diff --git a/spec/test/utilSpec.js b/spec/test/utilSpec.js
new file mode 100644
--- /dev/null
+++ b/spec/test/utilSpec.js
@@ -0,0 +1,27 @@
+/* global expect */
+
+describe("Util",function(){
+  var util = require("../../util.js");
+	var utf=[ // https://tools.ietf.org/html/rfc3629#page-8
+		["",[]],
+		["abc",[97,98,99]],
+		["å",[195,165]],
+		["🚅",[240,159,154,133]],
+		["žír",[0xc5,0xbe,0xc3,0xad,114]],
+		["A\u2262\u0391.",[0x41,0xE2,0x89,0xA2,0xCE,0x91,0x2E]],
+		["\uD55C\uAD6D\uC5B4",[0xED,0x95,0x9C,0xEA,0xB5,0xAD,0xEC,0x96,0xB4]],
+		["\ud84c\udfb4",[0xf0,0xa3,0x8e,0xb4]]
+	];
+	
+	describe("str2utf8",function(){
+		it("should encode a String into bytes in UTF-8",function(){
+			utf.forEach(couple=>expect(util.str2utf8(couple[0])).toEqual(couple[1]));
+		});
+	});
+	
+	describe("utf82str",function(){
+		it("should decode a String from UTF-8 bytes",function(){
+			utf.forEach(couple=>expect(util.utf82str(couple[1])).toEqual(couple[0]));
+		});
+	});
+});