Question: edge case with some undefined default exports?

[richardeschloss]

I have a library that is attempting to import from socket.io. Here is the related issue: https://github.com/richardeschloss/nuxt-socket-io/issues/278

When I attempt to import and the run nuxt3, I encounter the following error:

"Cannot start nuxt: Cannot destructure property 'Server' of '_engineIo.default' as it is undefined"
at node_modules/engine.io/wrapper.mjs:3:9
at jiti (node_modules/jiti/dist/jiti.js:1:247502)

Inside of wrapper.mjs, the first line seems to be the issue because ./build/engine.io.js does not seem to export a default:

import lib from "./build/engine.io.js"; // released, broken, gets installed with socket.io 4.5.3
// import * as lib from "./build/engine.io.js"; // works

My question is, I'm able to run the following successfully; i.e., inside wrapper, I can console.log(lib):

node node_modules/engine.io/wrapper.mjs

But when I run nuxi dev, I encounter the error. My follow up question is how does my command succeed when there appears to be no default? How can I get Nuxt to overcome this missing default?

Fwiw, I'm on Node 16 (LTS), nuxt3.0.0-rc.12-27768618.05fd222, my nuxt config is pretty minimal, and package type set to "module" in package.json

[richardeschloss]

Some more context: The wrapper I'm referencing follows the conventions listed here: https://nodejs.org/docs/latest-v16.x/api/packages.html#approach-1-use-an-es-module-wrapper

// ./node_modules/pkg/package.json
{
  "type": "module",
  "exports": {
    "import": "./wrapper.mjs",
    "require": "./index.cjs"
  }
}

// ./node_modules/pkg/index.cjs
exports.name = 'value';  // <-- In the CJS file, there's no "default" export but... (see below)

// ./node_modules/pkg/wrapper.mjs
import cjsModule from './index.cjs'; // NodeJS imports the CJS module wholly without issue; equivalent to `import * as cjsModule from './index.cjs';
export const name = cjsModule.name;

[Thy3634]

I think the question is:
jiti modify A.cjs, and A require B.cjs. And A has been converted to import pkg from B

B.cjs exports = { a: ..., b: ... }, If it converted, B.mjs would be export default {a: ..., b: ...}.
So far, it's OK.

But actually B has a B.mjs:

import lib from './B.js' // this B.js has not been converted
export const { a: ..., b: ...} = lib

[richardeschloss]

Should the conversion be something like?:

import * as pkg from "B"
const dfltExport = pkg.default || pkg // This way we always get a default in .mjs
export dfltExport