Mutation results don't include FieldPolicy changes

[stephenh]

I'm using a FieldPolicy to translate a custom Date scalar from strings like "2020-01-01" on the wire to a CalendarDate type for the application code to consume.

Basically as a solution to this long-standing feature request:

https://github.com/apollographql/apollo-feature-requests/issues/2

The FieldPolicy approach has been working great for regular queries, but if I invoke a mutation that, as part of the mutation response payload, returns a Date scalar, my application gets back the "just a string" date and blows up b/c it was expecting a CalendarDate.

Fwiw I can see, via debug points, that the FieldPolicy is being invoked while the mutation results are written to the cache, but the storeResult returned from QueryManager.mutate is the still as-returned-by-the-link-layer result, i.e. with the string dates.

Is this an intentional limitation of FieldPolicy, or should mutation results include the "post-FieldPolicy" changes?

[robertherber]

I'm having the exactly same issue on Apollo Client 3.3.15.

[benjamn]

@stephenh Fix incoming! #8280

[stephenh]

@benjamn amazing! I love your team's long grind to perfection. :-)

[hwillson]

This was addressed in #8280 - thanks!