Merge branch 'mc-1.18.x' into mc-1.19.x

build.gradle.kts

@@ -86,11 +86,17 @@ minecraft {
                 val testMod = configurations["testModRuntimeClasspath"].resolve()
                 val implementation = configurations.runtimeClasspath.get().resolve()
                 val new = (testMod - implementation)
-                    .asSequence().filter { it.isFile }.map { it.absolutePath }
+                    .asSequence()
+                    .filter { it.isFile && !it.name.endsWith("-test-fixtures.jar") }
+                    .map { it.absolutePath }
                     .joinToString(File.pathSeparator)
                 if (old == null) new else old.get() + File.pathSeparator + new
             }
 
+            property("cctest.sources", file("src/testMod/resources/data/cctest").absolutePath)
+
+            arg("--mixin.config=computercraft-gametest.mixins.json")
+
             mods.register("cctest") {
                 source(sourceSets["testMod"])
                 source(sourceSets["testFixtures"])
@@ -114,7 +120,6 @@ minecraft {
     mappings("parchment", "${libs.versions.parchmentMc.get()}-${libs.versions.parchment.get()}-$mcVersion")
 
     accessTransformer(file("src/main/resources/META-INF/accesstransformer.cfg"))
-    accessTransformer(file("src/testMod/resources/META-INF/accesstransformer.cfg"))
 }
 
 mixin {

config/checkstyle/checkstyle.xml

@@ -78,7 +78,9 @@
 
         <!-- Javadoc -->
         <!-- TODO: Missing* checks for the dan200.computercraft.api package? -->
-        <module name="AtclauseOrder" />
+        <module name="AtclauseOrder">
+            <property name="tagOrder" value="@param, @return, @throws, @deprecated"/>
+        </module>
         <module name="InvalidJavadocPosition" />
         <module name="JavadocBlockTagLocation" />
         <module name="JavadocMethod"/>
@@ -107,7 +109,9 @@
         <module name="LocalFinalVariableName" />
         <module name="LocalVariableName" />
         <module name="MemberName" />
-        <module name="MethodName" />
+        <module name="MethodName">
+            <property name="format" value="^(computercraft\$)?[a-z][a-zA-Z0-9]*$" />
+        </module>
         <module name="MethodTypeParameterName" />
         <module name="PackageName">
             <property name="format" value="^dan200\.computercraft(\.[a-z][a-z0-9]*)*" />
@@ -115,11 +119,6 @@
         <module name="ParameterName" />
         <module name="StaticVariableName">
             <property name="format" value="^[a-z][a-zA-Z0-9]*|CAPABILITY(_[A-Z_]+)?$" />
-            <property name="applyToPrivate" value="false" />
-        </module>
-        <module name="StaticVariableName">
-            <property name="format" value="^(s_)?[a-z][a-zA-Z0-9]*|CAPABILITY(_[A-Z_]+)?$" />
-            <property name="applyToPrivate" value="true" />
         </module>
         <module name="TypeName" />
 

doc/stub/fs.lua

@@ -22,13 +22,43 @@ directory exist) and one without it (meaning this entry is an immediate
 completion candidate). `include_dirs` can be set to @{false} to only include
 those with a trailing slash.
 
-@tparam string path The path to complete.
+@tparam[1] string path The path to complete.
-@tparam string location The location where paths are resolved from.
+@tparam[1] string location The location where paths are resolved from.
-@tparam[opt] boolean include_files When @{false}, only directories will be
+@tparam[1,opt=true] boolean include_files When @{false}, only directories will
-included in the returned list.
+be included in the returned list.
-@tparam[opt] boolean include_dirs When @{false}, "raw" directories will not be
+@tparam[1,opt=true] boolean include_dirs When @{false}, "raw" directories will
-included in the returned list.
+not be included in the returned list.
+
+@tparam[2] string path The path to complete.
+@tparam[2] string location The location where paths are resolved from.
+@tparam[2] {
+    include_dirs? = boolean, include_files? = boolean,
+    include_hidden? = boolean
+} options
+This table form is an expanded version of the previous syntax. The
+`include_files` and `include_dirs` arguments from above are passed in as fields.
+
+This table also accepts the following options:
+ - `include_hidden`: Whether to include hidden files (those starting with `.`)
+   by default. They will still be shown when typing a `.`.
+
 @treturn { string... } A list of possible completion candidates.
 @since 1.74
+@changed 1.101.0
+@usage Complete files in the root directory.
+
+    read(nil, nil, function(str)
+        return fs.complete(str, "", true, false)
+    end)
+
+@usage Complete files in the root directory, hiding hidden files by default.
+
+    read(nil, nil, function(str)
+        return fs.complete(str, "", {
+            include_files = true,
+            include_dirs = false,
+            included_hidden = false,
+        })
+    end)
 ]]
 function complete(path, location, include_files, include_dirs) end

gradle.properties

@@ -5,7 +5,7 @@ kotlin.stdlib.default.dependency=false
 kotlin.jvm.target.validation.mode=error
 
 # Mod properties
-modVersion=1.100.10
+modVersion=1.101.0
 
 # Minecraft properties: We want to configure this here so we can read it in settings.gradle
 mcVersion=1.19.2

gradle/libs.versions.toml

@@ -7,7 +7,7 @@ parchment = "2022.10.16"
 parchmentMc = "1.19.2"
 
 autoService = "1.0.1"
-cobalt = { strictly = "[0.5.7,0.6.0)", prefer = "0.5.7" }
+cobalt = { strictly = "[0.5.8,0.6.0)", prefer = "0.5.8" }
 jetbrainsAnnotations = "23.0.0"
 kotlin = "1.7.10"
 kotlin-coroutines = "1.6.0"

src/main/java/dan200/computercraft/ComputerCraft.java

@@ -15,6 +15,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.util.List;
+import java.util.OptionalInt;
 import java.util.concurrent.TimeUnit;
 
 @Mod( ComputerCraft.MOD_ID )
@@ -37,8 +38,8 @@ public final class ComputerCraft
     public static boolean httpEnabled = true;
     public static boolean httpWebsocketEnabled = true;
     public static List<AddressRule> httpRules = List.of(
-        AddressRule.parse( "$private", null, Action.DENY.toPartial() ),
+        AddressRule.parse( "$private", OptionalInt.empty(), Action.DENY.toPartial() ),
-        AddressRule.parse( "*", null, Action.ALLOW.toPartial() )
+        AddressRule.parse( "*", OptionalInt.empty(), Action.ALLOW.toPartial() )
     );
 
     public static int httpMaxRequests = 16;

src/main/java/dan200/computercraft/ComputerCraftAPIImpl.java

@@ -22,7 +22,7 @@ import dan200.computercraft.api.redstone.IBundledRedstoneProvider;
 import dan200.computercraft.core.apis.ApiFactories;
 import dan200.computercraft.core.asm.GenericMethod;
 import dan200.computercraft.core.filesystem.FileMount;
-import dan200.computercraft.core.filesystem.ResourceMount;
+import dan200.computercraft.shared.computer.core.ResourceMount;
 import dan200.computercraft.impl.ComputerCraftAPIService;
 import dan200.computercraft.impl.detail.DetailRegistryImpl;
 import dan200.computercraft.shared.BundledRedstone;

src/main/java/dan200/computercraft/client/gui/widgets/ComputerSidebar.java

@@ -16,6 +16,7 @@ import net.minecraft.network.chat.Component;
 import net.minecraft.resources.ResourceLocation;
 
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.function.BooleanSupplier;
 import java.util.function.Consumer;
 
@@ -56,9 +57,8 @@ public final class ComputerSidebar
             () -> isOn.getAsBoolean() ? Arrays.asList(
                 Component.translatable( "gui.computercraft.tooltip.turn_off" ),
                 Component.translatable( "gui.computercraft.tooltip.turn_off.key" ).withStyle( ChatFormatting.GRAY )
-            ) : Arrays.asList(
+            ) : Collections.singletonList(
-                Component.translatable( "gui.computercraft.tooltip.turn_on" ),
+                Component.translatable( "gui.computercraft.tooltip.turn_on" )
-                Component.translatable( "gui.computercraft.tooltip.turn_off.key" ).withStyle( ChatFormatting.GRAY )
             )
         ) );
 

src/main/java/dan200/computercraft/client/pocket/PocketComputerData.java

@@ -8,7 +8,8 @@ package dan200.computercraft.client.pocket;
 import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.core.terminal.Terminal;
 import dan200.computercraft.shared.computer.core.ComputerState;
-import dan200.computercraft.shared.network.client.TerminalState;
+import dan200.computercraft.shared.computer.terminal.NetworkedTerminal;
+import dan200.computercraft.shared.computer.terminal.TerminalState;
 import dan200.computercraft.shared.pocket.core.PocketServerComputer;
 
 import javax.annotation.Nonnull;
@@ -25,13 +26,13 @@ import javax.annotation.Nonnull;
  */
 public class PocketComputerData
 {
-    private final Terminal terminal;
+    private final NetworkedTerminal terminal;
     private ComputerState state = ComputerState.OFF;
     private int lightColour = -1;
 
     public PocketComputerData( boolean colour )
     {
-        terminal = new Terminal( ComputerCraft.pocketTermWidth, ComputerCraft.pocketTermHeight, colour );
+        terminal = new NetworkedTerminal( ComputerCraft.pocketTermWidth, ComputerCraft.pocketTermHeight, colour );
     }
 
     public int getLightState()

src/main/java/dan200/computercraft/core/apis/http/options/Action.java

@@ -6,13 +6,17 @@
 package dan200.computercraft.core.apis.http.options;
 
 import javax.annotation.Nonnull;
+import java.util.OptionalInt;
+import java.util.OptionalLong;
 
 public enum Action
 {
     ALLOW,
     DENY;
 
-    private final PartialOptions partial = new PartialOptions( this, null, null, null, null );
+    private final PartialOptions partial = new PartialOptions(
+        this, OptionalLong.empty(), OptionalLong.empty(), OptionalInt.empty(), OptionalInt.empty()
+    );
 
     @Nonnull
     public PartialOptions toPartial()

src/main/java/dan200/computercraft/core/apis/http/options/AddressRule.java

@@ -16,6 +16,7 @@ import java.net.Inet4Address;
 import java.net.Inet6Address;
 import java.net.InetAddress;
 import java.net.InetSocketAddress;
+import java.util.OptionalInt;
 import java.util.regex.Pattern;
 
 /**
@@ -29,10 +30,10 @@ public final class AddressRule
     public static final int WEBSOCKET_MESSAGE = 128 * 1024;
 
     private final AddressPredicate predicate;
-    private final Integer port;
+    private final OptionalInt port;
     private final PartialOptions partial;
 
-    private AddressRule( @Nonnull AddressPredicate predicate, @Nullable Integer port, @Nonnull PartialOptions partial )
+    private AddressRule( @Nonnull AddressPredicate predicate, OptionalInt port, @Nonnull PartialOptions partial )
     {
         this.predicate = predicate;
         this.partial = partial;
@@ -40,7 +41,7 @@ public final class AddressRule
     }
 
     @Nullable
-    public static AddressRule parse( String filter, @Nullable Integer port, @Nonnull PartialOptions partial )
+    public static AddressRule parse( String filter, OptionalInt port, @Nonnull PartialOptions partial )
     {
         int cidr = filter.indexOf( '/' );
         if( cidr >= 0 )
@@ -72,7 +73,7 @@ public final class AddressRule
      */
     private boolean matches( String domain, int port, InetAddress address, Inet4Address ipv4Address )
     {
-        if( this.port != null && this.port != port ) return false;
+        if( this.port.isPresent() && this.port.getAsInt() != port ) return false;
         return predicate.matches( domain )
             || predicate.matches( address )
             || (ipv4Address != null && predicate.matches( ipv4Address ));
@@ -80,8 +81,7 @@ public final class AddressRule
 
     public static Options apply( Iterable<? extends AddressRule> rules, String domain, InetSocketAddress socketAddress )
     {
-        PartialOptions options = null;
+        PartialOptions options = PartialOptions.DEFAULT;
-        boolean hasMany = false;
 
         int port = socketAddress.getPort();
         InetAddress address = socketAddress.getAddress();
@@ -91,24 +91,9 @@ public final class AddressRule
         for( AddressRule rule : rules )
         {
             if( !rule.matches( domain, port, address, ipv4Address ) ) continue;
-
+            options = options.merge( rule.partial );
-            if( options == null )
-            {
-                options = rule.partial;
-            }
-            else
-            {
-
-                if( !hasMany )
-                {
-                    options = options.copy();
-                    hasMany = true;
-                }
-
-                options.merge( rule.partial );
-            }
         }
 
-        return (options == null ? PartialOptions.DEFAULT : options).toOptions();
+        return options.toOptions();
     }
 }

src/main/java/dan200/computercraft/core/apis/http/options/AddressRuleConfig.java

@@ -14,6 +14,8 @@ import dan200.computercraft.ComputerCraft;
 import javax.annotation.Nullable;
 import java.util.Locale;
 import java.util.Optional;
+import java.util.OptionalInt;
+import java.util.OptionalLong;
 import java.util.concurrent.ConcurrentHashMap;
 
 /**
@@ -48,7 +50,7 @@ public class AddressRuleConfig
     public static boolean checkRule( UnmodifiableConfig builder )
     {
         String hostObj = get( builder, "host", String.class ).orElse( null );
-        Integer port = get( builder, "port", Number.class ).map( Number::intValue ).orElse( null );
+        OptionalInt port = unboxOptInt( get( builder, "port", Number.class ) );
         return hostObj != null && checkEnum( builder, "action", Action.class )
             && check( builder, "port", Number.class )
             && check( builder, "timeout", Number.class )
@@ -65,11 +67,11 @@ public class AddressRuleConfig
         if( hostObj == null ) return null;
 
         Action action = getEnum( builder, "action", Action.class ).orElse( null );
-        Integer port = get( builder, "port", Number.class ).map( Number::intValue ).orElse( null );
+        OptionalInt port = unboxOptInt( get( builder, "port", Number.class ) );
-        Integer timeout = get( builder, "timeout", Number.class ).map( Number::intValue ).orElse( null );
+        OptionalInt timeout = unboxOptInt( get( builder, "timeout", Number.class ) );
-        Long maxUpload = get( builder, "max_upload", Number.class ).map( Number::longValue ).orElse( null );
+        OptionalLong maxUpload = unboxOptLong( get( builder, "max_upload", Number.class ).map( Number::longValue ) );
-        Long maxDownload = get( builder, "max_download", Number.class ).map( Number::longValue ).orElse( null );
+        OptionalLong maxDownload = unboxOptLong( get( builder, "max_download", Number.class ).map( Number::longValue ) );
-        Integer websocketMessage = get( builder, "websocket_message", Number.class ).map( Number::intValue ).orElse( null );
+        OptionalInt websocketMessage = unboxOptInt( get( builder, "websocket_message", Number.class ).map( Number::intValue ) );
 
         PartialOptions options = new PartialOptions(
             action,
@@ -122,6 +124,16 @@ public class AddressRuleConfig
         return get( config, field, String.class ).map( x -> parseEnum( klass, x ) );
     }
 
+    private static OptionalLong unboxOptLong( Optional<? extends Number> value )
+    {
+        return value.map( Number::intValue ).map( OptionalLong::of ).orElse( OptionalLong.empty() );
+    }
+
+    private static OptionalInt unboxOptInt( Optional<? extends Number> value )
+    {
+        return value.map( Number::intValue ).map( OptionalInt::of ).orElse( OptionalInt.empty() );
+    }
+
     @Nullable
     private static <T extends Enum<T>> T parseEnum( Class<T> klass, String x )
     {

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

@@ -5,21 +5,25 @@
  */
 package dan200.computercraft.core.apis.http.options;
 
-import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import java.util.OptionalInt;
+import java.util.OptionalLong;
 
 public final class PartialOptions
 {
-    static final PartialOptions DEFAULT = new PartialOptions( null, null, null, null, null );
+    public static final PartialOptions DEFAULT = new PartialOptions(
+        null, OptionalLong.empty(), OptionalLong.empty(), OptionalInt.empty(), OptionalInt.empty()
+    );
 
-    Action action;
+    private final @Nullable Action action;
-    Long maxUpload;
+    private final OptionalLong maxUpload;
-    Long maxDownload;
+    private final OptionalLong maxDownload;
-    Integer timeout;
+    private final OptionalInt timeout;
-    Integer websocketMessage;
+    private final OptionalInt websocketMessage;
 
-    Options options;
+    private @Nullable Options options;
 
-    PartialOptions( Action action, Long maxUpload, Long maxDownload, Integer timeout, Integer websocketMessage )
+    public PartialOptions( @Nullable Action action, OptionalLong maxUpload, OptionalLong maxDownload, OptionalInt timeout, OptionalInt websocketMessage )
     {
         this.action = action;
         this.maxUpload = maxUpload;
@@ -28,31 +32,36 @@ public final class PartialOptions
         this.websocketMessage = websocketMessage;
     }
 
-    @Nonnull
     Options toOptions()
     {
         if( options != null ) return options;
 
         return options = new Options(
             action == null ? Action.DENY : action,
-            maxUpload == null ? AddressRule.MAX_UPLOAD : maxUpload,
+            maxUpload.orElse( AddressRule.MAX_UPLOAD ),
-            maxDownload == null ? AddressRule.MAX_DOWNLOAD : maxDownload,
+            maxDownload.orElse( AddressRule.MAX_DOWNLOAD ),
-            timeout == null ? AddressRule.TIMEOUT : timeout,
+            timeout.orElse( AddressRule.TIMEOUT ),
-            websocketMessage == null ? AddressRule.WEBSOCKET_MESSAGE : websocketMessage
+            websocketMessage.orElse( AddressRule.WEBSOCKET_MESSAGE )
         );
     }
 
-    void merge( @Nonnull PartialOptions other )
+    /**
+     * Perform a left-biased union of two {@link PartialOptions}.
+     *
+     * @param other The other partial options to combine with.
+     * @return The merged options map.
+     */
+    PartialOptions merge( PartialOptions other )
     {
-        if( action == null && other.action != null ) action = other.action;
+        // Short circuit for DEFAULT. This has no effect on the outcome, but avoids an allocation.
-        if( maxUpload == null && other.maxUpload != null ) maxUpload = other.maxUpload;
+        if( this == DEFAULT ) return other;
-        if( maxDownload == null && other.maxDownload != null ) maxDownload = other.maxDownload;
-        if( timeout == null && other.timeout != null ) timeout = other.timeout;
-        if( websocketMessage == null && other.websocketMessage != null ) websocketMessage = other.websocketMessage;
-    }
 
-    PartialOptions copy()
+        return new PartialOptions(
-    {
+            action == null && other.action != null ? other.action : action,
-        return new PartialOptions( action, maxUpload, maxDownload, timeout, websocketMessage );
+            maxUpload.isPresent() ? maxUpload : other.maxUpload,
+            maxDownload.isPresent() ? maxDownload : other.maxDownload,
+            timeout.isPresent() ? timeout : other.timeout,
+            websocketMessage.isPresent() ? websocketMessage : other.websocketMessage
+        );
     }
 }

src/main/java/dan200/computercraft/core/apis/http/websocket/NoOriginWebSocketHanshakder.java

@@ -0,0 +1,35 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.core.apis.http.websocket;
+
+import io.netty.handler.codec.http.FullHttpRequest;
+import io.netty.handler.codec.http.HttpHeaderNames;
+import io.netty.handler.codec.http.HttpHeaders;
+import io.netty.handler.codec.http.websocketx.WebSocketClientHandshaker13;
+import io.netty.handler.codec.http.websocketx.WebSocketVersion;
+
+import java.net.URI;
+
+/**
+ * A version of {@link WebSocketClientHandshaker13} which doesn't add the {@link HttpHeaderNames#ORIGIN} header to the
+ * original HTTP request.
+ */
+public class NoOriginWebSocketHanshakder extends WebSocketClientHandshaker13
+{
+    public NoOriginWebSocketHanshakder( URI webSocketURL, WebSocketVersion version, String subprotocol, boolean allowExtensions, HttpHeaders customHeaders, int maxFramePayloadLength )
+    {
+        super( webSocketURL, version, subprotocol, allowExtensions, customHeaders, maxFramePayloadLength );
+    }
+
+    @Override
+    protected FullHttpRequest newHandshakeRequest()
+    {
+        FullHttpRequest request = super.newHandshakeRequest();
+        HttpHeaders headers = request.headers();
+        if( !customHeaders.contains( HttpHeaderNames.ORIGIN ) ) headers.remove( HttpHeaderNames.ORIGIN );
+        return request;
+    }
+}

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

@@ -26,7 +26,6 @@ import io.netty.handler.codec.http.HttpHeaderNames;
 import io.netty.handler.codec.http.HttpHeaders;
 import io.netty.handler.codec.http.HttpObjectAggregator;
 import io.netty.handler.codec.http.websocketx.WebSocketClientHandshaker;
-import io.netty.handler.codec.http.websocketx.WebSocketClientHandshakerFactory;
 import io.netty.handler.codec.http.websocketx.WebSocketVersion;
 import io.netty.handler.ssl.SslContext;
 
@@ -152,7 +151,7 @@ public class Websocket extends Resource<Websocket>
                         }
 
                         String subprotocol = headers.get( HttpHeaderNames.SEC_WEBSOCKET_PROTOCOL );
-                        WebSocketClientHandshaker handshaker = WebSocketClientHandshakerFactory.newHandshaker(
+                        WebSocketClientHandshaker handshaker = new NoOriginWebSocketHanshakder(
                             uri, WebSocketVersion.V13, subprotocol, true, headers,
                             options.websocketMessage <= 0 ? MAX_MESSAGE_SIZE : options.websocketMessage
                         );

src/main/java/dan200/computercraft/core/computer/ComputerSide.java

@@ -5,14 +5,11 @@
  */
 package dan200.computercraft.core.computer;
 
