TypeScript RouteOptions interface generics missing defaults

[fox1t]

🐛 Bug Report

Working with routes definition I found that RouteOptions interface hasn't default generics declared. (https://github.com/fastify/fastify/blob/master/fastify.d.ts#L266) as opposed to RouteShorthandOptions(https://github.com/fastify/fastify/blob/master/fastify.d.ts#L230) that it extends from.
Is this a wanted behavior? I think this is too verbose since it forces to pass every time a route is declared a full set of same generics: RouteOptions<Server, IncomingMessage, ServerResponse>.

To Reproduce

Removing generics (<Server, IncomingMessage, ServerResponse>) TypeScript pops a compiler error:
Generic type 'RouteOptions<HttpServer, HttpRequest, HttpResponse, Query, Params, Headers, Body>' requires between 3 and 7 type arguments.

import { Server, IncomingMessage, ServerResponse } from 'http'
import { RouteOptions, RouteShorthandOptions } from 'fastify'

const listAttendance: RouteOptions<Server, IncomingMessage, ServerResponse> = {
  method: 'GET',
  url: '/',
  handler: (req, reply) => {
    reply.send([])
  },
}

const listAttendances: RouteShorthandOptions = {}

Expected behavior

Adding the defaults to RouteOptions the error goes away. I think this is the desirable behavior.

Paste the results here:

/**
   * Route configuration options such as "url" and "method"
   */
  interface RouteOptions<
    HttpServer = http.Server,
    HttpRequest = http.IncomingMessage,
    HttpResponse = http.ServerResponse,
    Query = DefaultQuery,
    Params = DefaultParams,
    Headers = DefaultHeaders,
    Body = DefaultBody
  >
    extends RouteShorthandOptions<
      HttpServer,
      HttpRequest,
      HttpResponse,
      Query,
      Params,
      Headers,
      Body
    > {
    method: HTTPMethod | HTTPMethod[]
    url: string
    handler: RequestHandler<HttpRequest, HttpResponse, Query, Params, Headers, Body>
  }

Your Environment

• node version: 10
• fastify version: 2.4.1
• os: Mac

[Ethan-Arrowood]

Yes this change would be valid (in fact it is almost identical to the upcoming v3 types just using different generics). Would you like to send a pr to update this on master?

[fox1t]

Done.