--- /dev/null
+
+USING: tools.test ;
+
+IN: rot13
+
+{ "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz" } [
+ "NOPQRSTUVWXYZABCDEFGHIJKLMnopqrstuvwxyzabcdefghijklm" rot13
+] unit-test
+
+{
+ "Ubj pna lbh gryy na rkgebireg sebz na\nvagebireg ng AFN? In the elevators,\nthe extrovert looks at the OTHER guy's shoes."
+} [
+ "How can you tell an extrovert from an\nintrovert at NSA? Va gur ryringbef,\ngur rkgebireg ybbxf ng gur BGURE thl'f fubrf."
+ rot13
+] unit-test