From version 5.0 onwards, ReSharper offers a “Go To Related Files” navigation which offers a list of files that R# thinks are related to the file currently being edited: for example, base types, derived types, .designer.cs to and from the relevant .cs, and so on.
I have looked in the R# Options and also online, but have not been able to find out:
Is there a way to add files to this list, either within R# natively or by an already-existing plug-in?
(My motivation is to be able to navigate at coding time between files containing classes that are connected by a run-time-only convention-over-configuration, er, convention)
I don’t know about existing plugins, but this feature is extendable.
You need to implement IRelatedFilesProvider interface in your plugin and mark it by RelatedFilesProvider attribute. As far as I know, NHibernate plugin do it for analogous task.