fix lists first

lib/parfait/list.rb

@@ -65,7 +65,7 @@ module Parfait
     end
 
     def first
-      return nil unless empty?
+      return nil if empty?
       get(1)
     end
 

test/parfait/test_list.rb

@@ -68,9 +68,23 @@ class TestList < MiniTest::Test
     assert_equal 3 , @list.index_of( :three )
     assert_equal nil , @list.index_of( :four )
   end
-  def test_incude
+  def test_inlcude
     test_many_get
     assert_equal true , @list.include?( :two )
     assert_equal false , @list.include?( :four )
   end
+  def test_empty_empty
+    assert_equal true , @list.empty?
+  end
+  def test_empty_notempty
+    assert_equal 1 , @list.set(1,1)
+    assert_equal false , @list.empty?
+  end
+  def test_first
+    test_many_get
+    assert_equal :one , @list.first
+  end
+  def test_first_empty
+    assert_equal nil , @list.first
+  end
 end