如何获取fastify钩子的返回值？

Question

How to pass parameters from hooks to request handler in Fastify?
For example, I want to get the username in the BasicAuth hook from the request.

const fastify = require('fastify')()
const authenticate = {realm: 'Westeros'}
fastify.register(require('@fastify/basic-auth'), { validate, authenticate })
function validate (username, password, req, reply, done) {
  if (username === 'Tyrion' && password === 'wine') {
    // How to return username from here?
    done()
  } else {
    done(new Error('Winter is coming'))
  }
}

fastify.after(() => {
  fastify.addHook('onRequest', fastify.basicAuth)

  fastify.get('/', (req, reply) => {
    // How to get the username here?
  })
})

Answer 1

You need to attach it to the request object:

const fastify = require('fastify')()
const authenticate = { realm: 'Westeros' }
fastify.register(require('@fastify/basic-auth'), { validate, authenticate })

// this decoration will help the V8 engine to improve the memory allocation for the request object
fastify.decorateRequest('user', null)

function validate(username, password, req, reply, done) {  
  if (username === 'Tyrion' && password === 'wine') {
    // add it to the 
    req.user = { username }
    done()
  } else {
    done(new Error('Winter is coming'))
  }
}

fastify.after(() => {
  fastify.addHook('onRequest', fastify.basicAuth)

  fastify.get('/', async (req, reply) => {
    return { hello: req.user.username }
  })
})

fastify.inject({
  method: 'GET',
  url: '/',
  headers: {
    authorization: 'Basic ' + Buffer.from('Tyrion:wine').toString('base64')
  }
}, (err, res) => {
  console.log(res.payload)
})