Example in read me does not work at all

[jacob-orbiit]

Prerequisites

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

Fastify version

4.3.0

Plugin version

8.0.0

Node.js version

18.7.0

Operating system

macOS

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

12.4

Description

The plugin does literally nothing. The response is not decorated and the plugin seems to have not even run.

Steps to Reproduce

import Fastify from 'fastify';
import cors from '@fastify/cors';
import middie from '@fastify/middie';

const fastify = Fastify();

await fastify.register(middie);
await fastify.register(cors);

I also tried the example from fastify.io, and that crashes immediately:

await fastify.register(middie);
fastify.use(cors());

[…]/@fastify/cors/index.js:20
  fastify.decorateRequest('corsPreflightEnabled', false)
          ^
TypeError: Cannot read properties of undefined (reading 'decorateRequest')

Expected Behavior

No response

[mcollina]

Good post! We have not updated the README.

This should work:

import fastify from 'fastify'
import cors from '@fastify/cors'

const app = fastify()

await app.register(cors, { 
  // put your options here
})

app.get('/', (req, reply) => {
  reply.send({ hello: 'world' })
})

await app.listen(3000)

I think you are confusing two things, this module and https://www.npmjs.com/package/cors.
You need middie only to use the cors middleware; otherwise, you can just use this plugin.

[jacob-orbiit]

Thanks for the response!

Sorry, when you say fastify.register(cors, {}), to which fastify are you referring—the library or the instance? (naming them the same in the docs is extremely confusing).

[mcollina]

I'm sorry but I don't see where the confusion is with require('cors') vs require('@fastify/cors). They are clearly two different modules.

[jacob-orbiit]

I'm not talking about cors vs fastify/cors (although that was also quite confusing). I'm talking about fastify.register(). What is fastify there? Is it the default factory export of this library or the instance created by that factory?

[mcollina]

Good spot! I've updated the example.

[jacob-orbiit]

Thanks! That ambiguity exists thorough the entire fastify docs btw.

The new/updated example you posted is exactly what I tried, and it didn't work (unless middie is interfering?).