`Math.random()` always returns the same number, when using the `uuid` library and instantiating `uuidv4()` outside the handler function

[mikkelhegn]

The code below result in Math.random() always returning the same number, on each request. Moving the constant requestId in to the handler function resolves it, so that Math.random() now returs a new number on each request.

import { HandleRequest, HttpRequest, HttpResponse } from "@fermyon/spin-sdk"
import { v4 as uuidv4 } from "uuid";

// Moving this inside the handler will solve the problem
const requestId = uuidv4()

export const handleRequest: HandleRequest = async function (request: HttpRequest): Promise<HttpResponse> {

  let number = Math.floor(Math.random() * 10)

  console.log(number)

  return {
    status: 200,
    headers: { "content-type": "text/plain" },
    body: JSON.stringify(number)
  }

}

[ThorstenHans]

I've tried the following, which also results in same values being returned for every execution:

let number = Math.floor(Math.random() * 10)

export const handleRequest: HandleRequest = async function (request: HttpRequest): Promise<HttpResponse> {
  const requestId = uuidv4()
  return {
    status: 200,
    headers: { "content-type": "text/plain" },
    body: JSON.stringify({ id: requestId, n: number})
  }
}

Even when I declare a variable outside the handler (either using Math.floor(Math.random() * 10) or uuidv4()) that is NOT used at all, it keeps on returning the same values across multiple requests:

let notUsedAtAll = Math.floor(Math.random() * 10) 

export const handleRequest: HandleRequest = async function (request: HttpRequest): Promise<HttpResponse> {
  const requestId = uuidv4()
  let number = Math.floor(Math.random() * 10) 
  return {
    status: 200,
    headers: { "content-type": "text/plain" },
    body: JSON.stringify({ id: requestId, n: number})
  }
}

However, defining a third variable, which is unrelated to some sort of randomness, it works as expected:

let bar = "baz"

export const handleRequest: HandleRequest = async function (request: HttpRequest): Promise<HttpResponse> {
  const requestId = uuidv4()
  let number = Math.floor(Math.random() * 10)

  return {
    status: 200,
    headers: { "content-type": "text/plain" },
    body: JSON.stringify({ id: requestId, n: number, foo: bar})
  }
}

[dicej]

This has the same underlying cause as https://github.com/fermyon/spin-python-sdk/issues/55, and will require the same solution. I'll open a PR later today.