+        {pos: [4, 2, 0], state: "minecraft:air"},
+        {pos: [4, 2, 1], state: "minecraft:air"},
+        {pos: [4, 2, 2], state: "minecraft:air"},
+        {pos: [4, 2, 3], state: "minecraft:air"},
+        {pos: [4, 2, 4], state: "minecraft:air"},
+        {pos: [0, 3, 0], state: "minecraft:air"},
+        {pos: [0, 3, 1], state: "minecraft:air"},
+        {pos: [0, 3, 2], state: "minecraft:air"},
+        {pos: [0, 3, 3], state: "minecraft:air"},
+        {pos: [0, 3, 4], state: "minecraft:air"},
+        {pos: [1, 3, 0], state: "minecraft:air"},
+        {pos: [1, 3, 1], state: "minecraft:air"},
+        {pos: [1, 3, 2], state: "minecraft:air"},
+        {pos: [1, 3, 3], state: "minecraft:air"},
+        {pos: [1, 3, 4], state: "minecraft:air"},
+        {pos: [2, 3, 0], state: "minecraft:air"},
+        {pos: [2, 3, 1], state: "minecraft:air"},
+        {pos: [2, 3, 2], state: "minecraft:air"},
+        {pos: [2, 3, 3], state: "minecraft:air"},
+        {pos: [2, 3, 4], state: "minecraft:air"},
+        {pos: [3, 3, 0], state: "minecraft:air"},
+        {pos: [3, 3, 1], state: "minecraft:air"},
+        {pos: [3, 3, 2], state: "minecraft:air"},
+        {pos: [3, 3, 3], state: "minecraft:air"},
+        {pos: [3, 3, 4], state: "minecraft:air"},
+        {pos: [4, 3, 0], state: "minecraft:air"},
+        {pos: [4, 3, 1], state: "minecraft:air"},
+        {pos: [4, 3, 2], state: "minecraft:air"},
+        {pos: [4, 3, 3], state: "minecraft:air"},
+        {pos: [4, 3, 4], state: "minecraft:air"},
+        {pos: [0, 4, 0], state: "minecraft:air"},
+        {pos: [0, 4, 1], state: "minecraft:air"},
+        {pos: [0, 4, 2], state: "minecraft:air"},
+        {pos: [0, 4, 3], state: "minecraft:air"},
+        {pos: [0, 4, 4], state: "minecraft:air"},
+        {pos: [1, 4, 0], state: "minecraft:air"},
+        {pos: [1, 4, 1], state: "minecraft:air"},
+        {pos: [1, 4, 2], state: "minecraft:air"},
+        {pos: [1, 4, 3], state: "minecraft:air"},
+        {pos: [1, 4, 4], state: "minecraft:air"},
+        {pos: [2, 4, 0], state: "minecraft:air"},
+        {pos: [2, 4, 1], state: "minecraft:air"},
+        {pos: [2, 4, 2], state: "minecraft:air"},
+        {pos: [2, 4, 3], state: "minecraft:air"},
+        {pos: [2, 4, 4], state: "minecraft:air"},
+        {pos: [3, 4, 0], state: "minecraft:air"},
+        {pos: [3, 4, 1], state: "minecraft:air"},
+        {pos: [3, 4, 2], state: "minecraft:air"},
+        {pos: [3, 4, 3], state: "minecraft:air"},
+        {pos: [3, 4, 4], state: "minecraft:air"},
+        {pos: [4, 4, 0], state: "minecraft:air"},
+        {pos: [4, 4, 1], state: "minecraft:air"},
+        {pos: [4, 4, 2], state: "minecraft:air"},
+        {pos: [4, 4, 3], state: "minecraft:air"},
+        {pos: [4, 4, 4], state: "minecraft:air"}
+    ],
+    entities: [],
+    palette: [
+        "minecraft:polished_andesite",
+        "minecraft:air",
+        "computercraft:disk_drive{facing:north,state:full}",
+        "computercraft:computer_advanced{facing:north,state:blinking}"
+    ]
+}

projects/core-api/src/main/java/dan200/computercraft/api/lua/ILuaAPI.java

@@ -4,6 +4,8 @@
 
 package dan200.computercraft.api.lua;
 
