refactor: clean up errors + unused code (#49473)

* refactor: use await/done to mollify eslint

* refactor: clean up unused code

It's also more of an express pattern. Fastify routes should be
registered as plugins.

api/db/index.ts

@@ -3,10 +3,10 @@ import fastifyMongo from '@fastify/mongodb';
 import { FastifyInstance } from 'fastify';
 
 const URI = process.env.MONGOHQ_URL || 'mongodb://localhost:27017/freecodecamp';
-// eslint-disable-next-line @typescript-eslint/require-await
+
 async function connect(fastify: FastifyInstance) {
   fastify.log.info(`Connecting to : ${URI}`);
-  void fastify.register(fastifyMongo, {
+  await fastify.register(fastifyMongo, {
     url: URI
   });
 }

api/routes/auth0.ts

@@ -1,8 +0,0 @@
-import { FastifyInstance } from 'fastify';
-
-// eslint-disable-next-line @typescript-eslint/require-await
-export async function auth0Routes(fastify: FastifyInstance) {
-  fastify.get('/oauth/token', async (_request, _reply) => {
-    return { a: 'b' };
-  });
-}

api/routes/test.ts

@@ -1,8 +1,7 @@
-import { FastifyInstance } from 'fastify';
+import { FastifyPluginCallback } from 'fastify';
 
-// eslint-disable-next-line @typescript-eslint/require-await
-export async function testRoutes(fastify: FastifyInstance) {
-  const collection = fastify?.mongo?.db?.collection('user');
+export const testRoutes: FastifyPluginCallback = (fastify, _options, done) => {
+  const collection = fastify.mongo.db?.collection('user');
 
   fastify.get('/test', async (_request, _reply) => {
     if (!collection) {
@@ -11,4 +10,5 @@ export async function testRoutes(fastify: FastifyInstance) {
     const user = await collection?.findOne({ email: 'bar@bar.com' });
     return { user };
   });
-}
+  done();
+};