-import net.minecraft.core.Direction;
-
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 
 /**
- * A side on a computer. Unlike {@link Direction}, this is relative to the direction the computer is
+ * A side on a computer. This is relative to the direction the computer is facing.
- * facing..
  */
 public enum ComputerSide
 {

src/main/java/dan200/computercraft/core/computer/mainthread/MainThreadExecutor.java

@@ -10,7 +10,6 @@ import dan200.computercraft.api.peripheral.IWorkMonitor;
 import dan200.computercraft.core.computer.Computer;
 import dan200.computercraft.core.metrics.Metrics;
 import dan200.computercraft.core.metrics.MetricsObserver;
-import net.minecraft.world.level.block.entity.BlockEntity;
 
 import java.util.ArrayDeque;
 import java.util.Queue;
@@ -28,7 +27,7 @@ import java.util.concurrent.TimeUnit;
  * this tick. At the beginning of the tick, we execute as many {@link MainThread} tasks as possible, until our
  * time-frame or the global time frame has expired.
  * <p>
- * Then, when other objects (such as {@link BlockEntity}) are ticked, we update how much time we've used using
+ * Then, when other objects (such as block entities or entities) are ticked, we update how much time we've used via
  * {@link IWorkMonitor#trackWork(long, TimeUnit)}.
  * <p>
  * Now, if anywhere during this period, we use more than our allocated time slice, the executor is marked as

src/main/java/dan200/computercraft/core/terminal/Terminal.java

@@ -7,8 +7,6 @@ package dan200.computercraft.core.terminal;
 
 import dan200.computercraft.shared.util.Colour;
 import dan200.computercraft.shared.util.Palette;
-import net.minecraft.nbt.CompoundTag;
-import net.minecraft.network.FriendlyByteBuf;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
@@ -16,23 +14,23 @@ import java.nio.ByteBuffer;
 
 public class Terminal
 {
-    private static final String BASE_16 = "0123456789abcdef";
+    protected static final String BASE_16 = "0123456789abcdef";
 
-    private int width;
+    protected int width;
-    private int height;
+    protected int height;
-    private final boolean colour;
+    protected final boolean colour;
 
-    private int cursorX = 0;
+    protected int cursorX = 0;
-    private int cursorY = 0;
+    protected int cursorY = 0;
-    private boolean cursorBlink = false;
+    protected boolean cursorBlink = false;
-    private int cursorColour = 0;
+    protected int cursorColour = 0;
-    private int cursorBackgroundColour = 15;
+    protected int cursorBackgroundColour = 15;
 
-    private TextBuffer[] text;
+    protected TextBuffer[] text;
-    private TextBuffer[] textColour;
+    protected TextBuffer[] textColour;
-    private TextBuffer[] backgroundColour;
+    protected TextBuffer[] backgroundColour;
 
-    private final Palette palette;
+    protected final Palette palette;
 
     private final @Nullable Runnable onChanged;
 
@@ -320,110 +318,6 @@ public class Terminal
         if( onChanged != null ) onChanged.run();
     }
 
-    public synchronized void write( FriendlyByteBuf buffer )
-    {
-        buffer.writeInt( cursorX );
-        buffer.writeInt( cursorY );
-        buffer.writeBoolean( cursorBlink );
-        buffer.writeByte( cursorBackgroundColour << 4 | cursorColour );
-
-        for( int y = 0; y < height; y++ )
-        {
-            TextBuffer text = this.text[y];
-            TextBuffer textColour = this.textColour[y];
-            TextBuffer backColour = backgroundColour[y];
-
-            for( int x = 0; x < width; x++ ) buffer.writeByte( text.charAt( x ) & 0xFF );
-            for( int x = 0; x < width; x++ )
-            {
-                buffer.writeByte( getColour(
-                    backColour.charAt( x ), Colour.BLACK ) << 4 |
-                    getColour( textColour.charAt( x ), Colour.WHITE )
-                );
-            }
-        }
-
-        palette.write( buffer );
-    }
-
-    public synchronized void read( FriendlyByteBuf buffer )
-    {
-        cursorX = buffer.readInt();
-        cursorY = buffer.readInt();
-        cursorBlink = buffer.readBoolean();
-
-        byte cursorColour = buffer.readByte();
-        cursorBackgroundColour = (cursorColour >> 4) & 0xF;
-        this.cursorColour = cursorColour & 0xF;
-
-        for( int y = 0; y < height; y++ )
-        {
-            TextBuffer text = this.text[y];
-            TextBuffer textColour = this.textColour[y];
-            TextBuffer backColour = backgroundColour[y];
-
-            for( int x = 0; x < width; x++ ) text.setChar( x, (char) (buffer.readByte() & 0xFF) );
-            for( int x = 0; x < width; x++ )
-            {
-                byte colour = buffer.readByte();
-                backColour.setChar( x, BASE_16.charAt( (colour >> 4) & 0xF ) );
-                textColour.setChar( x, BASE_16.charAt( colour & 0xF ) );
-            }
-        }
-
-        palette.read( buffer );
-        setChanged();
-    }
-
-    public synchronized CompoundTag writeToNBT( CompoundTag nbt )
-    {
-        nbt.putInt( "term_cursorX", cursorX );
-        nbt.putInt( "term_cursorY", cursorY );
-        nbt.putBoolean( "term_cursorBlink", cursorBlink );
-        nbt.putInt( "term_textColour", cursorColour );
-        nbt.putInt( "term_bgColour", cursorBackgroundColour );
-        for( int n = 0; n < height; n++ )
-        {
-            nbt.putString( "term_text_" + n, text[n].toString() );
-            nbt.putString( "term_textColour_" + n, textColour[n].toString() );
-            nbt.putString( "term_textBgColour_" + n, backgroundColour[n].toString() );
-        }
-
-        palette.writeToNBT( nbt );
-        return nbt;
-    }
-
-    public synchronized void readFromNBT( CompoundTag nbt )
-    {
-        cursorX = nbt.getInt( "term_cursorX" );
-        cursorY = nbt.getInt( "term_cursorY" );
-        cursorBlink = nbt.getBoolean( "term_cursorBlink" );
-        cursorColour = nbt.getInt( "term_textColour" );
-        cursorBackgroundColour = nbt.getInt( "term_bgColour" );
-
-        for( int n = 0; n < height; n++ )
-        {
-            text[n].fill( ' ' );
-            if( nbt.contains( "term_text_" + n ) )
-            {
-                text[n].write( nbt.getString( "term_text_" + n ) );
-            }
-            textColour[n].fill( BASE_16.charAt( cursorColour ) );
-            if( nbt.contains( "term_textColour_" + n ) )
-            {
-                textColour[n].write( nbt.getString( "term_textColour_" + n ) );
-            }
-            backgroundColour[n].fill( BASE_16.charAt( cursorBackgroundColour ) );
-            if( nbt.contains( "term_textBgColour_" + n ) )
-            {
-                backgroundColour[n].write( nbt.getString( "term_textBgColour_" + n ) );
-            }
-        }
-
-        palette.readFromNBT( nbt );
-        setChanged();
-    }
-
     public static int getColour( char c, Colour def )
     {
         if( c >= '0' && c <= '9' ) return c - '0';

src/main/java/dan200/computercraft/shared/CommonHooks.java

@@ -7,7 +7,7 @@ package dan200.computercraft.shared;
 
 import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.core.apis.http.NetworkUtils;
-import dan200.computercraft.core.filesystem.ResourceMount;
+import dan200.computercraft.shared.computer.core.ResourceMount;
 import dan200.computercraft.shared.command.CommandComputerCraft;
 import dan200.computercraft.shared.computer.core.ServerContext;
 import dan200.computercraft.shared.computer.metrics.ComputerMBean;

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

@@ -365,8 +365,7 @@ public final class CommandComputerCraft
     private static final List<AggregatedMetric> DEFAULT_FIELDS = Arrays.asList(
         new AggregatedMetric( Metrics.COMPUTER_TASKS, Aggregate.COUNT ),
         new AggregatedMetric( Metrics.COMPUTER_TASKS, Aggregate.NONE ),
-        new AggregatedMetric( Metrics.COMPUTER_TASKS, Aggregate.AVG ),
+        new AggregatedMetric( Metrics.COMPUTER_TASKS, Aggregate.AVG )
-        new AggregatedMetric( Metrics.COMPUTER_TASKS, Aggregate.MAX )
     );
 
     private static int displayTimings( CommandSourceStack source, AggregatedMetric sortField, List<AggregatedMetric> fields ) throws CommandSyntaxException

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

@@ -3,7 +3,7 @@
  * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
  * Send enquiries to dratcliffe@gmail.com
  */
-package dan200.computercraft.core.filesystem;
+package dan200.computercraft.shared.computer.core;
 
 import com.google.common.cache.Cache;
 import com.google.common.cache.CacheBuilder;
@@ -11,6 +11,7 @@ import com.google.common.io.ByteStreams;
 import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.api.filesystem.IMount;
 import dan200.computercraft.core.apis.handles.ArrayByteChannel;
+import dan200.computercraft.core.filesystem.FileSystem;
 import dan200.computercraft.shared.util.IoUtil;
 import net.minecraft.ResourceLocationException;
 import net.minecraft.resources.ResourceLocation;

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

@@ -15,12 +15,12 @@ import dan200.computercraft.core.computer.Computer;
 import dan200.computercraft.core.computer.ComputerEnvironment;
 import dan200.computercraft.core.computer.ComputerSide;
 import dan200.computercraft.core.metrics.MetricsObserver;
-import dan200.computercraft.core.terminal.Terminal;
 import dan200.computercraft.shared.computer.menu.ComputerMenu;
+import dan200.computercraft.shared.computer.terminal.NetworkedTerminal;
+import dan200.computercraft.shared.computer.terminal.TerminalState;
 import dan200.computercraft.shared.network.NetworkHandler;
 import dan200.computercraft.shared.network.NetworkMessage;
 import dan200.computercraft.shared.network.client.ComputerTerminalClientMessage;
-import dan200.computercraft.shared.network.client.TerminalState;
 import net.minecraft.core.BlockPos;
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.level.ServerLevel;
@@ -41,7 +41,7 @@ public class ServerComputer implements InputHandler, ComputerEnvironment
     private final MetricsObserver metrics;
     private final Computer computer;
 
-    private final Terminal terminal;
+    private final NetworkedTerminal terminal;
     private final AtomicBoolean terminalChanged = new AtomicBoolean( false );
 
     private boolean changedLastFrame;
@@ -54,7 +54,7 @@ public class ServerComputer implements InputHandler, ComputerEnvironment
 
         ServerContext context = ServerContext.get( level.getServer() );
         instanceID = context.registry().getUnusedInstanceID();
-        terminal = new Terminal( terminalWidth, terminalHeight, family != ComputerFamily.NORMAL, this::markTerminalChanged );
+        terminal = new NetworkedTerminal( terminalWidth, terminalHeight, family != ComputerFamily.NORMAL, this::markTerminalChanged );
         metrics = context.metrics().createMetricObserver( this );
 
         computer = new Computer( context.computerContext(), this, terminal, computerID );

src/main/java/dan200/computercraft/shared/computer/core/ServerContext.java

@@ -5,13 +5,17 @@
  */
 package dan200.computercraft.shared.computer.core;
 
+import com.google.common.annotations.VisibleForTesting;
 import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.ComputerCraftAPIImpl;
 import dan200.computercraft.api.ComputerCraftAPI;
 import dan200.computercraft.api.filesystem.IMount;
 import dan200.computercraft.core.ComputerContext;
+import dan200.computercraft.core.computer.ComputerThread;
 import dan200.computercraft.core.computer.GlobalEnvironment;
 import dan200.computercraft.core.computer.mainthread.MainThread;
+import dan200.computercraft.core.lua.CobaltLuaMachine;
+import dan200.computercraft.core.lua.ILuaMachine;
 import dan200.computercraft.shared.CommonHooks;
 import dan200.computercraft.shared.computer.metrics.GlobalMetrics;
 import dan200.computercraft.shared.util.IDAssigner;
@@ -41,6 +45,9 @@ public final class ServerContext
 {
     private static final LevelResource FOLDER = new LevelResource( ComputerCraft.MOD_ID );
 
+    @VisibleForTesting
+    public static ILuaMachine.Factory luaMachine = CobaltLuaMachine::new;
+
     private static @Nullable ServerContext instance;
 
     private final MinecraftServer server;
@@ -57,7 +64,11 @@ public final class ServerContext
         this.server = server;
         storageDir = server.getWorldPath( FOLDER );
         mainThread = new MainThread();
-        context = new ComputerContext( new Environment( server ), ComputerCraft.computerThreads, mainThread );
+        context = new ComputerContext(
+            new Environment( server ),
+            new ComputerThread( ComputerCraft.computerThreads ),
+            mainThread, luaMachine
+        );
         idAssigner = new IDAssigner( storageDir.resolve( "ids.json" ) );
     }
 

src/main/java/dan200/computercraft/shared/computer/inventory/ContainerComputerBase.java

@@ -11,7 +11,8 @@ import dan200.computercraft.shared.computer.core.ServerComputer;
 import dan200.computercraft.shared.computer.menu.ComputerMenu;
 import dan200.computercraft.shared.computer.menu.ServerInputHandler;
 import dan200.computercraft.shared.computer.menu.ServerInputState;
-import dan200.computercraft.shared.network.client.TerminalState;
+import dan200.computercraft.shared.computer.terminal.NetworkedTerminal;
+import dan200.computercraft.shared.computer.terminal.TerminalState;
 import dan200.computercraft.shared.network.container.ComputerContainerData;
 import dan200.computercraft.shared.util.SingleIntArray;
 import net.minecraft.world.entity.player.Player;
@@ -34,7 +35,7 @@ public abstract class ContainerComputerBase extends AbstractContainerMenu implem
     private final @Nullable ServerComputer computer;
     private final @Nullable ServerInputState<ContainerComputerBase> input;
 
-    private final @Nullable Terminal terminal;
+    private final @Nullable NetworkedTerminal terminal;
 
     private final ItemStack displayStack;
 

src/main/java/dan200/computercraft/shared/computer/menu/ComputerMenu.java

@@ -6,7 +6,7 @@
 package dan200.computercraft.shared.computer.menu;
 
 import dan200.computercraft.shared.computer.core.ServerComputer;
-import dan200.computercraft.shared.network.client.TerminalState;
+import dan200.computercraft.shared.computer.terminal.TerminalState;
 import net.minecraft.world.inventory.AbstractContainerMenu;
 
 /**

src/main/java/dan200/computercraft/shared/computer/terminal/NetworkedTerminal.java

@@ -0,0 +1,129 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.shared.computer.terminal;
+
+import dan200.computercraft.core.terminal.Terminal;
+import dan200.computercraft.core.terminal.TextBuffer;
+import dan200.computercraft.shared.util.Colour;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.network.FriendlyByteBuf;
+
+public class NetworkedTerminal extends Terminal
+{
+    public NetworkedTerminal( int width, int height, boolean colour )
+    {
+        super( width, height, colour );
+    }
+
+    public NetworkedTerminal( int width, int height, boolean colour, Runnable changedCallback )
+    {
+        super( width, height, colour, changedCallback );
+    }
+
+    public synchronized void write( FriendlyByteBuf buffer )
+    {
+        buffer.writeInt( cursorX );
+        buffer.writeInt( cursorY );
+        buffer.writeBoolean( cursorBlink );
+        buffer.writeByte( cursorBackgroundColour << 4 | cursorColour );
+
+        for( int y = 0; y < height; y++ )
+        {
+            TextBuffer text = this.text[y];
+            TextBuffer textColour = this.textColour[y];
+            TextBuffer backColour = backgroundColour[y];
+
+            for( int x = 0; x < width; x++ ) buffer.writeByte( text.charAt( x ) & 0xFF );
+            for( int x = 0; x < width; x++ )
+            {
+                buffer.writeByte( getColour(
+                    backColour.charAt( x ), Colour.BLACK ) << 4 |
+                    getColour( textColour.charAt( x ), Colour.WHITE )
+                );
+            }
+        }
+
+        palette.write( buffer );
+    }
+
+    public synchronized void read( FriendlyByteBuf buffer )
+    {
+        cursorX = buffer.readInt();
+        cursorY = buffer.readInt();
+        cursorBlink = buffer.readBoolean();
+
+        byte cursorColour = buffer.readByte();
+        cursorBackgroundColour = (cursorColour >> 4) & 0xF;
+        this.cursorColour = cursorColour & 0xF;
+
+        for( int y = 0; y < height; y++ )
+        {
+            TextBuffer text = this.text[y];
+            TextBuffer textColour = this.textColour[y];
+            TextBuffer backColour = backgroundColour[y];
+
+            for( int x = 0; x < width; x++ ) text.setChar( x, (char) (buffer.readByte() & 0xFF) );
+            for( int x = 0; x < width; x++ )
+            {
+                byte colour = buffer.readByte();
+                backColour.setChar( x, BASE_16.charAt( (colour >> 4) & 0xF ) );
+                textColour.setChar( x, BASE_16.charAt( colour & 0xF ) );
+            }
+        }
+
+        palette.read( buffer );
+        setChanged();
+    }
+
+    public synchronized CompoundTag writeToNBT( CompoundTag nbt )
+    {
+        nbt.putInt( "term_cursorX", cursorX );
+        nbt.putInt( "term_cursorY", cursorY );
+        nbt.putBoolean( "term_cursorBlink", cursorBlink );
+        nbt.putInt( "term_textColour", cursorColour );
+        nbt.putInt( "term_bgColour", cursorBackgroundColour );
+        for( int n = 0; n < height; n++ )
+        {
+            nbt.putString( "term_text_" + n, text[n].toString() );
+            nbt.putString( "term_textColour_" + n, textColour[n].toString() );
+            nbt.putString( "term_textBgColour_" + n, backgroundColour[n].toString() );
+        }
+
+        palette.writeToNBT( nbt );
+        return nbt;
+    }
+
+    public synchronized void readFromNBT( CompoundTag nbt )
+    {
+        cursorX = nbt.getInt( "term_cursorX" );
+        cursorY = nbt.getInt( "term_cursorY" );
+        cursorBlink = nbt.getBoolean( "term_cursorBlink" );
+        cursorColour = nbt.getInt( "term_textColour" );
+        cursorBackgroundColour = nbt.getInt( "term_bgColour" );
+
+        for( int n = 0; n < height; n++ )
+        {
+            text[n].fill( ' ' );
+            if( nbt.contains( "term_text_" + n ) )
+            {
+                text[n].write( nbt.getString( "term_text_" + n ) );
+            }
+            textColour[n].fill( BASE_16.charAt( cursorColour ) );
+            if( nbt.contains( "term_textColour_" + n ) )
+            {
+                textColour[n].write( nbt.getString( "term_textColour_" + n ) );
+            }
+            backgroundColour[n].fill( BASE_16.charAt( cursorBackgroundColour ) );
+            if( nbt.contains( "term_textBgColour_" + n ) )
+            {
+                backgroundColour[n].write( nbt.getString( "term_textBgColour_" + n ) );
+            }
+        }
+
+        palette.readFromNBT( nbt );
+        setChanged();
+    }
+}

src/main/java/dan200/computercraft/shared/computer/terminal/TerminalState.java

@@ -3,9 +3,8 @@
  * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
  * Send enquiries to dratcliffe@gmail.com
  */
-package dan200.computercraft.shared.network.client;
+package dan200.computercraft.shared.computer.terminal;
 
-import dan200.computercraft.core.terminal.Terminal;
 import dan200.computercraft.shared.util.IoUtil;
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.ByteBufInputStream;
@@ -42,12 +41,12 @@ public class TerminalState
 
     private ByteBuf compressed;
 
-    public TerminalState( @Nullable Terminal terminal )
+    public TerminalState( @Nullable NetworkedTerminal terminal )
     {
         this( terminal, true );
     }
 
-    public TerminalState( @Nullable Terminal terminal, boolean compress )
+    public TerminalState( @Nullable NetworkedTerminal terminal, boolean compress )
     {
         this.compress = compress;
 
@@ -115,17 +114,17 @@ public class TerminalState
         return buffer == null ? 0 : buffer.readableBytes();
     }
 
-    public void apply( Terminal terminal )
+    public void apply( NetworkedTerminal terminal )
     {
         if( buffer == null ) throw new NullPointerException( "buffer" );
         terminal.resize( width, height );
         terminal.read( new FriendlyByteBuf( buffer ) );
     }
 
-    public Terminal create()
+    public NetworkedTerminal create()
     {
         if( buffer == null ) throw new NullPointerException( "Terminal does not exist" );
-        Terminal terminal = new Terminal( width, height, colour );
+        NetworkedTerminal terminal = new NetworkedTerminal( width, height, colour );
         terminal.read( new FriendlyByteBuf( buffer ) );
         return terminal;
     }

src/main/java/dan200/computercraft/shared/computer/upload/UploadResult.java

@@ -13,8 +13,6 @@ public enum UploadResult
     CONSUMED,
     ERROR;
 
-    public static final Component SUCCESS_TITLE = Component.translatable( "gui.computercraft.upload.success" );
-
     public static final Component FAILED_TITLE = Component.translatable( "gui.computercraft.upload.failed" );
     public static final Component COMPUTER_OFF_MSG = Component.translatable( "gui.computercraft.upload.failed.computer_off" );
     public static final Component TOO_MUCH_MSG = Component.translatable( "gui.computercraft.upload.failed.too_much" );

src/main/java/dan200/computercraft/shared/network/client/ComputerTerminalClientMessage.java

@@ -6,6 +6,7 @@
 package dan200.computercraft.shared.network.client;
 
 import dan200.computercraft.shared.computer.menu.ComputerMenu;
+import dan200.computercraft.shared.computer.terminal.TerminalState;
 import dan200.computercraft.shared.network.NetworkMessage;
 import net.minecraft.client.Minecraft;
 import net.minecraft.network.FriendlyByteBuf;

src/main/java/dan200/computercraft/shared/network/client/MonitorClientMessage.java

