Fix

framework/Argument.js

@@ -11,10 +11,28 @@ module.exports = class Argument {
 		this.oneOf = options.oneOf;
 		this.default = options.default;
 		this.avatarSize = options.avatarSize || 2048;
+		this.validator = options.validate;
+		this.parser = options.parse;
+		this.emptyChecker = options.isEmpty;
 	}
 
 	get type() {
 		if (this.typeID.includes('|')) return new UnionType(this.client, this.typeID);
 		return this.client.registry.types.get(this.typeID);
 	}
+
+	validate(val, msg, arg) {
+		if (this.validator) return this.validator(val, msg, arg);
+		return this.type.validate(val, msg, arg);
+	}
+
+	parse(val, msg, arg) {
+		if (this.parser) return this.parser(val, msg, arg);
+		return this.type.parse(val, msg, arg);
+	}
+
+	isEmpty(val, msg, arg) {
+		if (this.emptyChecker) return this.emptyChecker(val, msg, arg);
+		return this.type.isEmpty(val, msg, arg);
+	}
 };