How to test with Jest and JSDom with Node.js?

[franciscop]

I am trying to test this with Jest (and jsdom), repro here, so I was wondering if someone got it working. The problem I'm having is that JSDom doesn't have TextEncoder/TextDecoder, which according to this guide should be polyfilled like this:

import * as util from "util";

Object.defineProperty(window, "TextEncoder", {
  writable: true,
  value: util.TextEncoder,
});
Object.defineProperty(window, "TextDecoder", {
  writable: true,
  value: util.TextDecoder,
});

However that, for some reason, makes even the simplest test code to fail, like this:

import { openKv } from "@deno/kv";

const db = await openKv("db/kv.db");
await db.set(["hello"], "world");
console.log(await db.get(["hello"]));

The error given is this:

"TypeError: The input must be a Uint8Array, a string, or an ArrayBuffer. Received a value of the type Buffer."

This seems to be some sort of mismatch between Node's util.TextEncoder and what Deno's KV is expecting. I made a repro here:

https://github.com/franciscop/jest-kv-repro

I'm not expecting a "fix" at this point, since it seems the linked Github issue is ongoing and what will eventually fix this, but I open this issue in case others are experiencing this issue and to see if anyone has/will come with a workaround!

[marvinhagemeister]

Took a quick look into this. It seems the problem stems from a difference in napi handling between Node and Deno. The tests in this repository are run with Deno and Deno returns a Uint8Array whereas Node returns a Buffer from atomicWrite():

denokv/npm/src/proto_based.ts

Line 127 in 7d47a7e

const { status, versionstamp } = await this.atomicWrite(write);