chore(tooling): modernize Next verification setup

eslint.config.mjs

@@ -0,0 +1,9 @@
+import { defineConfig, globalIgnores } from 'eslint/config';
+import nextVitals from 'eslint-config-next/core-web-vitals';
+import nextTypeScript from 'eslint-config-next/typescript';
+
+export default defineConfig([
+  ...nextVitals,
+  ...nextTypeScript,
+  globalIgnores(['.next/**', 'out/**', 'node_modules/**', 'next-env.d.ts']),
+]);

next-env.d.ts

@@ -1,6 +1,7 @@
 /// <reference types="next" />
 /// <reference types="next/image-types/global" />
-/// <reference path="./.next/types/routes.d.ts" />
+import "./.next/dev/types/routes.d.ts";
+import "./.next/dev/types/root-params.d.ts";
 
 // NOTE: This file should not be edited
 // see https://nextjs.org/docs/app/api-reference/config/typescript for more information.

package.json

@@ -6,11 +6,13 @@
     "dev": "next dev",
     "build": "next build",
     "start": "next start",
-    "lint": "next lint"
+    "lint": "eslint . --max-warnings=0",
+    "typecheck": "tsc --noEmit",
+    "test": "node --test tests/*.test.mjs"
   },
   "dependencies": {
     "lucide-react": "^1.16.0",
-    "next": "^15.1.7",
+    "next": "^16.3.4",
     "react": "^19.0.0",
     "react-dom": "^19.0.0",
     "three": "^0.180.0"
@@ -20,9 +22,8 @@
     "@types/react": "^19.0.10",
     "@types/react-dom": "^19.0.4",
     "@types/three": "^0.180.0",
+    "eslint": "^9.39.5",
+    "eslint-config-next": "^16.3.4",
     "typescript": "^5.7.3"
-  },
-  "optionalDependencies": {
-    "@next/swc-win32-x64-msvc": "^16.3.4"
   }
 }

tests/static-export.test.mjs

@@ -0,0 +1,26 @@
+import assert from 'node:assert/strict';
+import { access, readFile } from 'node:fs/promises';
+import path from 'node:path';
+import test from 'node:test';
+
+const exportRoot = path.resolve('out');
+
+test('the production build exports a usable home page', async () => {
+  const indexPath = path.join(exportRoot, 'index.html');
+  const html = await readFile(indexPath, 'utf8');
+
+  assert.match(html, /<!DOCTYPE html>/i);
+  assert.match(html, /<html[^>]*lang=/i);
+
+  const assetPaths = [
+    ...html.matchAll(/(?:src|href)="(\/_next\/static\/[^"?#]+)/g),
+  ].map((match) => match[1]);
+
+  assert.ok(assetPaths.length > 0, 'expected the home page to reference built assets');
+
+  await Promise.all(
+    [...new Set(assetPaths)].map((assetPath) =>
+      access(path.join(exportRoot, assetPath.replace(/^\//, ''))),
+    ),
+  );
+});

tsconfig.json

@@ -1,7 +1,11 @@
 {
   "compilerOptions": {
     "target": "ES2017",
-    "lib": ["dom", "dom.iterable", "esnext"],
+    "lib": [
+      "dom",
+      "dom.iterable",
+      "esnext"
+    ],
     "allowJs": true,
     "skipLibCheck": true,
     "strict": true,
@@ -11,7 +15,7 @@
     "moduleResolution": "bundler",
     "resolveJsonModule": true,
     "isolatedModules": true,
-    "jsx": "preserve",
+    "jsx": "react-jsx",
     "incremental": true,
     "plugins": [
       {
@@ -19,9 +23,19 @@
       }
     ],
     "paths": {
-      "@/*": ["./src/*"]
+      "@/*": [
+        "./src/*"
+      ]
     }
   },
-  "include": ["next-env.d.ts", "**/*.ts", "**/*.tsx", ".next/types/**/*.ts"],
-  "exclude": ["node_modules"]
+  "include": [
+    "next-env.d.ts",
+    "**/*.ts",
+    "**/*.tsx",
+    ".next/types/**/*.ts",
+    ".next/dev/types/**/*.ts"
+  ],
+  "exclude": [
+    "node_modules"
+  ]
 }