Types for SchemaDirectiveVisitor.visitSchemaDirectives broken in 5.0.0 branch

[DrewML]

To start with, congratulations on the big 5.0.0 release, and thank you for all the hard work!

I upgraded from 4.x.x, and it looks like the current typings aren't working as intended for one small thing.

Minimal Repro

SchemaDirectiveVisitor.visitSchemaDirectives(anyGQLSchema, {
    foo: class extends SchemaDirectiveVisitor {},
});

Type 'typeof foo' is 
not assignable to type 'typeof SchemaDirectiveVisitor'. 
Construct signature return types 'foo' and 'SchemaDirectiveVisitor<TArgs, TContext>' are incompatible.
    The types of 'context' are incompatible between these types.
      Type '{ [key: string]: any; }' is not assignable to type 'TContext'.
        '{ [key: string]: any; }' is assignable to the constraint of type 'TContext', but 'TContext' could be instantiated with a different subtype of constraint '{}'.

	foo: class extends SchemaDirectiveVisitor {},

Testing

I pulled down the repo locally and ran ./node_modules/.bin/tsc, and noticed that the same compiler errors are also happening in master.

It looks like this likely wasn't caught by the unit tests because diagnostics are disabled in ts-jest.

The issue can be seen by running tsc against src/test/directives.test.ts:

[yaacovCR]

Thanks so much for the wonderful reproduction!

[DrewML]

That was impressively fast @yaacovCR - I really appreciate you helping out!

[yaacovCR]

Thanks again for awesome reproduction.

Hoping to get a canary build out for you to test when #1368 lands.

[yaacovCR]

Also available with latest alpha, npm install graphql-tools@alpha.

[yaacovCR]

Closed by #1419.