import {WebMidi} from "webmidi" not working in node

[abulka]

Description
import {WebMidi} from "webmidi" is not working in node, despite what the official documentation says. I get an error about Named export 'WebMidi' not found.

To reproduce, simply create a new directory

• npm i webmidi
• add "type": "module", to the package.json
• create a file main.js with

import {WebMidi} from "webmidi";

run with node main.js and I get

$ node main.js 
file:///private/tmp/wwww/main.js:1
import {WebMidi} from "webmidi";
        ^^^^^^^
SyntaxError: Named export 'WebMidi' not found. The requested module 'webmidi' is a CommonJS module, which may not support all module.exports as named exports.
CommonJS modules can always be imported via the default export, for example using:

import pkg from 'webmidi';
const {WebMidi} = pkg;

my package.json is

{
  "type": "module",
  "dependencies": {
    "webmidi": "^3.0.19"
  }
}

Environment:

• Library version ESM
• Node.js version v16.13.1
• Language JavaScript
• Mac Os Monterey, Intel.

Seems also to be related to issues #89 and #82

• Also tried using node v16.14.2 on a different machine, an M1 mac - same problem.
• Also tried in a Ubuntu 22.04 VM using node v12.22.9 - same problem.
• Renaming from main.js to main.mjs does not change the error.

Details
Add any other information, context or details that could help track down the problem.

Trying an alternative import syntax

import * as WebMidi from "webmidi"

instead changes the error to:

$ node main.js 
(node:53862) Warning: To load an ES module, set "type": "module" in the package.json or use the .mjs extension.
(Use `node --trace-warnings ...` to show where the warning was created)
/private/tmp/wwww/node_modules/webmidi/dist/esm/webmidi.esm.min.js:395
 */const u=new class extends ................. WebMidi};
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            

SyntaxError: Unexpected token 'export'
    at Object.compileFunction (node:vm:352:18)
    at wrapSafe (node:internal/modules/cjs/loader:1031:15)
    at Module._compile (node:internal/modules/cjs/loader:1065:27)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1153:10)
    at Module.load (node:internal/modules/cjs/loader:981:32)
    at Function.Module._load (node:internal/modules/cjs/loader:822:12)
    at ModuleWrap.<anonymous> (node:internal/modules/esm/translators:190:29)
    at ModuleJob.run (node:internal/modules/esm/module_job:185:25)
    at async Promise.all (index 0)
    at async ESMLoader.import (node:internal/modules/esm/loader:281:24)

Taking node's advice and changing the import to

import pkg from 'webmidi';
const { WebMidi } = pkg;

fails with the same Warning: To load an ES module, set "type": "module" in the package.json or use the .mjs extension.... SyntaxError: Unexpected token 'export' error.

Discussion

Interestingly, the simple module example given in #252

import {WebMidi} from "webmidi";

WebMidi
  .enable()
  .then(onEnabled)
  .catch(err => console.log(err));

function onEnabled() {
  console.log('WebMIDI enabled!');
  const output = WebMidi.outputs[0]
  const channel = output.channels[1];
  console.log(channel);
  channel.playNote('C5', {duration: 5000})
}

supposedly works for @djipco - but I can't get past the import problem mentioned above.

[djipco]

You are very right. As I explain here, PR #254 introduced a regression problem that prevented Node.js from correctly identifying the type of module to load (ESM or CommonJS)

The problem has been fixed in release 3.0.20 and is now available on NPM.

This highlights the need for plaftorm-targeted unit tests going forward. Thanks a lot for reporting.