[no-type-alias] Readonly<[A, B]> should be allowed same as readonly [A, B] by allowTupleTypes

[JounQin]

• I have tried restarting my IDE and the issue persists.
• I have updated to the latest version of the packages.
• I have read the FAQ and my problem is not listed.

Repro

{
  "rules": {
    "@typescript-eslint/no-type-alias": [
      2,
      {
        "allowAliases": "in-unions-and-intersections",
        "allowCallbacks": "always",
        "allowConditionalTypes": "always",
        "allowConstructors": "always",
        "allowLiterals": "in-unions-and-intersections",
        "allowMappedTypes": "always",
        "allowTupleTypes": "always"
      }
    ]
  }
}

import type { JSXElement, JSXFragment } from '@babel/types'

// if tuple types are used as generic, it should be allowed
export type JsxTypes = Readonly<[JSXElement['type'], JSXFragment['type']]>

export type JsxType = JsxTypes[number] // any option to allow this?

Expected Result

No error

Actual Result

not allowed

Additional Info

Versions

package	version
@typescript-eslint/eslint-plugin	4.17.0
@typescript-eslint/parser	4.17.0
TypeScript	4.2.3
ESLint	7.21.0
node	14.16.0

[JounQin]

I think we can add a new option allowGeneric for the first case?

[JounQin]

Actually I just want to disable codes like type A = B, but it's not easy to set for now.

[JounQin]

@bradzacher Hi, do you have any idea to help? I'd like to work on it if there is a good option/way to handle type A = B only.

[bradzacher]

in type A = B, B is a TSTypeReference which falls under allowAliases.

[JounQin]

@bradzacher I mean disallow type A = B only but allow any other usages.

[bradzacher]

there is no mechanism to disable just type reference aliases.

All of the options and what they apply to are listed in the docs

You could likely build a selector to match this and block it via no-restricted-syntax - https://github.com/typescript-eslint/typescript-eslint/blob/master/docs/getting-started/linting/FAQ.md#how-can-i-ban-specific-language-feature

[JounQin]

Thanks, I'll give that a try.

[JounQin]

@bradzacher Thanks a lot, I finished up by:

{
  'no-restricted-syntax': [
    2,
    {
      selector:
        'TSTypeAliasDeclaration > .typeAnnotation[type=/^(TS.*Keyword|TSTypeReference)$/]:not(:has(TSTypeParameterInstantiation)):not(:has(TSQualifiedName))',
      message:
        'Type alias references simple `Ts*Keyword`s or `TSTypeReference` only is not allowed',
    },
  ],
}

Is it worth to add into no-type-alias's documentation?

[bradzacher]

This can now be allowed broadly via the option added in #3865