Meal API: Elysia backend serving the menu API and a single-file frontend

server.js

@@ -0,0 +1,62 @@
+import { Elysia, status } from 'elysia'
+import { readFileSync } from 'node:fs'
+import { fileURLToPath } from 'node:url'
+
+const PORT = process.env.PORT || 3000
+
+// Resolve index.html next to this file, so it works no matter where you run it from.
+const INDEX_HTML = readFileSync(fileURLToPath(new URL('./index.html', import.meta.url)), 'utf8')
+
+const HTML_HEADERS = {
+  'content-type': 'text/html; charset=utf-8',
+  'content-length': String(Buffer.byteLength(INDEX_HTML)),
+}
+
+// The food menu data.
+const menu = [
+  { id: 1, food: 'Adobo', price: 75 },
+  { id: 2, food: 'Fried Chicken', price: 50 },
+  { id: 3, food: 'Yum Burger', price: 70 },
+]
+
+// Elysia serves through Bun.serve on Bun, but it needs the Node adapter on Node.
+// This one file therefore runs on either runtime: `bun server.js` or `node server.js`.
+const adapter =
+  typeof Bun === 'undefined' ? (await import('@elysiajs/node')).node() : undefined
+
+new Elysia(adapter ? { adapter } : {})
+  .onRequest(({ request }) => {
+    if (request.method !== 'GET') {
+      return status(405, { error: 'Method not allowed' })
+    }
+  })
+
+  // GET /api/menu -> the whole menu
+  .get('/api/menu', () => menu)
+
+  // GET /api/menu/:id -> one item
+  .get('/api/menu/:id', ({ params: { id }, status }) => {
+    const num = Number(id)
+
+    if (!Number.isInteger(num) || num < 1) {
+      return status(400, { error: 'ID must be a whole number, like 1.' })
+    }
+
+    const item = menu.find((food) => food.id === num)
+    if (!item) {
+      return status(404, { error: `No menu item with ID ${num}.` })
+    }
+
+    return item
+  })
+
+  // GET / -> the frontend
+  .get('/', () => new Response(INDEX_HTML, { headers: HTML_HEADERS }))
+  .get('/index.html', () => new Response(INDEX_HTML, { headers: HTML_HEADERS }))
+
+  .get('*', () => status(404, 'Not found'))
+
+  .listen(PORT)
+
+const runtime = typeof Bun === 'undefined' ? 'Node.js' : 'Bun'
+console.log(`Meal API running at http://localhost:${PORT} (${runtime})`)