🧹 chore: setImmediate fallback

Author: SaltyAom

CHANGELOG.md

@@ -1,10 +1,11 @@
 # 1.4.19 - 9 Dec 2025
 Improvement
 - [#1588](https://github.com/elysiajs/elysia/pull/1588), [#1587](https://github.com/elysiajs/elysia/pull/1587) add seen weakset during mergeDeep
-- [#1607](https://github.com/elysiajs/elysia/issues/1607), [#1606](https://github.com/elysiajs/elysia/issues/1606), [#1139](https://github.com/elysiajs/elysia/issues/1138) nested form data
+- [#1607](https://github.com/elysiajs/elysia/issues/1607), [#1606](https://github.com/elysiajs/elysia/issues/1606), [#1139](https://github.com/elysiajs/elysia/issues/1138) data coercion on nested form data
 
 Bug fix:
 - [#1591](https://github.com/elysiajs/elysia/pull/1591), [#1590](https://github.com/elysiajs/elysia/pull/1591) merge set.headers without duplicating Response
+- add set immediate fallback
 
 # 1.4.18 - 4 Dec 2025
 Security:

example/a.ts

@@ -1,22 +1,12 @@
 import { Elysia, t } from '../src'
-import * as z from 'zod'
-import { post, req } from '../test/utils'
 
-const app = new Elysia({
-	cookie: {
-		domain: "\\` + console.log(c.q='pwn2') }) //"
-	}
-})
-	.get('/', ({ cookie: { session } }) => 'awd')
-
-console.log(app.routes[0].compile().toString())
-
-const root = await app.handle(
-	new Request('http://localhost/', {
-		headers: {
-			Cookie: 'session=1234'
-		}
-	})
-)
-
-console.log(await root.text())
+new Elysia({ aot: false })
+	.guard(
+		{
+			afterResponse: () => {
+				console.log('afterResponse')
+			}
+		},
+		(app) => app.get('/test', () => 'afterResponse')
+	)
+	.get('/', () => 'hi')

src/compose.ts

@@ -19,6 +19,7 @@ import {
 import {
 	ELYSIA_REQUEST_ID,
 	getLoosePath,
+	hasSetImmediate,
 	lifeCycleToFn,
 	randomId,
 	redirect,
@@ -444,6 +445,10 @@ const coerceTransformDecodeError = (
 	`throw error.error ?? new ValidationError('${type}',validator.${type},${value},${allowUnsafeValidationDetails})}` +
 	`}`
 
+const setImmediateFn = hasSetImmediate
+	? 'setImmediate'
+	: 'Promise.resolve().then'
+
 export const composeHandler = ({
 	app,
 	path,
@@ -804,7 +809,7 @@ export const composeHandler = ({
 		let afterResponse = ''
 
 		afterResponse +=
-			`\nsetImmediate(async()=>{` +
+			`\n${setImmediateFn}(async()=>{` +
 			`if(c.responseValue){` +
 			`if(c.responseValue instanceof ElysiaCustomStatusResponse) c.set.status=c.responseValue.code\n` +
 			(hasStream
@@ -1474,21 +1479,26 @@ export const composeHandler = ({
 						if (candidate) {
 							const isFirst = fileUnions.length === 0
 							// Handle case where schema is wrapped in a Union (e.g., ObjectString coercion)
-							let properties = candidate.schema?.properties ?? type.properties
+							let properties =
+								candidate.schema?.properties ?? type.properties
 
 							// If no properties but schema is a Union, try to find the Object in anyOf
 							if (!properties && candidate.schema?.anyOf) {
-								const objectSchema = candidate.schema.anyOf.find((s: any) => s.type === 'object')
+								const objectSchema =
+									candidate.schema.anyOf.find(
+										(s: any) => s.type === 'object'
+									)
 								if (objectSchema) {
 									properties = objectSchema.properties
 								}
 							}
 
 							if (!properties) continue
 
-							const iterator = Object.entries(
-								properties
-							) as [string, TSchema][]
+							const iterator = Object.entries(properties) as [
+								string,
+								TSchema
+							][]
 
