fix(app): improve instance caching

Author: pi0

examples/plugins/server/plugins/test.ts

@@ -1,7 +1,9 @@
 import { definePlugin } from "nitro";
+import { useNitroHooks } from "nitro/app";
 
 export default definePlugin((nitroApp) => {
- nitroApp.hooks.hook("response", (event) => {
+ const hooks = useNitroHooks();
+ hooks.hook("response", (event) => {
  event.headers.set("content-type", "html; charset=utf-8");
  });
 });

src/runtime/internal/app.ts

@@ -40,8 +40,16 @@ declare global {
 const APP_ID = import.meta.prerender ? "prerender" : "default";
 
 export function useNitroApp(_id = APP_ID): NitroApp {
+ let instance = globalThis.__nitro__?.[_id];
+ if (instance) {
+ return instance;
+ }
  globalThis.__nitro__ ??= {};
- return (globalThis.__nitro__[_id] ??= initNitroApp());
+ instance = globalThis.__nitro__[_id] = createNitroApp();
+ if (hasPlugins) {
+ initNitroPlugins(instance);
+ }
+ return instance;
 }
 
 export function useNitroHooks(_id = APP_ID): HookableCore<NitroRuntimeHooks> {
@@ -89,23 +97,6 @@ export function fetch(
  return fetch(resource, init);
 }
 
-function initNitroApp(): NitroApp {
- const nitroApp = (globalThis.__nitro__ = createNitroApp());
- if (hasPlugins) {
- for (const plugin of plugins) {
- try {
- plugin(
- nitroApp as NitroApp & { hooks: NonNullable<NitroApp["hooks"]> }
- );
- } catch (error: any) {
- nitroApp.captureError?.(error, { tags: ["plugin"] });
- throw error;
- }
- }
- }
- return nitroApp;
-}
-
 function createNitroApp(): NitroApp {
  const hooks = hasHooks ? new HookableCore<NitroRuntimeHooks>() : undefined;
 
@@ -171,6 +162,18 @@ function createNitroApp(): NitroApp {
  return app;
 }
 
+function initNitroPlugins(app: NitroApp) {
+ for (const plugin of plugins) {
+ try {
+ plugin(app as NitroApp & { hooks: NonNullable<NitroApp["hooks"]> });
+ } catch (error: any) {
+ app.captureError?.(error, { tags: ["plugin"] });
+ throw error;
+ }
+ }
+ return app;
+}
+
 function createH3App(config: H3Config) {
  // Create H3 app
  const h3App = new H3Core(config);