public void RfidReader_OnRfidRead_EventFired() { int Argument = 0; var wasCalled = false; _uut.RfidDetectedEvent += ((sender, e) => { wasCalled = true; Argument = e.id; }); _uut.RfidRead(200); Assert.True(wasCalled); Assert.That(Argument, Is.EqualTo(200)); }