This is why I wrote conf.h in the form of macros that expanded to
named structure field assignments, instead of just filling it with
named structure field assignments directly. This way, I can #include
the same file again with different macro definitions, and build up a
list of what fields were set in what config options.
This new code checks that if a config option has a default, then the
type of the default matches the declared type of the option value
itself. That's what caught the two goofs in the previous commit.
This is also the part of test_conf that I _won't_ want to delete once
I've finished with the refactoring: it can stay there forever, doing
type checking at test time that the compiler isn't doing for me at
build time.
Ahem. Of course I've been running it interactively until now, so I
never noticed that I'd forgotten to fill in that important point. But
now it's run as part of my build, it should make sure to fail if it
fails.
This aims to be a reasonably exhaustive test of what happens if you
set Conf values to various things, and then save your session, and
find out what ends up in the storage. Or vice versa.
Currently, the test program is written to match the existing
behaviour. The idea is that I can refactor the code that does the
loading and saving, and if this test still passes, I've probably done
it right.
However, in the long term, this test will be a liability: it's yet
another place you have to add every new config option. So my plan is
to get rid of it again once the refactorings I'm planning are
finished.
Or rather, I'll get rid of _that_ part of its functionality. I also
suspect I'll have added new kinds of consistency check by then, which
won't be a liability in the same way, and which I'll want to keep.
