fix: unwrap transform errors

src/compose.ts

@@ -2343,9 +2343,10 @@ export const composeErrorHandler = (
 	}
 
 	fnLiteral += `if(error.constructor.name === "ValidationError" || error.constructor.name === "TransformDecodeError") {
-		set.status = error.status ?? 422
+	    const reportedError = error.error ?? error
+		set.status = reportedError.status ?? 422
 		return new Response(
-			error.message,
+			reportedError.message,
 			{
 				headers: Object.assign(
 					{ 'content-type': 'application/json'},

src/dynamic-handle.ts

@@ -17,6 +17,7 @@ import { redirect, signCookie, StatusMap } from './utils'
 import { parseCookie } from './cookies'
 
 import type { Handler, LifeCycleStore, SchemaValidator } from './types'
+import { TransformDecodeError } from '@sinclair/typebox/value'
 
 // JIT Handler
 export type DynamicHandler = {
@@ -420,11 +421,13 @@ export const createDynamicHandler =
 
 			return (context.response = mapResponse(response, context.set))
 		} catch (error) {
-			if ((error as ElysiaErrors).status)
-				set.status = (error as ElysiaErrors).status
-
+			const reportedError = (error instanceof TransformDecodeError && error.error)
+				? error.error
+				: error
+			if ((reportedError as ElysiaErrors).status)
+				set.status = (reportedError as ElysiaErrors).status
 			// @ts-expect-error private
-			return app.handleError(context, error)
+			return app.handleError(context, reportedError)
 		} finally {
 			for (const afterResponse of app.event.afterResponse)
 				await afterResponse.fn(context as any)

test/core/handle-error.test.ts

@@ -204,4 +204,25 @@ describe('Handle Error', () => {
 			'APIError'
 		)
 	})
+
+	it('handle error in Transform', async () => {
+		const route = new Elysia().get('/', ({query: {aid}}) => aid, {
+			query: t.Object({
+				aid: t.Transform(t.String())
+					.Decode((value) => {
+						throw new NotFoundError('foo')
+					})
+					.Encode((value) => `1`)
+			})
+		})
+
+		let response = await (new Elysia({ aot: false })).use(route).handle(req('/?aid=a'))
+		expect(response.status).toEqual(404)
+		expect(await response.text()).toEqual('foo')
+
+		response = await (new Elysia({aot: true})).use(route).handle(req('/?aid=a'))
+		expect(response.status).toEqual(404)
+		expect(await response.text()).toEqual('foo')
+	})
+
 })