--- /dev/null
+-module(hex_tests).
+-include_lib("eunit/include/eunit.hrl").
+
+decode_test() -> ?assertEqual(
+ [1,35,69,103,137,171,205,239],
+ hex:decode("0123456789abcdef")).
+
+encode_test() -> ?assertEqual(
+ "0123456789abcdef",
+ hex:encode([1,35,69,103,137,171,205,239])).
+
+fixed_xor_test() -> ?assertEqual(
+ "746865206b696420646f6e277420706c6179",
+ hex:encode(hex:fixed_xor(
+ hex:decode("1c0111001f010100061a024b53535009181c"),
+ hex:decode("686974207468652062756c6c277320657965")))).