ESM Module: ERR_INVALID_PROTOCOL

[lukaszewczak]

• Version: v8.5.0
• Platform: Windows 64-bit
• Subsystem: Es module

Hi,

First of all, I want to thank you for your wonderful work!

I try to run simple example using es module (which @MylesBorins share on Twitter), but I stuck on error.

At first I updated today to node version 8.5.0. and write this two simple files

helper.mjs

export function helperMethod() {
    console.log(`I'm helping!`);
}

index.mjs

import {helperMethod} from './helper.mjs';

helperMethod();

and after running command node --experimental-modules index.mjs, I receive error

F:\Projekty\Learn\nodejs-workshop>node --experimental-modules index.mjs
(node:7036) ExperimentalWarning: The ESM module loader is experimental.
{ AssertionError [ERR_ASSERTION]: An invalid error message key was used: ERR_INVALID_PROTOCOL.
    at message (internal/errors.js:70:3)
    at NodeError (internal/errors.js:29:13)
    at resolveRequestUrl (internal/loader/resolveRequestUrl.js:84:11)
    at Loader.import (internal/loader/Loader.js:61:27)
    at Function.Module._load (module.js:462:27)
    at Function.Module.runMain (module.js:665:10)
    at startup (bootstrap_node.js:201:16)
    at bootstrap_node.js:626:3
  generatedMessage: false,
  name: 'AssertionError [ERR_ASSERTION]',
  code: 'ERR_ASSERTION',
  actual: undefined,
  expected: true,
  operator: '==' }

Additionally it looks like some problem with NodeErorr module.

I updated node source code and build it locally to test this behavior, and then I receive this error when I try to run this two files

F:\Projekty\Learn\node>cd Release

F:\Projekty\Learn\node\Release>node -e "console.log('Hello from Node.js', process.version)"
Hello from Node.js v9.0.0-pre

F:\Projekty\Learn\node\Release>node --experimental-modules index.mjs
(node:18136) ExperimentalWarning: The ESM module loader is experimental.
{ Error [ERR_INVALID_PROTOCOL]: Protocol "f:" not supported. Expected "file:"
    at resolveRequestUrl (internal/loader/resolveRequestUrl.js:84:11)
    at Loader.import (internal/loader/Loader.js:61:27)
    at Function.Module._load (module.js:438:27)
    at Function.Module.runMain (module.js:641:10)
    at startup (bootstrap_node.js:201:16)
    at bootstrap_node.js:626:3 [Symbol(code)]: 'ERR_INVALID_PROTOCOL' }

And this how specifier, baseUrl and url object looks like in resolveRequestURl.js module, after I put some console.log.

resolveRequestURl.js

  const baseURL = normalizeBaseURL(baseURLOrString);
  console.log(`log: ${specifier}, ${baseURL}`);
  let url = search(specifier, baseURL);
  console.log(url);

  if (url.protocol !== 'file:') {
    throw new errors.Error('ERR_INVALID_PROTOCOL', url.protocol, 'file:');
  }

result

log: F:\Projekty\Learn\node\Release\index.mjs, file:///F:/Projekty/Learn/node/Release/
URL {
  href: 'f:\\Projekty\\Learn\\node\\Release\\index.mjs',
  origin: 'null',
  protocol: 'f:',
  username: '',
  password: '',
  host: '',
  hostname: '',
  port: '',
  pathname: '\\Projekty\\Learn\\node\\Release\\index.mjs',
  search: '',
  searchParams: URLSearchParams {},
  hash: '' }

[beardedtim]

Is this related to this issue?

[Arnavion]

Linux:

> const { resolve } = process.binding('module_wrap'); resolve('/home/arnavion/main.mjs', 'file:///home/')

URL {
  href: 'file:///home/arnavion/main.mjs',
  origin: 'null',
  protocol: 'file:',
  username: '',
  password: '',
  host: '',
  hostname: '',
  port: '',
  pathname: '/home/arnavion/main.mjs',
  search: '',
  searchParams: URLSearchParams {},
  hash: '' }

Windows:

> const { resolve } = process.binding('module_wrap'); resolve('C:\\main.mjs', 'file://c/')

URL {
  href: 'c:\\main.mjs',
  origin: 'null',
  protocol: 'c:',
  username: '',
  password: '',
  host: '',
  hostname: '',
  port: '',
  pathname: '\\main.mjs',
  search: '',
  searchParams: URLSearchParams {},
  hash: '' }

Perhaps the code thinks the leading C: is a URL protocol so doesn't convert it to a file: URL.

[jdalton]

PR at #15389.

[XHMM]

Hi， I still encoutered this error.The following is my test :
node v8.5.0
npm v5.4.2

---

add.mjs

export function add(a,b) {
  return a+b;
}

test.mjs

import {add} from './add.mjs'
console.log(add(1,2));

run node --experimental-modules test.mjs

output

(node:16016) ExperimentalWarning: The ESM module loader is experimental.
{ AssertionError [ERR_ASSERTION]: An invalid error message key was used: ERR_INVALID_PROTOCOL.
    at message (internal/errors.js:70:3)
    at NodeError (internal/errors.js:29:13)
    at resolveRequestUrl (internal/loader/resolveRequestUrl.js:84:11)
    at Loader.import (internal/loader/Loader.js:61:27)
    at Function.Module._load (module.js:462:27)
    at Function.Module.runMain (module.js:665:10)
    at startup (bootstrap_node.js:201:16)
    at bootstrap_node.js:626:3
  generatedMessage: false,
  name: 'AssertionError [ERR_ASSERTION]',
  code: 'ERR_ASSERTION',
  actual: undefined,
  expected: true,
  operator: '==' }

---

I am confused , can someone tell me the reason ? Thanks in addvanced.

[amitport]

@XHMM, 8.5.0 has this issue. You need to wait for a new release.

[XHMM]

@amitport Thanks for reminding , I just thought this has been fixed .