diff --git a/test/aes-test.js b/test/aes-test.js
index <HASH>..<HASH> 100644
--- a/test/aes-test.js
+++ b/test/aes-test.js
@@ -27,5 +27,23 @@ describe("aes", () => {
         });
     });
 
+    describe("encrypt(str, key)", () => {
+        
+        it("should throw error on invalid key", () => {
+            assert.throws(() => aes.encrypt("data", "1515"), Error, "invalid key length");
+        });
+
+        it("should encrypt string of any length with given key that will decryptable by decrypt() function", () => {
+            function test(str, key) {
+                let encrypted = aes.encrypt(str, key);
+                let decrypted = aes.decrypt(encrypted, key);
+                expect(decrypted).to.be.equal(str);
+            }
+            test("1337");
+            test("русские буквы");
+            test("•Ý¹mÙO_‼|s¬¹Íе£—I♠f⌂5▓");
+            test("aaaaaaaa$aaaaaaaaaaaaa3abbbbbbt59bbbbbbbbbbbbbbb5)bbbbccccccc_ccccccc");
+        });
+    });
     
 });
\ No newline at end of file
Updates aes-test.js

* Adds test to check encryption/decryptoin.