fetchMore error handling

[micimize]

Basically, with our current implementation of fetchMore that uses apollo's approach, there is no way for the user to do error handling. In apollo they can .catch, but I don't think this is good enough - we should just pass both full results to updateQuery so that the user can handle or merge errors, etc however they want.

[mainawycliffe]

So, instead of just passing the data, we pass the QueryResults and the user checks for errors both?

[micimize]

@mainawycliffe yeah, and maybe have some helper on QueryResult for merging them, and some sane defaults

[mainawycliffe]

Okay, I will work on this over the weekend.

[mainawycliffe]

I will work on this tomorrow, am thinking of adding a onError callback with a default method, which merges the GraphQLError list, one can override it to handle errors differently.

[mainawycliffe]

@micimize I started working on this and realized there was a PR on having Library level exceptions. Can I work off this PR or should I wait for you to merge it?

[micimize]

@mainawycliffe the docs need to be reworked for lib level exceptions - idk when I'll get around to it

[micimize]

Added a basic mechanism here – https://github.com/micimize/graphql-flutter/tree/fetch_more_errors

I still think the full result merge approach is better though.