chore(eslint): migrate to eslint 9 flat config

eslint.config.js

@@ -0,0 +1,31 @@
+import eslint from '@eslint/js';
+import tseslint from 'typescript-eslint';
+import importPlugin from 'eslint-plugin-import';
+import jsxA11y from 'eslint-plugin-jsx-a11y';
+import react from 'eslint-plugin-react';
+import reactHooks from 'eslint-plugin-react-hooks';
+import reactCompiler from 'eslint-plugin-react-compiler';
+
+export default tseslint.config(
+  { ignores: ['dist/', 'website/'] },
+  eslint.configs.recommended,
+  tseslint.configs.recommended,
+  importPlugin.flatConfigs.recommended,
+  jsxA11y.flatConfigs.recommended,
+  react.configs.flat.recommended,
+  react.configs.flat['jsx-runtime'],
+  reactHooks.configs['recommended-latest'],
+  reactCompiler.configs.recommended,
+  {
+    settings: {
+      'import/resolver': { typescript: true },
+      react: { version: 'detect' },
+    },
+    rules: {
+      '@typescript-eslint/no-unused-vars': [
+        'error',
+        { argsIgnorePattern: '^_', varsIgnorePattern: '^_' },
+      ],
+    },
+  },
+);

examples/08_comparison/src/ContextWithMemo.tsx

@@ -1,3 +1,5 @@
+/* eslint-disable react-compiler/react-compiler */
+
 import {
   createContext,
   memo,

examples/08_comparison/src/ContextWithUseMemo.tsx

@@ -1,3 +1,5 @@
+/* eslint-disable react-compiler/react-compiler */
+
 import { createContext, useContext, useReducer, useRef, useMemo } from 'react';
 import type { Reducer } from 'react';
 

examples/08_comparison/src/NaiveContext.tsx

@@ -1,3 +1,5 @@
+/* eslint-disable react-compiler/react-compiler */
+
 import {
   createContext,
   useContext,

examples/08_comparison/src/ReactTracked.tsx

@@ -1,3 +1,5 @@
+/* eslint-disable react-compiler/react-compiler */
+
 import { useReducer, useRef, useEffect } from 'react';
 import type { Reducer } from 'react';
 

examples/08_comparison/src/SplitContext.tsx

@@ -1,3 +1,5 @@
+/* eslint-disable react-compiler/react-compiler */
+
 import {
   createContext,
   memo,

examples/12_async/src/store.ts

@@ -96,7 +96,7 @@ const asyncActionHandlers: AsyncActionHandlers<
         const firstName = data.data.first_name;
         if (typeof firstName !== 'string') throw new Error();
         dispatch({ type: 'FINISH_FETCH_USER', firstName });
-      } catch (_e) {
+      } catch {
         dispatch({ type: 'ERROR_FETCH_USER' });
       }
     },

examples/13_saga/src/store.ts

@@ -7,7 +7,6 @@ import {
   takeEvery,
   all,
 } from 'redux-saga/effects';
-// eslint-disable-next-line import/no-named-as-default
 import useSagaReducer from 'use-saga-reducer';
 import { createContainer } from 'react-tracked';
 
@@ -93,7 +92,7 @@ function* userFetcher(action: AsyncActionFetch) {
     const firstName = data.data.first_name;
     if (typeof firstName !== 'string') throw new Error();
     yield put<InnerAction>({ type: 'FINISH_FETCH_USER', firstName });
-  } catch (_e) {
+  } catch {
     yield put<InnerAction>({ type: 'ERROR_FETCH_USER' });
   }
 }

package.json

@@ -30,7 +30,7 @@
     "src",
     "dist"
   ],
-  "packageManager": "pnpm@8.15.0",
+  "packageManager": "pnpm@9.4.0",
   "scripts": {
     "compile": "rm -rf dist && pnpm run '/^compile:.*/'",
     "compile:esm": "tsc -p tsconfig.esm.json",
@@ -89,37 +89,38 @@
     "use-context-selector": "^2.0.0"
   },
   "devDependencies": {
-    "@testing-library/jest-dom": "^6.4.5",
-    "@testing-library/react": "^15.0.6",
-    "@testing-library/user-event": "^14.5.2",
-    "@types/node": "^20.12.10",
-    "@types/react": "^18.3.1",
-    "@types/react-dom": "^18.3.0",
-    "@typescript-eslint/eslint-plugin": "^7.8.0",
-    "@typescript-eslint/parser": "^7.8.0",
-    "eslint": "8.57.0",
-    "eslint-config-prettier": "^9.1.0",
-    "eslint-import-resolver-typescript": "^3.6.1",
-    "eslint-plugin-import": "^2.29.1",
-    "eslint-plugin-jsx-a11y": "^6.8.0",
-    "eslint-plugin-react": "^7.34.1",
-    "eslint-plugin-react-hooks": "^4.6.2",
-    "happy-dom": "^14.9.0",
+    "@eslint/js": "^9.19.0",
+    "@testing-library/jest-dom": "^6.6.3",
+    "@testing-library/react": "^16.2.0",
+    "@testing-library/user-event": "^14.6.1",
+    "@types/node": "^22.10.10",
+    "@types/react": "^19.0.8",
+    "@types/react-dom": "^19.0.3",
+    "eslint": "^9.19.0",
+    "eslint-import-resolver-typescript": "^3.7.0",
+    "eslint-plugin-import": "^2.31.0",
+    "eslint-plugin-jsx-a11y": "^6.10.2",
+    "eslint-plugin-react": "^7.37.4",
+    "eslint-plugin-react-compiler": "19.0.0-beta-decd7b8-20250118",
+    "eslint-plugin-react-hooks": "5.2.0-canary-de1eaa26-20250124",
+    "happy-dom": "^16.7.2",
     "immer": "^10.1.1",
     "npm-run-all": "^4.1.5",
-    "prettier": "^3.2.5",
-    "puppeteer": "^22.8.0",
-    "react": "^18.3.1",
-    "react-dom": "^18.3.1",
-    "react-tracked": "link:.",
+    "prettier": "^3.4.2",
+    "puppeteer": "^24.1.1",
+    "react": "^19.0.0",
+    "react-dom": "^19.0.0",
+    "react-tracked": "link:",
     "redux-saga": "^1.3.0",
-    "start-server-and-test": "^2.0.3",
+    "start-server-and-test": "^2.0.10",
     "ts-expect": "^1.3.0",
-    "typescript": "^5.4.5",
+    "typescript": "^5.7.3",
+    "typescript-eslint": "^8.21.0",
     "use-reducer-async": "^2.1.1",
     "use-saga-reducer": "^3.0.0",
-    "vite": "^5.2.11",
-    "vitest": "^1.6.0"
+    "vite": "^6.0.11",
+    "vite-tsconfig-paths": "^5.1.4",
+    "vitest": "^3.0.4"
   },
   "peerDependencies": {
     "react": ">=18.0.0",