🔧 fix: #1348 onAfterResponse runs twice if NotFoundError thrown and onError provided

Author: SaltyAom

CHANGELOG.md

@@ -1,3 +1,7 @@
+# 1.3.12 - 19 Aug 2025
+Bug fix:
+- [#1348](https://github.com/elysiajs/elysia/issues/1348) onAfterResponse runs twice if NotFoundError thrown and onError provided 
+
 # 1.3.11 - 18 Aug 2025
 Bug fix:
 - [#1346](https://github.com/elysiajs/elysia/issues/1346) cannot declare 'mep' twice 

example/a.ts

@@ -1,14 +1,26 @@
 import { Elysia, t } from '../src'
+import { req } from '../test/utils'
 
-const IdsModel = new Elysia().model({
-	ids: t.Object({
-		ids: t.Array(t.String())
-	})
-})
+let isAfterResponseCalled = false
 
-const app = new Elysia({ aot: false })
-	.use(IdsModel)
-	.get('/', ({ query }) => query, {
-		query: 'ids'
+const app = new Elysia({ precompile: true })
+	.onAfterResponse(() => {
+		isAfterResponseCalled = true
+	})
+	.onError(() => {
+		return new Response('a', {
+			status: 401,
+			headers: {
+				awd: 'b'
+			}
+		})
 	})
-	.listen(3000)
+	.compile()
+
+// console.log(app.handleError.toString())
+
+await app.handle(req('/'))
+// wait for next tick
+await Bun.sleep(1)
+
+console.log(isAfterResponseCalled)

package.json

@@ -1,7 +1,7 @@
 {
 	"name": "elysia",
 	"description": "Ergonomic Framework for Human",
-	"version": "1.3.11",
+	"version": "1.3.12",
 	"author": {
 		"name": "saltyAom",
 		"url": "https://github.com/SaltyAom",

src/compose.ts

@@ -2264,7 +2264,7 @@ export const composeGeneralHandler = (app: AnyElysia) => {
 	findDynamicRoute += router.http.root.ALL ? '??router.find("ALL",p)\n' : '\n'
 
 	let afterResponse = `c.error=notFound\n`
-	if (app.event.afterResponse?.length) {
+	if (app.event.afterResponse?.length && !app.event.error) {
 		const prefix = app.event.afterResponse.some(isAsync) ? 'async' : ''
 		afterResponse += `\nsetImmediate(${prefix}()=>{`
 
@@ -2532,7 +2532,9 @@ export const composeErrorHandler = (app: AnyElysia) => {
 			if (hasReturn(handler)) {
 				fnLiteral +=
 					`_r=${response}\nif(_r!==undefined){` +
-					`if(_r instanceof Response)return mapResponse(_r,set${adapter.mapResponseContext})\n` +
+					`if(_r instanceof Response){` +
+					afterResponse() +
+					`return mapResponse(_r,set${adapter.mapResponseContext})}` +
 					`if(_r instanceof ElysiaCustomStatusResponse){` +
 					`error.status=error.code\n` +
 					`error.message = error.response` +
@@ -2562,7 +2564,9 @@ export const composeErrorHandler = (app: AnyElysia) => {
 
 				mapResponseReporter.resolve()
 
-				fnLiteral += `return mapResponse(${saveResponse}_r,set${adapter.mapResponseContext})}`
+				fnLiteral +=
+					afterResponse() +
+					`return mapResponse(${saveResponse}_r,set${adapter.mapResponseContext})}`
 			} else fnLiteral += response
 
 			fnLiteral += '}'

test/lifecycle/response.test.ts

@@ -207,4 +207,29 @@ describe('On After Response Error', () => {
 		expect(isOnResponseCalled).toBeTrue()
 		expect(onResponseCalledCounter).toBe(1)
 	})
+
+	it.each([
+		{ aot: true, withOnError: true },
+		{ aot: true, withOnError: false },
+
+		{ aot: false, withOnError: true },
+		{ aot: false, withOnError: false }
+	])(
+		'should execute onAfterResponse once during NotFoundError aot=$aot,\twithOnError=$withOnError',
+		async ({ aot, withOnError }) => {
+			let counter = 0
+
+			const app = new Elysia({ aot }).onAfterResponse(() => {
+				counter++
+			})
+
+			if (withOnError) app.onError(() => {})
+
+			const req = new Request('http://localhost/notFound')
+			await app.handle(req)
+			await Bun.sleep(1)
+
+			expect(counter).toBe(1)
+		}
+	)
 })