feat: update to utilise the new ESLint flat file config.

[maclong9]

Is your feature request related to a problem? Please describe.

This cli tool is great for setting up a project with a good base stack really quickly, only snag in productivity at the moment is requiring the conversion of .eslintrc.json to the new eslint.config.{m|c}js format.

Describe the solution you'd like to see

Update the standard configuration to utilise the new flat file configuration.

Describe alternate solutions

Write a codemod script that can be run by developers who want to use the new format.

Additional information

No response

[juliusmarminge]

only snag in productivity at the moment is requiring the conversion of .eslintrc.json to the new eslint.config.{m|c}js format.

This is a bit of a stretch given a lot (probably a large majority actually) still doesn't support FlatConfig natively

[juliusmarminge]

Reviving this now that v8 has reached EOL.

Next 15 has official support for v9 (https://nextjs.org/blog/next-15-rc2#eslint-9-support) and also flat config (https://x.com/feedthejim/status/1846502242590802180)

If we assume Next 15 will be marked stable next week at NextConf we could start preparing a PR with the necessary bumps

[TheCukitoDev]

Now Next.js 15 is stable...

[dmurvihill]

Getting deprecation warnings from eslint 8 now.

npm warn deprecated [email protected]: This version is no longer supported. Please see https://eslint.org/version-support for other options.

[MGSimard]

Any news on this? Doing manual migrations to eslint.config.mjs is getting bothersome

[juliusmarminge]

Any news on this? Doing manual migrations to eslint.config.mjs is getting bothersome

Feel free to submit a PR !

[MGSimard]

Any news on this? Doing manual migrations to eslint.config.mjs is getting bothersome

Feel free to submit a PR !

Spent a couple hours catching up on all this stuff today, first time looking at monorepos. On CLI build I'm running into "tty" dynamic requires errors when adding imports to extras/config/_eslint.js necessary for the flat config (such as FlatCompat and plugin imports), so it's a bit annoying. Also is it me or the upgrade workspace is behind base/latest? Maybe it's just that I'm not familiar with monorepos/turborepos.

Anyways, for the time being if anyone is looking for a resource to convert manually, this is more or less the output from this codemod: https://eslint.org/blog/2024/05/eslint-configuration-migrator/. Seems to work fine? Made sure to also update tsconfig.json's eslint config file include to "eslint.config.mjs".

/** @ts-expect-error - @eslint/eslintrc is untyped */
import { FlatCompat } from "@eslint/eslintrc";
import tsEslint from "@typescript-eslint/eslint-plugin";
import tsParser from "@typescript-eslint/parser";
/** @ts-expect-error - eslint-plugin-drizzle is untyped */
import drizzle from "eslint-plugin-drizzle";

const compat = new FlatCompat({
  baseDirectory: import.meta.dirname,
});

/** @type {import("eslint").Linter.Config[]} */
export default [
  ...compat.extends(
    "next/core-web-vitals",
    "plugin:@typescript-eslint/recommended-type-checked",
    "plugin:@typescript-eslint/stylistic-type-checked"
  ),
  {
    plugins: {
      "@typescript-eslint": tsEslint,
      drizzle,
    },
    languageOptions: {
      parser: tsParser,
      ecmaVersion: "latest",
      sourceType: "module",
      parserOptions: {
        project: true,
      },
    },
    rules: {
      "@typescript-eslint/array-type": "off",
      "@typescript-eslint/consistent-type-definitions": "off",
      "@typescript-eslint/consistent-type-imports": [
        "warn",
        {
          prefer: "type-imports",
          fixStyle: "inline-type-imports",
        },
      ],
      "@typescript-eslint/no-unused-vars": [
        "warn",
        {
          argsIgnorePattern: "^_",
        },
      ],
      "@typescript-eslint/require-await": "off",
      "@typescript-eslint/no-misused-promises": [
        "error",
        {
          checksVoidReturn: {
            attributes: false,
          },
        },
      ],
      "drizzle/enforce-delete-with-where": [
        "error",
        {
          drizzleObjectName: ["db", "ctx.db"],
        },
      ],
      "drizzle/enforce-update-with-where": [
        "error",
        {
          drizzleObjectName: ["db", "ctx.db"],
        },
      ],
    },
  },
];