Fix permission level resetting & make entity in EntityMeta nullable (#595)

src/main/java/net/minestom/server/entity/Player.java

@@ -296,6 +296,7 @@ public class Player extends LivingEntity implements CommandSender, Localizable,
 
         // Some client updates
         this.playerConnection.sendPacket(getPropertiesPacket()); // Send default properties
+        triggerStatus((byte) (24 + permissionLevel)); // Set permission level
         refreshHealth(); // Heal and send health packet
         refreshAbilities(); // Send abilities packet
 
@@ -424,6 +425,7 @@ public class Player extends LivingEntity implements CommandSender, Localizable,
         RespawnPacket respawnPacket = new RespawnPacket(getDimensionType(), getDimensionType().getName().asString(),
                 0, gameMode, gameMode, false, levelFlat, true);
         getPlayerConnection().sendPacket(respawnPacket);
+
         PlayerRespawnEvent respawnEvent = new PlayerRespawnEvent(this);
         EventDispatcher.call(respawnEvent);
         triggerStatus((byte) (24 + permissionLevel)); // Set permission level
@@ -433,6 +435,16 @@ public class Player extends LivingEntity implements CommandSender, Localizable,
         teleport(respawnEvent.getRespawnPosition()).thenRun(this::refreshAfterTeleport);
     }
 
+    /**
+     * Sends necessary packets to synchronize player data after a {@link RespawnPacket}
+     */
+    private void refreshClientStateAfterRespawn() {
+        this.playerConnection.sendPacket(new UpdateHealthPacket(this.getHealth(), food, foodSaturation));
+        this.playerConnection.sendPacket(new SetExperiencePacket(exp, level, 0));
+        triggerStatus((byte) (24 + permissionLevel)); // Set permission level
+        refreshAbilities();
+    }
+
     /**
      * Refreshes the command list for this player. This checks the
      * {@link net.minestom.server.command.builder.condition.CommandCondition}s
@@ -901,6 +913,7 @@ public class Player extends LivingEntity implements CommandSender, Localizable,
         playerConnection.sendPacket(destroyEntitiesPacket);
         playerConnection.sendPacket(respawnPacket);
         playerConnection.sendPacket(addPlayerPacket);
+        refreshClientStateAfterRespawn();
 
         {
             // Remove player
@@ -1207,7 +1220,7 @@ public class Player extends LivingEntity implements CommandSender, Localizable,
     }
 
     /**
-     * Changes the player {@link GameMode}.
+     * Changes the player {@link GameMode}
      *
      * @param gameMode the new player GameMode
      */
@@ -1219,6 +1232,27 @@ public class Player extends LivingEntity implements CommandSender, Localizable,
             sendPacketToViewersAndSelf(new PlayerInfoPacket(PlayerInfoPacket.Action.UPDATE_GAMEMODE,
                     new PlayerInfoPacket.UpdateGameMode(getUuid(), gameMode)));
         }
+
+        // The client updates their abilities based on the GameMode as follows
+        switch (gameMode) {
+            case CREATIVE -> {
+                this.allowFlying = true;
+                this.instantBreak = true;
+                this.invulnerable = true;
+            }
+            case SPECTATOR -> {
+                this.allowFlying = true;
+                this.instantBreak = false;
+                this.invulnerable = true;
+                this.flying = true;
+            }
+            default -> {
+                this.allowFlying = false;
+                this.instantBreak = false;
+                this.invulnerable = false;
+                this.flying = false;
+            }
+        }
     }
 
     /**
@@ -1242,6 +1276,7 @@ public class Player extends LivingEntity implements CommandSender, Localizable,
         this.dimensionType = dimensionType;
         sendPacket(new RespawnPacket(dimensionType, dimensionType.getName().asString(),
                 0, gameMode, gameMode, false, levelFlat, true));
+        refreshClientStateAfterRespawn();
     }
 
     /**
@@ -1465,10 +1500,13 @@ public class Player extends LivingEntity implements CommandSender, Localizable,
 
         this.permissionLevel = permissionLevel;
 
-        // Magic values: https://wiki.vg/Entity_statuses#Player
-        // TODO remove magic values
-        final byte permissionLevelStatus = (byte) (24 + permissionLevel);
-        triggerStatus(permissionLevelStatus);
+        // Condition to prevent sending the packets before spawning the player
+        if (isActive()) {
+            // Magic values: https://wiki.vg/Entity_statuses#Player
+            // TODO remove magic values
+            final byte permissionLevelStatus = (byte) (24 + permissionLevel);
+            triggerStatus(permissionLevelStatus);
+        }
     }
 
     /**

src/test/java/net/minestom/server/entity/EntityInstanceIntegrationTest.java

@@ -32,20 +32,6 @@ public class EntityInstanceIntegrationTest {
         assertEquals(instance, player.getInstance());
     }
 
