invalid mutation plan is still cached and reused for valid mutations

[hos]

Summary

When mutation request is invalid, the plan is cached and reused for valid mutation plans.

Steps to reproduce

Here is an reproducible benjie/ouch-my-finger#19. First I failed to reproduce because, in graphiql, I was passing patch in the query instead of passing as variables. There is a query.graphql file with the query which can be used in graphiql. After server starts, first you need to run the mutation with invalid variables,
empty patch object, you will get error "no values were provided". After you update the patch and add some values there, you will still get the error.

Expected results

It should run successfully second time.

Actual results

It throws error like I didn't provide any values in the patch.

Additional context

Initially I tried to export the schema js, to see what is wrong in the plans. But I had a lot of custom plugins without EXPORTABLE, so I gave up. So for me it was a bit hard to debug this case to find what I'm doing wrong that I can't reproduce (I guess, it's a me issue), I'm curious if you have any advice for me to do smarter debugging of plans?

Possible Solution

1. The step for fieldArgs should be re-executed, I'm not sure why it's reusing the plan (do args have plan / plan cache?). I think this one is strangest thing happening here.

2. Does it makes sense to only cache the plans if they succeed?