This is a very simple test suite for nix expressions.
It should help us set up a good suite of unit tests for our nix-based
stuff.
Since we allow import from derivation, these tests can also depend on
derivations and e.g. use `builtins.readFile` to check outputs.
This is a first PoC to get us going, we can always replace it by
something different in the future if we don’t like it.
Change-Id: I206c7b624db2b1dabd9c73ffce4f87e658919958
Reviewed-on: https://cl.tvl.fyi/c/depot/+/662
Reviewed-by: tazjin <mail@tazj.in>
Tested-by: tazjin <mail@tazj.in>