@@ -5,6 +5,7 @@
  */
 package dan200.computercraft.shared.network.client;
 
+import dan200.computercraft.shared.computer.terminal.TerminalState;
 import dan200.computercraft.shared.network.NetworkMessage;
 import dan200.computercraft.shared.peripheral.monitor.TileMonitor;
 import net.minecraft.client.Minecraft;

src/main/java/dan200/computercraft/shared/network/client/PocketComputerDataMessage.java

@@ -7,8 +7,9 @@ package dan200.computercraft.shared.network.client;
 
 import dan200.computercraft.client.pocket.ClientPocketComputers;
 import dan200.computercraft.client.pocket.PocketComputerData;
-import dan200.computercraft.core.terminal.Terminal;
 import dan200.computercraft.shared.computer.core.ComputerState;
+import dan200.computercraft.shared.computer.terminal.NetworkedTerminal;
+import dan200.computercraft.shared.computer.terminal.TerminalState;
 import dan200.computercraft.shared.network.NetworkMessage;
 import dan200.computercraft.shared.pocket.core.PocketServerComputer;
 import net.minecraft.network.FriendlyByteBuf;
@@ -29,7 +30,7 @@ public class PocketComputerDataMessage implements NetworkMessage
         instanceId = computer.getInstanceID();
         state = computer.getState();
         lightState = computer.getLight();
-        terminal = sendTerminal ? computer.getTerminalState() : new TerminalState( (Terminal) null );
+        terminal = sendTerminal ? computer.getTerminalState() : new TerminalState( (NetworkedTerminal) null );
     }
 
     public PocketComputerDataMessage( FriendlyByteBuf buf )

src/main/java/dan200/computercraft/shared/network/container/ComputerContainerData.java

@@ -7,7 +7,7 @@ package dan200.computercraft.shared.network.container;
 
 import dan200.computercraft.shared.computer.core.ComputerFamily;
 import dan200.computercraft.shared.computer.core.ServerComputer;
-import dan200.computercraft.shared.network.client.TerminalState;
+import dan200.computercraft.shared.computer.terminal.TerminalState;
 import net.minecraft.network.FriendlyByteBuf;
 import net.minecraft.world.item.ItemStack;
 

src/main/java/dan200/computercraft/shared/peripheral/generic/methods/EnergyMethods.java

@@ -25,6 +25,7 @@ import javax.annotation.Nonnull;
  * :::
  *
  * @cc.module energy_storage
+ * @cc.since 1.94.0
  */
 public class EnergyMethods implements GenericPeripheral
 {

src/main/java/dan200/computercraft/shared/peripheral/generic/methods/FluidMethods.java

@@ -35,6 +35,7 @@ import static dan200.computercraft.shared.peripheral.generic.methods.ArgumentHel
  * Methods for interacting with tanks and other fluid storage blocks.
  *
  * @cc.module fluid_storage
+ * @cc.since 1.94.0
  */
 public class FluidMethods implements GenericPeripheral
 {

src/main/java/dan200/computercraft/shared/peripheral/generic/methods/InventoryMethods.java

@@ -37,6 +37,7 @@ import static dan200.computercraft.shared.peripheral.generic.methods.ArgumentHel
  * Methods for interacting with inventories.
  *
  * @cc.module inventory
+ * @cc.since 1.94.0
  */
 public class InventoryMethods implements GenericPeripheral
 {
@@ -170,6 +171,7 @@ public class InventoryMethods implements GenericPeripheral
      * end
      * print(total)
      * }</pre>
+     * @cc.since 1.96.0
      */
     @LuaFunction( mainThread = true )
     public static int getItemLimit( IItemHandler inventory, int slot ) throws LuaException

src/main/java/dan200/computercraft/shared/peripheral/monitor/ClientMonitor.java

@@ -9,7 +9,8 @@ import com.mojang.blaze3d.platform.GlStateManager;
 import dan200.computercraft.client.util.DirectBuffers;
 import dan200.computercraft.client.util.DirectVertexBuffer;
 import dan200.computercraft.core.terminal.Terminal;
-import dan200.computercraft.shared.network.client.TerminalState;
+import dan200.computercraft.shared.computer.terminal.NetworkedTerminal;
+import dan200.computercraft.shared.computer.terminal.TerminalState;
 import net.minecraft.core.BlockPos;
 import net.minecraftforge.api.distmarker.Dist;
 import net.minecraftforge.api.distmarker.OnlyIn;
@@ -36,7 +37,7 @@ public final class ClientMonitor
     public int tboUniform;
     public DirectVertexBuffer backgroundBuffer;
     public DirectVertexBuffer foregroundBuffer;
-    private Terminal terminal;
+    private NetworkedTerminal terminal;
     private boolean terminalChanged;
 
     public ClientMonitor( TileMonitor origin )
@@ -182,7 +183,7 @@ public final class ClientMonitor
     {
         if( state.hasTerminal() )
         {
-            if( terminal == null ) terminal = new Terminal( state.width, state.height, state.colour );
+            if( terminal == null ) terminal = new NetworkedTerminal( state.width, state.height, state.colour );
             state.apply( terminal );
             terminalChanged = true;
         }

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

@@ -8,7 +8,7 @@ package dan200.computercraft.shared.peripheral.monitor;
 import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.shared.network.NetworkHandler;
 import dan200.computercraft.shared.network.client.MonitorClientMessage;
-import dan200.computercraft.shared.network.client.TerminalState;
+import dan200.computercraft.shared.computer.terminal.TerminalState;
 import net.minecraft.core.BlockPos;
 import net.minecraft.server.level.ServerLevel;
 import net.minecraft.world.level.Level;

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

@@ -7,6 +7,7 @@ package dan200.computercraft.shared.peripheral.monitor;
 
 import com.google.common.annotations.VisibleForTesting;
 import dan200.computercraft.core.terminal.Terminal;
+import dan200.computercraft.shared.computer.terminal.NetworkedTerminal;
 import dan200.computercraft.shared.util.TickScheduler;
 
 import javax.annotation.Nullable;
@@ -18,7 +19,7 @@ public class ServerMonitor
 
     private final boolean colour;
     private int textScale = 2;
-    private @Nullable Terminal terminal;
+    private @Nullable NetworkedTerminal terminal;
     private final AtomicBoolean resized = new AtomicBoolean( false );
     private final AtomicBoolean changed = new AtomicBoolean( false );
 
@@ -46,7 +47,7 @@ public class ServerMonitor
 
         if( terminal == null )
         {
-            terminal = new Terminal( termWidth, termHeight, colour, this::markChanged );
+            terminal = new NetworkedTerminal( termWidth, termHeight, colour, this::markChanged );
             markChanged();
         }
         else
@@ -91,7 +92,7 @@ public class ServerMonitor
 
     @Nullable
     @VisibleForTesting
-    public Terminal getTerminal()
+    public NetworkedTerminal getTerminal()
     {
         return terminal;
     }

src/main/java/dan200/computercraft/shared/peripheral/monitor/TileMonitor.java

@@ -11,7 +11,7 @@ import dan200.computercraft.api.peripheral.IComputerAccess;
 import dan200.computercraft.api.peripheral.IPeripheral;
 import dan200.computercraft.core.terminal.Terminal;
 import dan200.computercraft.shared.common.TileGeneric;
-import dan200.computercraft.shared.network.client.TerminalState;
+import dan200.computercraft.shared.computer.terminal.TerminalState;
 import dan200.computercraft.shared.util.CapabilityUtil;
 import dan200.computercraft.shared.util.TickScheduler;
 import net.minecraft.core.BlockPos;

src/main/java/dan200/computercraft/shared/peripheral/printer/TilePrinter.java

@@ -8,6 +8,7 @@ package dan200.computercraft.shared.peripheral.printer;
 import dan200.computercraft.api.peripheral.IPeripheral;
 import dan200.computercraft.core.terminal.Terminal;
 import dan200.computercraft.shared.common.TileGeneric;
+import dan200.computercraft.shared.computer.terminal.NetworkedTerminal;
 import dan200.computercraft.shared.media.items.ItemPrintout;
 import dan200.computercraft.shared.util.*;
 import net.minecraft.core.BlockPos;
@@ -62,7 +63,7 @@ public final class TilePrinter extends TileGeneric implements DefaultSidedInvent
         SidedCaps.ofNullable( facing -> facing == null ? new InvWrapper( this ) : new SidedInvWrapper( this, facing ) );
     private LazyOptional<IPeripheral> peripheralCap;
 
-    private final Terminal page = new Terminal( ItemPrintout.LINE_MAX_LENGTH, ItemPrintout.LINES_PER_PAGE, true );
+    private final NetworkedTerminal page = new NetworkedTerminal( ItemPrintout.LINE_MAX_LENGTH, ItemPrintout.LINES_PER_PAGE, true );
     private String pageTitle = "";
     private boolean printing = false;
 

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

@@ -17,6 +17,7 @@ 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;
 
@@ -177,7 +178,7 @@ public final class NBTUtil
         {
             MessageDigest digest = MessageDigest.getInstance( "MD5" );
             DataOutput output = new DataOutputStream( new DigestOutputStream( digest ) );
-            NbtIo.write( tag, output );
+            writeTag( output, "", tag );
             byte[] hash = digest.digest();
             return ENCODING.encode( hash );
         }
@@ -188,6 +189,37 @@ public final class NBTUtil
         }
     }
 
+    /**
+     * An alternative version of {@link NbtIo#write(CompoundTag, DataOutput)}, which sorts keys. This
+     * should make the output slightly more deterministic.
+     *
+     * @param output The output to write to.
+     * @param name   The name of the key we're writing. Should be {@code ""} for the root node.
+     * @param tag    The tag to write.
+     * @throws IOException If the underlying stream throws.
+     * @see NbtIo#write(CompoundTag, DataOutput)
+     * @see CompoundTag#write(DataOutput)
+     */
+    private static void writeTag( DataOutput output, String name, Tag tag ) throws IOException
+    {
+        output.writeByte( tag.getId() );
+        if( tag.getId() == 0 ) return;
+        output.writeUTF( name );
+
+        if( tag instanceof CompoundTag compound )
+        {
+            String[] keys = compound.getAllKeys().toArray( new String[0] );
+            Arrays.sort( keys );
+            for( String key : keys ) writeTag( output, key, compound.get( key ) );
+
+            output.writeByte( 0 );
+        }
+        else
+        {
+            tag.write( output );
+        }
+    }
+
     private static final class DigestOutputStream extends OutputStream
     {
         private final MessageDigest digest;

src/main/resources/assets/computercraft/lang/en_us.json

@@ -111,13 +111,10 @@
     "gui.computercraft.tooltip.computer_id": "Computer ID: %s",
     "gui.computercraft.tooltip.disk_id": "Disk ID: %s",
     "gui.computercraft.tooltip.turn_on": "Turn this computer on",
-    "gui.computercraft.tooltip.turn_on.key": "Hold Ctrl+R",
     "gui.computercraft.tooltip.turn_off": "Turn this computer off",
     "gui.computercraft.tooltip.turn_off.key": "Hold Ctrl+S",
     "gui.computercraft.tooltip.terminate": "Stop the currently running code",
     "gui.computercraft.tooltip.terminate.key": "Hold Ctrl+T",
-    "gui.computercraft.upload.success": "Upload Succeeded",
-    "gui.computercraft.upload.success.msg": "%d files uploaded.",
     "gui.computercraft.upload.failed": "Upload Failed",
     "gui.computercraft.upload.failed.computer_off": "You must turn the computer on before uploading files.",
     "gui.computercraft.upload.failed.too_much": "Your files are too large to be uploaded.",

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

@@ -3,7 +3,7 @@
 -- Ideally we'd use require, but that is part of the shell, and so is not
 -- available to the BIOS or any APIs. All APIs load this using dofile, but that
 -- has not been defined at this point.
-local expect
+local expect, field
 
 do
     local h = fs.open("rom/modules/main/cc/expect.lua", "r")
@@ -11,7 +11,8 @@ do
     h.close()
 
     if not f then error(err) end
-    expect = f().expect
+    local res = f()
+    expect, field = res.expect, res.field
 end
 
 if _VERSION == "Lua 5.1" then
@@ -716,9 +717,17 @@ local tEmpty = {}
 function fs.complete(sPath, sLocation, bIncludeFiles, bIncludeDirs)
     expect(1, sPath, "string")
     expect(2, sLocation, "string")
-    expect(3, bIncludeFiles, "boolean", "nil")
+    local bIncludeHidden = nil
-    expect(4, bIncludeDirs, "boolean", "nil")
+    if type(bIncludeFiles) == "table" then
+        bIncludeDirs = field(bIncludeFiles, "include_dirs", "boolean", "nil")
+        bIncludeHidden = field(bIncludeFiles, "include_hidden", "boolean", "nil")
+        bIncludeFiles = field(bIncludeFiles, "include_files", "boolean", "nil")
+    else
+        expect(3, bIncludeFiles, "boolean", "nil")
+        expect(4, bIncludeDirs, "boolean", "nil")
+    end
 
+    bIncludeHidden = bIncludeHidden ~= false
     bIncludeFiles = bIncludeFiles ~= false
     bIncludeDirs = bIncludeDirs ~= false
     local sDir = sLocation
@@ -755,7 +764,9 @@ function fs.complete(sPath, sLocation, bIncludeFiles, bIncludeDirs)
         local tFiles = fs.list(sDir)
         for n = 1, #tFiles do
             local sFile = tFiles[n]
-            if #sFile >= #sName and string.sub(sFile, 1, #sName) == sName then
+            if #sFile >= #sName and string.sub(sFile, 1, #sName) == sName and (
+                bIncludeHidden or sFile:sub(1, 1) ~= "." or sName:sub(1, 1) == "."
+            ) then
                 local bIsDir = fs.isDir(fs.combine(sDir, sFile))
                 local sResult = string.sub(sFile, #sName + 1)
                 if bIsDir then
@@ -902,7 +913,7 @@ settings.define("paint.default_extension", {
 
 settings.define("list.show_hidden", {
     default = false,
-    description = [[Show hidden files (those starting with "." in the Lua REPL)]],
+    description = [[Show hidden files (those starting with "." in the Lua REPL).]],
     type = "boolean",
 })
 
@@ -937,6 +948,11 @@ settings.define("bios.strict_globals", {
     description = "Prevents assigning variables into a program's environment. Make sure you use the local keyword or assign to _G explicitly.",
     type = "boolean",
 })
+settings.define("shell.autocomplete_hidden", {
+    default = false,
+    description = [[Autocomplete hidden files and folders (those starting with ".").]],
+    type = "boolean",
+})
 
 if term.isColour() then
     settings.define("bios.use_multishell", {

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

@@ -1,10 +1,28 @@
+# New features in CC: Tweaked 1.101.0
+
+* Improvee Dutch translation (Quezler)
+* Better reporting of fatal computer timeouts in the server log.
+* Convert detail providers into a registry, allowing peripheral mods to read item/block details.
+* Redesign the metrics system. `/computercraft track` now allows computing aggregates (total, max, avg) on any metric, not just computer time.
+* File drag-and-drop now queues a `file_transfer` event on the computer. The
+  built-in shell or the `import` program must now be running to upload files.
+* The `peripheral` now searches for remote peripherals using any peripheral with the `peripheral_hub` type, not just wired modems.
+* Add `include_hidden` option to `fs.complete`, which can be used to prevent hidden files showing up in autocomplete results. (IvoLeal72)
+* Add `shell.autocomplete_hidden` setting. (IvoLeal72)
+
+Several bug fixes:
+* Prevent `edit`'s "Run" command scrolling the terminal output on smaller
+  screens.
+* Remove some non-determinism in computing item's `nbt` hash.
+* Don't set the `Origin` header on outgoing websocket requests.
+
 # New features in CC: Tweaked 1.100.10
 
 * Mention WAV support in speaker help (MCJack123).
 * Add http programs to the path, even when http is not enabled.
 
 Several bug fixes:
-* Fix example in textutils.pagedTabulate docs (IvoLeal72).
+* Fix example in `textutils.pagedTabulate` docs (IvoLeal72).
 * Fix help program treating the terminal one line longer than it was.
 * Send block updates to client when turtle moves (roland-a).
 * Resolve several monitor issues when running Occulus shaders.
@@ -236,7 +254,7 @@ And several bug fixes:
 # New features in CC: Tweaked 1.96.0
 
 * Use lightGrey for folders within the "list" program.
-* Add getLimit to inventory peripherals.
+* Add `getItemLimit` to inventory peripherals.
 * Expose the generic peripheral system to the public API.
 * Add cc.expect.range (Lupus590).
 * Allow calling cc.expect directly (MCJack123).

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

@@ -1,12 +1,19 @@
-New features in CC: Tweaked 1.100.10
+New features in CC: Tweaked 1.101.0
 
-* Mention WAV support in speaker help (MCJack123).
+* Improvee Dutch translation (Quezler)
-* Add http programs to the path, even when http is not enabled.
+* Better reporting of fatal computer timeouts in the server log.
+* Convert detail providers into a registry, allowing peripheral mods to read item/block details.
+* Redesign the metrics system. `/computercraft track` now allows computing aggregates (total, max, avg) on any metric, not just computer time.
+* File drag-and-drop now queues a `file_transfer` event on the computer. The
+  built-in shell or the `import` program must now be running to upload files.
+* The `peripheral` now searches for remote peripherals using any peripheral with the `peripheral_hub` type, not just wired modems.
+* Add `include_hidden` option to `fs.complete`, which can be used to prevent hidden files showing up in autocomplete results. (IvoLeal72)
+* Add `shell.autocomplete_hidden` setting. (IvoLeal72)
 
 Several bug fixes:
-* Fix example in textutils.pagedTabulate docs (IvoLeal72).
+* Prevent `edit`'s "Run" command scrolling the terminal output on smaller
-* Fix help program treating the terminal one line longer than it was.
+  screens.
-* Send block updates to client when turtle moves (roland-a).
+* Remove some non-determinism in computing item's `nbt` hash.
-* Resolve several monitor issues when running Occulus shaders.
+* Don't set the `Origin` header on outgoing websocket requests.
 
 Type "help changelog" to see the full version history.

src/main/resources/data/computercraft/lua/rom/modules/main/cc/audio/dfpwm.lua

@@ -27,9 +27,9 @@ application or development builds of [FFmpeg].
 