+import javax.annotation.Nullable;
+
 /**
  * Represents a Lua object which is stored as a global variable on computer startup. This must either provide
  * {@link LuaFunction} annotated functions or implement {@link IDynamicLuaObject}.
@@ -15,12 +17,31 @@ package dan200.computercraft.api.lua;
  */
 public interface ILuaAPI {
     /**
-     * Get the globals this API will be assigned to. This will override any other global, so you should
+     * Get the globals this API will be assigned to.
+     * <p>
+     * This will override any other global, so you should be careful to pick a unique name. Alternatively, you may
+     * return the empty array here, and instead override {@link #getModuleName()}.
      *
      * @return A list of globals this API will be assigned to.
      */
     String[] getNames();
 
+    /**
+     * Get the module name this API should be available as.
+     * <p>
+     * Rather than (or as well as) making this API available as a global, APIs can be exposed as {@code require}able
+     * modules. This is generally more idiomatic, as it avoids polluting the global environment.
+     * <p>
+     * Modules defined here take precedence over user-defined modules, and so like with {@link #getNames()}, you should
+     * be careful to pick a unique name. It is recommended that module names should be camel case, and live under a
+     * namespace associated with your mod. For instance, {@code "mod_id.a_custom_api"}.
+     *
+     * @return The module name of this API, or {@code null} if this API should not be loadable as a module.
+     */
+    default @Nullable String getModuleName() {
+        return null;
+    }
+
     /**
      * Called when the computer is turned on.
      * <p>

projects/core/build.gradle.kts

@@ -50,13 +50,6 @@ tasks.test {
     systemProperty("cct.test-files", layout.buildDirectory.dir("tmp/testFiles").getAbsolutePath())
 }
 
-tasks.testFixturesJar {
-    manifest {
-        // Ensure the test fixtures jar loads as a mod. Thanks FML >_>.
-        attributes("FMLModType" to "GAMELIBRARY")
-    }
-}
-
 val checkChangelog by tasks.registering(cc.tweaked.gradle.CheckChangelog::class) {
     version.set(modVersion)
     whatsNew.set(file("src/main/resources/data/computercraft/lua/rom/help/whatsnew.md"))

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

@@ -100,8 +100,8 @@ public abstract class AbstractHandle {
     /**
      * Read a number of bytes from this file.
      *
-     * @param countArg The number of bytes to read. When absent, a single byte will be read <em>as a number</em>. This
-     *                 may be 0 to determine we are at the end of the file.
+     * @param countArg The number of bytes to read. This may be 0 to determine we are at the end of the file. When
+     *                 absent, a single byte will be read.
      * @return The read bytes.
      * @throws LuaException When trying to read a negative number of bytes.
      * @throws LuaException If the file has been closed.

projects/core/src/main/java/dan200/computercraft/core/computer/computerthread/ComputerThread.java

@@ -835,8 +835,8 @@ public final class ComputerThread implements ComputerScheduler {
                 var allocated = ThreadAllocations.getAllocatedBytes(current) - info.allocatedBytes();
                 if (allocated > 0) {
                     metrics.observe(Metrics.JAVA_ALLOCATION, allocated);
-                } else {
-                    LOG.warn("Allocated a negative number of bytes!");
+                } else if (allocated < 0) {
+                    LOG.warn("Allocated a negative number of bytes ({})!", allocated);
                 }
             }
 

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

@@ -275,9 +275,9 @@ public final class MemoryMount extends AbstractInMemoryMount<MemoryMount.FileEnt
             checkClosed();
 
             var backing = Nullability.assertNonNull(entry.contents);
-            if (position >= backing.length) return -1;
+            if (position >= entry.length) return -1;
 
