From d80caac14cbb7c2f76f7e0188b1f95350129d1b4 Mon Sep 17 00:00:00 2001
From: Andy Yin <dev@fortheyin.com>
Date: Fri, 21 Nov 2025 10:22:38 -0800
Subject: [PATCH] feat: Custom property classes

---
 lib/literal/properties.rb                     |  3 +-
 test/properties/custom_property_class.test.rb | 86 +++++++++++++++++++
 2 files changed, 88 insertions(+), 1 deletion(-)
 create mode 100644 test/properties/custom_property_class.test.rb

diff --git a/lib/literal/properties.rb b/lib/literal/properties.rb
index 1bc5b50..56996ef 100644
--- a/lib/literal/properties.rb
+++ b/lib/literal/properties.rb
@@ -13,7 +13,7 @@ def self.extended(base)
 		base.include(base.__send__(:__literal_extension__))
 	end
 
-	def prop(name, type, kind = :keyword, reader: false, writer: false, predicate: false, default: nil, &coercion)
+	def prop(name, type, kind = :keyword, reader: false, writer: false, predicate: false, default: nil, **kwargs, &coercion)
 		if default && !(Proc === default || default.frozen?)
 			raise Literal::ArgumentError.new("The default must be a frozen object or a Proc.")
 		end
@@ -48,6 +48,7 @@ def prop(name, type, kind = :keyword, reader: false, writer: false, predicate: f
 			writer:,
 			predicate:,
 			default:,
+			**kwargs,
 			coercion:,
 		)
 
diff --git a/test/properties/custom_property_class.test.rb b/test/properties/custom_property_class.test.rb
new file mode 100644
index 0000000..57debc6
--- /dev/null
+++ b/test/properties/custom_property_class.test.rb
@@ -0,0 +1,86 @@
+# frozen_string_literal: true
+
+class DescriptionProperty < Literal::Property
+	def initialize(description: nil, **kwargs)
+		super(**kwargs)
+
+		@description = description
+	end
+
+	attr_reader :description
+end
+
+module DescriptionProperties
+	def prop(name, type, kind = :keyword, description: nil, **, &coercion)
+		super
+	end
+
+	def __literal_property_class__
+		DescriptionProperty
+	end
+end
+
+Example = Literal::Object
+
+test "custom property class can accept additional keyword arguments" do
+	example = Class.new(Example) do
+		extend DescriptionProperties
+
+		prop :name, String, description: "The person's name"
+		prop :age, Integer, description: "The person's age"
+	end
+
+	name_prop = example.literal_properties[:name]
+	age_prop = example.literal_properties[:age]
+
+	assert_equal name_prop.description, "The person's name"
+	assert_equal age_prop.description, "The person's age"
+	assert_equal name_prop.class, DescriptionProperty
+	assert_equal age_prop.class, DescriptionProperty
+end
+
+test "custom property class works with all property features" do
+	example = Class.new(Example) do
+		extend DescriptionProperties
+
+		prop :name, String, description: "Name", reader: :public
+		prop :age, Integer, description: "Age", default: 0, reader: :public
+	end
+
+	object = example.new(name: "John")
+	assert_equal object.name, "John"
+	assert_equal object.age, 0
+
+	name_prop = example.literal_properties[:name]
+	age_prop = example.literal_properties[:age]
+
+	assert_equal name_prop.description, "Name"
+	assert_equal age_prop.description, "Age"
+end
+
+test "custom property class with nil description" do
+	example = Class.new(Example) do
+		extend DescriptionProperties
+
+		prop :name, String
+	end
+
+	name_prop = example.literal_properties[:name]
+	assert_equal name_prop.description, nil
+end
+
+test "invalid keyword arguments on base Literal::Properties raise ArgumentError" do
+	example = Class.new(Example)
+
+	assert_raises(ArgumentError) do
+		example.prop :name, String, description: "This should fail"
+	end
+end
+
+test "invalid keyword arguments on base Literal::Properties raise ArgumentError for other unknown args" do
+	example = Class.new(Example)
+
+	assert_raises(ArgumentError) do
+		example.prop :name, String, unknown_arg: "This should fail"
+	end
+end