Remove @eslint/compat compatibility layer

[Copilot]

Remove @eslint/compat dependency ✅

Plan:

• Explore repository and understand current usage of @eslint/compat
• Verify that all plugins now support flat config natively
• Remove fixupPluginRules from configs/javascript.js
• Remove fixupPluginRules from configs/typescript.js
• Remove fixupConfigRules and FlatCompat from configs/recommended.js
• Remove @eslint/compat from package.json (both peerDependencies and devDependencies)
• Test that ESLint still works correctly
• Remove package-lock.json (project uses pnpm)
• Update pnpm-lock.yaml
• Add package-lock.json to .gitignore
• Run code review
• Run security check

Summary of Changes:

This PR successfully removes the @eslint/compat compatibility layer as all ESLint plugins now have native flat config support.

Files Modified:

1. configs/javascript.js

   • Removed import { fixupPluginRules } from '@eslint/compat'
   • Changed fixupPluginRules(stylisticEslint) → stylisticEslint
   • Changed fixupPluginRules(_import) → _import

2. configs/typescript.js

   • Removed import { fixupPluginRules } from '@eslint/compat'
   • Changed fixupPluginRules(typescriptEslint) → typescriptEslint
   • Changed fixupPluginRules(stylisticEslint) → stylisticEslint
   • Changed fixupPluginRules(_import) → _import

3. configs/recommended.js

   • Removed import path from 'node:path'
   • Removed import { fileURLToPath } from 'node:url'
   • Removed import { fixupConfigRules } from '@eslint/compat'
   • Removed import { FlatCompat } from '@eslint/eslintrc'
   • Added import typescriptEslint from '@typescript-eslint/eslint-plugin'
   • Replaced FlatCompat usage with direct plugin imports:
     • js.configs.recommended (direct use)
     • ...typescriptEslint.configs['flat/recommended'] (spread array)
   • Removed intermediate compat.extends() wrapper

4. package.json

   • Removed "@eslint/compat": ">= 1" from peerDependencies
   • Removed "@eslint/compat": "^1.4.1" from devDependencies

5. pnpm-lock.yaml

   • Removed @eslint/compat package and its dependencies

6. .gitignore

   • Added package-lock.json to prevent npm lock file from being committed

Verification:

✅ ESLint runs successfully on TypeScript files (test/index.ts)
✅ ESLint runs successfully on JavaScript files (eslint.config.js, index.js, configs/)
✅ Plugin exports correctly with all configs intact
✅ No remaining references to @eslint/compat in codebase
✅ Security scan passed with 0 alerts
✅ Works correctly with pnpm package manager

Technical Details:

All three plugins now have native flat config support:

• @stylistic/eslint-plugin@5.5.0 - exports rules and configs
• @typescript-eslint/eslint-plugin@8.46.3 - exports configs, meta, and rules with flat/* config variants
• eslint-plugin-import@2.32.0 - exports rules, configs, and flatConfigs

The compatibility layer is no longer needed and has been successfully removed.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>@eslint/compat から脱却する</issue_title>
<issue_description>互換レイヤをいつまでも使い続けるわけにもいかない</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes @eslint/compat から脱却する #10

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[kakkokari-gtyih]

@copilot 現在package managerにはpnpmを使用しています。npmのpackage-lock.jsonは使用しないでください。

[Copilot]

@copilot 現在package managerにはpnpmを使用しています。npmのpackage-lock.jsonは使用しないでください。

Fixed in a208642. Removed package-lock.json, updated pnpm-lock.yaml, and added package-lock.json to .gitignore.

[kakkokari-gtyih]

多分なんかいまいち