-            var remaining = Math.min(backing.length - (int) position, destination.remaining());
+            var remaining = Math.min(entry.length - (int) position, destination.remaining());
             destination.put(backing, (int) position, remaining);
             position += remaining;
             return remaining;
@@ -285,7 +285,7 @@ public final class MemoryMount extends AbstractInMemoryMount<MemoryMount.FileEnt
 
         private byte[] ensureCapacity(int capacity) {
             var contents = Nullability.assertNonNull(entry.contents);
-            if (capacity >= entry.length) {
+            if (capacity >= contents.length) {
                 var newCapacity = Math.max(capacity, contents.length << 1);
                 contents = entry.contents = Arrays.copyOf(contents, newCapacity);
             }

projects/core/src/main/java/dan200/computercraft/core/lua/BasicFunction.java

@@ -1,64 +0,0 @@
-// SPDX-FileCopyrightText: 2020 The CC: Tweaked Developers
-//
-// SPDX-License-Identifier: MPL-2.0
-
-package dan200.computercraft.core.lua;
-
-import dan200.computercraft.api.lua.ILuaContext;
-import dan200.computercraft.api.lua.LuaException;
-import dan200.computercraft.api.lua.MethodResult;
-import dan200.computercraft.core.Logging;
-import dan200.computercraft.core.methods.LuaMethod;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-import org.squiddev.cobalt.LuaError;
-import org.squiddev.cobalt.LuaState;
-import org.squiddev.cobalt.Varargs;
-import org.squiddev.cobalt.function.VarArgFunction;
-
-/**
- * An "optimised" version of {@link ResultInterpreterFunction} which is guaranteed to never yield.
- * <p>
- * As we never yield, we do not need to push a function to the stack, which removes a small amount of overhead.
- */
-class BasicFunction extends VarArgFunction {
-    private static final Logger LOG = LoggerFactory.getLogger(BasicFunction.class);
-    private final CobaltLuaMachine machine;
-    private final LuaMethod method;
-    private final Object instance;
-    private final ILuaContext context;
-    private final String funcName;
-
-    BasicFunction(CobaltLuaMachine machine, LuaMethod method, Object instance, ILuaContext context, String name) {
-        this.machine = machine;
-        this.method = method;
-        this.instance = instance;
-        this.context = context;
-        funcName = name;
-    }
-
-    @Override
-    public Varargs invoke(LuaState luaState, Varargs args) throws LuaError {
-        var arguments = VarargArguments.of(args);
-        MethodResult results;
-        try {
-            results = method.apply(instance, context, arguments);
-        } catch (LuaException e) {
-            throw wrap(e);
-        } catch (Throwable t) {
-            LOG.error(Logging.JAVA_ERROR, "Error calling {} on {}", funcName, instance, t);
-            throw new LuaError("Java Exception Thrown: " + t, 0);
-        } finally {
-            arguments.close();
-        }
-
-        if (results.getCallback() != null) {
-            throw new IllegalStateException("Cannot have a yielding non-yielding function");
-        }
-        return machine.toValues(results.getResult());
-    }
-
-    public static LuaError wrap(LuaException exception) {
-        return exception.hasLevel() ? new LuaError(exception.getMessage()) : new LuaError(exception.getMessage(), exception.getLevel());
-    }
-}

projects/core/src/main/java/dan200/computercraft/core/lua/CobaltLuaMachine.java

@@ -25,7 +25,6 @@ import org.squiddev.cobalt.lib.Bit32Lib;
 import org.squiddev.cobalt.lib.CoreLibraries;
 
 import javax.annotation.Nullable;
-import java.io.IOException;
 import java.io.InputStream;
 import java.io.Serial;
 import java.nio.ByteBuffer;
@@ -49,7 +48,7 @@ public class CobaltLuaMachine implements ILuaMachine {
 
     private @Nullable String eventFilter = null;
 
-    public CobaltLuaMachine(MachineEnvironment environment, InputStream bios) throws MachineException, IOException {
+    public CobaltLuaMachine(MachineEnvironment environment, InputStream bios) throws MachineException {
         timeout = environment.timeout();
         context = environment.context();
         luaMethods = environment.luaMethods();
@@ -81,7 +80,7 @@ public class CobaltLuaMachine implements ILuaMachine {
             globals.rawset("_CC_DEFAULT_SETTINGS", ValueFactory.valueOf(CoreConfig.defaultComputerSettings));
 
