Apollo Persisted Queries is a standard for sending queries as short hashes
instead of full strings, designed to work well with GET requests. It is
implemented by servers including the Apollo Engine Proxy, and by the
apollo-link-persisted-query client.
A common configuration is to set up persisted queries on production servers but
not in development. It is still convenient to leave apollo-link-persisted-query
always on, though. While apollo-link-persisted-query can detect that servers
don't support PQs, it works better if the server actually says it doesn't
support the PQ, instead of trying to process a request without a query and
potentially printing a confusing stack trace. This commit makes apollo-server
directly return PersistedQueryNotSupported instead of allowing confusing stack
traces to occur.
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
This fixes the default behavior for class-based contexts by also cloning the prototype, and it allows you to customize per-operation behavior by passing in a function as context.
