--es-module-specifier-resolution=node not working from v13.0.1

[jaydenseric]

--es-module-specifier-resolution=node is documented for v13.x:

Here is the specific example that works in v13.0.0, but not in v13.0.1 or v13.1.0:

node --experimental-modules --es-module-specifier-resolution=node index

As you can see in the screenshot above, the error is:

internal/modules/cjs/loader.js:895
    throw err;
    ^

Error: Cannot find module '/Users/jaydenseric/Desktop/test/index'
    at Function.Module._resolveFilename (internal/modules/cjs/loader.js:892:15)
    at Function.Module._load (internal/modules/cjs/loader.js:785:27)
    at Function.Module.runMain (internal/modules/cjs/loader.js:1143:12)
    at internal/main/run_main_module.js:16:11 {
  code: 'MODULE_NOT_FOUND',
  requireStack: []
}

[guybedford]

The fix for this would be to ensure that .mjs is included in require.extensions when this flag is enabled.

This is because the CJS loader is doing the main entry resolution, and does not include .mjs resolution by default in its require.extensions list.

A way to get it to work would be to write:

extensions.js

require._extensions['.mjs'] = require._extensions['.js'];

which would allow:

node -r extensions.js --es-module-specifier-resolution=node index

A PR to add this when the flag is set is welcome.

[pd4d10]

@guybedford Thanks for the explanation.

I tried to create a PR to fix this issue: #30574. Please correct me if I understand it wrong.

[dandv]

Has this flag been renamed to experimental-specifier-resolution?

[MylesBorins]

@dandv we have renamed the flag, but we continue to support --es-module-specifier-resolution=node which silently aliases to --experimnetal-specifier-resolution

[bolinfest]

@guybedford when I create extensions.js as you describe and run:

$ cat extensions.js
// https:/nodejs/node/issues/30520
require._extensions['.mjs'] = require._extensions['.js'];
$ node -r extensions.js --es-module-specifier-resolution=node --experimental-modules lib/server/main.js

I get:

internal/modules/cjs/loader.js:979
  throw err;
  ^

Error: Cannot find module 'extensions.js'
Require stack:
- internal/preload
    at Function.Module._resolveFilename (internal/modules/cjs/loader.js:976:15)
    at Function.Module._load (internal/modules/cjs/loader.js:859:27)
    at Module.require (internal/modules/cjs/loader.js:1036:19)
    at Module._preloadModules (internal/modules/cjs/loader.js:1292:12)
    at loadPreloadModules (internal/bootstrap/pre_execution.js:448:5)
    at prepareMainThreadExecution (internal/bootstrap/pre_execution.js:71:3)
    at internal/main/run_main_module.js:7:1 {
  code: 'MODULE_NOT_FOUND',
  requireStack: [ 'internal/preload' ]
}

what am I missing?

[trusktr]

@dandv we have renamed the flag, but we continue to support --es-module-specifier-resolution=node which silently aliases to --experimnetal-specifier-resolution

@MylesBorins I'm in Node 14.8 and trying to use --experimnetal-specifier-resolution gives me

node: bad option: --experimnetal-specifier-resolution

however using --es-module-specifier-resolution=node works.

[ljharb]

@trusktr experimental, not experimnetal?

[trusktr]

Oops, I copy-pasted from above. xD

[trusktr]

Ironically fixing the typo wasn't all. It requires a value: --experimental-specifier-resolution=node

[Santosh-13]

getting this error node: bad option: --es-module-specifier-resolution=node
Node version: 10.19.0

[wojtekmaj]

@Santosh-13 That flag is working on Node 12 and up.

[viT-1]

node v16.13.1, Windows 10

getting this error

Error [ERR_MODULE_NOT_FOUND]: Cannot find module '/C:/[local]/dist-gh-pages/src/common/GreeterUse.js' imported from C:\[local]\dist-gh-pages\src\main.js
    at new NodeError (node:internal/errors:371:5)
    at finalizeResolution (node:internal/modules/esm/resolve:405:11)
    at moduleResolve (node:internal/modules/esm/resolve:932:10)
    at defaultResolve (node:internal/modules/esm/resolve:1044:11)
    at ESMLoader.resolve (node:internal/modules/esm/loader:422:30)
    at ESMLoader.getModuleJob (node:internal/modules/esm/loader:222:40)
    at ModuleWrap.<anonymous> (node:internal/modules/esm/module_job:76:40)
    at link (node:internal/modules/esm/module_job:75:36) {
  code: 'ERR_MODULE_NOT_FOUND'
}

with script
"greetnode": "node --experimental-modules --es-module-specifier-resolution=node ./src/main.js"
and package.json

"type": "module",
"imports": {
	"#common/*": "./src/common/*.js"
},

Now it is the expected behaviour?
How can I run script without errors?

[jaybe78]

@viT-1 I've been getting the same issue for days. I'm also using node v16.13.1

Imports of ES^ module in my app are not resolved

- This thread says that you have to add the '.js' extension to solve the problem but that didn't work for me.

That's my ts.config.server.json

{
  "extends": "./tsconfig.json",
  "compilerOptions": {
    "jsx": "react",
    "baseUrl": ".",
    "module": "esnext",
    "target": "esnext",
    "paths": {
      "~/*": ["*"],
      "@today/shared/*": ["../../node_modules/@today/shared/dist/*"]
    },
    "outDir": ".next/",
    "downlevelIteration": true,
  },
  "include": ["server"]
}

ts-node command

NODE_OPTIONS="--loader ts-node/esm --es-module-specifier-resolution=node" NODE_ENV=development NEXT_PUBLIC_RUNNING_LOCAL_INSTANCE=true ts-node -r tsconfig-paths/register --project ./tsconfig.server.json server/index.mjs --watch 'src/**/*.ts' --ignore 'src/**/*.spec.ts'

fails with

 Cannot find module '/node_modules/@todaytix/shared/config/server/ssl.js' imported from /websites/lt-nytg/server/index.mjs

[viT-1]

@jaybe78 For ts-project I solved aliases 2 years ago.