public void GetPrice_SingleHose_ReturnsHosePrice() { var status = string.Empty; _mockIO.Setup(c => c.SendAndReceive(WayneCommands.GetPrice, "01", ref status)) .Callback(() => status = "00") .Returns("0000000002890"); var forecourt = new Wayne(_mockIO.Object); var price = forecourt.GetPrice(new Hose(1)); forecourt.Dispose(); status.Should().Be("00"); price.Should().Be(2.890d); }