Bun.build: Mark everything but one extension as external

[nobkd]

Hey, I wanted to use bun for minifying css files. I want css imports to be minified, but ignore e.g. url("img.png") altogether. In conclusion: I want to mark everything but css as external.

I tried something like glob negation, but it didn't work (though I'm not even sure if this is correct glob syntax).
Bun.build({ entrypoints: [someCssFile], ..., external: ['*.[!css]'] }

Does anyone know of a way to make everything external but a single file type, without manually listing all the file extensions?

Cross post with discord: https://discord.com/channels/876711213126520882/1333325554145034241

[nobkd]

Got it working with a plugin (on Bun v1.2):

Bun.build({
  entrypoints: ['mycssfile.css'],
  minify: true,
  plugins: [{
    name: 'mark non-css files as external',
    setup(build) {
      build.onResolve({ filter: /.*/, namespace: 'file' }, args => {
        // Mark non-css files external. Might need some more handling later on?
        if (args.kind === 'internal') return { ...args, external: true }
      })
    },
  }],
})