DI Integration Testing

[gdalle]

In DI, how will we handle the change from Array to other tangent types in 1.11?

[willtebbutt]

I think I should probably just add some conversion functionality to ensure that DI doesn't ever have to see weird tangent types for Array.

[willtebbutt]

I've realised that this was a false alarm -- apologies! The reason is that I need to keep gradients of Arrays as Arrays in order to retain compatibility with LTS. While I've not made a decision about whether the type of the gradient w.r.t. an object is part of the public API, and therefore must not change between Julia versions, my gut is that it would be kind of made to get Arrays on 1.10, and MutableTangents on 1.11.

I'm going to close this, but re-open if it becomes a problem again.

[gdalle]

Perhaps as a smoke test you could add DI testing to your test suite?

[willtebbutt]

Good shout. I'll make a point of doing this once the 1.11 transition PR is merged.

[gdalle]

The test file should be as simple as this:

using DifferentiationInterface, DifferentiationInterfaceTest
import Mooncake

backends = [AutoMooncake(; config=nothing), AutoMooncake(; config=Mooncake.Config())]

test_differentiation(
    backends;
    excluded=SECOND_ORDER,
    logging=true,
);

However if you release a breaking version on Mooncake, this will fail to resolve the environment until DI updates its compatibility bounds. That's the downside of handling backend compatibility in DI itself.