refactor: make attributes allow-listed instead of deny-listed

This is a better default - as a number of attributes are primarily synced through other means (potions, items), or were applied from a context-sensitive action that does not warrant syncing across server contexts (sprinting, flying)

bukkit/src/main/java/net/william278/husksync/data/BukkitData.java

@@ -571,9 +571,9 @@ public abstract class BukkitData implements Data {
             final AttributeSettings settings = plugin.getSettings().getSynchronization().getAttributes();
             Registry.ATTRIBUTE.forEach(id -> {
                 final AttributeInstance instance = player.getAttribute(id);
-                if (instance == null || Double.compare(instance.getValue(), instance.getDefaultValue()) == 0
-                    || settings.isIgnoredAttribute(id.getKey().toString())) {
-                    return; // We don't sync unmodified or disabled attributes
+                if (!settings.isSyncedAttribute(id.getKey().toString()) || instance == null
+                    || Double.compare(instance.getValue(), instance.getDefaultValue()) == 0) {
+                    return; // We don't sync attributes not marked as to be synced
                 }
                 attributes.add(adapt(instance, settings));
             });

common/src/main/java/net/william278/husksync/config/Settings.java

@@ -275,12 +275,19 @@ public class Settings {
         @NoArgsConstructor(access = AccessLevel.PRIVATE)
         public static class AttributeSettings {
 
-            @Comment({"Which attributes should not be saved when syncing users. Supports wildcard matching.",
+            @Comment({"Which attribute types should be saved as part of attribute syncing. Supports wildcard matching.",
                     "(e.g. ['minecraft:generic.max_health', 'minecraft:generic.*'])"})
             @Getter(AccessLevel.NONE)
-            private List<String> ignoredAttributes = new ArrayList<>(List.of(""));
+            private List<String> syncedAttributes = new ArrayList<>(List.of(
+                    "minecraft:generic.max_health", "minecraft:max_health",
+                    "minecraft:generic.max_absorption", "minecraft:max_absorption",
+                    "minecraft:generic.luck", "minecraft:luck",
+                    "minecraft:generic.scale", "minecraft:scale",
+                    "minecraft:generic.step_height", "minecraft:step_height",
+                    "minecraft:generic.gravity", "minecraft:gravity"
+            ));
 
-            @Comment({"Which modifiers should not be saved when syncing users. Supports wildcard matching.",
+            @Comment({"Which attribute modifiers should be saved. Supports wildcard matching.",
                     "(e.g. ['minecraft:effect.speed', 'minecraft:effect.*'])"})
             @Getter(AccessLevel.NONE)
             private List<String> ignoredModifiers = new ArrayList<>(List.of(
@@ -297,8 +304,8 @@ public class Settings {
                 return pat.contains("*") ? value.matches(pat.replace("*", ".*")) : pat.equals(value);
             }
 
-            public boolean isIgnoredAttribute(@NotNull String attribute) {
-                return ignoredAttributes.stream().anyMatch(wildcard -> matchesWildcard(wildcard, attribute));
+            public boolean isSyncedAttribute(@NotNull String attribute) {
+                return syncedAttributes.stream().anyMatch(wildcard -> matchesWildcard(wildcard, attribute));
             }
 
             public boolean isIgnoredModifier(@NotNull String modifier) {

docs/Config-File.md

@@ -136,10 +136,22 @@ synchronization:
     - '*'
   # Configuration for how to sync attributes
   attributes:
-    # Which attributes should not be saved when syncing users. Supports wildcard matching.
+    # Which attribute types should be saved as part of attribute syncing. Supports wildcard matching.
     # (e.g. ['minecraft:generic.max_health', 'minecraft:generic.*'])
-    ignored_attributes: []
-    # Which modifiers should not be saved when syncing users. Supports wildcard matching.
+    synced_attributes: 
+      - "minecraft:generic.max_health"
+      - "minecraft:max_health"
+      - "minecraft:generic.max_absorption"
+      - "minecraft:max_absorption"
+      - "minecraft:generic.luck"
+      - "minecraft:luck"
+      - "minecraft:generic.scale"
+      - "minecraft:scale"
+      - "minecraft:generic.step_height"
+      - "minecraft:step_height"
+      - "minecraft:generic.gravity"
+      - "minecraft:gravity"
+    # Which attribute modifiers should not be saved when syncing users. Supports wildcard matching.
     # (e.g. ['minecraft:effect.speed', 'minecraft:effect.*'])
     ignored_modifiers: ['minecraft:effect.*', 'minecraft:creative_mode_*']
   # Event priorities for listeners (HIGHEST, NORMAL, LOWEST). Change if you encounter plugin conflicts