[Windows] Failed to run ESM, throwing ERR_UNSUPPORTED_ESM_URL_SCHEME

[compulim]

Description

When running node-dev ./index.mjs on Windows, Node.js (14.* and 16.*) will throw ERR_UNSUPPORTED_ESM_URL_SCHEME. It works on Ubuntu.

According to doc, I renamed to .mjs and I believe this is the only change needed for ESM.

When using ESModule syntax and .mjs files, node-dev will automatically use a loader to know which files to watch.

Repro steps

I created a repo for bug repro, with GitHub Actions configured to run on both Ubuntu and Windows.

Error [ERR_UNSUPPORTED_ESM_URL_SCHEME]: Only file and data URLs are supported by the default ESM loader. On Windows, absolute paths must be valid file:// URLs. Received protocol 'd:'
    at Loader.defaultResolve [as _resolve] (internal/modules/esm/resolve.js:791:11)
    at Loader.resolve (internal/modules/esm/loader.js:89:40)
    at Loader.getModuleJob (internal/modules/esm/loader.js:242:28)
    at Loader.import (internal/modules/esm/loader.js:177:28)
    at internal/process/esm_loader.js:57:31
    at initializeLoader (internal/process/esm_loader.js:62:5)
    at Object.loadESM (internal/process/esm_loader.js:67:11)
    at runMainESM (internal/modules/run_main.js:47:31)
    at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:73:5)
    at internal/main/run_main_module.js:17:47 {
  code: 'ERR_UNSUPPORTED_ESM_URL_SCHEME'
}

The workflow runs the following steps:

1. Install Node.js (12.x, 14.x, 16.x)
2. npm install (with node-dev@^7.0.0)
3. npm start
   • It runs node-dev ./index.mjs
4. When index.mjs is loaded, it import hello from './hello.mjs'

To repro without a Windows box, please fork the repo and see the result of GitHub Actions. 😉

Instead of npm start, I also tried the followings and got same error:

• node_modules\.bin\node-dev .
• node_modules\.bin\node-dev ./index.mjs

[bjornstar]

According to nodejs/node#31710, we should use pathToFileUrl.

It's probably a good idea to add a windows build in our github actions.

[bjornstar]

I've added windows to the tests and can see the ESM tests are failing. I'll take a look at it when I get some more time.

[kherock]

I believe this is resolved by #279. Using fileURLToPath in the ESM loader seems to have fixed those tests on Windows

[bjornstar]

Tests are looking great, thanks @kherock. I'll go ahead and cut a release. Let's call this fixed in v7.4.0