Prisma-client-js: Generated typings are not working properly with JavaScript

[pantharshit00]

Currently, you won't get proper typing unless you manually add .default to you photon instance.

const Photon = require('@generated/photon');
const photon = new Photon.default();

What I will suggest is also to export a named model Photon. Otherwise, even though Babel will transform .default interop exports but we will lose typing information using default exports. Named exports solve this completely.

[pantharshit00]

with // @ts-check without .default vscode will show a lack of call signature error

without //@ts-check and without .default vscode will just assign any to the photon variable, this results in loss of autocompletion.

With .default, we get proper type definitions

[divyenduz]

Potential fix, named export for Photon.

[schickling]

I suggest to use named exports instead and change the API to:

// JS
const { Photon } = require('@prisma/photon')

// TS / modern JS
import { Photon } from '@prisma/photon'

This will guarantee consistent usage/examples "in the wild" (e.g. StackOverflow, tutorials, GH issues, ...)

[timsuchanek]

We had a longer internal discussion about this and want to go with

// JS
const { Photon } = require('@generated/photon')

// TS / modern JS
import Photon from '@generated/photon'

We will explore, if we can "enforce" the default export for TypeScript, if not, in TypeScript there will also be the named export of { Photon } available.

Multiple requirements that make the decision hard here:
We want to avoid as much as possible ambiguous usage of Photon.js. So having import { Photon } from '@generated/photon' and import Photon from '@generated/photon' could confuse users. However, as the name of "default" suggests - it's just a default for the simple use-case, so exporting it both as a default and a named export doesn't exclude each other.

Another option we were discussing but decided against: Setting

export = Photon

Which would need "esModuleInterop": true in the tsconfig.json and then allow

import Photon from '@generated/photon'

const Photon = require('@generated/photon')

However, this forces users to have a specific tsconfig.json, which may break their application if they're using import * as ... already.

[timsuchanek]

As it turned out if we want to have the named export for the JavaScript implementation, we can't remove it for TypeScript. To keep things consistent, we've decided to go with

import { Photon } from '@generated/photon'

for both TypeScript and JavaScript.