Serialization methods

src/main/java/net/minestom/server/permission/Permission.java

@@ -1,10 +1,14 @@
 package net.minestom.server.permission;
 
 import net.minestom.server.command.CommandSender;
+import net.minestom.server.data.Data;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 /**
  * Representation of a permission granted to a CommandSender
  */
+@FunctionalInterface
 public interface Permission {
 
     /**
@@ -14,5 +18,18 @@ public interface Permission {
      */
     boolean isValidFor(CommandSender commandSender);
 
-    // TODO: Serialization?
+    /**
+     * Writes any required data for this permission inside the given destination
+     * @param destination Data to write to
+     */
+    default void write(@NotNull Data destination) {}
+
+    /**
+     * Reads any required data for this permission from the given destination
+     * @param source Data to read from
+     * @return this for chaining
+     */
+    default Permission read(@Nullable Data source) {
+        return this;
+    }
 }

src/test/java/permissions/TestPermissions.java

@@ -2,8 +2,11 @@ package permissions;
 
 import net.minestom.server.MinecraftServer;
 import net.minestom.server.command.CommandSender;
+import net.minestom.server.data.Data;
 import net.minestom.server.entity.Player;
 import net.minestom.server.permission.Permission;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;