 @see guide!speaker_audio Gives a more general introduction to audio processing and the speaker.
 @see speaker.playAudio To play the decoded audio data.
+@since 1.100.0
 @usage Reads "data/example.dfpwm" in chunks, decodes them and then doubles the speed of the audio. The resulting audio
 is then re-encoded and saved to "speedy.dfpwm". This processed audio can then be played with the `speaker` program.
-@since 1.100.0
 
 ```lua
 local dfpwm = require("cc.audio.dfpwm")

src/main/resources/data/computercraft/lua/rom/modules/main/cc/shell/completion.lua

@@ -34,7 +34,11 @@ local completion = require "cc.completion"
 -- @tparam string text Current text to complete.
 -- @treturn { string... } A list of suffixes of matching files.
 local function file(shell, text)
-    return fs.complete(text, shell.dir(), true, false)
+    return fs.complete(text, shell.dir(), {
+        include_files = true,
+        include_dirs = false,
+        include_hidden = settings.get("shell.autocomplete_hidden"),
+    })
 end
 
 --- Complete the name of a directory relative to the current working directory.
@@ -43,7 +47,11 @@ end
 -- @tparam string text Current text to complete.
 -- @treturn { string... } A list of suffixes of matching directories.
 local function dir(shell, text)
-    return fs.complete(text, shell.dir(), false, true)
+    return fs.complete(text, shell.dir(), {
+        include_files = false,
+        include_dirs = true,
+        include_hidden = settings.get("shell.autocomplete_hidden"),
+    })
 end
 
 --- Complete the name of a file or directory relative to the current working
@@ -55,7 +63,11 @@ end
 -- @tparam[opt] boolean add_space Whether to add a space after the completed item.
 -- @treturn { string... } A list of suffixes of matching files and directories.
 local function dirOrFile(shell, text, previous, add_space)
-    local results = fs.complete(text, shell.dir(), true, true)
+    local results = fs.complete(text, shell.dir(), {
+        include_files = true,
+        include_dirs = true,
+        include_hidden = settings.get("shell.autocomplete_hidden"),
+    })
     if add_space then
         for n = 1, #results do
             local result = results[n]

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

@@ -55,19 +55,22 @@ term.redirect(current)
 term.setTextColor(term.isColour() and colours.yellow or colours.white)
 term.setBackgroundColor(colours.black)
 term.setCursorBlink(false)
-local _, y = term.getCursorPos()
-local _, h = term.getSize()
 if not ok then
     printError(err)
 end
-if ok and y >= h then
+
-    term.scroll(1)
+local message = "Press any key to continue."
+if ok then message = "Program finished. " .. message end
+local _, y = term.getCursorPos()
+local w, h = term.getSize()
+local wrapped = require("cc.strings").wrap(message, w)
+
+local start_y = h - #wrapped + 1
+if y >= start_y then term.scroll(y - start_y + 1) end
+for i = 1, #wrapped do
+    term.setCursorPos(1, start_y + i - 1)
+    term.write(wrapped[i])
 end
-term.setCursorPos(1, h)
-if ok then
-    write("Program finished. ")
-end
-write("Press any key to continue")
 os.pullEvent('key')
 ]]
 

src/main/resources/data/computercraft/lua/rom/programs/shell.lua

@@ -329,9 +329,14 @@ function shell.programs(include_hidden)
 end
 
 local function completeProgram(sLine)
+    local bIncludeHidden = settings.get("shell.autocomplete_hidden")
     if #sLine > 0 and (sLine:find("/") or sLine:find("\\")) then
         -- Add programs from the root
-        return fs.complete(sLine, sDir, true, false)
+        return fs.complete(sLine, sDir, {
+            include_files = true,
+            include_dirs = false,
+            include_hidden = bIncludeHidden,
+        })
 
     else
         local tResults = {}
@@ -349,7 +354,11 @@ local function completeProgram(sLine)
         end
 
         -- Add all subdirectories. We don't include files as they will be added in the block below
-        local tDirs = fs.complete(sLine, sDir, false, false)
+        local tDirs = fs.complete(sLine, sDir, {
+            include_files = false,
+            include_dirs = false,
+            include_hidden = bIncludeHidden,
+        })
         for i = 1, #tDirs do
             local sResult = tDirs[i]
             if not tSeen[sResult] then

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

@@ -12,6 +12,7 @@ import org.junit.jupiter.params.provider.ValueSource;
 
 import java.net.InetSocketAddress;
 import java.util.Collections;
+import java.util.OptionalInt;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
@@ -21,8 +22,8 @@ public class AddressRuleTest
     public void matchesPort()
     {
         Iterable<AddressRule> rules = Collections.singletonList( AddressRule.parse(
-            "127.0.0.1", 8080,
+            "127.0.0.1", OptionalInt.of( 8080 ),
-            new PartialOptions( Action.ALLOW, null, null, null, null )
+            Action.ALLOW.toPartial()
         ) );
 
         assertEquals( apply( rules, "localhost", 8080 ).action, Action.ALLOW );

src/test/java/dan200/computercraft/core/terminal/TerminalTest.java

@@ -9,9 +9,6 @@ import dan200.computercraft.api.lua.LuaValues;
 import dan200.computercraft.shared.util.Colour;
 import dan200.computercraft.test.core.CallCounter;
 import dan200.computercraft.test.core.terminal.TerminalMatchers;
-import io.netty.buffer.Unpooled;
-import net.minecraft.nbt.CompoundTag;
-import net.minecraft.network.FriendlyByteBuf;
 import org.hamcrest.Matcher;
 import org.junit.jupiter.api.Test;
 
@@ -597,92 +594,6 @@ class TerminalTest
         callCounter.assertNotCalled();
     }
 
-    @Test
-    void testPacketBufferRoundtrip()
-    {
-        Terminal writeTerminal = new Terminal( 2, 1, true );
-
-        blit( writeTerminal, "hi", "11", "ee" );
-        writeTerminal.setCursorPos( 2, 5 );
-        writeTerminal.setTextColour( 3 );
-        writeTerminal.setBackgroundColour( 5 );
-
-        FriendlyByteBuf packetBuffer = new FriendlyByteBuf( Unpooled.buffer() );
-        writeTerminal.write( packetBuffer );
-
-        CallCounter callCounter = new CallCounter();
-        Terminal readTerminal = new Terminal( 2, 1, true, callCounter );
-        packetBuffer.writeBytes( packetBuffer );
-        readTerminal.read( packetBuffer );
-
-        assertThat( readTerminal, allOf(
-            textMatches( new String[] { "hi", } ),
-            textColourMatches( new String[] { "11", } ),
-            backgroundColourMatches( new String[] { "ee", } )
-        ) );
-
-        assertEquals( 2, readTerminal.getCursorX() );
-        assertEquals( 5, readTerminal.getCursorY() );
-        assertEquals( 3, readTerminal.getTextColour() );
-        assertEquals( 5, readTerminal.getBackgroundColour() );
-        callCounter.assertCalledTimes( 1 );
-    }
-
-    @Test
-    void testNbtRoundtrip()
-    {
-        Terminal writeTerminal = new Terminal( 10, 5, true );
-        blit( writeTerminal, "hi", "11", "ee" );
-        writeTerminal.setCursorPos( 2, 5 );
-        writeTerminal.setTextColour( 3 );
-        writeTerminal.setBackgroundColour( 5 );
-
-        CompoundTag nbt = new CompoundTag();
-        writeTerminal.writeToNBT( nbt );
-
-        CallCounter callCounter = new CallCounter();
-        Terminal readTerminal = new Terminal( 2, 1, true, callCounter );
-
-        readTerminal.readFromNBT( nbt );
-
-        assertThat( readTerminal, allOf(
-            textMatches( new String[] { "hi", } ),
-            textColourMatches( new String[] { "11", } ),
-            backgroundColourMatches( new String[] { "ee", } )
-        ) );
-
-        assertEquals( 2, readTerminal.getCursorX() );
-        assertEquals( 5, readTerminal.getCursorY() );
-        assertEquals( 3, readTerminal.getTextColour() );
-        assertEquals( 5, readTerminal.getBackgroundColour() );
-        callCounter.assertCalledTimes( 1 );
-    }
-
-    @Test
-    void testReadWriteNBTEmpty()
-    {
-        Terminal terminal = new Terminal( 0, 0, true );
-
-        CompoundTag nbt = new CompoundTag();
-        terminal.writeToNBT( nbt );
-
-        CallCounter callCounter = new CallCounter();
-        terminal = new Terminal( 0, 1, true, callCounter );
-        terminal.readFromNBT( nbt );
-
-        assertThat( terminal, allOf(
-            textMatches( new String[] { "", } ),
-            textColourMatches( new String[] { "", } ),
-            backgroundColourMatches( new String[] { "", } )
-        ) );
-
-        assertEquals( 0, terminal.getCursorX() );
-        assertEquals( 0, terminal.getCursorY() );
-        assertEquals( 0, terminal.getTextColour() );
-        assertEquals( 15, terminal.getBackgroundColour() );
-        callCounter.assertCalledTimes( 1 );
-    }
-
     @Test
     void testGetColour()
     {

src/test/java/dan200/computercraft/shared/computer/core/ResourceMountTest.java

@@ -3,7 +3,7 @@
  * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
  * Send enquiries to dratcliffe@gmail.com
  */
-package dan200.computercraft.core.filesystem;
+package dan200.computercraft.shared.computer.core;
 
 import dan200.computercraft.api.filesystem.IMount;
 import net.minecraft.Util;

src/test/java/dan200/computercraft/shared/computer/terminal/NetworkedTerminalTest.java

@@ -0,0 +1,113 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.shared.computer.terminal;
+
+import dan200.computercraft.api.lua.LuaValues;
+import dan200.computercraft.core.terminal.Terminal;
+import dan200.computercraft.test.core.CallCounter;
+import io.netty.buffer.Unpooled;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.network.FriendlyByteBuf;
+import org.junit.jupiter.api.Test;
+
+import static dan200.computercraft.test.core.terminal.TerminalMatchers.*;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.allOf;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class NetworkedTerminalTest
+{
+    @Test
+    void testPacketBufferRoundtrip()
+    {
+        var writeTerminal = new NetworkedTerminal( 2, 1, true );
+
+        blit( writeTerminal, "hi", "11", "ee" );
+        writeTerminal.setCursorPos( 2, 5 );
+        writeTerminal.setTextColour( 3 );
+        writeTerminal.setBackgroundColour( 5 );
+
+        FriendlyByteBuf packetBuffer = new FriendlyByteBuf( Unpooled.buffer() );
+        writeTerminal.write( packetBuffer );
+
+        CallCounter callCounter = new CallCounter();
+        var readTerminal = new NetworkedTerminal( 2, 1, true, callCounter );
+        packetBuffer.writeBytes( packetBuffer );
+        readTerminal.read( packetBuffer );
+
+        assertThat( readTerminal, allOf(
+            textMatches( new String[] { "hi", } ),
+            textColourMatches( new String[] { "11", } ),
+            backgroundColourMatches( new String[] { "ee", } )
+        ) );
+
+        assertEquals( 2, readTerminal.getCursorX() );
+        assertEquals( 5, readTerminal.getCursorY() );
+        assertEquals( 3, readTerminal.getTextColour() );
+        assertEquals( 5, readTerminal.getBackgroundColour() );
+        callCounter.assertCalledTimes( 1 );
+    }
+
+    @Test
+    void testNbtRoundtrip()
+    {
+        var writeTerminal = new NetworkedTerminal( 10, 5, true );
+        blit( writeTerminal, "hi", "11", "ee" );
+        writeTerminal.setCursorPos( 2, 5 );
+        writeTerminal.setTextColour( 3 );
+        writeTerminal.setBackgroundColour( 5 );
+
+        CompoundTag nbt = new CompoundTag();
+        writeTerminal.writeToNBT( nbt );
+
+        CallCounter callCounter = new CallCounter();
+        var readTerminal = new NetworkedTerminal( 2, 1, true, callCounter );
+
+        readTerminal.readFromNBT( nbt );
+
+        assertThat( readTerminal, allOf(
+            textMatches( new String[] { "hi", } ),
+            textColourMatches( new String[] { "11", } ),
+            backgroundColourMatches( new String[] { "ee", } )
+        ) );
+
+        assertEquals( 2, readTerminal.getCursorX() );
+        assertEquals( 5, readTerminal.getCursorY() );
+        assertEquals( 3, readTerminal.getTextColour() );
+        assertEquals( 5, readTerminal.getBackgroundColour() );
+        callCounter.assertCalledTimes( 1 );
+    }
+
+    @Test
+    void testReadWriteNBTEmpty()
+    {
+        var terminal = new NetworkedTerminal( 0, 0, true );
+
+        CompoundTag nbt = new CompoundTag();
+        terminal.writeToNBT( nbt );
+
+        CallCounter callCounter = new CallCounter();
+        terminal = new NetworkedTerminal( 0, 1, true, callCounter );
+        terminal.readFromNBT( nbt );
+
+        assertThat( terminal, allOf(
+            textMatches( new String[] { "", } ),
+            textColourMatches( new String[] { "", } ),
+            backgroundColourMatches( new String[] { "", } )
+        ) );
+
+        assertEquals( 0, terminal.getCursorX() );
+        assertEquals( 0, terminal.getCursorY() );
+        assertEquals( 0, terminal.getTextColour() );
+        assertEquals( 15, terminal.getBackgroundColour() );
+        callCounter.assertCalledTimes( 1 );
+    }
+
+    private static void blit( Terminal terminal, String text, String fg, String bg )
+    {
+        terminal.blit( LuaValues.encode( text ), LuaValues.encode( fg ), LuaValues.encode( bg ) );
+    }
+}

src/test/java/dan200/computercraft/shared/computer/terminal/TerminalStateTest.java

@@ -3,7 +3,7 @@
  * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
  * Send enquiries to dratcliffe@gmail.com
  */
-package dan200.computercraft.shared.network.client;
+package dan200.computercraft.shared.computer.terminal;
 
 import dan200.computercraft.core.terminal.Terminal;
 import dan200.computercraft.core.terminal.TextBuffer;
@@ -23,7 +23,7 @@ public class TerminalStateTest
     @RepeatedTest( 5 )
     public void testCompressed()
     {
-        Terminal terminal = randomTerminal();
+        var terminal = randomTerminal();
 
         FriendlyByteBuf buffer = new FriendlyByteBuf( Unpooled.directBuffer() );
         new TerminalState( terminal, true ).write( buffer );
@@ -35,7 +35,7 @@ public class TerminalStateTest
     @RepeatedTest( 5 )
     public void testUncompressed()
     {
-        Terminal terminal = randomTerminal();
+        var terminal = randomTerminal();
 
         FriendlyByteBuf buffer = new FriendlyByteBuf( Unpooled.directBuffer() );
         new TerminalState( terminal, false ).write( buffer );
@@ -44,10 +44,10 @@ public class TerminalStateTest
         assertEquals( 0, buffer.readableBytes() );
     }
 
-    private static Terminal randomTerminal()
+    private static NetworkedTerminal randomTerminal()
     {
         Random random = new Random();
-        Terminal terminal = new Terminal( 10, 5, true );
+        NetworkedTerminal terminal = new NetworkedTerminal( 10, 5, true );
         for( int y = 0; y < terminal.getHeight(); y++ )
         {
             TextBuffer buffer = terminal.getLine( y );
@@ -70,14 +70,14 @@ public class TerminalStateTest
         }
     }
 
-    private static Terminal read( FriendlyByteBuf buffer )
+    private static NetworkedTerminal read( FriendlyByteBuf buffer )
     {
         TerminalState state = new TerminalState( buffer );
         assertTrue( state.colour );
 
         if( !state.hasTerminal() ) return null;
 
-        Terminal other = new Terminal( state.width, state.height, true );
+        var other = new NetworkedTerminal( state.width, state.height, true );
         state.apply( other );
         return other;
     }

src/test/resources/test-rom/spec/apis/fs_spec.lua

@@ -10,6 +10,46 @@ describe("The fs library", function()
             expect.error(fs.complete, "", "", 1):eq("bad argument #3 (expected boolean, got number)")
             expect.error(fs.complete, "", "", true, 1):eq("bad argument #4 (expected boolean, got number)")
         end)
+
+        describe("include_hidden", function()
+            local dir = "tmp/hidden"
+            local function setup_tree()
+                fs.delete(dir)
+                fs.makeDir(dir)
+                fs.open(dir .. "/file.txt", "w").close()
+                fs.open(dir .. "/.hidden.txt", "w").close()
+            end
+
+            it("hides hidden files", function()
+                setup_tree()
+                local opts = { include_files = true, include_dirs = false, include_hidden = false }
+
+                expect(fs.complete("", dir, opts)):same { "../", "file.txt" }
+                expect(fs.complete(dir .. "/", "", opts)):same { "file.txt" }
+            end)
+
+            it("shows hidden files when typing a dot", function()
+                setup_tree()
+                local opts = { include_files = true, include_dirs = false, include_hidden = false }
+
+                expect(fs.complete(".", dir, opts)):same { "./", "hidden.txt" }
+                expect(fs.complete(dir .. "/.", "", opts)):same { "hidden.txt" }
+
+                -- Also test
+                expect(fs.complete(dir .. "/file", "", opts)):same { ".txt" }
+                expect(fs.complete(dir .. "/file.", "", opts)):same { "txt" }
+                expect(fs.complete("file", dir, opts)):same { ".txt" }
+                expect(fs.complete("file.", dir, opts)):same { "txt" }
+            end)
+
+            it("shows hidden files when include_hidden is true", function()
+                setup_tree()
+                local opts = { include_files = true, include_dirs = false, include_hidden = true }
+
+                expect(fs.complete("", dir, opts)):same { "../", ".hidden.txt", "file.txt" }
+                expect(fs.complete(dir .. "/", "", opts)):same { ".hidden.txt", "file.txt" }
+            end)
+        end)
     end)
 
     describe("fs.isDriveRoot", function()

src/test/resources/test-rom/spec/apis/os_spec.lua

@@ -61,9 +61,9 @@ describe("The os library", function()
 
             -- TODO: Java 16 apparently no longer treats TextStyle.FULL as full and will render Sun instead of Sunday.
             exp_code("%a", "Sun")
-            -- exp_code("%A", "Sunday")
+            exp_code("%A", "Sunday")
             exp_code("%b", "Oct")
-            -- exp_code("%B", "October")
+            exp_code("%B", "October")
             exp_code("%c", "Sun Oct  1 23:12:17 2000")
             exp_code("%C", "20")
             exp_code("%d", "01")

src/testFixtures/kotlin/dan200/computercraft/test/core/computer/KotlinLuaMachine.kt

@@ -5,11 +5,9 @@ import dan200.computercraft.api.lua.ILuaContext
 import dan200.computercraft.core.lua.ILuaMachine
 import dan200.computercraft.core.lua.MachineEnvironment
 import dan200.computercraft.core.lua.MachineResult
-import kotlinx.coroutines.CoroutineName
+import kotlinx.coroutines.*
-import kotlinx.coroutines.CoroutineScope
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.launch
 import java.io.InputStream
+import kotlin.coroutines.CoroutineContext
 
 /**
  * An [ILuaMachine] which runs Kotlin functions instead.
@@ -26,7 +24,7 @@ abstract class KotlinLuaMachine(environment: MachineEnvironment) : ILuaMachine,
             queueEvent(eventName, arguments)
         } else {
             val task = getTask()
-            if (task != null) CoroutineScope(Dispatchers.Unconfined + CoroutineName("Computer")).launch { task() }
+            if (task != null) CoroutineScope(NeverDispatcher() + CoroutineName("Computer")).launch { task() }
         }
 
         return MachineResult.OK
@@ -38,4 +36,20 @@ abstract class KotlinLuaMachine(environment: MachineEnvironment) : ILuaMachine,
      * Get the next task to execute on this computer.
      */
     protected abstract fun getTask(): (suspend KotlinLuaMachine.() -> Unit)?
+
+    /**
+     * A [CoroutineDispatcher] which only allows resuming from the computer thread. In practice, this means the only
+     * way to yield is with [pullEvent].
+     */
+    private class NeverDispatcher : CoroutineDispatcher() {
+        private val expectedGroup = Thread.currentThread().threadGroup
+
+        override fun dispatch(context: CoroutineContext, block: Runnable) {
+            if (Thread.currentThread().threadGroup != expectedGroup) {
+                throw UnsupportedOperationException("Cannot perform arbitrary yields")
+            }
+
+            block.run()
+        }
+    }
 }

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

@@ -4,9 +4,11 @@ import dan200.computercraft.api.lua.ILuaAPI
 import dan200.computercraft.api.lua.ILuaContext
 import dan200.computercraft.api.lua.MethodResult
 import dan200.computercraft.api.lua.ObjectArguments
+import dan200.computercraft.core.apis.OSAPI
 import dan200.computercraft.core.apis.PeripheralAPI
 import kotlinx.coroutines.CancellableContinuation
 import kotlinx.coroutines.suspendCancellableCoroutine
+import kotlin.time.Duration
 
 /**
  * The context for tasks which consume Lua objects.
@@ -40,6 +42,19 @@ interface LuaTaskContext {
     /** Call a peripheral method. */
     suspend fun LuaTaskContext.callPeripheral(name: String, method: String, vararg args: Any?): Array<out Any?>? =
         getApi<PeripheralAPI>().call(context, ObjectArguments(name, method, *args)).await()
+
+    /**
+     * Sleep for the given duration. This uses the internal computer clock, so won't be accurate.
+     */
+    suspend fun LuaTaskContext.sleep(duration: Duration) {
+        val timer = getApi<OSAPI>().startTimer(duration.inWholeMilliseconds / 1000.0)
+        while (true) {
+            val event = pullEvent("timer")
+            if (event[0] == "timer" && event[1] is Number && (event[1] as Number).toInt() == timer) {
+                return
+            }
+        }
+    }
 }
 
 /** Get a registered API. */

src/testMod/java/dan200/computercraft/export/Exporter.java

@@ -10,8 +10,11 @@ import com.google.common.io.RecursiveDeleteOption;
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
 import com.mojang.blaze3d.systems.RenderSystem;
+import com.mojang.brigadier.CommandDispatcher;
+import com.mojang.brigadier.arguments.StringArgumentType;
+import com.mojang.brigadier.builder.LiteralArgumentBuilder;
+import com.mojang.brigadier.builder.RequiredArgumentBuilder;
