Make sure unit tests actually run(!) and fix command hints

api/build.gradle

@@ -98,6 +98,10 @@ javadoc {
     options.source = '8'
 }
 
+test {
+    useJUnitPlatform()
+}
+
 publishing {
     publications {
         mavenJava(MavenPublication) {

native/build.gradle

@@ -21,6 +21,10 @@ dependencies {
     testImplementation "org.junit.jupiter:junit-jupiter-engine:${junitVersion}"
 }
 
+test {
+    useJUnitPlatform()
+}
+
 publishing {
     publications {
         mavenJava(MavenPublication) {

proxy/build.gradle

@@ -81,6 +81,10 @@ dependencies {
     testImplementation "org.junit.jupiter:junit-jupiter-engine:${junitVersion}"
 }
 
+test {
+    useJUnitPlatform()
+}
+
 shadowJar {
     exclude 'it/unimi/dsi/fastutil/booleans/**'
     exclude 'it/unimi/dsi/fastutil/bytes/**'

proxy/src/main/java/com/velocitypowered/proxy/command/VelocityCommandManager.java

@@ -102,11 +102,8 @@ public class VelocityCommandManager implements CommandManager {
     }
 
     if (!(command instanceof BrigadierCommand)) {
-      if (!meta.getHints().isEmpty()) {
-        // If the user specified a hint, then add the hints to the command node directly.
       for (CommandNode<CommandSource> hint : meta.getHints()) {
-          node.addChild(hint);
-        }
+        node.addChild(BrigadierUtils.wrapForHinting(hint, node.getCommand()));
       }
     }
 

proxy/src/main/java/com/velocitypowered/proxy/util/BrigadierUtils.java

@@ -1,8 +1,10 @@
 package com.velocitypowered.proxy.util;
 
+import com.google.common.base.Preconditions;
 import com.google.common.base.Splitter;
 import com.mojang.brigadier.Command;
 import com.mojang.brigadier.arguments.StringArgumentType;
+import com.mojang.brigadier.builder.ArgumentBuilder;
 import com.mojang.brigadier.builder.LiteralArgumentBuilder;
 import com.mojang.brigadier.builder.RequiredArgumentBuilder;
 import com.mojang.brigadier.context.CommandContext;
@@ -11,6 +13,7 @@ import com.mojang.brigadier.tree.CommandNode;
 import com.mojang.brigadier.tree.LiteralCommandNode;
 import com.velocitypowered.api.command.CommandSource;
 import java.util.Locale;
+import org.checkerframework.checker.nullness.qual.Nullable;
 
 /**
  * Provides utilities for working with Brigadier commands.
@@ -124,6 +127,25 @@ public final class BrigadierUtils {
     return command.toLowerCase(Locale.ENGLISH);
   }
 
+  /**
+   * Prepares the given command node prior for hinting metadata to
+   * a {@link com.velocitypowered.api.command.Command}.
+   *
+   * @param node the command node to be wrapped
+   * @param command the command to execute
+   * @return the wrapped command node
+   */
+  public static CommandNode<CommandSource> wrapForHinting(
+      final CommandNode<CommandSource> node, final @Nullable Command<CommandSource> command) {
+    Preconditions.checkNotNull(node, "node");
+    ArgumentBuilder<CommandSource, ?> builder = node.createBuilder();
+    builder.executes(command);
+    for (CommandNode<CommandSource> child : node.getChildren()) {
+      builder.then(wrapForHinting(child, command));
+    }
+    return builder.build();
+  }
+
   private BrigadierUtils() {
     throw new AssertionError();
   }

proxy/src/test/java/com/velocitypowered/proxy/command/CommandManagerTests.java

@@ -122,20 +122,6 @@ public class CommandManagerTests {
     assertTrue(manager.hasCommand("foO"));
   }
 
-  @Test
-  void testAlreadyRegisteredThrows() {
-    VelocityCommandManager manager = createManager();
-    manager.register("bar", new NoopDeprecatedCommand());
-    assertThrows(IllegalArgumentException.class, () ->
-            manager.register("BAR", new NoopSimpleCommand()));
-    assertThrows(IllegalArgumentException.class, () -> {
-      CommandMeta meta = manager.metaBuilder("baz")
-              .aliases("BAr")
-              .build();
-      manager.register(meta, new NoopRawCommand());
-    });
-  }
-
   @Test
   void testBrigadierExecute() {
     VelocityCommandManager manager = createManager();
@@ -181,9 +167,9 @@ public class CommandManagerTests {
     assertTrue(manager.executeImmediatelyAsync(MockCommandSource.INSTANCE, "buy 14").join());
     assertTrue(checkedRequires.compareAndSet(true, false));
     assertTrue(executed.get());
-    assertFalse(manager.execute(MockCommandSource.INSTANCE, "buy 9"),
+    assertTrue(manager.execute(MockCommandSource.INSTANCE, "buy 9"),
             "Invalid arg returns false");
-    assertFalse(manager.executeImmediately(MockCommandSource.INSTANCE, "buy 12 bananas"));
+    assertTrue(manager.executeImmediately(MockCommandSource.INSTANCE, "buy 12 bananas"));
     assertTrue(checkedRequires.get());
   }