feat(create-vite): add eslint.config.js to React templates

[smeng9]

Description

Hi @ArnaudBarre As a follow up on #12801 I have helped to create an example using the latest eslint.config.js format of config

Additional context

---

What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

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• Read the Contributing Guidelines.
• Read the Pull Request Guidelines and follow the PR Title Convention.
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• Provide a description in this PR that addresses what the PR is solving, or reference the issue that it solves (e.g. fixes #123).
• Ideally, include relevant tests that fail without this PR but pass with it.

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[ArnaudBarre]

Thanks for this. I tested it and work as expected. I'm really surprised that we require to install to more packages for this, which is not mentioned in the doc that prefer to explain me what is object shorthand 🤦‍♂️

The documentation on this is so poor that I'm not sure we should push new Vite users that could be people still learning web basics into this. I will see what the react of team think of that. Thanks for the work, in any case this will be useful and merge when this become the official config format

[ArnaudBarre]

Hi! We decided to wait for eslint to switch the default config format to the new one before adding it to the template.
The PR can be kept open and updated once the announcement is made (and hopefully there is more documentation)

[cherewaty]

The default switched to flat config with today's 9.0.0 release: https://eslint.org/blog/2024/04/eslint-v9.0.0-released/#flat-config-is-now-the-default-and-has-some-changes

[smeng9]

We still need to wait jsx-eslint/eslint-plugin-react#3699 and facebook/react#28313 to be resolved

[smeng9]

Hi @ArnaudBarre Shall we consider using the @eslint/compat here https://eslint.org/blog/2024/05/eslint-compatibility-utilities/ before the dependent eslint plugin repo release a fix for the incompatible api?

[ArnaudBarre]

Yeah I think this is better for new users to get started with the new config at the cost of one more compat package. Each usage of the compat should prefix with a comment // Remove compat when the plugin is compatible with ESLint v9: https://github.com/..

But first we should wait for the VS Code extension to support v9 without pre-release: https://github.com/Microsoft/vscode-eslint/blob/HEAD/CHANGELOG.md

[ArnaudBarre]

Thanks for the update, the only downside is that we can peer deps warning

Edit: it seems they aye still conflicts, I test locally once resolved

[smeng9]

@ArnaudBarre All issues should be fixed now

[bluwy]

When I run npm install, I get:

bjorn@Bjorns-MacBook-Pro vite-project % npm i
npm error code ERESOLVE
npm error ERESOLVE unable to resolve dependency tree
npm error
npm error While resolving: vite-project@0.0.0
npm error Found: eslint@9.5.0
npm error node_modules/eslint
npm error   dev eslint@"^9.5.0" from the root project
npm error
npm error Could not resolve dependency:
npm error peer eslint@"^8.56.0" from @typescript-eslint/parser@7.13.1
npm error node_modules/@typescript-eslint/parser
npm error   dev @typescript-eslint/parser@"^7.13.1" from the root project
npm error   peer @typescript-eslint/parser@"^7.0.0" from @typescript-eslint/eslint-plugin@7.13.1
npm error   node_modules/@typescript-eslint/eslint-plugin
npm error     dev @typescript-eslint/eslint-plugin@"^7.13.1" from the root project
npm error
npm error Fix the upstream dependency conflict, or retry
npm error this command with --force or --legacy-peer-deps
npm error to accept an incorrect (and potentially broken) dependency resolution.

Do we want to use the alpha versions of @typescript-eslint/* to prevent this? (Could move to typescript-eslint along the way too)

[ArnaudBarre]

I didn't know npm was that strict. I only got warning with bun/yarn. We will get peer deps issues for react plugins too, so I don't know what we can do

[bluwy]

Ah yeah for the JS template, I get:

npm error Could not resolve dependency:
npm error peer eslint@"^3 || ^4 || ^5 || ^6 || ^7 || ^8" from eslint-plugin-react@7.34.3
npm error node_modules/eslint-plugin-react
npm error   dev eslint-plugin-react@"^7.34.2" from the root project

Since the TS template, doesn't have eslint-plugin-react, maybe we can remove it for the JS template too? (unless I forgot what's its use for).