             // Add default APIs
-            for (var api : environment.apis()) addAPI(globals, api);
+            for (var api : environment.apis()) addAPI(state, globals, api);
 
             // And load the BIOS
             var value = LoadState.load(state, bios, "@bios.lua", globals);
@@ -93,7 +92,7 @@ public class CobaltLuaMachine implements ILuaMachine {
         timeout.addListener(timeoutListener);
     }
 
-    private void addAPI(LuaTable globals, ILuaAPI api) {
+    private void addAPI(LuaState state, LuaTable globals, ILuaAPI api) throws LuaError {
         // Add the methods of an API to the global table
         var table = wrapLuaObject(api);
         if (table == null) {
@@ -103,6 +102,9 @@ public class CobaltLuaMachine implements ILuaMachine {
 
         var names = api.getNames();
         for (var name : names) globals.rawset(name, table);
+
+        var moduleName = api.getModuleName();
+        if (moduleName != null) state.registry().getSubTable(Constants.LOADED).rawset(moduleName, table);
     }
 
     private void updateTimeout() {
@@ -164,9 +166,7 @@ public class CobaltLuaMachine implements ILuaMachine {
     private LuaTable wrapLuaObject(Object object) {
         var table = new LuaTable();
         var found = luaMethods.forEachMethod(object, (target, name, method, info) ->
-            table.rawset(name, info != null && info.nonYielding()
-                ? new BasicFunction(this, method, target, context, name)
-                : new ResultInterpreterFunction(this, method, target, context, name)));
+            table.rawset(name, new ResultInterpreterFunction(this, method, target, context, name)));
 
         return found ? table : null;
     }

projects/core/src/main/java/dan200/computercraft/core/lua/ResultInterpreterFunction.java

@@ -73,7 +73,7 @@ class ResultInterpreterFunction extends ResumableVarArgFunction<ResultInterprete
     }
 
     @Override
-    protected Varargs resumeThis(LuaState state, Container container, Varargs args) throws LuaError, UnwindThrowable {
+    public Varargs resume(LuaState state, Container container, Varargs args) throws LuaError, UnwindThrowable {
         MethodResult results;
         var arguments = CobaltLuaMachine.toObjects(args);
         try {
@@ -98,6 +98,6 @@ class ResultInterpreterFunction extends ResumableVarArgFunction<ResultInterprete
         if (!exception.hasLevel() && adjust == 0) return new LuaError(exception.getMessage());
 
         var level = exception.getLevel();
-        return new LuaError(exception.getMessage(), level <= 0 ? level : level + adjust + 1);
+        return new LuaError(exception.getMessage(), level <= 0 ? level : level + adjust);
     }
 }

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

@@ -1,3 +1,32 @@
+# New features in CC: Tweaked 1.109.6
+
+* Improve several Lua parser error messages.
+* Allow addon mods to register `require`able modules.
+
+Several bug fixes:
+* Fix weak tables becoming malformed when keys are GCed.
+
+# New features in CC: Tweaked 1.109.5
+
+* Add a new `/computercraft-computer-folder` command to open a computer's folder
+  in singleplayer.
+
+Several bug fixes:
+* Discard characters being typed into the editor when closing `edit`'s `Run` screen.
+
+# New features in CC: Tweaked 1.109.4
+
+Several bug fixes:
+* Don't log warnings when a computer allocates no bytes.
+* Fix incorrect list index in command computer's NBT conversion (lonevox).
+* Fix `endPage()` not updating the printer's block state.
+* Several documentation improvements (znepb).
+* Correctly mount disks before computer startup, not afterwards.
+* Update to Cobalt 0.9
+  * Debug hooks are now correctly called for every function.
+  * Fix several minor inconsistencies with `debug.getinfo`.
+  * Fix Lua tables being sized incorrectly when created from varargs.
+
 # New features in CC: Tweaked 1.109.3
 
 * Command computers now display in the operator items creative tab.
@@ -6,7 +35,7 @@ Several bug fixes:
 * Error if too many websocket messages are queued to be sent at once.
 * Fix trailing-comma on method calls (e.g. `x:f(a, )` not using our custom error message.
 * Fix internal compiler error when using `goto` as the first statement in an `if` block.
-* Fix incorrect incorrect resizing of a tables' hash part when adding and removing keys.
+* Fix incorrect resizing of a tables' hash part when adding and removing keys.
 
