What happens to app.config in a referenced project

Question

Say I have 2 projects, where project A references project B. Project A is a web application project and project B is a class library.

The class library has an app.confi

Answer 1

App.config is configuration, not application - so it's not saved into dll and it can't be displayed by reflector or decompiled.

You have to configure Project B with settings for Project A (in web.config as it is web app).

There is no mechanism to automagicaly configure external modules, unless they have coded default fall-back values.