Testing Complex FRAME Pallets: Discussion + Tools

[OliverTY]

It is indeed a bit too much to react to all of it. Maybe we just collect ideas in here and then create dedicated discussions for each part.

@kianenigma

Lastly, if and once we have storage types that can have on_insert, on_update, on_remove hooks etc., we can integrate all of these checks at a much lower level.

I like this idea. Imagine writing the invariants actually as code and not as comment:

#[pallet::storage] 
pub type Map = StorageMap<u32, u32>;

#[pallet::storage]
#[pallet::invariant(
    event: changed(_previous, current) {
        assert!(current == Map::iter().count());
    },
    check_on: StorageLayerCommit,
    // Could think of when to check these conditions; per Extrinsic, per Block, Always…
)]
pub type Counter = StorageValue<u32>;