typescript not throwing error for wrong type

[buoyant condor]

import { Ticket } from '@prisma/client';
const prisma = require('../db');

const router = require('express').Router();

router.get('/all', async (req: Request, res: Response) => {
    try {
        const tickets: Ticket[] = await prisma.Assigned_Ticket.findMany();
        console.log(tickets)
        res.json(tickets)
    } catch (error) {
        console.log(error);
        res.sendStatus(500);
    }
})
module.exports = router;```

I am using express, nodejs, ts. I am trying to return an array of Tickets. I tried changing the type to string, and it still works even though the query will never return a string.

[dark vault]

multiple things:

• don't use require in TypeScript

if you need to import something, uses the import {} from "" syntax

so in your case import { Router } from "express"

this way, TypeScript can know the type of the Router function, which was previously unknown because of the require
if you need a default import, use import prisma from "../db"

• don't use module.exports =

if you need to export something in TypeScript, add export in front of the function or variable when you declare it, like so export const router = Router()

or if you want a default export const router = Router(); export default router;

• don't use try {} catch() {} with await

this one is more a personal opinion, but using .then() and .catch() makes the code much cleaner

you can also avoid typying all your functions as async, since you won't be using the await keyword anymore

• don't type your parameters when not needed
  this is a bit of a special case here, since your req and res parameters might have a type that is more than just a simple Request or Response

these two types are generic, meaning they can contain much more information
information that would be lost if your re-assign them a type in your route handler

also, by omitting those types, the code is more concise and TS can infer the right types just fine

[wooden creek]

Ascor8522#7606

Playground Link

Preview:```ts
// @filename: ../db
interface Ticket {

}
export declare const prisma: {
Assigned_Ticket: {
findMany(): Promise<Ticket[]>;
}
};

// @filename: index
import { Router } from 'express';
import prisma from '../db';

const router = Router();

router.get('/all', (req, res) => {
...```

You can choose specific lines to embed by selecting them before copying the link.

[dark vault]

this is what the final result looks like

but to come back to your original problem...

I am trying to return an array of Tickets. I tried changing the type to string, and it still works even though the query will never return a string.
findMany should return an array, you can't really change that
res.json accepts about anything (any) and tries to turn that object into a JSON string
so since it accepts anything but not everything is serializable, it might throw an error at runtime, but not at compile time

also, don't forget calling res.json or res.sendStatus doesn't return anything or doesn't make the code exit the current function, you're just setting a few fields in the response object

@buoyant condor

[buoyant condor]

Thank youuu

I just jumped into TS so im picking up little bits here and there

[dark vault]

the imports should be one of the few things that are different from JavaScript

but for the most part, those rules also apply to JS (import/export in ESM, await vs then, etc.)

[buoyant condor]

Exactly what i was looking for and more

[buoyant condor]

thanksss everything is working as expected now

!solved

[dark vault]

!resolved