Add a new test by adding a foo.h file, create two empty files named foo_rs_api.rs and foo_rs_api_impl.cc, and then executing cc_bindings_from_rs/test/golden/update.sh. This will generate the corresponding bindings files.
If a test in this directory fails, look at the output. It should contain a diff of the failure.
If you get spurious failures in this directory: Run cc_bindings_from_rs/test/golden/update.sh.