Thoughts around supporting Node.js subpath imports

[thetutlage]

The subpath imports are the aliases one can use with the project to avoid typing relative paths during imports.

Back story

• So, instead of typing:

  import foo from './src/foo.js'

• You can define a subpath import alias inside the package.json file

  {
    "imports": {
      "#src/*": "./src/*.js"
    }
  }

• And then write imports as follows

  import foo from '#src/foo'

The tsc behavior

Now there are a few issues in order to make it work.

• First, once I compile my TypeScript code to JavaScript, it is written inside a sub-directory called build and the subpath import alias becomes invalid. To overcome this issue, I define the import alias to look inside the build directory instead.

  {
    "imports": {
      "#src/*": "./build/src/*.js"
    }
  }

• Luckily with Typescript >= 4.7, I have been able to compile this code using tsc. Even though the build directory does not exists pre-build, the TypeScript compiler is smartly able to resolve these imports.

The ts-node behavior

However, now ts-node is not able to find the imports where the alias is pointing inside the ./build directory (because there is no build directory).

Now, the main question is, are there any on-going discussions or ideas on how to make subpath imports work when they are pointing within the build directory, because tsc is able to handle them.

I am using node --loader=ts-node/esm to execute the file

[cspotcode]

I believe that this issue can be renamed to something like this: Support resolving from outDir to srcDir Because that's really what we're talking about. We do support subpath imports. The problem is that we don't attempt to jump from the outDir back to the srcDir when resolving modules. Does this assessment sound accurate to you?

…

On Fri, Jun 17, 2022, 4:55 AM Harminder Virk ***@***.***> wrote: The subpath imports <https://nodejs.org/api/packages.html#imports> are the aliases one can use with the project to avoid typing relative paths during imports. Back story - So, instead of typing: import foo from './src/foo.js' - You can define a subpath import alias inside the package.json file { "imports": { "#src/*": "./src/*.js" } } - And then write imports as follows import foo from '#src/foo' The tsc behavior Now there are a few issues in order to make it work. - First, once I compile my TypeScript code to JavaScript, it is written inside a sub-directory called build and the subpath import alias becomes invalid. To overcome this issue, I define the import alias to look inside the build directory instead. { "imports": { "#src/*": "./build/src/*.js" } } - Luckily with Typescript >= 4.7, I have been able to compile this code using tsc. Even though the build directory does not exists pre-build, the TypeScript compiler is smartly able to resolve these imports. The ts-node behavior However, now ts-node is not able to find the imports where the alias is pointing inside the ./build directory (because there is no build directory). Now, the main question is, are there any on-going discussions or ideas on how to make subpath imports work when they are pointing within the build directory, because tsc is able to handle them. — Reply to this email directly, view it on GitHub <#1799>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAC35ODMHPZQM646KT3IP3DVPQ4OXANCNFSM5ZBSOG7Q> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[thetutlage]

I am not deeply aware of the features ts-node supports. So apologies for that :)

Does this assessment sound accurate to you?

Yup, seems like a better explanation

[cspotcode]

No problem, I ask to determine the work that would be required to enable what you want to do.

package.json has a field "publishConfig" which can be used to overwrite package.json fields for publication. This allows you to use different values in local development and when publishing. I haven't tested this, but you might try using "publishConfig" to have two different "imports" objects: one for local development, pointing to your src directory, and another for publication, pointing to your build directory.

I haven't tested this so I will not be able to provide further guidance. But if you research this option, you might consider sharing your results here to help other users of ts-node. Or perhaps someone else has already done this, in which case you might find their posts by searching around. I'm not sure.

[thetutlage]

I didn't find anything related to imports in relation with publishConfig. But yes, I can tweak my workflow to make it work somehow.

However, I always wanted to understand if this is something you guys think worth supporting or addressing within the tool or not. If its not, then I am happy tweaking my workflow

[cspotcode]

Yeah, I've thought about it, and it's planned. I think it is mentioned in the pinned "Epics" issue, somewhere. Probably in the one about resolver.

[thetutlage]

Cool. Will look forward to it. Thanks for your time :)