next 16; react 19; node 24 (#263)

* next 16; react 19

* fix build errors

* add typecheck to workflow

* use node 24

* claude update

.github/workflows/test-app.yml

@@ -14,7 +14,7 @@ jobs:
             - name: Setup Node.js
               uses: actions/setup-node@v4
               with:
-                  node-version: 22
+                  node-version: 24
                   cache: npm
 
             - name: Install dependencies
@@ -33,7 +33,7 @@ jobs:
             - name: Setup Node.js
               uses: actions/setup-node@v4
               with:
-                  node-version: 22
+                  node-version: 24
                   cache: npm
 
             - name: Install dependencies
@@ -42,9 +42,8 @@ jobs:
             - name: Test
               run: npm test
 
-    build:
+    typecheck:
-        name: Build
+        name: Type Check
-        needs: [lint, test]
         runs-on: ubuntu-latest
         steps:
             - name: Checkout
@@ -53,7 +52,27 @@ jobs:
             - name: Setup Node.js
               uses: actions/setup-node@v4
               with:
-                  node-version: 22
+                  node-version: 24
+                  cache: npm
+
+            - name: Install dependencies
+              run: npm ci
+
+            - name: Type check
+              run: npx tsc --noEmit
+
+    build:
+        name: Build
+        needs: [lint, test, typecheck]
+        runs-on: ubuntu-latest
+        steps:
+            - name: Checkout
+              uses: actions/checkout@v4
+
+            - name: Setup Node.js
+              uses: actions/setup-node@v4
+              with:
+                  node-version: 24
                   cache: npm
 
             - name: Install dependencies

CLAUDE.md

@@ -14,7 +14,7 @@ Website for the Art School of Shlisselburg ([art.shlisselburg.org](https://art.s
 - `npm run format` — auto-fix lint issues
 - `npm test` — run unit tests (Vitest, non-watch mode)
 
-Node 22 required (see `mise.toml`). Deployed on Vercel.
+Node 24 required (see `mise.toml`). Deployed on Vercel.
 
 ## Git Workflow
 
@@ -28,7 +28,7 @@ Feature branches are named `issue-XXX` where `XXX` is the related GitHub issue n
 
 ## Code Style
 
-ESLint 9 flat config (`eslint.config.js`) using `FlatCompat` from `@eslint/eslintrc` to bridge `eslint-config-next` (which doesn't support native flat config in Next.js 15.x). Extends `next/core-web-vitals`. Enforces: no semicolons, double quotes, 4-space indentation, always-multiline trailing commas, `eol-last`.
+ESLint 9 flat config (`eslint.config.js`) with native `eslint-config-next` 16.x support. Extends `next/core-web-vitals`. Enforces: no semicolons, double quotes, 4-space indentation, always-multiline trailing commas, `eol-last`.
 
 **React components:** Use regular function declarations (not arrow functions) and `type` for props. Do not use `React.FC`.
 

Dockerfile

@@ -1,4 +1,4 @@
-FROM node:22.19.0-alpine AS base
+FROM node:24.12.0-alpine AS base
 
 # Install dependencies only when needed
 FROM base AS deps

eslint.config.js

@@ -1,15 +1,7 @@
-import { dirname } from "path"
-import { fileURLToPath } from "url"
-import { FlatCompat } from "@eslint/eslintrc"
 import { defineConfig, globalIgnores } from "eslint/config"
+import nextVitals from "eslint-config-next/core-web-vitals"
 import globals from "globals"
 
-const __dirname = dirname(fileURLToPath(import.meta.url))
-
-const compat = new FlatCompat({
-    baseDirectory: __dirname,
-})
-
 export default defineConfig([
     globalIgnores([
         ".next/**",
@@ -19,7 +11,7 @@ export default defineConfig([
         "public/static/**",
         "next-env.d.ts",
     ]),
-    ...compat.extends("next/core-web-vitals"),
+    ...nextVitals,
     {
         languageOptions: {
             globals: globals.browser,

mise.toml

@@ -1,2 +1,2 @@
 [tools]
-node = "22"
+node = "24"

next-env.d.ts

@@ -1,7 +1,7 @@
 /// <reference types="next" />
 /// <reference types="next/image-types/global" />
 /// <reference types="next/navigation-types/compat/navigation" />
-/// <reference path="./.next/types/routes.d.ts" />
+import "./.next/types/routes.d.ts";
 
 // NOTE: This file should not be edited
 // see https://nextjs.org/docs/app/api-reference/config/typescript for more information.

