Nasty misleading bug: Cannot return null for non-nullable field

[mschipperheyn]

This bug report should include:

• [o ] A short, but descriptive title. The title doesn't need "Apollo" in it.
• The package name and version of Apollo showing the problem.
• [0] If applicable, the last version of Apollo where the problem did not occur.
• The expected behavior.
• The actual behavior.
• [o ] A simple, runnable reproduction!

So, TDLR. GraphQLError: Cannot return null for non-nullable field is thrown with a field reference that is not the correct nulled field.

In my case, I spent hours and hours debugging GraphQLError: Cannot return null for non-nullable field Social__User.id.. And the id was there! Turns out, I returned a null value on another non nullable field on that type and either graphql or apollo indicates the wrong frigging field on the error message!

Apollo client: 2.6.2
Apollo server express 2.6.2
graphql 14.3.1
graphql-tools 4.0.4

[timcosta]

We're also seeing this issue. It seems to happen when we dont try/catch something in an async resolver function that then throws.

[mschipperheyn]

So, yeah, this is definitely a graphql bug. I reported it there: graphql/graphql-js#1989