How do folks like to package up QuickCheck tests for their libraries?  In the main library?  As a separate repo & package?  Same repo & separate package?  Keeping tests with the tested code allows testing of non-exported functionality, but can add quite a lot of clutter.

My current leaning is to split a package "foo" into packages "foo" and "foo-test", but first I'd like to hear about others' experiences, insights, and preferences.

Thanks,  - Conal