Binary package “python3-webtest” in ubuntu bionic

wraps any WSGI application and makes it easy to test

 WebTest helps you test your WSGI-based web applications. This can be any
 application that has a WSGI (Web Server Gateway Interface) interface,
 including an application written in a framework that supports WSGI (which
 includes most actively developed Python web frameworks – almost anything
 that even nominally supports WSGI should be testable).
 .
 This is the Python 3 version of the package.