 import dan200.computercraft.ComputerCraft;
-import dan200.computercraft.ingame.mod.TestMod;
 import net.minecraft.client.Minecraft;
 import net.minecraft.core.NonNullList;
 import net.minecraft.network.chat.Component;
@@ -19,10 +22,6 @@ import net.minecraft.resources.ResourceLocation;
 import net.minecraft.world.item.Item;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.item.crafting.*;
-import net.minecraftforge.api.distmarker.Dist;
-import net.minecraftforge.client.event.ClientChatEvent;
-import net.minecraftforge.eventbus.api.SubscribeEvent;
-import net.minecraftforge.fml.common.Mod;
 import net.minecraftforge.registries.ForgeRegistries;
 
 import java.io.File;
@@ -37,19 +36,24 @@ import java.util.Set;
 /**
  * Provides a {@literal /ccexport <path>} command which exports icons and recipes for all ComputerCraft items.
  */
-@Mod.EventBusSubscriber( modid = TestMod.MOD_ID, value = Dist.CLIENT )
 public class Exporter
 {
     private static final Gson GSON = new GsonBuilder().setPrettyPrinting().create();
 
-    @SubscribeEvent
+    public static <S> void register( CommandDispatcher<S> dispatcher )
-    public static void onClientCommands( ClientChatEvent event )
     {
-        String prefix = "/ccexport";
+        dispatcher.register(
-        if( !event.getMessage().startsWith( prefix ) ) return;
+            LiteralArgumentBuilder.<S>literal( "ccexport" )
-        event.setCanceled( true );
+                .then( RequiredArgumentBuilder.<S, String>argument( "path", StringArgumentType.string() )
+                    .executes( c -> {
+                        run( c.getArgument( "name", String.class ) );
+                        return 0;
+                    } ) ) );
+    }
 
-        Path output = new File( event.getMessage().substring( prefix.length() ).trim() ).getAbsoluteFile().toPath();
+    private static void run( String path )
+    {
+        Path output = new File( path ).getAbsoluteFile().toPath();
         if( !Files.isDirectory( output ) )
         {
             Minecraft.getInstance().gui.getChat().addMessage( Component.literal( "Output path does not exist" ) );

src/testMod/java/dan200/computercraft/gametest/api/ComputerState.java

@@ -3,9 +3,9 @@
  * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
  * Send enquiries to dratcliffe@gmail.com
  */
-package dan200.computercraft.ingame.api;
+package dan200.computercraft.gametest.api;
 
-import dan200.computercraft.ingame.mod.TestAPI;
+import dan200.computercraft.gametest.core.TestAPI;
 import net.minecraft.gametest.framework.GameTestAssertException;
 import net.minecraft.gametest.framework.GameTestSequence;
 

src/testMod/java/dan200/computercraft/gametest/api/GameTestHolder.java

@@ -0,0 +1,24 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.gametest.api;
+
+import net.minecraft.gametest.framework.GameTest;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Marks classes containing {@linkplain GameTest game tests}.
+ * <p>
+ * This is used by Forge to automatically load and test classes.
+ */
+@Target( ElementType.TYPE )
+@Retention( RetentionPolicy.RUNTIME )
+public @interface GameTestHolder
+{
+}

src/testMod/java/dan200/computercraft/gametest/core/CCTestCommand.java

@@ -3,17 +3,16 @@
  * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
  * Send enquiries to dratcliffe@gmail.com
  */
-package dan200.computercraft.ingame.mod;
+package dan200.computercraft.gametest.core;
 
 import com.mojang.brigadier.CommandDispatcher;
 import dan200.computercraft.ComputerCraft;
+import dan200.computercraft.mixin.gametest.TestCommandAccessor;
 import net.minecraft.ChatFormatting;
-import net.minecraft.client.Minecraft;
 import net.minecraft.commands.CommandSourceStack;
 import net.minecraft.core.BlockPos;
 import net.minecraft.gametest.framework.GameTestRegistry;
 import net.minecraft.gametest.framework.StructureUtils;
-import net.minecraft.gametest.framework.TestCommand;
 import net.minecraft.gametest.framework.TestFunction;
 import net.minecraft.nbt.CompoundTag;
 import net.minecraft.network.chat.Component;
@@ -24,10 +23,10 @@ import net.minecraft.world.entity.EntityType;
 import net.minecraft.world.entity.decoration.ArmorStand;
 import net.minecraft.world.level.block.entity.StructureBlockEntity;
 import net.minecraft.world.level.storage.LevelResource;
-import net.minecraftforge.fml.loading.FMLLoader;
 
 import java.io.IOException;
 import java.io.UncheckedIOException;
+import java.nio.file.Path;
 
 import static dan200.computercraft.shared.command.builder.HelpingArgumentBuilder.choice;
 import static net.minecraft.commands.Commands.literal;
@@ -37,6 +36,8 @@ import static net.minecraft.commands.Commands.literal;
  */
 class CCTestCommand
 {
+    public static final LevelResource LOCATION = new LevelResource( ComputerCraft.MOD_ID );
+
     public static void register( CommandDispatcher<CommandSourceStack> dispatcher )
     {
         dispatcher.register( choice( "cctest" )
@@ -49,7 +50,7 @@ class CCTestCommand
 
                 for( TestFunction function : GameTestRegistry.getAllTestFunctions() )
                 {
-                    TestCommand.exportTestStructure( context.getSource(), function.getStructureName() );
+                    TestCommandAccessor.callExportTestStructure( context.getSource(), function.getStructureName() );
                 }
                 return 0;
             } ) )
@@ -57,17 +58,11 @@ class CCTestCommand
                 for( TestFunction function : GameTestRegistry.getAllTestFunctions() )
                 {
                     dispatcher.execute( "test import " + function.getTestName(), context.getSource() );
-                    TestCommand.exportTestStructure( context.getSource(), function.getStructureName() );
+                    TestCommandAccessor.callExportTestStructure( context.getSource(), function.getStructureName() );
                 }
                 return 0;
             } ) )
 
-            .then( literal( "promote" ).executes( context -> {
-                if( !FMLLoader.getDist().isClient() ) return error( context.getSource(), "Cannot run on server" );
-
-                promote();
-                return 0;
-            } ) )
             .then( literal( "marker" ).executes( context -> {
                 ServerPlayer player = context.getSource().getPlayerOrException();
                 BlockPos pos = StructureUtils.findNearestStructureBlock( player.blockPosition(), 15, player.getLevel() );
@@ -99,7 +94,7 @@ class CCTestCommand
     {
         try
         {
-            Copier.replicate( TestMod.sourceDir.resolve( "computers" ), server.getWorldPath( new LevelResource( ComputerCraft.MOD_ID ) ) );
+            Copier.replicate( getSourceComputerPath(), getWorldComputerPath( server ) );
         }
         catch( IOException e )
         {
@@ -111,7 +106,7 @@ class CCTestCommand
     {
         try
         {
-            Copier.replicate( server.getWorldPath( new LevelResource( ComputerCraft.MOD_ID ) ), TestMod.sourceDir.resolve( "computers" ) );
+            Copier.replicate( getWorldComputerPath( server ), getSourceComputerPath() );
         }
         catch( IOException e )
         {
@@ -119,20 +114,14 @@ class CCTestCommand
         }
     }
 
-    private static void promote()
+    private static Path getWorldComputerPath( MinecraftServer server )
     {
-        try
+        return server.getWorldPath( LOCATION ).resolve( "computer" ).resolve( "0" );
-        {
+    }
-            Copier.replicate(
+
-                Minecraft.getInstance().gameDirectory.toPath().resolve( "screenshots" ),
+    private static Path getSourceComputerPath()
-                TestMod.sourceDir.resolve( "screenshots" ),
+    {
-                x -> !x.toFile().getName().endsWith( ".diff.png" )
+        return TestHooks.sourceDir.resolve( "computer" );
-            );
-        }
-        catch( IOException e )
-        {
-            throw new UncheckedIOException( e );
-        }
     }
 
     private static int error( CommandSourceStack source, String message )

src/testMod/java/dan200/computercraft/gametest/core/ClientHooks.java

@@ -3,7 +3,7 @@
  * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
  * Send enquiries to dratcliffe@gmail.com
  */
-package dan200.computercraft.ingame.mod;
+package dan200.computercraft.gametest.core;
 
 import net.minecraft.client.CloudStatus;
 import net.minecraft.client.Minecraft;
@@ -17,7 +17,7 @@ import net.minecraftforge.fml.common.Mod;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
-@Mod.EventBusSubscriber( modid = TestMod.MOD_ID, value = Dist.CLIENT )
+@Mod.EventBusSubscriber( modid = "cctest", value = Dist.CLIENT )
 public final class ClientHooks
 {
     private static final Logger LOG = LogManager.getLogger( TestHooks.class );

src/testMod/java/dan200/computercraft/gametest/core/Copier.java

@@ -3,7 +3,7 @@
  * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
  * Send enquiries to dratcliffe@gmail.com
  */
-package dan200.computercraft.ingame.mod;
+package dan200.computercraft.gametest.core;
 
 import com.google.common.io.MoreFiles;
 import com.google.common.io.RecursiveDeleteOption;

src/testMod/java/dan200/computercraft/gametest/core/TestAPI.java

@@ -3,22 +3,22 @@
  * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
  * Send enquiries to dratcliffe@gmail.com
  */
-package dan200.computercraft.ingame.mod;
+package dan200.computercraft.gametest.core;
 
 import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.api.lua.IComputerSystem;
 import dan200.computercraft.api.lua.ILuaAPI;
 import dan200.computercraft.api.lua.LuaException;
 import dan200.computercraft.api.lua.LuaFunction;
-import dan200.computercraft.ingame.api.ComputerState;
+import dan200.computercraft.gametest.api.ComputerState;
-import dan200.computercraft.ingame.api.TestExtensionsKt;
+import dan200.computercraft.gametest.api.TestExtensionsKt;
 import net.minecraft.gametest.framework.GameTestSequence;
 
 import java.util.Optional;
 
 /**
  * API exposed to computers to help write tests.
- *
+ * <p>
  * Note, we extend this API within startup file of computers (see {@code cctest.lua}).
  *
  * @see TestExtensionsKt#thenComputerOk(GameTestSequence, String, String)   To check tests on the computer have passed.

src/testMod/java/dan200/computercraft/gametest/core/TestHooks.java

@@ -0,0 +1,60 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.gametest.core;
+
+import dan200.computercraft.api.ComputerCraftAPI;
+import dan200.computercraft.gametest.api.Times;
+import dan200.computercraft.shared.computer.core.ServerContext;
+import net.minecraft.core.BlockPos;
+import net.minecraft.gametest.framework.GameTestRunner;
+import net.minecraft.gametest.framework.GameTestTicker;
+import net.minecraft.gametest.framework.StructureUtils;
+import net.minecraft.server.MinecraftServer;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.world.level.GameRules;
+import net.minecraft.world.level.Level;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.nio.file.Path;
+import java.nio.file.Paths;
+
+public class TestHooks
+{
+    public static final Logger LOGGER = LoggerFactory.getLogger( TestHooks.class );
+
+    public static final Path sourceDir = Paths.get( System.getProperty( "cctest.sources" ) ).normalize().toAbsolutePath();
+
+    public static void init()
+    {
+        ServerContext.luaMachine = ManagedComputers.INSTANCE;
+        ComputerCraftAPI.registerAPIFactory( TestAPI::new );
+        StructureUtils.testStructuresDir = sourceDir.resolve( "structures" ).toString();
+    }
+
+    public static void onServerStarted( MinecraftServer server )
+    {
+        GameRules rules = server.getGameRules();
+        rules.getRule( GameRules.RULE_DAYLIGHT ).set( false, server );
+
+        ServerLevel world = server.getLevel( Level.OVERWORLD );
+        if( world != null ) world.setDayTime( Times.NOON );
+
+        LOGGER.info( "Cleaning up after last run" );
+        GameTestRunner.clearAllTests( server.overworld(), new BlockPos( 0, -60, 0 ), GameTestTicker.SINGLETON, 200 );
+
+        // Delete server context and add one with a mutable machine factory. This allows us to set the factory for
+        // specific test batches without having to reset all computers.
+        for( var computer : ServerContext.get( server ).registry().getComputers() )
+        {
+            var label = computer.getLabel() == null ? "#" + computer.getID() : computer.getLabel();
+            LOGGER.warn( "Unexpected computer {}", label );
+        }
+
+        LOGGER.info( "Importing files" );
+        CCTestCommand.importFiles( server );
+    }
+}

src/testMod/java/dan200/computercraft/gametest/core/TestMod.java

@@ -0,0 +1,144 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.gametest.core;
+
+import dan200.computercraft.export.Exporter;
+import dan200.computercraft.gametest.api.GameTestHolder;
+import net.minecraft.gametest.framework.GameTest;
+import net.minecraft.gametest.framework.GameTestRegistry;
+import net.minecraft.gametest.framework.StructureUtils;
+import net.minecraft.gametest.framework.TestFunction;
+import net.minecraft.resources.ResourceLocation;
+import net.minecraftforge.client.event.RegisterClientCommandsEvent;
+import net.minecraftforge.common.MinecraftForge;
+import net.minecraftforge.event.RegisterCommandsEvent;
+import net.minecraftforge.event.RegisterGameTestsEvent;
+import net.minecraftforge.event.server.ServerStartedEvent;
+import net.minecraftforge.eventbus.api.EventPriority;
+import net.minecraftforge.fml.ModList;
+import net.minecraftforge.fml.common.Mod;
+import net.minecraftforge.fml.javafmlmod.FMLJavaModLoadingContext;
+import net.minecraftforge.forgespi.language.ModFileScanData;
+import net.minecraftforge.gametest.PrefixGameTestTemplate;
+import org.objectweb.asm.Type;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
+import java.util.Collection;
+import java.util.Locale;
+import java.util.function.Consumer;
+
+@Mod( "cctest" )
+public class TestMod
+{
+    public TestMod()
+    {
+        TestHooks.init();
+
+        var bus = MinecraftForge.EVENT_BUS;
+        bus.addListener( EventPriority.LOW, ( ServerStartedEvent e ) -> TestHooks.onServerStarted( e.getServer() ) );
+        bus.addListener( ( RegisterCommandsEvent e ) -> CCTestCommand.register( e.getDispatcher() ) );
+        bus.addListener( ( RegisterClientCommandsEvent e ) -> Exporter.register( e.getDispatcher() ) );
+
+        var modBus = FMLJavaModLoadingContext.get().getModEventBus();
+        modBus.addListener( ( RegisterGameTestsEvent event ) -> {
+            var holder = Type.getType( GameTestHolder.class );
+            ModList.get().getAllScanData().stream()
+                .map( ModFileScanData::getAnnotations )
+                .flatMap( Collection::stream )
+                .filter( a -> holder.equals( a.annotationType() ) )
+                .forEach( x -> registerClass( x.clazz().getClassName(), event::register ) );
+        } );
+    }
+
+
+    private static Class<?> loadClass( String name )
+    {
+        try
+        {
+            return Class.forName( name, true, TestMod.class.getClassLoader() );
+        }
+        catch( ReflectiveOperationException e )
+        {
+            throw new RuntimeException( e );
+        }
+    }
+
+    private static void registerClass( String className, Consumer<Method> fallback )
+    {
+        var klass = loadClass( className );
+        for( var method : klass.getDeclaredMethods() )
+        {
+            var testInfo = method.getAnnotation( GameTest.class );
+            if( testInfo == null )
+            {
+                fallback.accept( method );
+                continue;
+            }
+
+            GameTestRegistry.getAllTestFunctions().add( turnMethodIntoTestFunction( method, testInfo ) );
+            GameTestRegistry.getAllTestClassNames().add( className );
+        }
+    }
+
+    /**
+     * Custom implementation of {@link GameTestRegistry#turnMethodIntoTestFunction(Method)} which makes
+     * {@link GameTest#template()} behave the same as Fabric, namely in that it points to a {@link ResourceLocation},
+     * rather than a test-class-specific structure.
+     * <p>
+     * This effectively acts as a global version of {@link PrefixGameTestTemplate}, just one which doesn't require Forge
+     * to be present.
+     *
+     * @param method   The method to register.
+     * @param testInfo The test info.
+     * @return The constructed test function.
+     */
+    private static TestFunction turnMethodIntoTestFunction( Method method, GameTest testInfo )
+    {
+        var className = method.getDeclaringClass().getSimpleName().toLowerCase( Locale.ROOT );
+        var testName = className + "." + method.getName().toLowerCase( Locale.ROOT );
+        return new TestFunction(
+            testInfo.batch(),
+            testName,
+            testInfo.template().isEmpty() ? testName : testInfo.template(),
+            StructureUtils.getRotationForRotationSteps( testInfo.rotationSteps() ), testInfo.timeoutTicks(), testInfo.setupTicks(),
+            testInfo.required(), testInfo.requiredSuccesses(), testInfo.attempts(),
+            turnMethodIntoConsumer( method )
+        );
+    }
+
+    private static <T> Consumer<T> turnMethodIntoConsumer( Method method )
+    {
+        return value -> {
+            try
+            {
+                Object instance = null;
+                if( !Modifier.isStatic( method.getModifiers() ) )
+                {
+                    instance = method.getDeclaringClass().getConstructor().newInstance();
+                }
+
+                method.invoke( instance, value );
+            }
+            catch( InvocationTargetException e )
+            {
+                if( e.getCause() instanceof RuntimeException )
+                {
+                    throw (RuntimeException) e.getCause();
+                }
+                else
+                {
+                    throw new RuntimeException( e.getCause() );
+                }
+            }
+            catch( ReflectiveOperationException e )
+            {
+                throw new RuntimeException( e );
+            }
+        };
+    }
+}

src/testMod/java/dan200/computercraft/ingame/Computer_Test.kt

@@ -1,38 +0,0 @@
-package dan200.computercraft.ingame
-
-import dan200.computercraft.ComputerCraft
-import dan200.computercraft.ingame.api.modifyBlock
-import dan200.computercraft.ingame.api.sequence
-import net.minecraft.core.BlockPos
-import net.minecraft.gametest.framework.GameTest
-import net.minecraft.gametest.framework.GameTestHelper
-import net.minecraft.world.level.block.LeverBlock
-import net.minecraft.world.level.block.RedstoneLampBlock
-import net.minecraftforge.gametest.GameTestHolder
-
-@GameTestHolder(ComputerCraft.MOD_ID)
-class Computer_Test {
-    /**
-     * Ensures redstone signals do not travel through computers.
-     *
-     * @see [#548](https://github.com/cc-tweaked/CC-Tweaked/issues/548)
-     */
-    @GameTest
-    fun No_through_signal(context: GameTestHelper) = context.sequence {
-        val lamp = BlockPos(2, 2, 4)
-        val lever = BlockPos(2, 2, 0)
-        this
-            .thenExecute {
-                context.assertBlockState(lamp, { !it.getValue(RedstoneLampBlock.LIT) }, { "Lamp should not be lit" })
-                context.modifyBlock(lever) { x -> x.setValue(LeverBlock.POWERED, true) }
-            }
-            .thenIdle(3)
-            .thenExecute {
-                context.assertBlockState(
-                    lamp,
-                    { !it.getValue(RedstoneLampBlock.LIT) },
-                    { "Lamp should still not be lit" },
-                )
-            }
-    }
-}

src/testMod/java/dan200/computercraft/ingame/CraftOs_Test.kt

@@ -1,17 +0,0 @@
-package dan200.computercraft.ingame
-
-import dan200.computercraft.ComputerCraft
-import dan200.computercraft.ingame.api.sequence
-import dan200.computercraft.ingame.api.thenComputerOk
-import net.minecraft.gametest.framework.GameTest
-import net.minecraft.gametest.framework.GameTestHelper
-import net.minecraftforge.gametest.GameTestHolder
-
-@GameTestHolder(ComputerCraft.MOD_ID)
-class CraftOs_Test {
-    /**
-     * Sends a rednet message to another a computer and back again.
-     */
-    @GameTest(timeoutTicks = 200)
-    fun Sends_basic_rednet_messages(context: GameTestHelper) = context.sequence { thenComputerOk("main") }
-}

src/testMod/java/dan200/computercraft/ingame/Disk_Drive_Test.kt

@@ -1,29 +0,0 @@
-package dan200.computercraft.ingame
-
-import dan200.computercraft.ComputerCraft
-import dan200.computercraft.ingame.api.sequence
-import dan200.computercraft.ingame.api.thenComputerOk
-import net.minecraft.core.BlockPos
-import net.minecraft.gametest.framework.GameTest
-import net.minecraft.gametest.framework.GameTestHelper
-import net.minecraft.world.item.Items
-import net.minecraftforge.gametest.GameTestHolder
-
-@GameTestHolder(ComputerCraft.MOD_ID)
-class Disk_Drive_Test {
-    /**
-     * Ensure audio disks exist and we can play them.
-     *
-     * @see [#688](https://github.com/cc-tweaked/CC-Tweaked/issues/688)
-     */
-    @GameTest(timeoutTicks = Modem_Test.TIMEOUT)
-    fun Audio_disk(helper: GameTestHelper) = helper.sequence { thenComputerOk() }
-
-    @GameTest(timeoutTicks = Modem_Test.TIMEOUT)
-    fun Ejects_disk(helper: GameTestHelper) = helper.sequence {
-        val stackAt = BlockPos(2, 2, 2)
-        this
-            .thenComputerOk()
-            .thenWaitUntil { helper.assertItemEntityPresent(Items.MUSIC_DISC_13, stackAt, 0.0) }
-    }
-}

src/testMod/java/dan200/computercraft/ingame/Modem_Test.kt

@@ -1,45 +0,0 @@
-package dan200.computercraft.ingame
-
-import dan200.computercraft.ComputerCraft
-import dan200.computercraft.ingame.api.sequence
-import dan200.computercraft.ingame.api.thenComputerOk
-import dan200.computercraft.shared.Registry
-import dan200.computercraft.shared.peripheral.modem.wired.BlockCable
