Different behaviour when using Bun's runtime

[azizramdan]

Describe the bug

import { existsSync } from 'node:fs'
import { $ } from 'bun'

existsSync('foo')
$`echo "foo"`

That script is valid when using bunx eslint . but get error when force to use Bun's runtime bunx --bun eslint .

╭─velo@velotek ~/projects/eslint-config-bun ‹main●› 
╰─$ bunx eslint .
╭─velo@velotek ~/projects/eslint-config-bun ‹main› 
╰─$ bunx --bun eslint .

/home/velo/projects/eslint-config-bun/index.ts
  2:1  error  Expected "bun" to come before "node:fs"  perfectionist/sort-imports

✖ 1 problem (1 error, 0 warnings)
  1 error and 0 warnings potentially fixable with the `--fix` option.

This becomes inconsistent between vscode auto format and cli command.

References:

• https://bun.sh/docs/cli/bunx#shebangs

Reproduction

https://github.com/azizramdan/eslint-config-bun

System Info

System:
    OS: Linux 6.12 EndeavourOS
    CPU: (4) x64 Intel(R) Core(TM) i7-7600U CPU @ 2.80GHz
    Memory: 3.66 GB / 15.51 GB
    Container: Yes
    Shell: 5.9 - /usr/bin/zsh
  Binaries:
    Node: 22.13.1 - ~/.nvm/versions/node/v22.13.1/bin/node
    npm: 10.9.2 - ~/.nvm/versions/node/v22.13.1/bin/npm
    bun: 1.2.2 - ~/.bun/bin/bun

Used Package Manager

bun

Validations

• Follow our Code of Conduct
• Read the Contributing Guide.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Check that this is a concrete bug. For Q&A, please open a GitHub Discussion instead.
• The provided reproduction is a minimal reproducible of the bug.

Contributions

• I am willing to submit a PR to fix this issue
• I am willing to submit a PR with failing tests (actually just go ahead and do it, thanks!)

[SukkaW]

I suspect perfectionist/sort-imports uses module.builtinModules or module.isBuiltin. On Node.js, bun is treated as an external module, but on Bun (--bunx enforces code to be run on Bun even with a #!/usr/bin/env node shebang) bun is a built-in module.

[azizramdan]

You are right, perfectionist/sort-imports have config to choose environment https://perfectionist.dev/rules/sort-imports.html#environment

How to override antfu's config only for environment in perfectionist/sort-imports?

Currently, I am using the following approach but i don't think this is right way

import antfu, { perfectionist } from '@antfu/eslint-config'

const perfectionistRules = await perfectionist()

export default antfu({
  rules: {
    'perfectionist/sort-imports': [
      'error',
      {
        ...perfectionistRules[0].rules['perfectionist/sort-imports'][1],
        environment: 'bun',
      },
    ],
  },
})