Path param in express being typed as string[]

[ebon delta]

router.get("/tip/:id", (req: Request, res: Response): void => {
  const id: number = parseInt(req.params.id);

  const tip: string = tips[id - 1];

  res.render("tip", {
    title: "Tip",
    id: id,
    tip: tip,
  });
});

TSError: ⨯ Unable to compile TypeScript:
server/routes.ts:23:31 - error TS2345: Argument of type 'string | string[]' is not assignable to parameter of type 'string'.
Type 'string[]' is not assignable to type 'string'.

23 const id: number = parseInt(req.params.id);
                                ~~~~~~~~~~~~

Can someone explain why the path param is being considered as both an array of string and not only a string pls

[unkempt meteor]

i'm not able to reproduce that behavior in the playground, when i annotate req and res like you did i get a different error, and when i don't it typechecks (because req.params is any 😱):

[eager quarry]

mkantor#0

Playground Link

Preview:```ts
import express from "express"

const router = express()

const tips = ["blah"]

router.get("/tip/:id", (req, res): void => {
const id: number = parseInt(req.params.id)

const tip: string = tips[id - 1]

res.render("tip", {
title: "Tip",
id: i
...```

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[unkempt meteor]

what version of express are you using? are those Request and Response types the ones exported from express or something else?

[ebon delta]

tbh, that's come from someone else, I was intrigued by this behaviour too, so I just asked :c but I believed it might have something to do with the version of express like you said

I'm going to ask for the version and about the Request and Response types