Do you know what tooling is available for testing atomicity guarantees?
Anyway, I wrote lots of unit tests to cover those atomicity issues. You can also write a custom python/nodejs/golang/... scripts that simultenusly write and read from the same multiple keys in such way that some invariant is preserved. For example, "mset x {i}, y {i}" for random `i` and in parallel do "mget x y" and to check that the response returns same values. You can also test this for other families using transactions like "MULTI; lpush x ${foo}; lpush y ${foo}; EXEC" .. and then similarly test that x and y have exactly the same lists.
I wonder if there could be a tool that instruments in the same way that afl does to try to detect races or inconsistent states.