Gauche ships with a fairly large number of SRFI tests using SRFI 64:

https://github.com/shirok/Gauche/blob/master/test/srfi.scm
https://github.com/shirok/Gauche/tree/master/test/include

With light extensions, in particular a `test*` macro:

http://practical-scheme.net/gauche/man/gauche-refe/Unit-testing.html