Feature request: Allow testing migration logic

[matyascimbulka]

Allow for testing migration logic of our Actors

Currently there is no way for the testing library to (gracefully) abort a run, evaluate its aborted state. And then resurrect the run and evaluate the final state of the Actor. This feature would allow us to test that migration logic within the Actor is set up correctly and all of the internal state survives migration.

Example

In e-commerce scraping tool we have several counters that keep track of returned results. If one of these counters isn't properly saved into KV store a migration will cause the counter to reset and for the Actor to return more results than requested.

[JuanGalilea]

here something like

const abortedHalfway = await testActorWithAbort(....., { abortAfterSecs: 4 });
expect(abortedHalfway)....

const finished = await abortedHalfway.resume();
expect(finished)...

Sounds like a pretty cool thing to use and check the whole abort-migrate flow.

The only issue i see is that we have to be really conscious of what we are doing as to not produce flaky tests due to race conditions on the abortedHalfway state. But thats on us keeping our wits about it while doing this.

[metalwarrior665]

I think we can expose the underlying API client and let users do it themselves?

[ruocco-l]

I think we can expose the underlying API client and let users do it themselves?

That's a great idea! @matyascimbulka would that be a good solution for you?