-import net.minecraft.core.BlockPos
-import net.minecraft.gametest.framework.GameTest
-import net.minecraft.gametest.framework.GameTestHelper
-import net.minecraftforge.gametest.GameTestHolder
-
-@GameTestHolder(ComputerCraft.MOD_ID)
-class Modem_Test {
-    @GameTest(timeoutTicks = TIMEOUT)
-    fun Have_peripherals(helper: GameTestHelper) = helper.sequence { thenComputerOk() }
-
-    @GameTest(timeoutTicks = TIMEOUT)
-    fun Gains_peripherals(helper: GameTestHelper) = helper.sequence {
-        val position = BlockPos(2, 2, 2)
-        this
-            .thenComputerOk(marker = "initial")
-            .thenExecute {
-                helper.setBlock(
-                    position,
-                    BlockCable.correctConnections(
-                        helper.level,
-                        helper.absolutePos(position),
-                        Registry.ModBlocks.CABLE.get().defaultBlockState().setValue(BlockCable.CABLE, true),
-                    ),
-                )
-            }
-            .thenComputerOk()
-    }
-
-    /**
-     * Sends a modem message to another computer on the same network
-     */
-    @GameTest(timeoutTicks = TIMEOUT)
-    fun Transmits_messages(context: GameTestHelper) = context.sequence { thenComputerOk("receive") }
-
-    companion object {
-        const val TIMEOUT = 200
-    }
-}

src/testMod/java/dan200/computercraft/ingame/Monitor_Test.kt

@@ -1,87 +0,0 @@
-package dan200.computercraft.ingame
-
-import dan200.computercraft.ComputerCraft
-import dan200.computercraft.ingame.api.*
-import dan200.computercraft.shared.Capabilities
-import dan200.computercraft.shared.Registry
-import dan200.computercraft.shared.peripheral.monitor.MonitorRenderer
-import dan200.computercraft.shared.peripheral.monitor.TileMonitor
-import net.minecraft.commands.arguments.blocks.BlockInput
-import net.minecraft.core.BlockPos
-import net.minecraft.gametest.framework.GameTest
-import net.minecraft.gametest.framework.GameTestHelper
-import net.minecraft.nbt.CompoundTag
-import net.minecraft.world.level.block.Blocks
-import net.minecraftforge.gametest.GameTestHolder
-import java.util.*
-
-@GameTestHolder(ComputerCraft.MOD_ID)
-class Monitor_Test {
-    @GameTest
-    fun Ensures_valid_on_place(context: GameTestHelper) = context.sequence {
-        val pos = BlockPos(2, 2, 2)
-        val tag = CompoundTag()
-        tag.putInt("Width", 2)
-        tag.putInt("Height", 2)
-
-        val toSet = BlockInput(
-            Registry.ModBlocks.MONITOR_ADVANCED.get().defaultBlockState(),
-            Collections.emptySet(),
-            tag,
-        )
-
-        context.setBlock(pos, Blocks.AIR.defaultBlockState())
-        context.setBlock(pos, toSet)
-
-        this
-            .thenIdle(2)
-            .thenExecute {
-                val tile = context.getBlockEntity(pos)
-                if (tile !is TileMonitor) {
-                    context.fail("Expected tile to be monitor, is $tile", pos)
-                    return@thenExecute
-                }
-
-                if (tile.width != 1 || tile.height != 1) {
-                    context.fail("Tile has width and height of ${tile.width}x${tile.height}, but should be 1x1", pos)
-                }
-            }
-    }
-
-    private fun looksAcceptable(helper: GameTestHelper, renderer: MonitorRenderer) = helper.sequence {
-        this
-            .thenExecute {
-                ComputerCraft.monitorRenderer = renderer
-                helper.positionAtArmorStand()
-
-                // Get the monitor and peripheral. This forces us to create a server monitor at this location.
-                val monitor = helper.getBlockEntity(BlockPos(2, 2, 3), Registry.ModBlockEntities.MONITOR_ADVANCED.get())
-                monitor.getCapability(Capabilities.CAPABILITY_PERIPHERAL)
-
-                val terminal = monitor.cachedServerMonitor!!.terminal!!
-                terminal.write("Hello, world!")
-                terminal.setCursorPos(1, 2)
-                terminal.textColour = 2
-                terminal.backgroundColour = 3
-                terminal.write("Some coloured text")
-            }
-            .thenScreenshot()
-    }
-
-    // @GameTest(batch = "Monitor_Test.Looks_acceptable", template = LOOKS_ACCEPTABLE)
-    fun Looks_acceptable(helper: GameTestHelper) = looksAcceptable(helper, renderer = MonitorRenderer.TBO)
-
-    // @GameTest(batch = "Monitor_Test.Looks_acceptable_dark", template = LOOKS_ACCEPTABLE_DARK)
-    fun Looks_acceptable_dark(helper: GameTestHelper) = looksAcceptable(helper, renderer = MonitorRenderer.TBO)
-
-    // @GameTest(batch = "Monitor_Test.Looks_acceptable_vbo", template = LOOKS_ACCEPTABLE)
-    fun Looks_acceptable_vbo(helper: GameTestHelper) = looksAcceptable(helper, renderer = MonitorRenderer.VBO)
-
-    // @GameTest(batch = "Monitor_Test.Looks_acceptable_dark_vbo", template = LOOKS_ACCEPTABLE_DARK)
-    fun Looks_acceptable_dark_vbo(helper: GameTestHelper) = looksAcceptable(helper, renderer = MonitorRenderer.VBO)
-
-    private companion object {
-        const val LOOKS_ACCEPTABLE = "looks_acceptable"
-        const val LOOKS_ACCEPTABLE_DARK = "looks_acceptable_dark"
-    }
-}

src/testMod/java/dan200/computercraft/ingame/Printout_Test.kt

@@ -1,15 +0,0 @@
-package dan200.computercraft.ingame
-
-import dan200.computercraft.ingame.api.positionAtArmorStand
-import dan200.computercraft.ingame.api.sequence
-import dan200.computercraft.ingame.api.thenScreenshot
-import net.minecraft.gametest.framework.GameTestHelper
-
-class Printout_Test {
-    // @GameTest(batch = "Printout_Test.In_frame_at_night", timeoutTicks = Timeouts.CLIENT_TIMEOUT)
-    fun In_frame_at_night(helper: GameTestHelper) = helper.sequence {
-        this
-            .thenExecute { helper.positionAtArmorStand() }
-            .thenScreenshot()
-    }
-}

src/testMod/java/dan200/computercraft/ingame/Turtle_Test.kt

@@ -1,101 +0,0 @@
-package dan200.computercraft.ingame
-
-import dan200.computercraft.ComputerCraft
-import dan200.computercraft.api.detail.BasicItemDetailProvider
-import dan200.computercraft.api.detail.DetailRegistries
-import dan200.computercraft.ingame.api.*
-import dan200.computercraft.ingame.api.Timeouts.COMPUTER_TIMEOUT
-import dan200.computercraft.shared.media.items.ItemPrintout
-import net.minecraft.gametest.framework.GameTest
-import net.minecraft.gametest.framework.GameTestHelper
-import net.minecraft.world.item.ItemStack
-import net.minecraftforge.gametest.GameTestHolder
-
-@GameTestHolder(ComputerCraft.MOD_ID)
-class Turtle_Test {
-    @GameTest(timeoutTicks = COMPUTER_TIMEOUT)
-    fun Unequip_refreshes_peripheral(helper: GameTestHelper) = helper.sequence { thenComputerOk() }
-
-    /**
-     * Checks turtles can sheer sheep (and drop items)
-     *
-     * @see [#537](https://github.com/cc-tweaked/CC-Tweaked/issues/537)
-     */
-    @GameTest(timeoutTicks = COMPUTER_TIMEOUT)
-    fun Shears_sheep(helper: GameTestHelper) = helper.sequence { thenComputerOk() }
-
-    /**
-     * Checks turtles can place lava.
-     *
-     * @see [#518](https://github.com/cc-tweaked/CC-Tweaked/issues/518)
-     */
-    @GameTest(timeoutTicks = COMPUTER_TIMEOUT)
-    fun Place_lava(helper: GameTestHelper) = helper.sequence { thenComputerOk() }
-
-    /**
-     * Checks turtles can place when waterlogged.
-     *
-     * @see [#385](https://github.com/cc-tweaked/CC-Tweaked/issues/385)
-     */
-    @GameTest(timeoutTicks = COMPUTER_TIMEOUT)
-    fun Place_waterlogged(helper: GameTestHelper) = helper.sequence { thenComputerOk() }
-
-    /**
-     * Checks turtles can pick up lava
-     *
-     * @see [#297](https://github.com/cc-tweaked/CC-Tweaked/issues/297)
-     */
-    @GameTest(timeoutTicks = COMPUTER_TIMEOUT)
-    fun Gather_lava(helper: GameTestHelper) = helper.sequence { thenComputerOk() }
-
-    /**
-     * Checks turtles can hoe dirt.
-     *
-     * @see [#258](https://github.com/cc-tweaked/CC-Tweaked/issues/258)
-     */
-    @GameTest(timeoutTicks = COMPUTER_TIMEOUT)
-    fun Hoe_dirt(helper: GameTestHelper) = helper.sequence { thenComputerOk() }
-
-    /**
-     * Checks turtles can place monitors
-     *
-     * @see [#691](https://github.com/cc-tweaked/CC-Tweaked/issues/691)
-     */
-    @GameTest(timeoutTicks = COMPUTER_TIMEOUT)
-    fun Place_monitor(helper: GameTestHelper) = helper.sequence { thenComputerOk() }
-
-    /**
-     * Checks turtles can place into compostors. These are non-typical inventories, so
-     * worth testing.
-     */
-    @GameTest(timeoutTicks = COMPUTER_TIMEOUT)
-    fun Use_compostors(helper: GameTestHelper) = helper.sequence { thenComputerOk() }
-
-    /**
-     * Checks turtles can be cleaned in cauldrons.
-     *
-     * Currently not required as turtles can no longer right-click cauldrons.
-     */
-    @GameTest(timeoutTicks = COMPUTER_TIMEOUT, required = false)
-    fun Cleaned_with_cauldrons(helper: GameTestHelper) = helper.sequence { thenComputerOk() }
-
-    /**
-     * Checks turtles can use IDetailProviders by getting details for a printed page.
-     */
-    @GameTest(timeoutTicks = COMPUTER_TIMEOUT)
-    fun Item_detail_provider(helper: GameTestHelper) = helper.sequence {
-        this
-            .thenComputerOk(marker = "initial")
-            .thenExecute {
-                // Register a dummy provider for printout items
-                DetailRegistries.ITEM_STACK.addProvider(
-                    object : BasicItemDetailProvider<ItemPrintout>("printout", ItemPrintout::class.java) {
-                        override fun provideDetails(data: MutableMap<in String, Any>, stack: ItemStack, item: ItemPrintout) {
-                            data["type"] = item.type.toString()
-                        }
-                    },
-                )
-            }
-            .thenComputerOk()
-    }
-}

src/testMod/java/dan200/computercraft/ingame/api/TestExtensions.kt

@@ -1,183 +0,0 @@
-package dan200.computercraft.ingame.api
-
-import dan200.computercraft.ingame.mod.ImageUtils
-import dan200.computercraft.ingame.mod.TestMod
-import net.minecraft.client.Minecraft
-import net.minecraft.client.Screenshot
-import net.minecraft.commands.arguments.blocks.BlockInput
-import net.minecraft.core.BlockPos
-import net.minecraft.gametest.framework.GameTestAssertException
-import net.minecraft.gametest.framework.GameTestAssertPosException
-import net.minecraft.gametest.framework.GameTestHelper
-import net.minecraft.gametest.framework.GameTestSequence
-import net.minecraft.resources.ResourceLocation
-import net.minecraft.world.entity.decoration.ArmorStand
-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.minecraftforge.registries.ForgeRegistries
-import java.nio.file.Files
-import java.util.concurrent.CompletableFuture
-import java.util.concurrent.ExecutionException
-import java.util.concurrent.atomic.AtomicBoolean
-import java.util.function.Supplier
-import javax.imageio.ImageIO
-
-object Times {
-    const val NOON: Long = 6000
-}
-
-/**
- * Custom timeouts for various test types.
- */
-object Timeouts {
-    private const val SECOND: Int = 20
-
-    const val COMPUTER_TIMEOUT: Int = SECOND * 15
-
-    const val CLIENT_TIMEOUT: Int = SECOND * 20
-}
-
-/**
- * Wait until a computer has finished running and check it is OK.
- */
-fun GameTestSequence.thenComputerOk(name: String? = null, marker: String = ComputerState.DONE): GameTestSequence {
-    val label = parent.testName + (if (name == null) "" else ".$name")
-    return this.thenWaitUntil {
-        val computer = ComputerState.get(label)
-        if (computer == null || !computer.isDone(marker)) throw GameTestAssertException("Computer '$label' has not reached $marker yet.")
-    }.thenExecute {
-        ComputerState.get(label).check(marker)
-    }
-}
-
-/**
- * Run a task on the client
- */
-fun GameTestSequence.thenOnClient(task: ClientTestHelper.() -> Unit): GameTestSequence {
-    var future: CompletableFuture<Unit>? = null
-    return this
-        .thenExecute { future = Minecraft.getInstance().submit(Supplier { task(ClientTestHelper()) }) }
-        .thenWaitUntil { if (!future!!.isDone) throw GameTestAssertException("Not done task yet") }
-        .thenExecute {
-            try {
-                future!!.get()
-            } catch (e: ExecutionException) {
-                throw e.cause ?: e
-            }
-        }
-}
-
-/**
- * Idle for one tick to allow the client to catch up, then take a screenshot.
- */
-fun GameTestSequence.thenScreenshot(name: String? = null): GameTestSequence {
-    val suffix = if (name == null) "" else "-$name"
-    val fullName = "${parent.testName}$suffix"
-
-    var counter = 0
-    val hasScreenshot = AtomicBoolean()
-
-    return this
-        // Wait until all chunks have been rendered and we're idle for an extended period.
-        .thenExecute { counter = 0 }
-        .thenWaitUntil {
-            val renderer = Minecraft.getInstance().levelRenderer
-            if (renderer.chunkRenderDispatcher != null && renderer.hasRenderedAllChunks()) {
-                val idleFor = ++counter
-                if (idleFor <= 20) throw GameTestAssertException("Only idle for $idleFor ticks")
-            } else {
-                counter = 0
-                throw GameTestAssertException("Waiting for client to finish rendering")
-            }
-        }
-        // Now disable the GUI, take a screenshot and reenable it. We sleep either side to give the client time to do
-        // its thing.
-        .thenExecute {
-            Minecraft.getInstance().options.hideGui = true
-            hasScreenshot.set(false)
-        }
-        .thenIdle(5) // Some delay before/after to ensure the render thread has caught up.
-        .thenOnClient { screenshot("$fullName.png") { hasScreenshot.set(true) } }
-        .thenWaitUntil { if (!hasScreenshot.get()) throw GameTestAssertException("Screenshot does not exist") }
-        .thenExecute {
-            Minecraft.getInstance().options.hideGui = false
-
-            val screenshotsPath = Minecraft.getInstance().gameDirectory.toPath().resolve("screenshots")
-            val screenshotPath = screenshotsPath.resolve("$fullName.png")
-            val originalPath = TestMod.sourceDir.resolve("screenshots").resolve("$fullName.png")
-
-            if (!Files.exists(originalPath)) throw GameTestAssertException("$fullName does not exist. Use `/cctest promote' to create it.")
-
-            val screenshot = ImageIO.read(screenshotPath.toFile())
-                ?: throw GameTestAssertException("Error reading screenshot from $screenshotPath")
-            val original = ImageIO.read(originalPath.toFile())
-
-            if (screenshot.width != original.width || screenshot.height != original.height) {
-                throw GameTestAssertException("$fullName screenshot is ${screenshot.width}x${screenshot.height} but original is ${original.width}x${original.height}")
-            }
-
-            ImageUtils.writeDifference(screenshotsPath.resolve("$fullName.diff.png"), screenshot, original)
-            if (!ImageUtils.areSame(screenshot, original)) throw GameTestAssertException("Images are different.")
-        }
-}
-
-val GameTestHelper.testName: String get() = testInfo.testName
-
-val GameTestHelper.structureName: String get() = testInfo.structureName
-
-/**
- * Modify a block state within the test.
- */
-fun GameTestHelper.modifyBlock(pos: BlockPos, modify: (BlockState) -> BlockState) {
-    setBlock(pos, modify(getBlockState(pos)))
-}
-
-fun GameTestHelper.sequence(run: GameTestSequence.() -> GameTestSequence) {
-    run(startSequence()).thenSucceed()
-}
-
-private fun getName(type: BlockEntityType<*>): ResourceLocation = ForgeRegistries.BLOCK_ENTITY_TYPES.getKey(type)!!
-
-fun <T : BlockEntity> GameTestHelper.getBlockEntity(pos: BlockPos, type: BlockEntityType<T>): T {
-    val tile = getBlockEntity(pos)
-    @Suppress("UNCHECKED_CAST")
-    return when {
-        tile == null -> throw GameTestAssertPosException("Expected ${getName(type)}, but no tile was there", absolutePos(pos), pos, 0)
-        tile.type != type -> throw GameTestAssertPosException("Expected ${getName(type)} but got ${getName(tile.type)}", absolutePos(pos), pos, 0)
-        else -> tile as T
-    }
-}
-
-/**
- * Set a block within the test structure.
- */
-fun GameTestHelper.setBlock(pos: BlockPos, state: BlockInput) = state.place(level, absolutePos(pos), 3)
-
-/**
- * Position the player at an armor stand.
- */
-fun GameTestHelper.positionAtArmorStand() {
-    val entities = level.getEntities(null, bounds) { it.name.string == structureName }
-    if (entities.size <= 0 || entities[0] !is ArmorStand) throw GameTestAssertException("Cannot find armor stand")
-
-    val stand = entities[0] as ArmorStand
-    val player = level.randomPlayer ?: throw GameTestAssertException("Player does not exist")
-
-    player.connection.teleport(stand.x, stand.y, stand.z, stand.yRot, stand.xRot)
-}
-
-class ClientTestHelper {
-    val minecraft: Minecraft = Minecraft.getInstance()
-
-    fun screenshot(name: String, callback: () -> Unit = {}) {
-        Screenshot.grab(
-            minecraft.gameDirectory,
-            name,
-            minecraft.mainRenderTarget,
-        ) {
-            TestMod.log.info(it.string)
-            callback()
-        }
-    }
-}

src/testMod/java/dan200/computercraft/ingame/mod/ImageUtils.java

@@ -1,82 +0,0 @@
-/*
- * This file is part of ComputerCraft - http://www.computercraft.info
- * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
- * Send enquiries to dratcliffe@gmail.com
- */
-package dan200.computercraft.ingame.mod;
-
-import org.apache.logging.log4j.LogManager;
-import org.apache.logging.log4j.Logger;
-
-import javax.imageio.ImageIO;
-import java.awt.image.BufferedImage;
-import java.io.IOException;
-import java.nio.file.Path;
-
-public final class ImageUtils
-{
-    private static final Logger LOG = LogManager.getLogger( ImageUtils.class );
-
-    /**
-     * Allow 0.3% of pixels to fail. This allows for slight differences at the edges.
-     */
-    private static final double PIXEL_THRESHOLD = 0.003;
-
-    /**
-     * Maximum possible distance between two colours. Floating point differences means we need some fuzziness here.
-     */
-    public static final int DISTANCE_THRESHOLD = 5;
-
-    private ImageUtils()
-    {
-    }
-
-    public static boolean areSame( BufferedImage left, BufferedImage right )
-    {
-        int width = left.getWidth(), height = left.getHeight();
-        if( width != right.getWidth() || height != right.getHeight() ) return false;
-
-        int failed = 0, threshold = (int) (width * height * PIXEL_THRESHOLD);
-        for( int x = 0; x < width; x++ )
-        {
-            for( int y = 0; y < height; y++ )
-            {
-                int l = left.getRGB( x, y ), r = right.getRGB( x, y );
-                if( (l & 0xFFFFFF) != (r & 0xFFFFFF) && distance( l, r, 0 ) + distance( l, r, 8 ) + distance( l, r, 16 ) >= DISTANCE_THRESHOLD )
-                {
-                    failed++;
-                }
-            }
-        }
-
-        if( failed > 0 ) LOG.warn( "{} pixels failed comparing (threshold is {})", failed, threshold );
-        return failed <= threshold;
-    }
-
-    public static void writeDifference( Path path, BufferedImage left, BufferedImage right ) throws IOException
-    {
-        int width = left.getWidth(), height = left.getHeight();
-
-        BufferedImage copy = new BufferedImage( width, height, left.getType() );
-        for( int x = 0; x < width; x++ )
-        {
-            for( int y = 0; y < height; y++ )
-            {
-                int l = left.getRGB( x, y ), r = right.getRGB( x, y );
-                copy.setRGB( x, y, difference( l, r, 0 ) | difference( l, r, 8 ) | difference( l, r, 16 ) | 0xFF000000 );
-            }
-        }
-
-        ImageIO.write( copy, "png", path.toFile() );
-    }
-
-    private static int difference( int l, int r, int shift )
-    {
-        return Math.abs( ((l >> shift) & 0xFF) - ((r >> shift) & 0xFF) ) << shift;
-    }
-
-    private static int distance( int l, int r, int shift )
-    {
-        return Math.abs( ((l >> shift) & 0xFF) - ((r >> shift) & 0xFF) );
-    }
-}

src/testMod/java/dan200/computercraft/ingame/mod/TestHooks.java

@@ -1,49 +0,0 @@
-/*
- * This file is part of ComputerCraft - http://www.computercraft.info
- * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
- * Send enquiries to dratcliffe@gmail.com
- */
-package dan200.computercraft.ingame.mod;
-
-import dan200.computercraft.ingame.api.Times;
-import net.minecraft.server.MinecraftServer;
-import net.minecraft.server.level.ServerLevel;
-import net.minecraft.world.level.GameRules;
-import net.minecraft.world.level.Level;
-import net.minecraftforge.event.RegisterCommandsEvent;
-import net.minecraftforge.event.server.ServerStartedEvent;
-import net.minecraftforge.eventbus.api.SubscribeEvent;
-import net.minecraftforge.fml.common.Mod;
-import org.apache.logging.log4j.LogManager;
-import org.apache.logging.log4j.Logger;
-
-@Mod.EventBusSubscriber( modid = TestMod.MOD_ID )
-public class TestHooks
-{
-    private static final Logger LOG = LogManager.getLogger( TestHooks.class );
-
-    @SubscribeEvent
-    public static void onRegisterCommands( RegisterCommandsEvent event )
-    {
-        LOG.info( "Starting server, registering command helpers." );
-        CCTestCommand.register( event.getDispatcher() );
-    }
-
-    @SubscribeEvent
-    public static void onServerStarted( ServerStartedEvent event )
-    {
-        MinecraftServer server = event.getServer();
-        GameRules rules = server.getGameRules();
-        rules.getRule( GameRules.RULE_DAYLIGHT ).set( false, server );
-
-        ServerLevel world = event.getServer().getLevel( Level.OVERWORLD );
-        if( world != null ) world.setDayTime( Times.NOON );
-
-        // LOG.info( "Cleaning up after last run" );
-        // CommandSourceStack source = server.createCommandSourceStack();
