Vision: Simplify test setup

[xlc]

They are many duplicated setup code required for any new modules, mostly config system::Trait. There must be a way to avoid duplicate this code all over the places.
It also make any modification to system::Trait tedious as it have to change every single module test setup.

I am not sure what is the best way, but at least a macro can avoid most of the duplications.

All those code are duplicated and irrelevant for most of the tests

https://github.com/paritytech/substrate/blob/9b3e9f32cd5243d2eeff3d5d8337033aa64c091b/srml/aura/src/mock.rs#L35-L63

[kianenigma]

I cannot agree more. The system::Trait is becoming a bottleneck.

Ideally, I imagine this as the least that we can do:

• Each module must expose its default Trait implementation and types.
• When module x with runtime Test wants to have tests, it can implement Trait for Test or fallback to the default.

With a bit more effort we can also probably generalize the Builder() pattern with proc-macros to enable all tests to have it.

At some point if I have the time, I would really like to work on this.

[stale]

Hey, is anyone still working on this? Due to the inactivity this issue has been automatically marked as stale. It will be closed if no further activity occurs. Thank you for your contributions.

[kianenigma]

I have a vague guess that maybe @KiChjang would be interested in this.

[KiChjang]

Indeed, it looks to me that a derive macro like DefaultTestSetup could generate all the necessary code for the default test framework setup. Let me see what I can do here.

[kianenigma]

Re-posting my suggestion paritytech/substrate#12130 (comment) since I think it might be a good starting point for this.

[kianenigma]

The vision in paritytech/substrate#12130 (comment) can also be achieved with something like this:

• #[pallet::genesis_config] is structurally very similar to a pallet's hypothetical ExtBuilder.
• Why not have #[pallet::genesis_config] generate a basic ExtBuilder for you, that you can extend?
• crucially, this ExtBuilder would have a given fn build_and_execute(..) that can automatically call into try_state and such for you.