public void Hash_GeneratesValidHash_ForInput() { // Arrange string input = "hello"; string key = "test"; string expected = "F151EA24BDA91A18E89B8BB5793EF324B2A02133CCE15A28A719ACBD2E58A986"; // Act byte[] output = _hmac.Hash(input, key); string outputHex = BitConverter.ToString(output).Replace("-", "").ToUpper(); // Assert expected.Should().Be(outputHex); }