Change date conversion to work with date objects

CHANGELOG.md

@@ -6,6 +6,7 @@
 * Change permit setting to work with parameters converted to an array or a hash
 * Change formatting of a hash value in parameter validation error message
 * Change array and hash conversions to work with non-string values
+* Change date conversion to work with date objects
 
 ### Fixed
 * Fix argument check against permitted values to allow nil value when optional

lib/tty/option/conversions.rb

@@ -23,8 +23,10 @@ module Conversions
       end
 
       convert :date do |val|
+        require "date" unless defined?(::Date)
+        next val if val.is_a?(::Date)
+
         begin
-          require "date" unless defined?(::Date)
           ::Date.parse(val)
         rescue ArgumentError, TypeError
           Const::Undefined

spec/unit/conversions_spec.rb

@@ -38,14 +38,15 @@
     {
       "28/03/2020" => Date.parse("28/03/2020"),
       "March 28th 2020" => Date.parse("28/03/2020"),
-      "Sun, March 28th, 2020" => Date.parse("28/03/2020")
+      "Sun, March 28th, 2020" => Date.parse("28/03/2020"),
+      Date.parse("28/03/2020") => Date.parse("28/03/2020")
     }.each do |input, obj|
       it "converts #{input.inspect} to #{obj.inspect}" do
         expect(described_class[:date].(input)).to eq(obj)
       end
     end
 
-    it "fails to convert" do
+    it "fails to convert a string" do
       expect(described_class[:date].("invalid")).to eq(undefined)
     end