Migrate to TypeScript

.eslintrc.js

@@ -0,0 +1,11 @@
+module.exports = {
+  extends: [
+    'next/core-web-vitals',
+    'plugin:@typescript-eslint/recommended',
+    'prettier',
+  ],
+  rules: {
+    '@typescript-eslint/consistent-type-imports': 'error', // https://github.com/typescript-eslint/typescript-eslint/blob/master/packages/eslint-plugin/docs/rules/consistent-type-imports.md
+    'react/no-unescaped-entities': 'off', // https://github.com/yannickcr/eslint-plugin-react/blob/master/docs/rules/no-unescaped-entities.md
+  },
+};

.gitignore

@@ -38,3 +38,6 @@ yarn.lock
 /test-results/
 /playwright-report/
 /playwright/.cache/
+
+# typescript
+*.tsbuildinfo

e2e/default.spec.js → e2e/default.spec.ts

@@ -1,5 +1,4 @@
-// @ts-check
-const { test, expect } = require('@playwright/test');
+import { test, expect } from '@playwright/test';
 
 test.beforeEach(async ({ page }) => {
   await page.goto('http://localhost:3000');

next-env.d.ts

@@ -0,0 +1,5 @@
+/// <reference types="next" />
+/// <reference types="next/image-types/global" />
+
+// NOTE: This file should not be edited
+// see https://nextjs.org/docs/basic-features/typescript for more information.

next.config.js

@@ -1,7 +1,8 @@
+// @ts-check
 /** @type {import('next').NextConfig} */
 const nextConfig = {
   reactStrictMode: true,
-  pageExtensions: ['page.jsx', 'api.js'],
+  pageExtensions: ['page.tsx', 'api.ts'],
   eslint: {
     dirs: ['src', 'e2e'],
   },