 # New features in CC: Tweaked 1.109.2
 

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

@@ -1,11 +1,9 @@
-New features in CC: Tweaked 1.109.3
+New features in CC: Tweaked 1.109.6
 
-* Command computers now display in the operator items creative tab.
+* Improve several Lua parser error messages.
+* Allow addon mods to register `require`able modules.
 
 Several bug fixes:
-* Error if too many websocket messages are queued to be sent at once.
-* Fix trailing-comma on method calls (e.g. `x:f(a, )` not using our custom error message.
-* Fix internal compiler error when using `goto` as the first statement in an `if` block.
-* Fix incorrect incorrect resizing of a tables' hash part when adding and removing keys.
+* Fix weak tables becoming malformed when keys are GCed.
 
 Type "help changelog" to see the full version history.

projects/core/src/main/resources/data/computercraft/lua/rom/modules/main/cc/internal/event.lua

@@ -0,0 +1,37 @@
+-- SPDX-FileCopyrightText: 2024 The CC: Tweaked Developers
+--
+-- SPDX-License-Identifier: MPL-2.0
+
+--[[- Utilities for working with events.
+
+> [!DANGER]
+> This is an internal module and SHOULD NOT be used in your own code. It may
+> be removed or changed at any time.
+
+@local
+]]
+
+--[[-
+Attempt to discard a [`event!char`] event that may follow a [`event!key`] event.
+
+This attempts to flush the event queue via a timer, stopping early if we observe
+another key or char event.
+
+We flush the event queue by waiting a single tick. It is technically possible
+the key and char events will be delivered in different ticks, but it should be
+very rare, and not worth adding extra delay for.
+]]
+local function discard_char()
+    local timer = os.startTimer(0)
+    while true do
+        local event, id = os.pullEvent()
+        if event == "timer" and id == timer then break
+        elseif event == "char" or event == "key" or event == "key_up" then
+            os.cancelTimer(timer)
+            break
+        end
+    end
+end
+
+
+return { discard_char = discard_char }

projects/core/src/main/resources/data/computercraft/lua/rom/modules/main/cc/internal/syntax/errors.lua

@@ -453,32 +453,53 @@ function errors.local_function_dot(local_start, local_end, dot_start, dot_end)
     }
 end
 
---[[- A statement of the form `x.y z`
+--[[- A statement of the form `x.y`
 
+@tparam number token The token id.
 @tparam number pos The position right after this name.
 @return The resulting parse error.
 ]]
-function errors.standalone_name(pos)
-    expect(1, pos, "number")
+function errors.standalone_name(token, pos)
+    expect(1, token, "number")
+    expect(2, pos, "number")
 
     return {
-        "Unexpected symbol after name.",
+        "Unexpected " .. token_names[token] .. " after name.",
         annotate(pos),
         "Did you mean to assign this or call it as a function?",
     }
 end
 
+--[[- A statement of the form `x.y, z`
+
+@tparam number token The token id.
+@tparam number pos The position right after this name.
+@return The resulting parse error.
+]]
+function errors.standalone_names(token, pos)
+    expect(1, token, "number")
+    expect(2, pos, "number")
+
+    return {
+        "Unexpected " .. token_names[token] .. " after name.",
+        annotate(pos),
+        "Did you mean to assign this?",
+    }
+end
+
 --[[- A statement of the form `x.y`. This is similar to [`standalone_name`], but
 when the next token is on another line.
 
