Is there a tool available that will tell me if the cabal file for my library or application has any unnecessary build-depends?

I have a habit of developing new modules within an application and then moving them out to separate libraries. For instance, I might move module Foo out of my application and into a new or existing library package. If Foo was the only module in my application to explicitly import any modules from the Bar package, I would like to know that I can now remove the dependency on Bar from my application's build-depends in the cabal file.

My strategy right now would be to search my whole application for other imports of any of the modules from the Bar package, or just remove Bar from build-depends and check if the application still compiles. Neither solution is particularly scalable or satisfying.

Cheers,
Jason Whittle