 							let validator = isFirst ? '\n' : ' else '
 							validator += `if(fileUnions[${fileUnions.length}].Check(c.body)){`
@@ -1773,7 +1783,7 @@ export const composeHandler = ({
 					(hasTrace || hooks.afterResponse?.length
 						? `afterHandlerStreamListener=stream[2]\n`
 						: '') +
-					`setImmediate(async ()=>{` +
+					`${setImmediateFn}(async ()=>{` +
 					`if(listener)for await(const v of listener){}\n`
 				handleReporter.resolve()
 				fnLiteral += `})` + (maybeAsync ? '' : `})()`) + `}else{`
@@ -2337,7 +2347,7 @@ export const composeGeneralHandler = (app: AnyElysia) => {
 
 		const prefix = app.event.afterResponse.some(isAsync) ? 'async' : ''
 		afterResponse +=
-			`\nsetImmediate(${prefix}()=>{` +
+			`\n${setImmediateFn}(${prefix}()=>{` +
 			`if(c.responseValue instanceof ElysiaCustomStatusResponse) c.set.status=c.responseValue.code\n`
 
 		for (let i = 0; i < app.event.afterResponse.length; i++) {
@@ -2571,7 +2581,7 @@ export const composeErrorHandler = (app: AnyElysia) => {
 
 		let afterResponse = ''
 		const prefix = hooks.afterResponse?.some(isAsync) ? 'async' : ''
-		afterResponse += `\nsetImmediate(${prefix}()=>{`
+		afterResponse += `\n${setImmediateFn}(${prefix}()=>{`
 
 		const reporter = createReport({
 			context: 'context',

src/dynamic-handle.ts

@@ -13,7 +13,7 @@ import { parseQuery } from './parse-query'
 import type { ElysiaTypeCheck } from './schema'
 import type { TypeCheck } from './type-system'
 import type { Handler, LifeCycleStore, SchemaValidator } from './types'
-import { redirect, StatusMap, signCookie } from './utils'
+import { hasSetImmediate, redirect, StatusMap, signCookie } from './utils'
 
 // JIT Handler
 export type DynamicHandler = {
@@ -79,6 +79,8 @@ export const createDynamicHandler = (app: AnyElysia) => {
 			response: unknown
 		}
 
+		let hooks: DynamicHandler['hooks']
+
 		try {
 			if (app.event.request)
 				for (let i = 0; i < app.event.request.length; i++) {
@@ -109,7 +111,8 @@ export const createDynamicHandler = (app: AnyElysia) => {
 				throw new NotFoundError()
 			}
 
-			const { handle, hooks, validator, content, route } = handler.store
+			const { handle, validator, content, route } = handler.store
+			hooks = handler.store.hooks
 
 			let body: string | Record<string, any> | undefined
 			if (request.method !== 'GET' && request.method !== 'HEAD') {
@@ -661,11 +664,22 @@ export const createDynamicHandler = (app: AnyElysia) => {
 			// @ts-expect-error private
 			return app.handleError(context, reportedError)
 		} finally {
-			if (app.event.afterResponse)
-				setImmediate(async () => {
-					for (const afterResponse of app.event.afterResponse!)
-						await afterResponse.fn(context as any)
-				})
+			const afterResponses = hooks!
+				? hooks.afterResponse
+				: app.event.afterResponse
+
+			if (afterResponses) {
+				if (hasSetImmediate)
+					setImmediate(async () => {
+						for (const afterResponse of afterResponses)
+							await afterResponse.fn(context as any)
+					})
+				else
+					Promise.resolve().then(async () => {
+						for (const afterResponse of afterResponses)
+							await afterResponse.fn(context as any)
+					})
+			}
 		}
 	}
 }

src/utils.ts

@@ -399,6 +399,7 @@ export const lifeCycleToArray = (a: LifeCycleStore) => {
 
 const isBun = typeof Bun !== 'undefined'
 const hasBunHash = isBun && typeof Bun.hash === 'function'
+export const hasSetImmediate = typeof setImmediate === 'function'
 
 // https://stackoverflow.com/a/52171480
 export const checksum = (s: string) => {