fix: only apply to modules

[tpluscode]

This is an attempt to fix #1

I would like to add some tests but this is my first time writing code for an eslint plugins and not sure how to proceed

About the change itself, it find the actual module in the filesystem and applies to rule only when a module exists with one of the extensions

For example, given code like

import foo from './bar.json'

An error will be shown when there is a source file bar.json.js or bar.json.ts but not when it's simply bar.json

I'm not sure if it's correct to also include jsx and tsx in the extensions to check.

[tpluscode]

Ping @jordansexton ?

[jordaaash]

@tpluscode Ah, thanks for the ping, didn't see this. Will review today.

[tpluscode]

Super, thanks

[jordaaash]

Hmm, I don't think we need to actually check for the existence of the file, do we? Importing a file that doesn't exist should be allowed, as long as the required extension (.js) is provided. This should typically get handled by a different eslint rule, which will have a more helpful error description.

I don't know if this is a good idea or not, but a possible fix could be to look for an extension at the end of the filename, and if one is there, look for a corresponding file at that full path. If the file exists, don't enforce the .js extension, but just allow any extension to be imported, and assume the dev knows what they are doing.

[tpluscode]

Aha, I wrote that lengthy reply before realising I misunderstood your point. 😅

Yes, you're right, a file which does no exist should have the .js suffix added which will inevitably lead to a different rule kicking in, or TS compiler error, ot runtime loader error. Not this plugin's concern

There are quite some cases, some of which are not handled by this PR not the base branch. It would really be good to add unit tests but I do not have experience testing eslint rules. Do you?

[tpluscode]

What do you think about my updated code @jordansexton ?

[jordaaash]

I reviewed again, but it looks like the first review wasn't fully addressed.

Looking @ #1, it seems that the problem is that imports of files with explicit extensions (.json, maybe others?) should not have .js extensions added.

Is this right? If so, it seems like the fix could be as simple as checking for a file extension on the import. If it's there, and perhaps if it's not .js/x or .ts/x, we don't do anything with that import. I don't think we care about the actual file, right?

[jordaaash]

Published in v0.1.2! Please let me know if it works well for you, and thank you for working on this!

[tpluscode]

Super, thanks for releasing