-        // GameTestRunner.clearAllTests( source.getLevel(), getStart( source ), GameTestTicker.SINGLETON, 200 );
-
-        LOG.info( "Importing files" );
-        CCTestCommand.importFiles( server );
-    }
-}

src/testMod/java/dan200/computercraft/ingame/mod/TestMod.java

@@ -1,33 +0,0 @@
-/*
- * This file is part of ComputerCraft - http://www.computercraft.info
- * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
- * Send enquiries to dratcliffe@gmail.com
- */
-package dan200.computercraft.ingame.mod;
-
-import dan200.computercraft.api.ComputerCraftAPI;
-import net.minecraft.gametest.framework.StructureUtils;
-import net.minecraftforge.fml.common.Mod;
-import org.apache.logging.log4j.LogManager;
-import org.apache.logging.log4j.Logger;
-
-import java.nio.file.Path;
-import java.nio.file.Paths;
-
-@Mod( TestMod.MOD_ID )
-public class TestMod
-{
-    public static final Path sourceDir = Paths.get( "../../src/testMod/server-files" ).normalize().toAbsolutePath();
-
-    public static final String MOD_ID = "cctest";
-
-    public static final Logger log = LogManager.getLogger( MOD_ID );
-
-    public TestMod()
-    {
-        log.info( "CC: Test initialised" );
-        ComputerCraftAPI.registerAPIFactory( TestAPI::new );
-
-        StructureUtils.testStructuresDir = sourceDir.resolve( "structures" ).toString();
-    }
-}

src/testMod/java/dan200/computercraft/mixin/gametest/GameTestHelperAccessor.java

@@ -0,0 +1,23 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.mixin.gametest;
+
+import net.minecraft.gametest.framework.GameTestHelper;
+import net.minecraft.gametest.framework.GameTestInfo;
+import net.minecraft.world.phys.AABB;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.gen.Accessor;
+import org.spongepowered.asm.mixin.gen.Invoker;
+
+@Mixin( GameTestHelper.class )
+public interface GameTestHelperAccessor
+{
+    @Invoker
+    AABB callGetBounds();
+
+    @Accessor
+    GameTestInfo getTestInfo();
+}

src/testMod/java/dan200/computercraft/mixin/gametest/GameTestInfoAccessor.java

@@ -0,0 +1,17 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.mixin.gametest;
+
+import net.minecraft.gametest.framework.GameTestInfo;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.gen.Invoker;
+
+@Mixin( GameTestInfo.class )
+public interface GameTestInfoAccessor
+{
+    @Invoker( "getTick" )
+    long computercraft$getTick();
+}

src/testMod/java/dan200/computercraft/mixin/gametest/GameTestSequenceAccessor.java

@@ -0,0 +1,18 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.mixin.gametest;
+
+import net.minecraft.gametest.framework.GameTestInfo;
+import net.minecraft.gametest.framework.GameTestSequence;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.gen.Accessor;
+
+@Mixin( GameTestSequence.class )
+public interface GameTestSequenceAccessor
+{
+    @Accessor
+    GameTestInfo getParent();
+}

src/testMod/java/dan200/computercraft/mixin/gametest/GameTestSequenceMixin.java

@@ -0,0 +1,58 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.mixin.gametest;
+
+import dan200.computercraft.gametest.core.TestHooks;
+import net.minecraft.gametest.framework.GameTestAssertException;
+import net.minecraft.gametest.framework.GameTestInfo;
+import net.minecraft.gametest.framework.GameTestSequence;
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Overwrite;
+import org.spongepowered.asm.mixin.Shadow;
+
+@Mixin( GameTestSequence.class )
+class GameTestSequenceMixin
+{
+    @Shadow
+    @Final
+    GameTestInfo parent;
+
+    /**
+     * Override {@link GameTestSequence#tickAndContinue(long)} to catch non-{@link GameTestAssertException} failures.
+     *
+     * @param ticks The current tick.
+     * @author Jonathan Coates
+     * @reason There's no sense doing this in a more compatible way for game tests.
+     */
+    @Overwrite
+    public void tickAndContinue( long ticks )
+    {
+        try
+        {
+            tick( ticks );
+        }
+        catch( GameTestAssertException ignored )
+        {
+            // Mimic the original behaviour.
+        }
+        catch( AssertionError e )
+        {
+            parent.fail( e );
+        }
+        catch( Exception e )
+        {
+            // Fail the test, rather than crashing the server.
+            TestHooks.LOGGER.error( "{} threw unexpected exception", parent.getTestName(), e );
+            parent.fail( e );
+        }
+    }
+
+    @Shadow
+    private void tick( long tick )
+    {
+    }
+}

src/testMod/java/dan200/computercraft/mixin/gametest/TestCommandAccessor.java

@@ -0,0 +1,21 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.mixin.gametest;
+
+import net.minecraft.commands.CommandSourceStack;
+import net.minecraft.gametest.framework.TestCommand;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.gen.Invoker;
+
+@Mixin( TestCommand.class )
+public interface TestCommandAccessor
+{
+    @Invoker
+    static int callExportTestStructure( CommandSourceStack source, String structure )
+    {
+        return 0;
+    }
+}

src/testMod/kotlin/dan200/computercraft/gametest/Computer_Test.kt

@@ -0,0 +1,67 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.gametest
+
+import dan200.computercraft.core.apis.RedstoneAPI
+import dan200.computercraft.core.computer.ComputerSide
+import dan200.computercraft.gametest.api.*
+import dan200.computercraft.test.core.computer.getApi
+import net.minecraft.core.BlockPos
+import net.minecraft.gametest.framework.GameTest
+import net.minecraft.gametest.framework.GameTestHelper
+import net.minecraft.world.level.block.Blocks
+import net.minecraft.world.level.block.LeverBlock
+import net.minecraft.world.level.block.RedstoneLampBlock
+
+@GameTestHolder
+class Computer_Test {
+    /**
+     * Ensures redstone signals do not travel through computers.
+     *
+     * @see [#548](https://github.com/cc-tweaked/CC-Tweaked/issues/548)
+     */
+    @GameTest
+    fun No_through_signal(context: GameTestHelper) = context.sequence {
+        val lamp = BlockPos(2, 2, 4)
+        val lever = BlockPos(2, 2, 0)
+        thenExecute {
+            context.assertBlockHas(lamp, RedstoneLampBlock.LIT, false, "Lamp should not be lit")
+            context.modifyBlock(lever) { x -> x.setValue(LeverBlock.POWERED, true) }
+        }
+        thenIdle(3)
+        thenExecute { context.assertBlockHas(lamp, RedstoneLampBlock.LIT, false, "Lamp should still not be lit") }
+    }
+
+    /**
+     * Similar to the above, but with a repeater before the computer
+     */
+    @GameTest
+    fun No_through_signal_reverse(context: GameTestHelper) = context.sequence {
+        val lamp = BlockPos(2, 2, 4)
+        val lever = BlockPos(2, 2, 0)
+        thenExecute {
+            context.assertBlockHas(lamp, RedstoneLampBlock.LIT, false, "Lamp should not be lit")
+            context.modifyBlock(lever) { x -> x.setValue(LeverBlock.POWERED, true) }
+        }
+        thenIdle(3)
+        thenExecute { context.assertBlockHas(lamp, RedstoneLampBlock.LIT, false, "Lamp should still not be lit") }
+    }
+
+    @GameTest
+    fun Set_and_destroy(context: GameTestHelper) = context.sequence {
+        val lamp = BlockPos(2, 2, 3)
+
+        thenOnComputer { getApi<RedstoneAPI>().setOutput(ComputerSide.BACK, true) }
+        thenIdle(3)
+        thenExecute { context.assertBlockHas(lamp, RedstoneLampBlock.LIT, true, "Lamp should be lit") }
+        thenExecute { context.setBlock(BlockPos(2, 2, 2), Blocks.AIR) }
+        thenIdle(4)
+        thenExecute { context.assertBlockHas(lamp, RedstoneLampBlock.LIT, false, "Lamp should not be lit") }
+    }
+
+    // TODO: More redstone connectivity tests!
+    // TODO: Computer peripherals (including command computers)
+}

src/testMod/kotlin/dan200/computercraft/gametest/CraftOs_Test.kt

@@ -0,0 +1,22 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.gametest
+
+import dan200.computercraft.gametest.api.GameTestHolder
+import dan200.computercraft.gametest.api.Timeouts
+import dan200.computercraft.gametest.api.sequence
+import dan200.computercraft.gametest.api.thenComputerOk
+import net.minecraft.gametest.framework.GameTest
+import net.minecraft.gametest.framework.GameTestHelper
+
+@GameTestHolder
+class CraftOs_Test {
+    /**
+     * Sends a rednet message to another a computer and back again.
+     */
+    @GameTest(timeoutTicks = Timeouts.COMPUTER_TIMEOUT)
+    fun Sends_basic_rednet_messages(context: GameTestHelper) = context.sequence { thenComputerOk("main") }
+}

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

@@ -0,0 +1,43 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.gametest
+
+import dan200.computercraft.gametest.api.GameTestHolder
+import dan200.computercraft.gametest.api.sequence
+import dan200.computercraft.gametest.api.thenOnComputer
+import dan200.computercraft.test.core.assertArrayEquals
+import net.minecraft.core.BlockPos
+import net.minecraft.gametest.framework.GameTest
+import net.minecraft.gametest.framework.GameTestHelper
+import net.minecraft.world.item.Items
+
+@GameTestHolder
+class Disk_Drive_Test {
+    /**
+     * Ensure audio disks exist and we can play them.
+     *
+     * @see [#688](https://github.com/cc-tweaked/CC-Tweaked/issues/688)
+     */
+    @GameTest
+    fun Audio_disk(helper: GameTestHelper) = helper.sequence {
+        thenOnComputer {
+            callPeripheral("right", "hasAudio")
+                .assertArrayEquals(true, message = "Disk has audio")
+
+            callPeripheral("right", "getAudioTitle")
+                .assertArrayEquals("C418 - 13", message = "Correct audio title")
+        }
+    }
+
+    @GameTest
+    fun Ejects_disk(helper: GameTestHelper) = helper.sequence {
+        val stackAt = BlockPos(2, 2, 2)
+        thenOnComputer { callPeripheral("right", "ejectDisk") }
+        thenWaitUntil { helper.assertItemEntityPresent(Items.MUSIC_DISC_13, stackAt, 0.0) }
+    }
+
+    // TODO: Ejecting disk unmounts and closes files
+}

src/testMod/kotlin/dan200/computercraft/gametest/Loot_Test.kt

@@ -0,0 +1,37 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.gametest
+
+import dan200.computercraft.gametest.api.GameTestHolder
+import dan200.computercraft.gametest.api.Structures
+import dan200.computercraft.gametest.api.sequence
+import dan200.computercraft.shared.Registry
+import net.minecraft.core.BlockPos
+import net.minecraft.gametest.framework.GameTest
+import net.minecraft.gametest.framework.GameTestHelper
+import net.minecraft.world.level.block.Blocks
+import net.minecraft.world.level.block.entity.ChestBlockEntity
+import net.minecraft.world.level.storage.loot.BuiltInLootTables
+
+@GameTestHolder
+class Loot_Test {
+    /**
+     * Test that the loot tables will spawn in treasure disks.
+     */
+    @GameTest(template = Structures.DEFAULT)
+    fun Chest_contains_disk(context: GameTestHelper) = context.sequence {
+        thenExecute {
+            val pos = BlockPos(2, 2, 2)
+
+            context.setBlock(pos, Blocks.CHEST)
+            val chest = context.getBlockEntity(pos) as ChestBlockEntity
+            chest.setLootTable(BuiltInLootTables.SIMPLE_DUNGEON, 123)
+            chest.unpackLootTable(null)
+
+            context.assertContainerContains(pos, Registry.ModItems.TREASURE_DISK.get())
+        }
+    }
+}

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

@@ -0,0 +1,102 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+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.shared.peripheral.modem.wired.BlockCable
+import dan200.computercraft.test.core.assertArrayEquals
+import dan200.computercraft.test.core.computer.LuaTaskContext
+import dan200.computercraft.test.core.computer.getApi
+import net.minecraft.core.BlockPos
+import net.minecraft.gametest.framework.GameTest
+import net.minecraft.gametest.framework.GameTestHelper
+import org.junit.jupiter.api.Assertions.assertEquals
+import kotlin.time.Duration.Companion.milliseconds
+
+@GameTestHolder
+class Modem_Test {
+    @GameTest
+    fun Have_peripherals(helper: GameTestHelper) = helper.sequence {
+        thenOnComputer {
+            assertEquals(listOf("monitor_0", "printer_0", "right"), getPeripheralNames(), "Starts with peripherals")
+        }
+    }
+
+    @GameTest
+    fun Gains_peripherals(helper: GameTestHelper) = helper.sequence {
+        val position = BlockPos(2, 2, 2)
+        thenOnComputer {
+            assertEquals(listOf("back"), getPeripheralNames(), "Starts with peripherals")
+        }
+        thenExecute {
+            helper.setBlock(
+                position,
+                BlockCable.correctConnections(
+                    helper.level,
+                    helper.absolutePos(position),
+                    dan200.computercraft.shared.Registry.ModBlocks.CABLE.get().defaultBlockState().setValue(BlockCable.CABLE, true),
+                ),
+            )
+        }
+        thenIdle(1)
+        thenOnComputer {
+            assertEquals(listOf("back", "monitor_1", "printer_1"), getPeripheralNames(), "Gains new peripherals")
+        }
+    }
+
+    /**
+     * Sends a modem message to another computer on the same network
+     */
+    @GameTest
+    fun Transmits_messages(context: GameTestHelper) = context.sequence {
+        thenStartComputer("send") {
+            val modem = findPeripheral("modem") ?: throw IllegalStateException("Cannot find modem")
+            while (true) {
+                callPeripheral(modem, "transmit", 12, 34, "Hello")
+                sleep(50.milliseconds)
+            }
+        }
+        thenOnComputer("receive") {
+            val modem = findPeripheral("modem") ?: throw IllegalStateException("Cannot find modem")
+            callPeripheral(modem, "open", 12)
+
+            pullEvent("modem_message")
+                .assertArrayEquals("modem_message", "left", 12, 34, "Hello", 4, message = "Modem message")
+        }
+    }
+}
+
+private fun LuaTaskContext.findPeripheral(type: String): String? {
+    val peripheral = getApi<PeripheralAPI>()
+    for (side in ComputerSide.NAMES) {
+        val hasType = peripheral.hasType(side, type)
+        if (hasType != null && hasType[0] == true) return side
+    }
+
+    return null
+}
+
+private suspend fun LuaTaskContext.getPeripheralNames(): List<String> {
+    val peripheral = getApi<PeripheralAPI>()
+    val peripherals = mutableListOf<String>()
+    for (side in ComputerSide.NAMES) {
+        if (!peripheral.isPresent(side)) continue
+        peripherals.add(side)
+
+        val hasType = peripheral.hasType(side, "modem")
+        if (hasType == null || hasType[0] != true) continue
+
+        val names = peripheral.call(context, ObjectArguments(side, "getNamesRemote")).await() ?: continue
+        @Suppress("UNCHECKED_CAST")
+        peripherals.addAll(names[0] as Collection<String>)
+    }
+
+    peripherals.sort()
+    return peripherals
+}

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

@@ -0,0 +1,50 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.gametest
+
+import dan200.computercraft.gametest.api.GameTestHolder
+import dan200.computercraft.gametest.api.getBlockEntity
+import dan200.computercraft.gametest.api.sequence
+import dan200.computercraft.gametest.api.setBlock
+import dan200.computercraft.shared.Registry
+import net.minecraft.commands.arguments.blocks.BlockInput
+import net.minecraft.core.BlockPos
+import net.minecraft.gametest.framework.GameTest
+import net.minecraft.gametest.framework.GameTestHelper
+import net.minecraft.nbt.CompoundTag
+import net.minecraft.world.level.block.Blocks
+import java.util.*
+
+@GameTestHolder
+class Monitor_Test {
+    @GameTest
+    fun Ensures_valid_on_place(context: GameTestHelper) = context.sequence {
+        val pos = BlockPos(2, 2, 2)
+
+        thenExecute {
+            val tag = CompoundTag()
+            tag.putInt("Width", 2)
+            tag.putInt("Height", 2)
+
+            val toSet = BlockInput(
+                Registry.ModBlocks.MONITOR_ADVANCED.get().defaultBlockState(),
+                Collections.emptySet(),
+                tag,
+            )
+
+            context.setBlock(pos, Blocks.AIR.defaultBlockState())
+            context.setBlock(pos, toSet)
+        }
+        thenIdle(2)
+        thenExecute {
+            val tile = context.getBlockEntity(pos, Registry.ModBlockEntities.MONITOR_ADVANCED.get())
+
+            if (tile.width != 1 || tile.height != 1) {
+                context.fail("Tile has width and height of ${tile.width}x${tile.height}, but should be 1x1", pos)
+            }
+        }
+    }
+}

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

@@ -0,0 +1,61 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.gametest
+
+import dan200.computercraft.gametest.api.GameTestHolder
+import dan200.computercraft.gametest.api.Structures
+import dan200.computercraft.gametest.api.sequence
+import dan200.computercraft.shared.Registry
+import net.minecraft.gametest.framework.GameTest
+import net.minecraft.gametest.framework.GameTestAssertException
+import net.minecraft.gametest.framework.GameTestHelper
+import net.minecraft.nbt.CompoundTag
+import net.minecraft.world.entity.player.Player
+import net.minecraft.world.inventory.AbstractContainerMenu
+import net.minecraft.world.inventory.CraftingContainer
+import net.minecraft.world.inventory.MenuType
+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.*
+
+@GameTestHolder
+class Recipe_Test {
+    /**
+     * Test that crafting results contain NBT data.
+     *
+     * Mostly useful for Fabric, where we need a mixin for this.
+     */
+    @GameTest(template = Structures.DEFAULT)
+    fun Craft_result_has_nbt(context: GameTestHelper) = context.sequence {
+        thenExecute {
+            val container = CraftingContainer(DummyMenu, 3, 3)
+            container.setItem(0, ItemStack(Items.SKELETON_SKULL))
+            container.setItem(1, ItemStack(Registry.ModItems.COMPUTER_ADVANCED.get()))
+
+            val recipe: Optional<CraftingRecipe> = context.level.server.recipeManager
+                .getRecipeFor(RecipeType.CRAFTING, container, context.level)
+            if (!recipe.isPresent) throw GameTestAssertException("No recipe matches")
+
+            val result = recipe.get().assemble(container)
+
+            val owner = CompoundTag()
+            owner.putString("Name", "dan200")
+            owner.putString("Id", "f3c8d69b-0776-4512-8434-d1b2165909eb")
+            val tag = CompoundTag()
+            tag.put("SkullOwner", owner)
+
+            assertEquals(tag, result.tag, "Expected NBT tags to be the same")
+        }
+    }
+
+    object DummyMenu : AbstractContainerMenu(MenuType.GENERIC_9x1, 0) {
+        override fun quickMoveStack(player: Player, slot: Int): ItemStack = ItemStack.EMPTY
+        override fun stillValid(p0: Player): Boolean = true
+    }
+}

src/testMod/kotlin/dan200/computercraft/gametest/Turtle_Test.kt

@@ -0,0 +1,252 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.gametest
+
+import dan200.computercraft.api.detail.BasicItemDetailProvider
+import dan200.computercraft.api.detail.DetailRegistries
+import dan200.computercraft.api.lua.ObjectArguments
+import dan200.computercraft.core.apis.PeripheralAPI
+import dan200.computercraft.gametest.api.*
+import dan200.computercraft.shared.Registry
+import dan200.computercraft.shared.media.items.ItemPrintout
+import dan200.computercraft.shared.peripheral.monitor.BlockMonitor
+import dan200.computercraft.shared.peripheral.monitor.MonitorEdgeState
+import dan200.computercraft.shared.turtle.apis.TurtleAPI
+import dan200.computercraft.test.core.assertArrayEquals
+import dan200.computercraft.test.core.computer.LuaTaskContext
+import dan200.computercraft.test.core.computer.getApi
+import net.minecraft.core.BlockPos
+import net.minecraft.gametest.framework.GameTest
+import net.minecraft.gametest.framework.GameTestHelper
+import net.minecraft.world.entity.EntityType
+import net.minecraft.world.entity.item.PrimedTnt
+import net.minecraft.world.item.ItemStack
+import net.minecraft.world.level.block.Blocks
+import net.minecraft.world.level.block.FenceBlock
+import org.hamcrest.MatcherAssert.assertThat
+import org.hamcrest.Matchers.array
+import org.hamcrest.Matchers.instanceOf
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Assertions.assertNotEquals
+import java.util.*
+
+@GameTestHolder
+class Turtle_Test {
+    @GameTest
+    fun Unequip_refreshes_peripheral(helper: GameTestHelper) = helper.sequence {
+        thenOnComputer {
+            getApi<PeripheralAPI>().getType("right").assertArrayEquals("modem", message = "Starts with a modem")
+            getApi<TurtleAPI>().equipRight().await()
+            getApi<PeripheralAPI>().getType("right").assertArrayEquals("drive", message = "Unequipping gives a drive")
+        }
+    }
+
+    /**
+     * Checks turtles can sheer sheep (and drop items)
+     *
+     * @see [#537](https://github.com/cc-tweaked/CC-Tweaked/issues/537)
+     */
+    @GameTest
+    fun Shears_sheep(helper: GameTestHelper) = helper.sequence {
+        thenOnComputer {
+            getApi<TurtleAPI>().placeDown(ObjectArguments()).await()
+                .assertArrayEquals(true, message = "Shears the sheep")
+
+            assertEquals("minecraft:white_wool", getTurtleItemDetail(2)["name"])
+        }
+    }
+
+    /**
+     * Checks turtles can place lava.
+     *
+     * @see [#518](https://github.com/cc-tweaked/CC-Tweaked/issues/518)
+     */
+    @GameTest
+    fun Place_lava(helper: GameTestHelper) = helper.sequence {
+        thenOnComputer {
+            getApi<TurtleAPI>().placeDown(ObjectArguments()).await()
+                .assertArrayEquals(true, message = "Placed lava")
+        }
+        thenExecute { helper.assertBlockPresent(Blocks.LAVA, BlockPos(2, 2, 2)) }
+    }
+
+    /**
+     * Checks turtles can place when waterlogged.
+     *
+     * @see [#385](https://github.com/cc-tweaked/CC-Tweaked/issues/385)
+     */
+    @GameTest
+    fun Place_waterlogged(helper: GameTestHelper) = helper.sequence {
