The application requires Python 3.5 or above

First, create a virtual environment

pip install virtualenv
virtualenv venv

To activate venv on Windows

venv\Scripts\activate

To activate venv on Linux

source venv/bin/activate

To run tests:

python -m unittest -v

To run the application:

python -m task_list

For end-to-end testing, a subprocess was used instead of threading. The subprocess module allows you to create a new process and connect to their input and output pipes.

The application test runs main from task_list module and then injects the inputs into stdin. The IO Pipe is blocking which more closely emulates the real behavior of stdin when calling readline. The call will block until data is written to stdin. Likewise stdout.read will block until there is data to be read.

Because of the potential for blocking, a threaded timer was introduced to kill the subprocess on deadlock. The timeout is currently set to 2 seconds but if additional tests run longer than that the timeout should be increased.

As the subprocess captures all input and output, using print statements for debugging during tests will not work as expected.