Issue #303 contains a fix in order to get the viewport to fill the entire window. That fix unfortunately seems to contain a bug which causes a crash when the user resizes the window.
Looks like the unit tests are failing for a missing get_viewport_size method on Window. I'm assuming the unit tests are stubbing the Window type and this method needs to be stubbed out too?
Issue #303 contains a fix in order to get the viewport to fill the entire window. That fix unfortunately seems to contain a bug which causes a crash when the user resizes the window.
This fix attempts to address both issues.