+@tparam number token The token id.
 @tparam number pos The position right after this name.
 @return The resulting parse error.
 ]]
-function errors.standalone_name_call(pos)
-    expect(1, pos, "number")
+function errors.standalone_name_call(token, pos)
+    expect(1, token, "number")
+    expect(2, pos, "number")
 
     return {
-        "Unexpected symbol after variable.",
+        "Unexpected " .. token_names[token] .. " after name.",
         annotate(pos + 1, "Expected something before the end of the line."),
         "Tip: Use " .. code("()") .. " to call with no arguments.",
     }

projects/core/src/main/resources/data/computercraft/lua/rom/modules/main/cc/require.lua

@@ -124,13 +124,22 @@ local function make_package(env, dir)
     local package = {}
     package.loaded = {
         _G = _G,
-        bit32 = bit32,
-        coroutine = coroutine,
-        math = math,
         package = package,
-        string = string,
-        table = table,
     }
+
+    -- Copy everything from the global package table to this instance.
+    --
+    -- This table is an internal implementation detail - it is NOT intended to
+    -- be extended by user code.
+    local registry = debug.getregistry()
+    if registry and type(registry._LOADED) == "table" then
+        for k, v in next, registry._LOADED do
+            if type(k) == "string" then
+                package.loaded[k] = v
+            end
+        end
+    end
+
     package.path = "?;?.lua;?/init.lua;/rom/modules/main/?;/rom/modules/main/?.lua;/rom/modules/main/?/init.lua"
     if turtle then
         package.path = package.path .. ";/rom/modules/turtle/?;/rom/modules/turtle/?.lua;/rom/modules/turtle/?/init.lua"

projects/core/src/main/resources/data/computercraft/lua/rom/programs/edit.lua

@@ -88,6 +88,7 @@ for i = 1, #wrapped do
     term.write(wrapped[i])
 end
 os.pullEvent('key')
+require "cc.internal.event".discard_char()
 ]]
 
 -- Menus

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

@@ -300,7 +300,7 @@ local menu_choices = {
         return false
     end,
     Exit = function()
-        sleep(0) -- Super janky, but consumes stray "char" events from pressing Ctrl then E separately.
+        require "cc.internal.event".discard_char() -- Consume stray "char" events from pressing Ctrl then E separately.
         return true
     end,
 }

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

@@ -257,7 +257,7 @@ while true do
             offset = print_height - content_height
             draw()
         elseif param == keys.q then
-            sleep(0) -- Super janky, but consumes stray "char" events.
+            require "cc.internal.event".discard_char()
             break
         end
     elseif event == "mouse_scroll" then

projects/core/src/test/java/dan200/computercraft/core/asm/MethodTest.java

@@ -67,8 +67,8 @@ public class MethodTest {
     public void testPeripheralThrow() {
         ComputerBootstrap.run(
             "local throw = peripheral.wrap('top')\n" +
-                "local _, err = pcall(throw.thisThread) assert(err == 'pcall: !', err)\n" +
-                "local _, err = pcall(throw.mainThread) assert(err == 'pcall: !', err)",
+                "local _, err = pcall(function() throw.thisThread() end) assert(err == '/test.lua:2: !', (\"thisThread: %q\"):format(err))\n" +
+                "local _, err = pcall(function() throw.mainThread() end) assert(err == '/test.lua:3: !', (\"mainThread: %q\"):format(err))\n",
             x -> x.getEnvironment().setPeripheral(ComputerSide.TOP, new PeripheralThrow()),
             50
         );
@@ -89,6 +89,16 @@ public class MethodTest {
             x -> x.addApi(new ReturnFunction()), 50);
     }
 
+
+    @Test
+    public void testModule() {
+        ComputerBootstrap.run(
+            """
+            assert(require "test.module".func() == 123)
+            """,
+            x -> x.addApi(new IsModule()), 50);
+    }
+
     public static class MainThread implements ILuaAPI, IPeripheral {
         public final String thread = Thread.currentThread().getName();
 
@@ -206,7 +216,7 @@ public class MethodTest {
         }
 
         @Override
-        public MethodResult callMethod(ILuaContext context, int method, IArguments arguments) throws LuaException {
+        public MethodResult callMethod(ILuaContext context, int method, IArguments arguments) {
             return MethodResult.of();
         }
 
