test: replace var with const and add mustCall cb
Checklist
-
make -j4 test
(UNIX), orvcbuild test nosign
(Windows) passes -
tests and/or benchmarks are included -
commit message follows commit guidelines
Affected core subsystem(s)
test
Description of change
Replaced all var
usage with const
.
Replaced all provided callbacks with the common.mustCall
helper
method.
Removed the funny comment because, thanks to mustCall, it actually
runs.