How to test the microcontroller via COM port?

Question

Software testing

A device is being developed that communicates with peripheral modules / sensors. A request for a dozen bytes is sent, we get a response. It is necessary to test the interaction of the device with the peripherals. To do this, instead of the sensor, we connect a computer with a COM port.
Question: what means can be used to emulate the operation of peripherals and, accordingly, test the performance of the device? It is supposed to transfer data in packets, limited pauses are possible between packets. It is necessary to take into account possible communication disruptions - the device should work normally.
But it needs to be tested!
What programs are more convenient to conduct such tests?

Answer 1

The computer, unfortunately, will not be able to simulate a disconnection in the middle of a byte, floating logic levels and other joys of life, all this will probably have to be checked by hand.
And so - take any convenient scripting language and library bindings for working with ports to it. Under Windows - yes, at least python + pyserial.