@@ -227,4 +237,21 @@ public class MethodTest {
             return new String[]{ "func" };
         }
     }
+
+    public static class IsModule implements ILuaAPI {
+        @Override
+        public String[] getNames() {
+            return new String[0];
+        }
+
+        @Override
+        public @Nullable String getModuleName() {
+            return "test.module";
+        }
+
+        @LuaFunction
+        public final int func() {
+            return 123;
+        }
+    }
 }

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

@@ -15,6 +15,7 @@ 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 org.intellij.lang.annotations.Language;
 import org.junit.jupiter.api.Assertions;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -31,7 +32,7 @@ public class ComputerBootstrap {
     private static final int TPS = 20;
     public static final int MAX_TIME = 10;
 
-    public static void run(String program, Consumer<Computer> setup, int maxTimes) {
+    public static void run(@Language("lua") String program, Consumer<Computer> setup, int maxTimes) {
         var mount = new MemoryMount()
             .addFile("test.lua", program)
             .addFile("startup.lua", "assertion.assert(pcall(loadfile('test.lua', nil, _ENV))) os.shutdown()");
@@ -39,7 +40,7 @@ public class ComputerBootstrap {
         run(mount, setup, maxTimes);
     }
 
-    public static void run(String program, int maxTimes) {
+    public static void run(@Language("lua") String program, int maxTimes) {
         run(program, x -> {
         }, maxTimes);
     }

projects/core/src/test/resources/test-rom/spec/modules/cc/internal/event_spec.lua

@@ -0,0 +1,43 @@
+-- SPDX-FileCopyrightText: 2023 The CC: Tweaked Developers
+--
+-- SPDX-License-Identifier: MPL-2.0
+
+local timeout = require "test_helpers".timeout
+
+describe("cc.internal.event", function()
+    local event = require "cc.internal.event"
+    describe("discard_char", function()
+
+        local function test(events)
+            local unique_event = "flush_" .. math.random(2 ^ 30)
+
+            -- Queue and pull to flush the queue once.
+            os.queueEvent(unique_event)
+            os.pullEvent(unique_event)
+
+            -- Queue our desired events
+            for i = 1, #events do os.queueEvent(table.unpack(events[i])) end
+
+            timeout(0.1, function()
+                event.discard_char()
+
+                -- Then read the remainder of the event queue, and check there's
+                -- no char event.
+                os.queueEvent(unique_event)
+                while true do
+                    local event = os.pullEvent()
+                    if event == unique_event then break end
+                    expect(event):ne("char")
+                end
+            end)
+        end
+
+        it("discards char events", function()
+            test { { "char", "a" } }
+        end)
+
+        it("handles an empty event queue", function()
+            test {}
+        end)
+    end)
+end)

projects/core/src/test/resources/test-rom/spec/modules/cc/internal/syntax/parser_exhaustive_spec.md

@@ -347,7 +347,7 @@ function ( xyz , while
 ```
 
 ```txt
-Unexpected while.
+Unexpected while. Expected a variable name.
    |
  1 | function ( xyz , while
    |                  ^^^^^
@@ -483,11 +483,11 @@ xyz , xyz while
 ```
 
 ```txt
-Unexpected symbol after name.
+Unexpected while after name.
    |
  1 | xyz , xyz while
    |           ^
-Did you mean to assign this or call it as a function?
+Did you mean to assign this?
 ```
 
 
@@ -831,7 +831,7 @@ xyz while
 ```
 
 ```txt
-Unexpected symbol after name.
+Unexpected while after name.
    |
  1 | xyz while
    |     ^
@@ -858,7 +858,7 @@ xyz while
 ```
 
 ```txt
-Unexpected symbol after name.
+Unexpected while after name.
    |
  1 | xyz while
    |     ^
@@ -1056,7 +1056,7 @@ local while
 ```
 
 ```txt
-Unexpected while.
+Unexpected while. Expected a variable name.
    |
  1 | local while
    |       ^^^^^
@@ -1272,7 +1272,7 @@ repeat --[[eof]]
 ```
 
 ```txt
-Unexpected end of file. Expected a statement.
+Unexpected end of file. Expected a variable name.
    |
  2 | -- Line 1: 'until' expected near <eof> (program)
    |                                                 ^
@@ -1389,7 +1389,7 @@ while
 ```
 
 ```txt
-Unexpected while.
+Unexpected while. Expected an expression.
    |
  1 | while
    | ^^^^^

projects/core/src/test/resources/test-rom/spec/modules/cc/internal/syntax/parser_spec.md

@@ -38,6 +38,20 @@ Unexpected = in expression.
 Tip: Wrap the preceding expression in [ and ] to use it as a table key.
 ```
 