+        thenOnComputer {
+            getApi<TurtleAPI>().place(ObjectArguments()).await()
+                .assertArrayEquals(true, message = "Placed oak fence")
+        }
+        thenExecute {
+            helper.assertBlockIs(BlockPos(2, 2, 2), { it.block == Blocks.OAK_FENCE && it.getValue(FenceBlock.WATERLOGGED) })
+        }
+    }
+
+    /**
+     * Checks turtles can pick up lava
+     *
+     * @see [#297](https://github.com/cc-tweaked/CC-Tweaked/issues/297)
+     */
+    @GameTest
+    fun Gather_lava(helper: GameTestHelper) = helper.sequence {
+        thenOnComputer {
+            getApi<TurtleAPI>().placeDown(ObjectArguments()).await()
+                .assertArrayEquals(true, message = "Picked up lava")
+
+            assertEquals("minecraft:lava_bucket", getTurtleItemDetail()["name"])
+        }
+        thenExecute { helper.assertBlockPresent(Blocks.AIR, BlockPos(2, 2, 2)) }
+    }
+
+    /**
+     * Checks turtles can hoe dirt.
+     *
+     * @see [#258](https://github.com/cc-tweaked/CC-Tweaked/issues/258)
+     */
+    @GameTest
+    fun Hoe_dirt(helper: GameTestHelper) = helper.sequence {
+        thenOnComputer {
+            getApi<TurtleAPI>().dig(Optional.empty()).await()
+                .assertArrayEquals(true, message = "Dug with hoe")
+        }
+        thenExecute { helper.assertBlockPresent(Blocks.FARMLAND, BlockPos(1, 2, 1)) }
+    }
+
+    /**
+     * Checks turtles can place monitors
+     *
+     * @see [#691](https://github.com/cc-tweaked/CC-Tweaked/issues/691)
+     */
+    @GameTest
+    fun Place_monitor(helper: GameTestHelper) = helper.sequence {
+        thenOnComputer {
+            getApi<TurtleAPI>().place(ObjectArguments()).await()
+                .assertArrayEquals(true, message = "Block was placed")
+        }
+        thenIdle(1)
+        thenExecute { helper.assertBlockHas(BlockPos(1, 2, 3), BlockMonitor.STATE, MonitorEdgeState.LR) }
+    }
+
+    /**
+     * Checks turtles can place into compostors. These are non-typical inventories, so
+     * worth testing.
+     */
+    @GameTest
+    fun Use_compostors(helper: GameTestHelper) = helper.sequence {
+        thenOnComputer {
+            getApi<TurtleAPI>().dropDown(Optional.empty()).await()
+                .assertArrayEquals(true, message = "Item was dropped")
+            assertEquals(63, getApi<TurtleAPI>().getItemCount(Optional.of(1)), "Only dropped one item")
+        }
+    }
+
+    /**
+     * Checks turtles can be cleaned in cauldrons.
+     *
+     * Currently not required as turtles can no longer right-click cauldrons.
+     */
+    @GameTest(required = false)
+    fun Cleaned_with_cauldrons(helper: GameTestHelper) = helper.sequence {
+        thenOnComputer {
+            val details = getTurtleItemDetail(1, true)
+            getApi<TurtleAPI>().place(ObjectArguments()).await()
+                .assertArrayEquals(true, message = "Used item on cauldron")
+            val newDetails = getTurtleItemDetail(1, true)
+
+            assertEquals("computercraft:turtle_normal", newDetails["name"], "Still a turtle")
+            assertNotEquals(details["nbt"], newDetails["nbt"], "Colour should have changed")
+        }
+    }
+
+    /**
+     * Checks turtles can use IDetailProviders by getting details for a printed page.
+     */
+    @GameTest
+    fun Item_detail_provider(helper: GameTestHelper) = helper.sequence {
+        // Register a dummy provider for printout items
+        thenExecute {
+            DetailRegistries.ITEM_STACK.addProvider(
+                object :
+                    BasicItemDetailProvider<ItemPrintout>("printout", ItemPrintout::class.java) {
+                    override fun provideDetails(data: MutableMap<in String, Any>, stack: ItemStack, item: ItemPrintout) {
+                        data["type"] = item.type.toString().lowercase()
+                    }
+                },
+            )
+        }
+        thenOnComputer {
+            val details = getTurtleItemDetail(detailed = true)
+            assertEquals(mapOf("type" to "page"), details["printout"]) {
+                "Printout information is returned (whole map is $details)"
+            }
+        }
+    }
+
+    /**
+     * Advanced turtles resist all explosions but normal ones don't.
+     */
+    @GameTest
+    fun Resists_explosions(helper: GameTestHelper) = helper.sequence {
+        thenExecute {
+            val pos = helper.absolutePos(BlockPos(2, 2, 2))
+            val tnt = PrimedTnt(helper.level, pos.x + 0.5, pos.y + 1.0, pos.z + 0.5, null)
+            tnt.fuse = 1
+            helper.level.addFreshEntity(tnt)
+        }
+        thenWaitUntil { helper.assertEntityNotPresent(EntityType.TNT) }
+        thenExecute {
+            helper.assertBlockPresent(Registry.ModBlocks.TURTLE_ADVANCED.get(), BlockPos(2, 2, 2))
+            helper.assertBlockPresent(Blocks.AIR, BlockPos(2, 2, 1))
+        }
+    }
+
+    /**
+     * Turtles resist mob explosions
+     */
+    @GameTest
+    fun Resists_entity_explosions(helper: GameTestHelper) = helper.sequence {
+        thenExecute { helper.getEntity(EntityType.CREEPER).ignite() }
+        thenWaitUntil { helper.assertEntityNotPresent(EntityType.CREEPER) }
+        thenExecute {
+            helper.assertBlockPresent(Registry.ModBlocks.TURTLE_ADVANCED.get(), BlockPos(2, 2, 2))
+            helper.assertBlockPresent(Registry.ModBlocks.TURTLE_NORMAL.get(), BlockPos(2, 2, 1))
+        }
+    }
+
+    /**
+     * Test calling `turtle.drop` into an inventory.
+     */
+    @GameTest
+    fun Drop_to_chest(helper: GameTestHelper) = helper.sequence {
+        val turtle = BlockPos(2, 2, 2)
+        val chest = BlockPos(2, 2, 3)
+
+        thenOnComputer {
+            getApi<TurtleAPI>().drop(Optional.of(32)).await()
+                .assertArrayEquals(true, message = "Could not drop items")
+        }
+        thenExecute {
+            helper.assertContainerExactly(turtle, listOf(ItemStack(Blocks.DIRT, 32), ItemStack.EMPTY, ItemStack(Blocks.DIRT, 32)))
+            helper.assertContainerExactly(chest, listOf(ItemStack(Blocks.DIRT, 48)))
+        }
+    }
+
+    // TODO: Ghost peripherals?
+    // TODO: Dropping into minecarts
+    // TODO: Turtle sucking from items
+}
+
+private suspend fun LuaTaskContext.getTurtleItemDetail(slot: Int = 1, detailed: Boolean = false): Map<String, *> {
+    val item = getApi<TurtleAPI>().getItemDetail(context, Optional.of(slot), Optional.of(detailed)).await()
+    assertThat("Returns details", item, array(instanceOf(Map::class.java)))
+
+    @Suppress("UNCHECKED_CAST")
+    return item!![0] as Map<String, *>
+}

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

@@ -0,0 +1,222 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.gametest.api
+
+import dan200.computercraft.gametest.core.ManagedComputers
+import dan200.computercraft.mixin.gametest.GameTestHelperAccessor
+import dan200.computercraft.mixin.gametest.GameTestSequenceAccessor
+import dan200.computercraft.test.core.computer.LuaTaskContext
+import net.minecraft.commands.arguments.blocks.BlockInput
+import net.minecraft.core.BlockPos
+import net.minecraft.gametest.framework.*
+import net.minecraft.resources.ResourceLocation
+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.entity.BlockEntity
+import net.minecraft.world.level.block.entity.BlockEntityType
+import net.minecraft.world.level.block.state.BlockState
+import net.minecraft.world.level.block.state.properties.Property
+import net.minecraftforge.registries.ForgeRegistries
+
+/**
+ * Globally usable structures.
+ *
+ * @see GameTest.template
+ */
+object Structures {
+    /** The "default" structure, a 5x5 area with a polished Andesite floor */
+    const val DEFAULT = "default"
+}
+
+/** Pre-set in-game times */
+object Times {
+    const val NOON: Long = 6000
+}
+
+/**
+ * Custom timeouts for various test types.
+ *
+ * @see GameTest.timeoutTicks
+ */
+object Timeouts {
+    private const val SECOND: Int = 20
+
+    const val COMPUTER_TIMEOUT: Int = SECOND * 15
+}
+
+/**
+ * Equivalent to [GameTestSequence.thenExecute], but which won't run the next steps if the parent fails.
+ */
+fun GameTestSequence.thenExecuteFailFast(task: Runnable): GameTestSequence =
+    thenExecute(task).thenWaitUntil {
+        val failure = (this as GameTestSequenceAccessor).parent.error
+        if (failure != null) throw failure
+    }
+
+/**
+ * Wait until a computer has finished running and check it is OK.
+ */
+fun GameTestSequence.thenComputerOk(name: String? = null, marker: String = ComputerState.DONE): GameTestSequence {
+    val label = (this as GameTestSequenceAccessor).parent.testName + (if (name == null) "" else ".$name")
+
+    thenWaitUntil {
+        val computer = ComputerState.get(label)
+        if (computer == null || !computer.isDone(marker)) throw GameTestAssertException("Computer '$label' has not reached $marker yet.")
+    }
+    thenExecuteFailFast { ComputerState.get(label)!!.check(marker) }
+    return this
+}
+
+/**
+ * Run a task on a computer but don't wait for it to finish.
+ */
+fun GameTestSequence.thenStartComputer(name: String? = null, action: suspend LuaTaskContext.() -> Unit): GameTestSequence {
+    val test = (this as GameTestSequenceAccessor).parent
+    val label = test.testName + (if (name == null) "" else ".$name")
+    return thenExecuteFailFast { ManagedComputers.enqueue(test, label, action) }
+}
+
+/**
+ * Run a task on a computer and wait for it to finish.
+ */
+fun GameTestSequence.thenOnComputer(name: String? = null, action: suspend LuaTaskContext.() -> Unit): GameTestSequence {
+    val test = (this as GameTestSequenceAccessor).parent
+    val label = test.testName + (if (name == null) "" else ".$name")
+    var monitor: ManagedComputers.Monitor? = null
+    thenExecuteFailFast { monitor = ManagedComputers.enqueue(test, label, action) }
+    thenWaitUntil { if (!monitor!!.isFinished) throw GameTestAssertException("Computer '$label' has not finished yet.") }
+    thenExecuteFailFast { monitor!!.check() }
+    return this
+}
+
+/**
+ * Create a new game test sequence
+ */
+fun GameTestHelper.sequence(run: GameTestSequence.() -> Unit) {
+    val sequence = startSequence()
+    run(sequence)
+    sequence.thenSucceed()
+}
+
+/**
+ * A custom instance of [GameTestAssertPosException] which allows for longer error messages.
+ */
+private class VerboseGameTestAssertPosException(message: String, absolutePos: BlockPos, relativePos: BlockPos, tick: Long) :
+    GameTestAssertPosException(message, absolutePos, relativePos, tick) {
+    override fun getMessageToShowAtBlock(): String = message!!.lineSequence().first()
+}
+
+/**
+ * Fail this test. Unlike [GameTestHelper.fail], this trims the in-game error message to the first line.
+ */
+private fun GameTestHelper.failVerbose(message: String, pos: BlockPos): Nothing {
+    throw VerboseGameTestAssertPosException(message, absolutePos(pos), pos, tick)
+}
+
+/** Fail with an optional context message. */
+private fun GameTestHelper.fail(message: String?, detail: String, pos: BlockPos): Nothing {
+    failVerbose(if (message.isNullOrEmpty()) detail else "$message: $detail", pos)
+}
+
+/**
+ * A version of [GameTestHelper.assertBlockState] which also includes the current block state.
+ */
+fun GameTestHelper.assertBlockIs(pos: BlockPos, predicate: (BlockState) -> Boolean, message: String = "") {
+    val state = getBlockState(pos)
+    if (!predicate(state)) fail(message, state.toString(), pos)
+}
+
+/**
+ * A version of [GameTestHelper.assertBlockProperty] which includes the current block state in the error message.
+ */
+fun <T : Comparable<T>> GameTestHelper.assertBlockHas(pos: BlockPos, property: Property<T>, value: T, message: String = "") {
+    val state = getBlockState(pos)
+    if (!state.hasProperty(property)) {
+        val id = ForgeRegistries.BLOCKS.getKey(state.block)
+        fail(message, "block $id does not have property ${property.name}", pos)
+    } else if (state.getValue(property) != value) {
+        fail(message, "${property.name} is ${state.getValue(property)}, expected $value", pos)
+    }
+}
+
+/**
+ * Assert a container contains exactly these items and no more.
+ *
+ * @param pos The position of the container.
+ * @param items The list of items this container must contain. This should be equal to the expected contents of the
+ * first `n` slots - the remaining are required to be empty.
+ */
+fun GameTestHelper.assertContainerExactly(pos: BlockPos, items: List<ItemStack>) {
+    val container = getBlockEntity(pos) ?: failVerbose("Expected a container at $pos, found nothing", pos)
+    if (container !is Container) {
+        failVerbose("Expected a container at $pos, found ${getName(container.type)}", pos)
+    }
+
+    val slot = (0 until container.containerSize).indexOfFirst { slot ->
+        val expected = if (slot >= items.size) ItemStack.EMPTY else items[slot]
+        !ItemStack.matches(container.getItem(slot), expected)
+    }
+
+    if (slot >= 0) {
+        failVerbose(
+            """
+            Items do not match (first mismatch at slot $slot).
+            Expected:  $items
+            Container: ${(0 until container.containerSize).map { container.getItem(it) }.dropLastWhile { it.isEmpty }}
+            """.trimIndent(),
+            pos,
+        )
+    }
+}
+
+private fun getName(type: BlockEntityType<*>): ResourceLocation = ForgeRegistries.BLOCK_ENTITIES.getKey(type)!!
+
+/**
+ * Get a [BlockEntity] of a specific type.
+ */
+fun <T : BlockEntity> GameTestHelper.getBlockEntity(pos: BlockPos, type: BlockEntityType<T>): T {
+    val tile = getBlockEntity(pos)
+    @Suppress("UNCHECKED_CAST")
+    return when {
+        tile == null -> failVerbose("Expected ${getName(type)}, but no tile was there", pos)
+        tile.type != type -> failVerbose("Expected ${getName(type)} but got ${getName(tile.type)}", pos)
+        else -> tile as T
+    }
+}
+
+/**
+ * Get all entities of a specific type within the test structure.
+ */
+fun <T : Entity> GameTestHelper.getEntities(type: EntityType<T>): List<T> {
+    val info = (this as GameTestHelperAccessor).testInfo
+    return level.getEntities(type, info.structureBounds!!) { it.isAlive }
+}
+
+/**
+ * Get an [Entity] inside the game structure, requiring there to be a single one.
+ */
+fun <T : Entity> GameTestHelper.getEntity(type: EntityType<T>): T {
+    val entities = getEntities(type)
+    when (entities.size) {
+        0 -> throw GameTestAssertException("No $type entities")
+        1 -> return entities[0]
+        else -> throw GameTestAssertException("Multiple $type entities (${entities.size} in bounding box)")
+    }
+}
+
+/**
+ * Set a block within the test structure.
+ */
+fun GameTestHelper.setBlock(pos: BlockPos, state: BlockInput) = state.place(level, absolutePos(pos), 3)
+
+/**
+ * Modify a block state within the test.
+ */
+fun GameTestHelper.modifyBlock(pos: BlockPos, modify: (BlockState) -> BlockState) {
+    setBlock(pos, modify(getBlockState(pos)))
+}

src/testMod/kotlin/dan200/computercraft/gametest/core/ManagedComputers.kt

@@ -0,0 +1,137 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.gametest.core
+
+import dan200.computercraft.api.lua.ILuaAPI
+import dan200.computercraft.core.apis.OSAPI
+import dan200.computercraft.core.lua.CobaltLuaMachine
+import dan200.computercraft.core.lua.ILuaMachine
+import dan200.computercraft.core.lua.MachineEnvironment
+import dan200.computercraft.core.lua.MachineResult
+import dan200.computercraft.gametest.api.thenOnComputer
+import dan200.computercraft.mixin.gametest.GameTestInfoAccessor
+import dan200.computercraft.shared.computer.core.ServerContext
+import dan200.computercraft.test.core.computer.KotlinLuaMachine
+import dan200.computercraft.test.core.computer.LuaTaskContext
+import net.minecraft.gametest.framework.GameTestAssertException
+import net.minecraft.gametest.framework.GameTestAssertPosException
+import net.minecraft.gametest.framework.GameTestInfo
+import net.minecraft.gametest.framework.GameTestSequence
+import org.apache.logging.log4j.LogManager
+import java.io.InputStream
+import java.util.*
+import java.util.concurrent.ConcurrentLinkedDeque
+import java.util.concurrent.atomic.AtomicReference
+
+/**
+ * Provides a custom [ILuaMachine] which allows computers to run Kotlin or Lua code, depending on their ID.
+ *
+ * This allows writing game tests which consume Lua APIs, without having the overhead of starting a new computer for
+ * each test.
+ *
+ * @see GameTestSequence.thenOnComputer
+ */
+object ManagedComputers : ILuaMachine.Factory {
+    private val LOGGER = LogManager.getLogger(ManagedComputers::class.java)
+    private val computers: MutableMap<String, Queue<suspend LuaTaskContext.() -> Unit>> = mutableMapOf()
+
+    internal fun enqueue(test: GameTestInfo, label: String, task: suspend LuaTaskContext.() -> Unit): Monitor {
+        val monitor = Monitor(test, label)
+        computers.computeIfAbsent(label) { ConcurrentLinkedDeque() }.add {
+            try {
+                LOGGER.info("Running $label")
+                task()
+                monitor.result.set(Result.success(Unit))
+            } catch (e: Throwable) {
+                if (e !is AssertionError) LOGGER.error("Computer $label failed", e)
+                monitor.result.set(Result.failure(e))
+                throw e
+            } finally {
+                LOGGER.info("Finished $label")
+            }
+        }
+
+        ServerContext.get(test.level.server).registry().computers
+            .firstOrNull { it.label == label }?.queueEvent("test_wakeup")
+
+        return monitor
+    }
+
+    override fun create(environment: MachineEnvironment): ILuaMachine = DelegateMachine(environment)
+
+    private class DelegateMachine(private val environment: MachineEnvironment) : ILuaMachine {
+        private val apis = mutableListOf<ILuaAPI>()
+        private var delegate: ILuaMachine? = null
+
+        override fun addAPI(api: ILuaAPI) {
+            val delegate = this.delegate
+            if (delegate != null) return delegate.addAPI(api)
+
+            apis.add(api)
+
+            if (api is OSAPI) {
+                val newMachine = if (api.computerID != 1) {
+                    CobaltLuaMachine(environment)
+                } else if (api.computerLabel != null) {
+                    KotlinMachine(environment, api.computerLabel[0] as String)
+                } else {
+                    LOGGER.error("Kotlin Lua machine must have a label")
+                    CobaltLuaMachine(environment)
+                }
+
+                this.delegate = newMachine
+                for (api in apis) newMachine.addAPI(api)
+            }
+        }
+
+        override fun loadBios(bios: InputStream): MachineResult {
+            val delegate = this.delegate ?: return MachineResult.error("Computer not created")
+            return delegate.loadBios(bios)
+        }
+
+        override fun handleEvent(eventName: String?, arguments: Array<out Any>?): MachineResult {
+            val delegate = this.delegate ?: return MachineResult.error("Computer not created")
+            return delegate.handleEvent(eventName, arguments)
+        }
+
+        override fun printExecutionState(out: StringBuilder) {
+            delegate?.printExecutionState(out)
+        }
+
+        override fun close() {
+            delegate?.close()
+        }
+    }
+
+    private class KotlinMachine(environment: MachineEnvironment, private val label: String) : KotlinLuaMachine(environment) {
+        override fun getTask(): (suspend KotlinLuaMachine.() -> Unit)? = computers[label]?.poll()
+    }
+
+    class Monitor(private val test: GameTestInfo, private val label: String) {
+        internal val result = AtomicReference<Result<Unit>>()
+
+        val isFinished
+            get() = result.get() != null
+
+        fun check() {
+            val result = result.get() ?: fail("Computer $label did not finish")
+            val error = result.exceptionOrNull()
+            if (error != null) fail(error.message ?: error.toString())
+        }
+
+        private fun fail(message: String): Nothing {
+            val computer =
+                ServerContext.get(test.level.server).registry().computers.firstOrNull { it.label == label }
+            if (computer == null) {
+                throw GameTestAssertException(message)
+            } else {
+                val pos = computer.position
+                val relativePos = pos.subtract(test.structureBlockPos)
+                throw GameTestAssertPosException(message, pos, relativePos, (test as GameTestInfoAccessor).`computercraft$getTick`())
+            }
+        }
+    }
+}

src/testMod/resources/META-INF/accesstransformer.cfg

@@ -1,6 +0,0 @@
-public net.minecraft.gametest.framework.TestCommand m_128010_(Lnet/minecraft/commands/CommandSourceStack;Ljava/lang/String;)I # exportTestStructure
-
-public net.minecraft.gametest.framework.GameTestHelper m_177448_()Lnet/minecraft/world/phys/AABB; # getBounds
-public net.minecraft.gametest.framework.GameTestHelper f_127595_ # testInfo
-
-public net.minecraft.gametest.framework.GameTestSequence f_127774_ # parent

src/testMod/resources/META-INF/mods.toml

@@ -16,3 +16,10 @@ displayName="CC: Tweaked test framework"
 description='''
 A test framework for ensuring CC: Tweaked works correctly.
 '''
+
+[[dependencies.cctest]]
+modId="computercraft"
+mandatory=true
+versionRange="[1.0,)"
+ordering="AFTER"
+side="BOTH"

src/testMod/resources/computercraft-gametest.mixins.json

@@ -0,0 +1,16 @@
+{
+    "required": true,
+    "package": "dan200.computercraft.mixin.gametest",
+    "minVersion": "0.8",
+    "compatibilityLevel": "JAVA_17",
+    "injectors": {
+        "defaultRequire": 1
+    },
+    "mixins": [
+        "GameTestHelperAccessor",
+        "GameTestInfoAccessor",
+        "GameTestSequenceAccessor",
+        "GameTestSequenceMixin",
+        "TestCommandAccessor"
+    ]
+}