addResolversToSchema should not lose directives

[yaacovCR]

first attempt at fix for #1587

requires some thinking as to whether this is a breaking change.

requires some new tests?

[theguild-bot]

The latest changes of this PR are available as alpha in npm: 6.0.10-alpha-5b93e0e.0

Quickly update your package.json by running:

npx match-version @graphql-tools 6.0.10-alpha-5b93e0e.0

[yaacovCR]

after a few false starts, I added one test.

@ardatan and all,

This PR merges in the astNode, extensionASTNodes and also extensions.

It does a deep merge for extensions. Is that right? Should it replace by key instead?

[yaacovCR]

switched it to a shallow merge, i think that is more well-defined.

Not likely to be an issue...probably a pretty rare workflow which is using addResolversToSchema for scalars/enums with extensions defined on both the original schema and the new types in the resolvers map.

[yaacovCR]

We do have to wonder if this is a breaking change, as now addResolversToSchema doesn't overwrite the astNode, extensionASTNodes, and extension fields, and maybe there were some out there relying on that. Seems unlikely, but just a point to consider.

Thoughts?

[ardatan]

Shallow merging sounds good to me. If we get bug reports, we can think it again later.