types: improve typing to allow custom request and reply

[Puppo]

This PR closes #207

Checklist

• run npm run test and npm run benchmark
• tests and/or benchmarks are included
• documentation is changed or added
• commit message and code follows the Developer's Certification of Origin
  and the Code of conduct

[mcollina]

lgtm

[mcollina]

lgtm

[Uzlopak]

Hmm, looks not correct. Why is Request and Reply not depending on the Generic Types from FastifyInstance?

Suggested change

	Request extends FastifyRequest = FastifyRequest,
	Reply extends FastifyReply = FastifyReply
	Request extends FastifyRequest = Request extends FastifyRequest = FastifyRequest<RawServerDefault, RawRequest, FastifySchema, TypeProvider, ContextConfigDefault, Logger>,
	Reply extends FastifyReply = FastifyReply<RawServer, RawRequest, RawReply, RouteGenericInterface, ContextConfigDefault, FastifySchema, TypeProvider>

Untested but I would expect this.

[Puppo]

The FastifyRequest and FastifyReply interfaces have changed from your example.
The default should be equal to the old value to prevent breaking the previous code.
Furthermore, now the FastifyRequest accepts other generic types, for instance, RouteGeneric, and in this way, the users can pass the request as they prefer.
If you take a look at the tests, I tried to break nothing and include your request to leave the power to the user to choose the request type.

[Uzlopak]

Please check my comment.

[hershmire]

@Puppo thanks for the PR!

@mcollina @Uzlopak any resolution on this?

[Puppo]

@Uzlopak any news on this one? otherwise Matteo cannot merge the PR.

[Uzlopak]

@fastify/typescript

Can somebody else have a look at it. I dont want to be a blocker, but I dont think that the arguments are valid as the generic types are not passed down to the FastifyReply and FastifyRequest.

I dont want to block, but I am not convinced either.

[climba03003]

I dont think that the arguments are valid as the generic types are not passed down to the FastifyReply and FastifyRequest.

That is true, but most of the time people use only the default server then it would be fine.
It worth a trial how it impact.

[Uzlopak]

@mcollina

Somebody has to decide if this gets merged and published or not.