Add the parser to parse the string as an integer if it's needed.

test/cipher_analytical_machine/parsers/parsers_test.clj

@@ -4,7 +4,7 @@
    [cipher-analytical-machine.parsers.parsers :refer :all]))
 
 (deftest unsigned-int?-test
-  (testing ""
+  (testing "The function return true only for an unsingned integer as a string."
     (are [str expected]
         (= expected
            (unsigned-int? str))
@@ -13,3 +13,13 @@
       "-10" false
       "abc" false)))
 
+(deftest parse-unsigned-int-test
+  (testing "The function parse the integer if the string is an integer."
+    (are [str-or-int expected]
+        (= expected
+           (parse-unsigned-int str-or-int))
+      "9"   9
+      9     9
+      "10"  10
+      "-10" nil
+      "abc" nil)))