Bug/Feature Request: Better Error for Modules Requiring File Extension

[merlinstardust]

• Version: v16.0.0
• Platform: Mac
• Subsystem:

What steps will reproduce the bug?

1. Start a new project with "type": "module" in package.json
2. Create two files (fileA.js and fileB.js)
3. Relative import one file into the other (import fileB from './fileB';)
4. Run the file with the import (node fileA.js)

How often does it reproduce? Is there a required condition?

Import without a file extension or the flag

What is the expected behavior?

Gives a vague error about not finding the module

What do you see instead?

Give a more specific error that file extensions need to be added in imports (import fileB from './fileB.js'; and/or that node should be run with --experimental-specifier-resolution=node

Additional Info

I'm asking for this because I spent the last two hours trying to debug the below errors in my project.

Any documentation/tutorials should be updated with a strongly emphasized note about this as well as it is not obvious at all.

Error [ERR_MODULE_NOT_FOUND]: Cannot find module '/Users/merlin/code/inclusion-bot/index.js' imported from /Users/merlin/code/inclusion-bot/
    at new NodeError (node:internal/errors:363:5)
    at finalizeResolution (node:internal/modules/esm/resolve:296:11)
    at moduleResolve (node:internal/modules/esm/resolve:742:10)
    at Loader.defaultResolve [as _resolve] (node:internal/modules/esm/resolve:853:11)
    at Loader.resolve (node:internal/modules/esm/loader:89:40)
    at Loader.getModuleJob (node:internal/modules/esm/loader:242:28)
    at Loader.import (node:internal/modules/esm/loader:177:28)
    at node:internal/modules/run_main:50:28
    at Object.loadESM (node:internal/process/esm_loader:68:11) {
  code: 'ERR_MODULE_NOT_FOUND'
}

Error [ERR_MODULE_NOT_FOUND]: Cannot find module '/Users/merlin/code/ib2/events' imported from /Users/merlin/code/ib2/index.js
Did you mean to import ../events.js?
    at new NodeError (node:internal/errors:363:5)
    at finalizeResolution (node:internal/modules/esm/resolve:307:11)
    at moduleResolve (node:internal/modules/esm/resolve:742:10)
    at Loader.defaultResolve [as _resolve] (node:internal/modules/esm/resolve:853:11)
    at Loader.resolve (node:internal/modules/esm/loader:89:40)
    at Loader.getModuleJob (node:internal/modules/esm/loader:242:28)
    at ModuleWrap.<anonymous> (node:internal/modules/esm/module_job:73:40)
    at link (node:internal/modules/esm/module_job:72:36) {
  code: 'ERR_MODULE_NOT_FOUND'
}

[GeoffreyBooth]

The error you’re asking for is already in your example:

Error [ERR_MODULE_NOT_FOUND]: Cannot find module '/Users/merlin/code/ib2/events' imported from /Users/merlin/code/ib2/index.js
Did you mean to import ../events.js?

[merlinstardust]

I'm aware of what the error says.

The error is not clear.

I'm in the root of the project and importing ./events

Suggesting that I import one level up makes no sense. Furthermore when I did that, which obviously didn't work, it gives the same error.

And the error does not specify that the extension is required. This is what I am asking for. Offer more info what might be wrong and how to fix it.

Most tutorials do not include file extensions and as evidence by the issue I linked from, many people do not expect to use the extension.

So please add more info and possible solutions to the error message

[bitsapien]

Would just saying, Did you forget to put an extension - import ./events.js be a good enough help message ?

[merlinstardust]

That shouldn't be the only solution offered. The --experimental-specifier-resolution should also be mentioned as an option.

Additionally it would be nice to provide justification as to why imports require file extensions now.

Most guides, readmes, and code samples do not use the file extension. As such, many people expect to not need a file extension so a justification should be provided.