-    @Test
-    public void playerJoinPacket(Env env) {
-        var instance = env.createFlatInstance();
-        var connection = env.createConnection();
-        var tracker = connection.trackIncoming(JoinGamePacket.class);
-        var tracker2 = connection.trackIncoming(ServerPacket.class);
-        var player = connection.connect(instance, new Pos(0, 40, 0)).join();
-        assertEquals(instance, player.getInstance());
-        assertEquals(new Pos(0, 40, 0), player.getPosition());
-
-        assertEquals(1, tracker.collect().size());
-        assertTrue(tracker2.collect().size() > 1);
-    }
-
     @Test
     public void playerSwitch(Env env) {
         var instance = env.createFlatInstance();

src/test/java/net/minestom/server/entity/player/PlayerIntegrationTest.java

@@ -0,0 +1,122 @@
+package net.minestom.server.entity.player;
+
+import net.minestom.server.api.Env;
+import net.minestom.server.api.EnvTest;
+import net.minestom.server.api.TestConnection;
+import net.minestom.server.coordinate.Pos;
+import net.minestom.server.entity.GameMode;
+import net.minestom.server.entity.Player;
+import net.minestom.server.network.packet.server.ServerPacket;
+import net.minestom.server.network.packet.server.play.*;
+import net.minestom.server.utils.NamespaceID;
+import net.minestom.server.world.DimensionType;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+import java.time.Duration;
+import java.util.ArrayList;
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+@EnvTest
+public class PlayerIntegrationTest {
+
+    /**
+     * Test to see whether player abilities are updated correctly when changing gamemodes
+     */
+    @Test
+    public void gamemodeTest(Env env) {
+        var instance = env.createFlatInstance();
+        var connection = env.createConnection();
+        var player = connection.connect(instance, new Pos(0, 42, 0)).join();
+        assertEquals(instance, player.getInstance());
+
+        player.setGameMode(GameMode.CREATIVE);
+        assertAbilities(player, true, false, true, true);
+        player.setGameMode(GameMode.SPECTATOR);
+        assertAbilities(player, true, true, true, false);
+        player.setGameMode(GameMode.CREATIVE);
+        assertAbilities(player, true, true, true, true);
+        player.setGameMode(GameMode.ADVENTURE);
+        assertAbilities(player, false, false, false, false);
+        player.setGameMode(GameMode.SURVIVAL);
+        assertAbilities(player, false, false, false, false);
+    }
+
+    private void assertAbilities(Player player, boolean isInvulnerable, boolean isFlying, boolean isAllowFlying,
+                                 boolean isInstantBreak) {
+        assertEquals(isInvulnerable, player.isInvulnerable());
+        assertEquals(isFlying, player.isFlying());
+        assertEquals(isAllowFlying, player.isAllowFlying());
+        assertEquals(isInstantBreak, player.isInstantBreak());
+    }
+
+    @Test
+    public void playerJoinPackets(Env env) {
+        var instance = env.createFlatInstance();
+        var connection = env.createConnection();
+        
+        final var packets = List.of(
+            JoinGamePacket.class, ServerDifficultyPacket.class, SpawnPositionPacket.class,
+            DeclareCommandsPacket.class, EntityPropertiesPacket.class, EntityStatusPacket.class,
+            UpdateHealthPacket.class, PlayerAbilitiesPacket.class
+        );
+        final List<TestConnection.PacketTracker<?>> trackers = new ArrayList<>();
+        for (var packet : packets) {
+            trackers.add(connection.trackIncoming(packet));
+        }
+
+        var trackerAll = connection.trackIncoming(ServerPacket.class);
+
+        var player = connection.connect(instance, new Pos(0, 40, 0)).join();
+        assertEquals(instance, player.getInstance());
+        assertEquals(new Pos(0, 40, 0), player.getPosition());
+
+        for (var tracker : trackers) {
+            assertEquals(1, tracker.collect().size());
+        }
+        assertTrue(trackerAll.collect().size() > packets.size());
+    }
+
+    /**
+     * Test to see whether the packets from Player#refreshPlayer are sent
+     * when changing dimensions
+     */
+    @Test
+    public void refreshPlayerTest(Env env) {
+        final int TEST_PERMISSION_LEVEL = 2;
+        final var testDimension = DimensionType.builder(NamespaceID.from("minestom:test_dimension")).build();
+        env.process().dimension().addDimension(testDimension);
+
+        var instance = env.createFlatInstance();
+        var instance2 = env.process().instance().createInstanceContainer(testDimension);
+
+        var connection = env.createConnection();
+        var player = connection.connect(instance, new Pos(0, 42, 0)).join();
+        assertEquals(instance, player.getInstance());
+
+        var tracker1 = connection.trackIncoming(UpdateHealthPacket.class);
+        var tracker2 = connection.trackIncoming(SetExperiencePacket.class);
+        var trackerStatus = connection.trackIncoming(EntityStatusPacket.class);
+        var tracker4 = connection.trackIncoming(PlayerAbilitiesPacket.class);
+
+        player.setPermissionLevel(TEST_PERMISSION_LEVEL);
+
+        // #join may cause the thread to hang as scheduled for the next tick when initially in a pool
+        Assertions.assertTimeout(Duration.ofSeconds(2), () -> player.setInstance(instance2).join());
+        assertEquals(instance2, player.getInstance());
+
+        assertEquals(1, tracker1.collect().size());
+        assertEquals(1, tracker2.collect().size());
+        assertEquals(2, trackerStatus.collect().size());
+        assertEquals(1, tracker4.collect().size());
+
+        // Ensure that the player was sent the permission levels
+        for (var statusPacket : trackerStatus.collect()) {
+            assertEquals(player.getEntityId(), statusPacket.entityId());
+            assertEquals(24 + TEST_PERMISSION_LEVEL, statusPacket.status()); // TODO: Remove magic value of 24
+        }
+    }
+
+}