[Feature]: named config and positive filter

[xc2]

What problem does this feature solve?

To build with specific lib configs (aka environment) only. For example, a library has 5 lib configs:

1. esm build with modern syntax
2. cjs build with modern syntax
3. esm build with legacy syntax
4. dts build
5. other package files

and only 1 or 2 is useful for development/test. we can filter out the others

What does the proposed API look like?

Rslib Config

{
  "lib": [
    { "name": "x", ... },
    { "name": "y", ... },
    { "name": "z", ... },
    { ... },
    { ... },
  ]
}

Rslib CLI

--only x --only y
--only x,y

Rsbuild

createRsbuild({
  rsbuildConfig: {
    environments: {
      x: { ... },
      y: { ... },
      z: { ... },
      esm0: { ... },
      esm1: { ... },
    }
  },
  environment: args.only
}

[fi3ework]

Nice suggestion. Today, we are adding similar functionality to this pull request. It will work like rslib mf dev --lib a --lib b, and the --lib parameter can be expanded to the build command, as described here.

Currently, Rslib is based on Rsbuild environments, which follow a default naming convention. You can find the code here. If there is only one ESM component, it will be named esm. If there are multiple environments, they will be named esm1, esm2, and so on. We initially chose format as the prefix for convenience in testing, but I think we should reconsider whether this is a good naming convention (it seems acceptable so far).

Using "name" as an explicit way to name environments is a good idea. My only concern is that this field is quite common while may only be necessary in specific situations (just personal feeling).

[xc2]

My only concern is that this field is quite common while may only be necessary in specific situations (just personal feeling).

neutral alternatives:

• "id"
• Record<string, LibConfig>

[Timeless0911]

filter is supported now, we should work on name field now.