typescript doc bug change "import fastify from 'fastify'" to "import { fastify } from 'fastify'"

[mortifia]

Prerequisites

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

Fastify version

4.5.3

Plugin version

x.x.x

Node.js version

16.16.0

Operating system

Windows

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

win 11 ( insider )

Description

ts(2349) with current importl in doc when i call "fastify()"

Steps to Reproduce

npm init -y
npm i fastify
npm i -D typescript @types/node

{
  "compilerOptions": {
    ..., //ect
    "target": "ESNext",
    "esModuleInterop": true,
    ..., //ect
  }
}

import fastify from 'fastify'

const server = fastify()

server.get('/ping', async (request, reply) => {
  return 'pong\n'
})

server.listen({ port: 8080 }, (err, address) => {
  if (err) {
    console.error(err)
    process.exit(1)
  }
  console.log(`Server listening at ${address}`)
})

Expected Behavior

no ts(2349) when following example

[mcollina]

cc @fastify/typescript

[Uzlopak]

Typescript itself says, that you should then set moduleResolution to "node" or "nodeNext". Setting it to "node" or "nodeNext" fixes that issue.

Also see
https://stackoverflow.com/a/57383664/3619994

[mortifia]

should add it in the doc of fastify on typescript

by following the documentation as it is, there will be this problem

[Uzlopak]

Imho this is a common typescript issue. Also on the documentation of tsconfig

https://www.typescriptlang.org/tsconfig#target

The special ESNext value refers to the highest version your version of TypeScript supports. This setting should be used with caution, since it doesn’t mean the same thing between different TypeScript versions and can make upgrades less predictable.

So we would be forced to keep our documentation up to date with the typescript versions and tbh I dont think we are responsible to set up the tsconfig properly. It is the responsibility of the programmer to set tsconfig correct and to know what he/she is doing by setting this or that option in tsconfig other than what we recommend in our docs.

You are free to provide a PR to extend the documentation. But I think it is out of scope.

I reopen it to get feedback by @mcollina , @jsumners or others.

[mortifia]

I said that it will be necessary to specify it due to the note on the target

after yes I am talking about it because as it is there will be this error

[Uzlopak]

The strange thing is, that I dont get ts 2349 but ts 2792 if moduleResolution is set to "classic". If I use typescript 3.9.2 I get ts 2307. Using typescript version 4.0.2 up to next (4.9.0-dev.20220901) throws 2792.

And 2792 clearly states to change the moduleResolution to "node".

Other than that, I think an average developer will be able to fix that typescript issue without additional documentation.

But still, why do you get 2349 and not 2792.
Which version of typescript do you use?
Can you please provide a mvce to check why you dont get 2792?

[mortifia]

ps: Setting it to "node" or "nodeNext" in tsconfig dont fix error

node version : v16.16.0

package.json (currently migrate of express to fastify)

{
  "name": "xxxxxx",
  "version": "0.0.0",
  "description": "",
  "type": "module",
  "main": "build/index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "build": "tsc",
    "start": "node build/index.js",
    "dev": "concurrently \"tsc -w\" \"nodemon build/index.js\""
  },
  "author": "",
  "license": "",
  "dependencies": {
    "@fastify/cors": "^8.1.0",
    "@fastify/swagger": "^7.4.1",
    "@prisma/client": "^3.15.2",
    "bcrypt": "^5.0.1",
    "body-parser": "^1.19.0",
    "cors": "^2.8.5",
    "express": "^4.18.1",
    "fastify": "^4.5.3",
    "jsonwebtoken": "^8.5.1",
    "minio": "^7.0.32",
    "multer": "^1.4.5-lts.1"
  },
  "devDependencies": {
    "@types/bcrypt": "^5.0.0",
    "@types/cors": "^2.8.12",
    "@types/express": "^4.17.13",
    "@types/jsonwebtoken": "^8.5.9",
    "@types/minio": "^7.0.13",
    "@types/multer": "^1.4.7",
    "@types/node": "^18.7.14",
    "concurrently": "^7.3.0",
    "json-schema-to-ts": "^2.5.5",
    "nodemon": "^2.0.19",
    "prisma": "^3.15.2",
    "typescript": "^4.8.2"
  }
}

tsconfig

{
  "compilerOptions": {
    /* Language and Environment */
    "target": "ESNext" /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */,

    /* Modules */
    "module": "ESNext" /* Specify what module code is generated. */,
    "rootDir": "./src/" /* Specify the root folder within your source files. */,
    "moduleResolution": "NodeNext" /* Specify how TypeScript looks up a file from a given module specifier. */,

    /* JavaScript Support */

    /* Emit */
    "sourceMap": true /* Create source map files for emitted JavaScript files. */,
    "outDir": "./build" /* Specify an output folder for all emitted files. */,
    /* Interop Constraints */
    "esModuleInterop": true /* Emit additional JavaScript to ease support for importing CommonJS modules. This enables 'allowSyntheticDefaultImports' for type compatibility. */,
    "forceConsistentCasingInFileNames": true /* Ensure that casing is correct in imports. */

    /* Type Checking */
    "strict": true /* Enable all strict type-checking options. */,

    /* Completeness */
    "skipLibCheck": true /* Skip type checking all .d.ts files. */
  },
  "compileOnSave": true,
  "include": ["src/**/*.ts"]
}

src/index.ts (go to minimal to generate erorr)

import fastify from 'fastify'
const server = fastify()

ts generate error on "fastify()" ts(2349)

[climba03003]

It is expected to have error when you use NodeNext with module.
The current typings do not allow this combination.
See: fastify/fastify-cookie#184 and fastify/fastify-static#311

It require heavy refactor to support it.
Even if we change fastify, all the plugins you use need the same refactor to support the specified combination.

[mortifia]

thanks to your respond @climba03003 with : "moduleResolution": "Node" it's ok

ps : should still specify it in the note on the doc ^^

[Uzlopak]

Can you provide a PR?