jest 27.5.1

[Darek]

lowdb 1.0 worked fine with jest, but 3.0 does not seem to work with jest 27.5.1. Does anyone know how to fix it? Thx

My sample 3.0 index.test.ts code:

import { Low, JSONFile } from 'lowdb'
it('test file upload', async () => { 
  const adapter = new JSONFile("db.json")  
  const db = new Low(adapter)  
  console.log("Test:", db)  
})

using jest 27.5.1, I get the following error:

({"Object.<anonymous>":function(module,exports,require,__dirname,__filename,jest){export * from './adapters/JSONFile.js';

I have tried the following babel.config.js:

module.exports = {
    presets: [
      ['@babel/preset-env', {targets: {node: 'current'}}],
      '@babel/preset-typescript',
    ],
  };

[Sander]

Struggling with the same.

Especially lowdb 3.0.0 (which is purely esm) in combination with jest.
I have tried running it with yarn node --experimental-vm-modules $(yarn bin jest) on node 16.x

[Darek]

I have switched to Playwright and it works fine.

low.spec.js

import { test, expect } from '@playwright/test';
import { Low, JSONFile } from 'lowdb'

test('lowdb test', async () => {
  const adapter = new JSONFile("./db.json");
  const db = new Low(adapter);

  await db.read()
  expect(db.data.users).toBeTruthy();
});

[Sander]

Thanks @Bidek56 , I'm gonna give that a try!

[Kevin Rodríguez]

Playwright is neither working.

[Darek]

This simple example using Node 19.3 and this package.json works fine for me:

{
  "name": "lowdb-test",
  "version": "1.0.0",
  "description": "Test of lowdb and jest",
  "type": "module",
  "scripts": {
    "test": "playwright test",
    "build": "rm -rf dist/ && tsc"
  },
  "author": "Darek",
  "license": "ISC",
  "devDependencies": {
    "@playwright/test": "^1.29.1",
    "@types/lowdb": "^1.0.11",
    "playwright": "^1.29.1",
    "typescript": "^4.9.4"
  },
  "dependencies": {
    "lowdb": "5.0.5"
  }
}

low.spec.js

import { test, expect } from '@playwright/test';
import { Low } from 'lowdb'
import { JSONFile } from 'lowdb/node'

test('lowdb test', async () => {
  const adapter = new JSONFile("./db.json");
  const db = new Low(adapter);

  await db.read()
  expect(db.data.users).toBeTruthy();
});