feat(hono): Add hono.request spans for internal .request() calls

dev-packages/e2e-tests/test-applications/hono-4/src/route-groups/test-multi-fetch.ts

@@ -0,0 +1,99 @@
+import { Hono } from 'hono';
+import { HTTPException } from 'hono/http-exception';
+
+const ITEMS: Record<string, { name: string; stock: number; price: number }> = {
+  'self-watering-plant': { name: 'Self-Watering Plant', stock: 5, price: 2500 },
+  'solar-powered-cyberdeck': { name: 'Solar-Powered Cyberdeck', stock: 0, price: 5000 },
+};
+
+// Inventory service — standalone sub-app used as a data source.
+// Mounted on the main app AND called internally via .request() from the storefront.
+const inventoryApp = new Hono();
+
+inventoryApp.get('/item/:productId', c => {
+  const productId = c.req.param('productId');
+  const item = ITEMS[productId];
+  if (!item) {
+    throw new HTTPException(404, { message: `Item ${productId} not found` });
+  }
+  return c.json({ productId, ...item });
+});
+
+inventoryApp.get('/item/:productId/stock', c => {
+  const productId = c.req.param('productId');
+  const item = ITEMS[productId];
+  if (!item) {
+    throw new HTTPException(404, { message: `Stock check failed: ${productId}` });
+  }
+  return c.json({ productId, inStock: item.stock > 0, quantity: item.stock });
+});
+
+// Storefront service — orchestrates internal .request() calls to inventoryApp.
+const storefrontApp = new Hono();
+
+storefrontApp.use('/*', async function storefrontAuth(_c, next) {
+  await new Promise(resolve => setTimeout(resolve, 10));
+  await next();
+});
+
+// Single internal fetch: look up one product
+storefrontApp.get('/product/:productId', async c => {
+  const res = await inventoryApp.request(`/item/${c.req.param('productId')}`);
+  if (!res.ok) {
+    throw new HTTPException(404, { message: 'Product not found' });
+  }
+  const item = await res.json();
+  return c.json({ product: item, source: 'storefront' });
+});
+
+// Parallel internal fetches: compare two products via Promise.all
+storefrontApp.get('/compare/:productId1/:productId2', async c => {
+  const [res1, res2] = await Promise.all([
+    inventoryApp.request(`/item/${c.req.param('productId1')}`),
+    inventoryApp.request(`/item/${c.req.param('productId2')}`),
+  ]);
+  if (!res1.ok || !res2.ok) {
+    throw new HTTPException(404, { message: 'One or more products not found' });
+  }
+  const [item1, item2] = (await Promise.all([res1.json(), res2.json()])) as [
+    Record<string, number>,
+    Record<string, number>,
+  ];
+  return c.json({
+    items: [item1, item2],
+    priceDifference: Math.abs(item1.price - item2.price),
+  });
+});
+
+// Sequential chained fetches: look up item, then check its stock
+storefrontApp.get('/product/:productId/availability', async c => {
+  const itemRes = await inventoryApp.request(`/item/${c.req.param('productId')}`);
+  if (!itemRes.ok) {
+    throw new HTTPException(404, { message: 'Product not found' });
+  }
+  const item: Record<string, string | number> = await itemRes.json();
+
+  const stockRes = await inventoryApp.request(`/item/${item.productId}/stock`);
+  const stock: Record<string, string | number | boolean> = await stockRes.json();
+
+  return c.json({
+    product: item.name,
+    available: stock.inStock,
+    quantity: stock.quantity,
+  });
+});
+
+// Error propagation: internal 404 causes the handler to throw a plain Error
+storefrontApp.get('/product-or-throw/:productId', async c => {
+  const res = await inventoryApp.request(`/item/${c.req.param('productId')}`);
+  if (!res.ok) {
+    throw new Error(`Failed to fetch product: ${c.req.param('productId')}`);
+  }
+  return c.json({ product: await res.json() });
+});
+
+const multiFetchRoutes = new Hono();
+multiFetchRoutes.route('/inventory', inventoryApp);
+multiFetchRoutes.route('/storefront', storefrontApp);
+
+export { multiFetchRoutes };

dev-packages/e2e-tests/test-applications/hono-4/src/routes.ts

@@ -3,6 +3,7 @@ import { HTTPException } from 'hono/http-exception';
 import { failingMiddleware, middlewareA, middlewareB } from './middleware';
 import { errorRoutes } from './route-groups/test-errors';
 import { middlewareRoutes, subAppWithInlineMiddleware, subAppWithMiddleware } from './route-groups/test-middleware';
+import { multiFetchRoutes } from './route-groups/test-multi-fetch';
 import { routePatterns } from './route-groups/test-route-patterns';
 
 export function addRoutes(app: Hono<{ Bindings?: { E2E_TEST_DSN: string } }>): void {
@@ -48,4 +49,7 @@ export function addRoutes(app: Hono<{ Bindings?: { E2E_TEST_DSN: string } }>): v
 
   // Error-specific routes: onError handler, nested sub-apps, middleware HTTPException
   app.route('/test-errors', errorRoutes);
+
+  // Multi-fetch routes: storefront sub-app calls inventoryApp via .request()
+  app.route('/test-multi-fetch', multiFetchRoutes);
 }