Split data targets for 1.21.4 and remove deprecations.

loader/src/main/java/net/neoforged/fml/loading/ImmediateWindowHandler.java

@@ -46,7 +46,7 @@ public static void load(final String launchTarget, final String[] arguments) {
                     LOGGER.debug("Invoking bootstrap method {}", bootstrap.name());
                     bootstrap.bootstrap(arguments);
                 });
-        if (!List.of("forgeclient", "forgeclientuserdev", "forgeclientdev").contains(launchTarget)) {
+        if (!List.of("neoforgeclient", "neoforgeclientdev").contains(launchTarget)) {
             provider = new DummyProvider();
             LOGGER.info("ImmediateWindowProvider not loading because launch target is {}", launchTarget);
         } else if (!FMLConfig.getBoolConfigValue(FMLConfig.ConfigValue.EARLY_WINDOW_CONTROL)) {

loader/src/main/java/net/neoforged/fml/loading/targets/CommonLaunchHandler.java

@@ -41,10 +41,6 @@ public abstract class CommonLaunchHandler implements ILaunchHandlerService {
 
     public abstract boolean isProduction();
 
-    public boolean isData() {
-        return false;
-    }
-
     /**
      * Return additional locators to be used for locating mods when this launch handler is used.
      */
@@ -128,10 +124,6 @@ protected void serverService(final String[] arguments, final ModuleLayer layer)
         runTarget("net.minecraft.server.Main", arguments, layer);
     }
 
-    protected void dataService(final String[] arguments, final ModuleLayer layer) throws Throwable {
-        runTarget("net.minecraft.data.Main", arguments, layer);
-    }
-
     protected void runTarget(final String target, final String[] arguments, final ModuleLayer layer) throws Throwable {
         Class.forName(layer.findModule("minecraft").orElseThrow(), target).getMethod("main", String[].class).invoke(null, (Object) arguments);
     }

loader/src/main/java/net/neoforged/fml/loading/targets/JUnitDevLaunchTarget.java

@@ -10,7 +10,7 @@
 /**
  * A launch target for bootstrapping a slim Minecraft environment in forgedev, to be used in JUnit tests.
  */
-public class JUnitDevLaunchTarget extends CommonDevLaunchHandler {
+public class JUnitDevLaunchTarget extends NeoForgeDevLaunchHandler {
     @Override
     public Dist getDist() {
         return Dist.DEDICATED_SERVER;

loader/src/main/java/net/neoforged/fml/loading/targets/NeoForgeDataDevLaunchHandler.java → loader/src/main/java/net/neoforged/fml/loading/targets/NeoForgeClientDataDevLaunchHandler.java

@@ -7,24 +7,19 @@
 
 import net.neoforged.api.distmarker.Dist;
 
-public class NeoForgeDataDevLaunchHandler extends CommonDevLaunchHandler {
+public class NeoForgeClientDataDevLaunchHandler extends NeoForgeDevLaunchHandler {
     @Override
     public String name() {
-        return "forgedatadev";
+        return "neoforgeclientdatadev";
     }
 
     @Override
     public Dist getDist() {
         return Dist.CLIENT;
     }
 
-    @Override
-    public boolean isData() {
-        return true;
-    }
-
     @Override
     public void runService(String[] arguments, ModuleLayer layer) throws Throwable {
-        dataService(arguments, layer);
+        runTarget("net.minecraft.client.data.Main", arguments, layer);
     }
 }

loader/src/main/java/net/neoforged/fml/loading/targets/NeoForgeClientDevLaunchHandler.java

@@ -5,21 +5,52 @@
 
 package net.neoforged.fml.loading.targets;
 
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 import net.neoforged.api.distmarker.Dist;
 
-public class NeoForgeClientDevLaunchHandler extends CommonDevLaunchHandler {
+public class NeoForgeClientDevLaunchHandler extends NeoForgeDevLaunchHandler {
     @Override
     public String name() {
-        return "forgeclientdev";
+        return "neoforgeclientdev";
     }
 
     @Override
     public Dist getDist() {
         return Dist.CLIENT;
     }
 
+    @Override
+    protected String[] preLaunch(String[] arguments, ModuleLayer layer) {
+        var args = ArgumentList.from(arguments);
+
+        String username = args.get("username");
+        if (username != null) { // Replace '#' placeholders with random numbers
+            Matcher m = Pattern.compile("#+").matcher(username);
+            var replaced = new StringBuilder();
+            while (m.find()) {
+                m.appendReplacement(replaced, getRandomNumbers(m.group().length()));
+            }
+            m.appendTail(replaced);
+            args.put("username", replaced.toString());
+        } else {
+            args.putLazy("username", "Dev");
+        }
+
+        if (!args.hasValue("accessToken")) {
+            args.put("accessToken", "0");
+        }
+
+        return super.preLaunch(arguments, layer);
+    }
+
     @Override
     public void runService(String[] arguments, ModuleLayer layer) throws Throwable {
         clientService(arguments, layer);
     }
+
+    private static String getRandomNumbers(int length) {
+        // Generate a time-based random number, to mimic how n.m.client.Main works
+        return Long.toString(System.nanoTime() % (int) Math.pow(10, length));
+    }
 }

loader/src/main/java/net/neoforged/fml/loading/targets/NeoForgeClientLaunchHandler.java

@@ -7,29 +7,46 @@
 
 import java.util.List;
 import java.util.function.Consumer;
+import net.neoforged.api.distmarker.Dist;
 import net.neoforged.fml.loading.LibraryFinder;
 import net.neoforged.fml.loading.MavenCoordinate;
 import net.neoforged.fml.loading.VersionInfo;
 import net.neoforged.fml.loading.moddiscovery.locators.PathBasedLocator;
+import net.neoforged.fml.loading.moddiscovery.locators.ProductionClientProvider;
 import net.neoforged.neoforgespi.locating.IModFileCandidateLocator;
 
-public class NeoForgeClientLaunchHandler extends CommonClientLaunchHandler {
+/**
+ * For production client environments (i.e. vanilla launcher).
+ */
+public class NeoForgeClientLaunchHandler extends CommonLaunchHandler {
     @Override
     public String name() {
-        return "forgeclient";
+        return "neoforgeclient";
     }
 
-    /**
-     * Overlays the unpatched but renamed Minecraft classes with our patched versions of those classes.
-     */
     @Override
-    protected List<MavenCoordinate> getAdditionalMinecraftJarContent(VersionInfo versionInfo) {
-        return List.of(new MavenCoordinate("net.neoforged", "neoforge", "", "client", versionInfo.neoForgeVersion()));
+    public Dist getDist() {
+        return Dist.CLIENT;
+    }
+
+    @Override
+    public boolean isProduction() {
+        return true;
+    }
+
+    @Override
+    protected void runService(String[] arguments, ModuleLayer gameLayer) throws Throwable {
+        clientService(arguments, gameLayer);
     }
 
     @Override
     public void collectAdditionalModFileLocators(VersionInfo versionInfo, Consumer<IModFileCandidateLocator> output) {
         super.collectAdditionalModFileLocators(versionInfo, output);
+
+        // Overlays the unpatched but renamed Minecraft classes with our patched versions of those classes.
+        var additionalContent = List.of(new MavenCoordinate("net.neoforged", "neoforge", "", "client", versionInfo.neoForgeVersion()));
+        output.accept(new ProductionClientProvider(additionalContent));
+
         var nfJar = LibraryFinder.findPathForMaven("net.neoforged", "neoforge", "", "universal", versionInfo.neoForgeVersion());
         output.accept(new PathBasedLocator("neoforge", nfJar));
     }