Testing GC and finalizers

a) How is GC tested in Julia (read as: method)?
b) Where could i find test code (read as: where in the julia repo)?
c) Are there known tests for finalizers somewhere in packages?

For reference: you are asking because of this issue, right?
https://github.com/JuliaGraphics/Cairo.jl/issues/248

Not only. There is the pending CairoScript should probably not use finalizers · Issue #215 · JuliaGraphics/Cairo.jl · GitHub and i had the feeling, that Memory leak when destroying a surface · Issue #225 · JuliaGraphics/Cairo.jl · GitHub is somehow connected.