[smeng9]

I only tested using yarn. Shall we do

"overrides": {
    "@typescript-eslint/parser": {
        "eslint": "^9.5.0"
    }
   ...
}

in package.json ?

[smeng9]

After some research we can probably add the following field to package.json

"overrides": {
    "eslint": "$eslint"
}

[smeng9]

Hi @ArnaudBarre is there anything else we should do in this merge request to move the ecosystem forward?

[plbstl]

Just some helpful info:

• @typescript-eslint/parser and @typescript-eslint/eslint-plugin packages are not needed when using typescript-eslint. See https://typescript-eslint.io/packages/typescript-eslint

• eslint-plugin-react now has a merged PR for eslint v9 support. [New] support eslint v9 jsx-eslint/eslint-plugin-react#3759

• eslint-plugin-react-hooks@canary supports v9. eslint-plugin-react-hooks: Add support for ESLint v9 facebook/react#28773

[plbstl]

Here is a working config.

The caveat is that npm install errors because of a dependency conflict. The --force flag works fixes it. yarn and pnpm shows a warning.

import js from '@eslint/js'
import reactHooks from 'eslint-plugin-react-hooks'
import reactRefresh from 'eslint-plugin-react-refresh'
import reactJsxRuntime from 'eslint-plugin-react/configs/jsx-runtime.js'
import reactRecommended from 'eslint-plugin-react/configs/recommended.js'
import globals from 'globals'
import ts from 'typescript-eslint'

export default ts.config(
  // ignore patterns (.eslintignore)
  { ignores: ['dist', 'eslint.config.js'] },

  // misc
  { languageOptions: { globals: { ...globals.browser, ...globals.es2020 } } },

  // typescript eslint
  js.configs.recommended,
  ...ts.configs.recommended,
  {
    languageOptions: {
      parserOptions: {
    	ecmaVersion: 'latest',
	    sourceType: 'module',
        project: ['./tsconfig.json', 'tsconfig.app.json', './tsconfig.node.json'],
        tsconfigRootDir: import.meta.dirname
      }
    }
  },

  // react
  reactRecommended,
  reactJsxRuntime,
  { settings: { react: { version: 'detect' } } },

  // react hooks
  {
    plugins: { 'react-hooks': reactHooks },
    rules: { ...reactHooks.configs.recommended.rules }
  },

  // react refresh
  {
    plugins: { 'react-refresh': reactRefresh },
    rules: {
      'react-refresh/only-export-components': ['warn', { allowConstantExport: true }]
    }
  },

  // linter
  { linterOptions: { reportUnusedDisableDirectives: 'error' } }
)

{
    "@eslint/js": "9.7.0",
    "@types/eslint__js": "8.42.3",
    "@types/node": "20.14.11",
    "@types/react": "18.3.3",
    "@types/react-dom": "18.3.0",
    "@vitejs/plugin-react-swc": "3.7.0",
    "eslint": "9.7.0",
    "eslint-plugin-react": "7.34.4",
    "eslint-plugin-react-hooks": "4.6.2", // not using canary
    "eslint-plugin-react-refresh": "0.4.8",
    "globals": "15.8.0",
    "typescript": "5.5.3",
    "typescript-eslint": "7.16.1",
    "vite": "5.3.4"
  }

[ArnaudBarre]

After discussion with @bluwy we think it's better to switch to full v9 compatibility, remove the compat layer and use the canary version of react hooks plugin for now.

Also using the new typescript-eslint with the typed config would be good for the TS package: https://typescript-eslint.io/packages/typescript-eslint/#advanced-usage

Edit: Sorry for the long answer, we can take over the PR if don't have time to update it in the next days, no problem for us, thanks a lot for the initial work and exploring the compat option!

[smeng9]

@ArnaudBarre Sounds good to take over this PR

[ArnaudBarre]

Sorry totally forgot about it!