+and also
+
+```lua
+return { x + 1 = 1 }
+```
+
+```txt
+Unexpected = in expression.
+   |
+ 1 | return { x + 1 = 1 }
+   |                ^
+Tip: Wrap the preceding expression in [ and ] to use it as a table key.
+```
+
 Note this doesn't occur if this there's already a table key here:
 
 ```lua
@@ -102,6 +116,7 @@ Unexpected end of file. Are you missing a closing bracket?
 ```
 
 ## Missing commas in tables
+We try to detect missing commas in tables, and print an appropriate error message.
 
 ```lua
 return { 1 2 }
@@ -129,6 +144,39 @@ Unexpected number in table.
  1 | return { 1, 2 3 }
    |              ^ Are you missing a comma here?
 ```
+
+This also works with table keys.
+
+```lua
+print({ x = 1 y = 2 })
+```
+
+```txt
+Unexpected identifier in table.
+   |
+ 1 | print({ x = 1 y = 2 })
+   |               ^
+   |
+ 1 | print({ x = 1 y = 2 })
+   |              ^ Are you missing a comma here?
+```
+
+```lua
+print({ ["x"] = 1 ["y"] = 2 })
+```
+
+```txt
+Unexpected [ in table.
+   |
+ 1 | print({ ["x"] = 1 ["y"] = 2 })
+   |                   ^
+   |
+ 1 | print({ ["x"] = 1 ["y"] = 2 })
+   |                  ^ Are you missing a comma here?
+```
+
+We gracefully handle the case where we are actually missing a closing brace.
+
 ```lua
 print({ 1, )
 ```
@@ -172,7 +220,7 @@ local _ = 1
 ```
 
 ```txt
-Unexpected symbol after variable.
+Unexpected local after name.
    |
  1 | term.clear
    |           ^ Expected something before the end of the line.
@@ -186,7 +234,7 @@ x 1
 ```
 
 ```txt
-Unexpected symbol after name.
+Unexpected number after name.
    |
  1 | x 1
    |   ^
@@ -200,13 +248,41 @@ term.clear
 ```
 
 ```txt
-Unexpected symbol after variable.
+Unexpected end of file after name.
    |
  1 | term.clear
    |           ^ Expected something before the end of the line.
 Tip: Use () to call with no arguments.
 ```
 
+When we've got a list of variables, we only suggest assigning it.
+
+```lua
+term.clear, foo
+```
+
+```txt
+Unexpected end of file after name.
+   |
+ 1 | term.clear, foo
+   |                ^
+Did you mean to assign this?
+```
+
+And when we've got a partial expression, we only suggest calling it.
+
+```lua
+(a + b)
+```
+
+```txt
+Unexpected end of file after name.
+   |
+ 1 | (a + b)
+   |        ^ Expected something before the end of the line.
+Tip: Use () to call with no arguments.
+```
+
 ## If statements
 For if statements, we say when we expected the `then` keyword.
 
@@ -425,7 +501,7 @@ goto 2
 ```
 
 ```txt
-Unexpected symbol after name.
+Unexpected number after name.
    |
  1 | goto 2
    |      ^
@@ -460,6 +536,31 @@ Unexpected end of file.
    |   ^
 ```
 
+## Missing function arguments
+We provide an error message for missing arguments in function definitions:
+
+```lua
+function f
+```
+
+```txt
+Unexpected end of file. Expected ( to start function arguments.
+   |
+ 1 | function f
+   |           ^
+```
+
+```lua
+return function
+```
+
+```txt
+Unexpected end of file. Expected ( to start function arguments.
+   |
+ 1 | return function
+   |                ^
+```
+
 # Function calls
 
 ## Additional commas