How to access mongodb via the plugin fastify-mongodb - mongodb

Question

My plugin looks like
import fp from 'fastify-plugin';
import mongodb from 'fastify-mongodb';
export default fp(async (fastify) => {
fastify.register(mongodb, {
url: 'mongodb+srv://dbuser:password#cluster0.otigz.mongodb.net/myapp?retryWrites=true&w=majority',
});
});
and my handler looks like
const postJoinHandler = async (
request: any,
reply: any
): Promise<{ id: string; name: string }> => {
try {
const { username, password } = request.body;
const test = await reply.mongo.db.users.insertOne({
username,
password,
});
console.log(test);
return reply.code(201).send(username);
} catch (error) {
request.log.error(error);
return reply.send(400);
}
};
Expected it to insert the username and password into the collection named users, but it didn't? and the error is Cannot read property 'db' of undefined
I also tried
reply.mongodb.users.insertOne({...
and
const test = await request.mongodb.collection('users');
test.insertOne({
username,
password,
});
console.log(test);
and
const test = await this.mongo.db.collection('users'); //<= Object is possibly 'undefined'
Routes look like
import { FastifyPluginAsync } from 'fastify';
import { postJoinSchema, postLoginSchema } from '../schemas/auth';
const auth: FastifyPluginAsync = async (fastify): Promise<void> => {
fastify.post('/auth/join', postJoinSchema);
fastify.post('/auth/login', postLoginSchema);
};
export default auth;

Answer 1

The mongo decorator is attached to the fastify instance, not to the request nor reply object.
You should move your handlers into the routes file and read for fastify.mongo or use a named function as the handler.
In the latter case, the handler has this bounded to the fastify instance.
async function postJoinHandler (
request,
reply
) {
try {
const { username, password } = request.body;
const test = await this.mongo.db.users.insertOne({
username,
password,
});
console.log(test);
reply.code(201)
return username
} catch (error) {
request.log.error(error);
reply.code(400);
return {}
}
};