Path Alias Helpers

[theutz]

This might be beyond the scope of what you're trying to do with import-tree, but here's a thought.

When you're doing module imports in TypeScript, you can define import aliases to reference internal paths as if they were modules. So, if you have a project structure like this:

my-app/
├─ node_modules/
├─ public/
│  ├─ favicon.ico
│  ├─ index.html
│  ├─ robots.txt
├─ src/
│  ├─ things/
│  │  ├─ stuff/
│  │  │  ├─ index.js
│  ├─ index.css
│  ├─ index.js
├─ .gitignore
├─ package.json
├─ README.md

You can define a module alias like @stuff that maps to src/things, and it uses that as the base path for imports.

I wonder if we could/should do something similar with import-tree to help people create path construction helpers. So that you could have a structure like:

flake.nix
modules/
├─ aspects/
│  ├─ gui/
│  │  ├─ niri/
│  │  │  ├─ niri.nix
│  │  │  ├─ config.kdl

And you could define an "alias" that put a helper in the top-level args of the same name, defined like this:

{
  outputs = import-tree.withAliases { gui = "aspects/gui"; } ./modules;
}

And then invoked like this:

{ gui, ... }:
{
  den.aspects.niri = {
    homeManager.xdg.configFile.source = gui ./niri/config.kdl;
}

[vic]

Hey @theutz,

I think that adding _module.args via import-tree is a bit out of scope, given that it is agnostic to how you invoke it (it can be used with/without modules). However here are some tips that can help with the use-case you mention:

• Since you have inputs.import-tree, you can have a dendritic module whose only responsability
  is to add the aliases you want to have available at module.args.

  No need to do this at flake outputs function level.

• Each import-tree api returns a new import-tree you can assign (or pass as module args):

  _module.args.gui = import-tree.filter (hasPrefix "aspects/gui")

  See the advanced API to see how you can add filters or predefined paths to it.

• By the default calling an import-tree object will return a list of modules (for use at imports)
  If you actually want a list of files see the .leafs and .files functions

[theutz]

Oh, that's awesome! I'll definitely use some combination of those first two. Thanks for the tip!