diff --git a/__test__/hertzy.js b/__test__/hertzy.js
index <HASH>..<HASH> 100644
--- a/__test__/hertzy.js
+++ b/__test__/hertzy.js
@@ -57,4 +57,24 @@ describe('When access to WARNING property', function () {
         Hertzy.WARNING = false
     })
     
+})
+
+describe('When call tune method with no name (valid string)', function () {
+
+    it("should return an error", function () {
+        expect(function () { Hertzy.tune() })
+        .toThrow(new Error('Hertzy: frequency need to be a valid string'))
+    })
+
+})
+
+describe('When call tune method with valid string it return a frequency', function () {
+
+    it("should return a frequancy object", function () {
+        let fq = Hertzy.tune('user')
+        expect(fq).not.toBeNull()
+        expect(fq).not.toBeUndefined()
+        expect(typeof fq).toBe('object')
+    })
+
 })
\ No newline at end of file
Added unit tests for tune method
See: <URL>