Duplicate 'passport' decorator error when instantiating multiple Authenticator instances

[thaDude]

Prerequisites

• [X] I have written a descriptive issue title
• [X] I have searched existing issues to ensure the bug has not already been reported

Fastify version

4.17.0

Plugin version

2.3.0

Node.js version

16.2

Operating system

macOS

Operating system version (i.e. 20.04, 11.3, 10)

14.2.1

Description

Hello,

I followed instructions as per documentation but the Fastify server does not start up with the error quoted below:

{
    "level": 50,
    "time": 1706381991730,
    "pid": 19819,
    "hostname": "<redacted>",
    "err":
    {
        "type": "FastifyError",
        "message": "The decorator 'passport' has already been added!",
        "stack": "FastifyError: The decorator 'passport' has already been added!\n    at decorateConstructor (/Users/<redacted>/Work/<redacted>/node_modules/fastify/lib/decorate.js:41:11)\n    at Object.decorateRequest (/Users/<redacted>/Work/<redacted>/node_modules/fastify/lib/decorate.js:123:3)\n    at /Users/<redacted>/Work/<redacted>/node_modules/@fastify/passport/dist/CreateInitializePlugin.js:10:17\n    at Plugin.exec (/Users/<redacted>/Work/<redacted>/node_modules/avvio/plugin.js:130:19)\n    at Boot.loadPlugin (/Users/<redacted>/Work/<redacted>/node_modules/avvio/plugin.js:272:10)\n    at processTicksAndRejections (node:internal/process/task_queues:83:21)",
        "name": "FastifyError",
        "code": "FST_ERR_DEC_ALREADY_PRESENT",
        "statusCode": 500
    },
    "msg": "The decorator 'passport' has already been added!"
}

Best regards,

David

Steps to Reproduce

'use strict'

const fastify = require('fastify')({
    disableRequestLogging: true,
    logger: true,
    level: 'info'
});

const {Authenticator} = require('@fastify/passport');

const fastifyCookie = require('@fastify/cookie');
const fastifySession = require('@fastify/session');
fastify.register(fastifyCookie);
fastify.register(fastifySession, {
    secret: '6b8de8c5-2440-4903-8157-595adeaed92e',
    cookie: { secure: false },
    expires: 1800000
})

const _username1='user1';
const _password1 = 'password1';

const _username2 = 'user2';
const _password2 = 'password2';

const LocalStrategy = require('passport-local');

let passport1 = new Authenticator({ key: 'userAuth1', userProperty: 'user1' })
passport1.use('local-1', new LocalStrategy({},
    function (username, password, done) {
        if (username === _username1 && password == _password1) {
            return done(null, {username});
        }
        return done('local-1: You got this wrong');
    }));
fastify.register(passport1.initialize());
fastify.register(passport1.secureSession());

let passport2 = new Authenticator({ key: 'userAuth2', userProperty: 'user2' })
passport2.use('local-2', new LocalStrategy({},
    function (username, password, done) {
        if (username === _username2 && password == _password2) {
            return done(null, {username});
        }
        return done('local-2: You got this wrong');
    }));
fastify.register(passport2.initialize());
fastify.register(passport2.secureSession());

passport1.registerUserSerializer(async (user, request) => user);
passport1.registerUserDeserializer(async (serUser, request) => {
    return {...serUser}
});

passport2.registerUserSerializer(async (user, request) => user);
passport2.registerUserDeserializer(async (serUser, request) => {
    return {...serUser}
});

fastify.post("/login-password-1", {
    preValidation: passport1.authenticate('local-1', {
        failureMessage: true,
        failWithError: true,
    })
}, async function (request, reply) {
    console.log(request.user)
    reply.code(200).send({...request.user1})
})

fastify.post("/login-password-2", {
    preValidation: passport2.authenticate('local-2', {
        failureMessage: true,
        failWithError: true,
    })
}, async function (request, reply) {
    console.log(request.user)
    reply.code(200).send({...request.user2})
})

fastify.post("/auth-test", {
}, async function (request, reply) {
    console.log(request.user)
    reply.code(200).send({...request.user})
})

fastify.listen({ port: 3000, host: '0.0.0.0' }, function (err, address) {
    if (err) {
        fastify.log.error(err)
        process.exit(1)
    }
})

Expected Behavior

The fastify server should start up and I should have 2 authentication stacks.

[mcollina]

You'd need to encapsulate the two instances in separate plugins.

[thaDude]

Thank you for your reply Matteo and sorry for the n00b question but how do I do this? Any examples are appreciated. I am using fastify-passport in a commonJS setting.

/David

[mcollina]

Something like:

fastify.register(async (fastify) => {
const LocalStrategy = require('passport-local');

let passport1 = new Authenticator({ key: 'userAuth1', userProperty: 'user1' })
passport1.use('local-1', new LocalStrategy({},
    function (username, password, done) {
        if (username === _username1 && password == _password1) {
            return done(null, {username});
        }
        return done('local-1: You got this wrong');
    }));
fastify.register(passport1.initialize());
fastify.register(passport1.secureSession());

fastify.post("/login-password-1", {
    preValidation: passport1.authenticate('local-1', {
        failureMessage: true,
        failWithError: true,
    })
}, async function (request, reply) {
    console.log(request.user)
    reply.code(200).send({...request.user1})
})

})

Do the same for passport2