Clarify monorepo setup where there is a base file

[maelp]

Clear and concise description of the problem

I want to have a root eslint config, and then in apps/libs, be able to set the "type: lib", but when I try this it fails, and it's not obvious from the doc how I should do it?

import config from "../../eslint.config.mjs";

export default config.override({
  type: "app",
});

Suggested solution

Add it to the documentation

Alternative

No response

Additional context

No response

Validations

• [x] Follow our Code of Conduct
• [x] Read the Contributing Guide.
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[imbytecat]

Same question

[kvoon3]

I noticed that type: 'lib' and type: 'app' only differ by one rule: ts/explicit-function-return-type.

https://github.com/antfu/eslint-config/blob/56262ef7962ce310d29348060d8941d420f410fc/src/configs/typescript.ts#L165

In fact, we could override this rule

// @ts-check

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

export default antfu(
  {
    type: 'app',
  },
  {
    files: ['./your-lib-path/**/*.?([cm])ts', './your-lib-path/**/*.?([cm])tsx'],
    rules: {
      'ts/explicit-function-return-type': 'on',
    },
  },
)

or override antfu/typescript/rules

// @ts-check

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

export default antfu(
  {
    type: 'app',
  },
)
  .override(
    'antfu/typescript/rules',
    {
      ignores: ['./your-lib-path/**/*'],
    },
  )
  .append(typescript({
    type: 'lib',
  }).then(configs =>
    configs
      .filter(c => c.name === 'antfu/typescript/rules')
      .map((c) => {
        if (c.name)
          c.name = `your-lib-name/typescript/rules`

        if (c.files)
          c.files = ['./your-lib-path/**/*.?([cm])ts', './your-lib-path/**/*.?([cm])tsx']

        return c
      }),
  ))