Exceptions

Field resolvers are responsible for catching any exceptions that occur.

Uncaught exceptions are not converted to errors; they are caught, wrapped in a new exception to identify the field name, field arguments, query path, and query location, but then allowed to bubble up out of Lacinia entirely.

This is not desirable: better to return a partial result along with errors.

Field resolvers should catch exceptions and use ResolverResults to communicate errors back to Lacinia for inclusion in the :errors key of the result.

Failure to catch exceptions is even more damaging when using async field resolvers, as this can cause query execution to entirely halt, due to resolver result promises never being delivered.