Handle invalid empty command inputs (#3606)

api/src/main/java/net/luckperms/api/node/types/DisplayNameNode.java

@@ -79,6 +79,7 @@ public interface DisplayNameNode extends ScopedNode<DisplayNameNode, DisplayName
          *
          * @param displayName the display name
          * @return the builder
+         * @throws IllegalArgumentException if {@code displayName} is empty
          */
         @NonNull Builder displayName(@NonNull String displayName);
 

api/src/main/java/net/luckperms/api/node/types/InheritanceNode.java

@@ -96,6 +96,7 @@ public interface InheritanceNode extends ScopedNode<InheritanceNode, Inheritance
          *
          * @param group the group name
          * @return the builder
+         * @throws IllegalArgumentException if {@code group} is not a valid group name
          */
         @NonNull Builder group(@NonNull String group);
 

api/src/main/java/net/luckperms/api/node/types/MetaNode.java

@@ -87,6 +87,7 @@ public interface MetaNode extends ScopedNode<MetaNode, MetaNode.Builder> {
          *
          * @param key the meta key
          * @return the builder
+         * @throws IllegalArgumentException if {@code key} is empty
          */
         @NonNull Builder key(@NonNull String key);
 

api/src/main/java/net/luckperms/api/node/types/PermissionNode.java

@@ -104,6 +104,7 @@ public interface PermissionNode extends ScopedNode<PermissionNode, PermissionNod
          *
          * @param permission the permission
          * @return the builder
+         * @throws IllegalArgumentException if {@code permission} is empty
          */
         @NonNull Builder permission(@NonNull String permission);
 

api/src/main/java/net/luckperms/api/node/types/RegexPermissionNode.java

@@ -101,6 +101,7 @@ public interface RegexPermissionNode extends ScopedNode<RegexPermissionNode, Reg
          *
          * @param pattern the pattern
          * @return the builder
+         * @throws IllegalArgumentException if {@code pattern} is empty
          */
         @NonNull Builder pattern(@NonNull String pattern);