This change was introduced by the changes in apollographql/apollo-server#802
but first showed its head in apollographql/apollo-server#908. The reason that
violations in new type definitions aren't being found until subsequent PRs
isn't entirely clear but, ignoring that CI-related annoyance, the problem
itself here is very concrete.
It traces back to a major version update to `@types/mocha` via [Exhibit A],
which makes it unacceptable to return anything besides a `Promise` or
_nothing_ from a Mocha test factory.
I agree with this change in principle, since generally speaking there can be
multiple `expect` statements in each test and there is no particular reason
that the last one's value should be getting returned as Mocha doesn't do
anything functional with it.
More than anything, this seems like an artifact of an ESLint rule which
mandated that the last value in a function be returned, à la CoffeeScript or
other languages.
This will fix the failing tests on apollographql/apollo-server#908 and other
PRs currently in-flight.
Exhibit A: https://github.com/DefinitelyTyped/DefinitelyTyped/pull/24301