next.config.ts

@@ -3,9 +3,6 @@ import type { NextConfig } from "next"
 const config: NextConfig = {
     output: "standalone",
     trailingSlash: false,
-    eslint: {
-        ignoreDuringBuilds: true,
-    },
     images: {
         remotePatterns: [
             { hostname: "hudozkacdn.tmshv.com" },

package.json

@@ -19,32 +19,36 @@
     "author": "Roman Timashev",
     "license": "ISC",
     "dependencies": {
-        "@radix-ui/react-navigation-menu": "^1.0.0",
+        "@radix-ui/react-navigation-menu": "^1.2.0",
-        "@radix-ui/react-tooltip": "^1.0.0",
+        "@radix-ui/react-tooltip": "^1.2.0",
         "classnames": "^2.5.0",
         "dangerously-set-html-content": "^1.0.13",
         "date-fns": "^4.0.0",
         "markdown-it": "^13.0.1",
-        "next": "^15.5.0",
+        "next": "^16.1.0",
         "next-seo": "^5.15.0",
-        "react": "^18.3.0",
+        "react": "^19.2.0",
-        "react-dom": "^18.3.0",
+        "react-dom": "^19.2.0",
         "react-icons": "^4.2.0",
         "sharp": "^0.34.0",
         "typograf": "^6.11.1",
         "valtio": "^2.1.7"
     },
+    "overrides": {
+        "dangerously-set-html-content": {
+            "react": "$react"
+        }
+    },
     "devDependencies": {
-        "@eslint/eslintrc": "^3.3.1",
         "@testing-library/jest-dom": "^6.9.1",
         "@testing-library/react": "^16.3.2",
         "@types/markdown-it": "^12.2.3",
         "@types/node": "^22.19.9",
-        "@types/react": "^18.0.18",
+        "@types/react": "^19.2.0",
         "@typescript-eslint/eslint-plugin": "^8.54.0",
         "@typescript-eslint/parser": "^8.54.0",
         "eslint": "^9.0.0",
-        "eslint-config-next": "^15.5.0",
+        "eslint-config-next": "^16.1.0",
         "globals": "^16.0.0",
         "happy-dom": "^20.5.0",
         "typescript": "^5.9.0",

src/hooks/useToggle.ts

@@ -1,8 +1,9 @@
-import { useReducer } from "react"
+import { useCallback, useState } from "react"
 
 export function useToggle(initialValue: boolean): [boolean, (nextValue?: boolean) => void] {
-    return useReducer(
+    const [state, setState] = useState(initialValue)
-        (state: boolean, next?: boolean) => typeof next === "boolean" ? next : !state,
+    const toggle = useCallback((next?: boolean) => {
-        initialValue,
+        setState(prev => typeof next === "boolean" ? next : !prev)
-    )
+    }, [])
+    return [state, toggle]
 }

src/ui/Overlay/Transition.tsx

@@ -1,4 +1,4 @@
-import { useCallback, useEffect, useMemo, useState } from "react"
+import { useCallback, useEffect, useMemo, useRef, useState } from "react"
 
 export type TransitionProps = {
     children?: React.ReactNode
@@ -7,9 +7,11 @@ export type TransitionProps = {
     show: boolean
 }
 
-export const Transition: React.FC<TransitionProps> = props => {
+export function Transition(props: TransitionProps) {
     const [mounted, setMounted] = useState(props.show)
     const [opacity, setOpacity] = useState(0)
+    const timerRef = useRef<ReturnType<typeof setTimeout>>(null)
+
     const onTransitionEnd = useCallback(() => {
         if (opacity === 0) {
             setMounted(false)
@@ -20,19 +22,27 @@ export const Transition: React.FC<TransitionProps> = props => {
         [props.duration],
     )
 
+    if (props.show && !mounted) {
+        setMounted(true)
+    }
+
+    if (!props.show && opacity !== 0) {
+        setOpacity(0)
+    }
+
     useEffect(() => {
         if (!props.show) {
-            setOpacity(0)
             return
         }
 
-        setMounted(true)
+        timerRef.current = setTimeout(() => {
-        let t = setTimeout(() => {
             setOpacity(1)
         }, 16)
 
         return () => {
-            clearTimeout(t)
+            if (timerRef.current) {
+                clearTimeout(timerRef.current)
+            }
         }
     }, [props.show])
 

tsconfig.json

@@ -23,7 +23,7 @@
     "resolveJsonModule": true,
     "verbatimModuleSyntax": true,
     "moduleDetection": "force",
-    "jsx": "preserve",
+    "jsx": "react-jsx",
     "incremental": true,
     "plugins": [
       {
@@ -39,6 +39,7 @@
     "next-env.d.ts",
     "**/*.ts",
     "**/*.tsx",
-    ".next/types/**/*.ts"
+    ".next/types/**/*.ts",
+    ".next/dev/types/**/*.ts"
   ]
 }