diff --git a/test/cipher_analytical_machine/cipher_analyzers_test.clj b/test/cipher_analytical_machine/cipher_analyzers_test.clj
new file mode 100644
index 0000000..16991f2
--- /dev/null
+++ b/test/cipher_analytical_machine/cipher_analyzers_test.clj
@@ -0,0 +1,25 @@
+(ns cipher-analytical-machine.cipher-analyzers-test
+  (:require
+   [clojure.test :refer :all]
+   [cipher-analytical-machine.cipher-analyzers :refer :all]))
+
+(deftest count-characters-test
+  (testing "Count two dublicates and one uniq character from a string."
+    (is (= {\a 2 \b 1}
+           (count-characters "aba")))))
+
+(deftest chi-squared-letter-statistic-test
+  (testing "If the frequence of A is 0.1, the text length is 100 and contains 20 times, then the chi-squared is 10."
+    (is (= 10.0
+           (chi-squared-letter-statistic 20 0.1 100))))
+
+  (testing "If the frequence of A is 0.1, the text length is 10 and contains 5 times, then the chi-squared is 16.0."
+    (is (= 16.0
+           (chi-squared-letter-statistic 5 0.1 10)))))
+
+(deftest chi-squared-statistic-test
+  (let [text "aaaaabbbbb"]
+  (testing "If the frequences of a and b is 0.1, the text length is 10 and contains them 5 times, then score is 32."
+    (is (= 32.0
+           (chi-squared-statistic text {\a 0.1 \b 0.1}))))))
+