🔧 fix: #1700

CHANGELOG.md

@@ -1,6 +1,11 @@
 # 1.4.23
+Bug fix:
+- [#1700](https://github.com/elysiajs/elysia/issues/1700) distinct union object
 - [#1683](https://github.com/elysiajs/elysia/pull/1683) response validation returns 500 instead of 422 for nested schemas in dynamic mode
 
+Change:
+- update exact-mirror to 0.2.7
+
 # 1.4.22 - 14 Jan 2026
 Improvement:
 - use imperative check for `replaceURLPath` instead of allocating `new URL`

bun.lock

@@ -6,7 +6,7 @@
       "name": "elysia",
       "dependencies": {
         "cookie": "^1.1.1",
-        "exact-mirror": "^0.2.6",
+        "exact-mirror": "^0.2.7",
         "fast-decode-uri-component": "^1.0.1",
         "memoirist": "^0.4.0",
       },
@@ -34,7 +34,7 @@
       "peerDependencies": {
         "@sinclair/typebox": ">= 0.34.0 < 1",
         "@types/bun": ">= 1.2.0",
-        "exact-mirror": ">= 0.0.9",
+        "exact-mirror": "^0.2.6",
         "file-type": ">= 20.0.0",
         "openapi-types": ">= 12.0.0",
         "typescript": ">= 5.0.0",
@@ -363,7 +363,7 @@
 
     "esutils": ["esutils@2.0.3", "", {}, "sha512-kVscqXk4OCp68SZ0dkgEKVi6/8ij300KBWTJq32P/dYeWTSwK41WyTxalN1eRmA5Z9UU/LX9D7FWSmV9SAYx6g=="],
 
-    "exact-mirror": ["exact-mirror@0.2.6", "", { "peerDependencies": { "@sinclair/typebox": "^0.34.15" }, "optionalPeers": ["@sinclair/typebox"] }, "sha512-7s059UIx9/tnOKSySzUk5cPGkoILhTE4p6ncf6uIPaQ+9aRBQzQjc9+q85l51+oZ+P6aBxh084pD0CzBQPcFUA=="],
+    "exact-mirror": ["exact-mirror@0.2.7", "", { "peerDependencies": { "@sinclair/typebox": "^0.34.15" }, "optionalPeers": ["@sinclair/typebox"] }, "sha512-+MeEmDcLA4o/vjK2zujgk+1VTxPR4hdp23qLqkWfStbECtAq9gmsvQa3LW6z/0GXZyHJobrCnmy1cdeE7BjsYg=="],
 
     "expect-type": ["expect-type@1.2.2", "", {}, "sha512-JhFGDVJ7tmDJItKhYgJCGLOWjuK9vPxiXoUFLwLDc99NlmklilbiQJwoctZtt13+xMw91MCk/REan6MWHqDjyA=="],
 

example/a.ts

@@ -1,24 +1,20 @@
 import { Elysia, t } from '../src'
+import { req } from '../test/utils'
 
-const verifyToken = new Elysia()
-	.macro('verifyToken', {
-		headers: t.Object({
-			authorization: t.String()
-		}),
-		resolve({ headers }) {
-			// headers should be typed as { authorization: string }
-			// but TypeScript shows: Record<string, string | undefined>
-			const token = headers.authorization // Type is 'string | undefined', not 'string'
-				? headers.authorization.substring(7)
-				: undefined
-
-			return { token }
+const app = new Elysia()
+	.get('/health', () => ({ status: 'healthy' }) as const, {
+		response: {
+			200: t.Union([
+				t.Object({
+					status: t.Literal('a'),
+					a: t.Object({ b: t.Integer() }) // <-- if you comment this line, you won't have an error
+				}),
+				t.Object({ status: t.Literal('healthy') })
+			])
 		}
 	})
-	.get(
-		'/',
-		({ token }) => {},
-		{
-			verifyToken: true
-		}
-	)
+	.listen(3000)
+
+app.handle(req('/health'))
+	.then((x) => x.status)
+	.then(console.log)

package.json

@@ -191,7 +191,7 @@
 	},
 	"dependencies": {
 		"cookie": "^1.1.1",
-		"exact-mirror": "^0.2.6",
+		"exact-mirror": "^0.2.7",
 		"fast-decode-uri-component": "^1.0.1",
 		"memoirist": "^0.4.0"
 	},

src/error.ts

@@ -8,7 +8,7 @@ import type {
 
 import { StatusMap, InvertedStatusMap } from './utils'
 import type { ElysiaTypeCheck } from './schema'
-import { Prettify, StandardSchemaV1Like } from './types'
+import { StandardSchemaV1Like } from './types'
 
 // ? Cloudflare worker support
 const env =
@@ -160,7 +160,7 @@ interface ValueErrorWithSummary extends ValueError {
 	summary?: string
 }
 
-export const mapValueError = (error: ValueError): ValueErrorWithSummary => {
+export const mapValueError = (error: ValueError | undefined): ValueErrorWithSummary | undefined => {
 	if (!error) return error
 
 	let { message, path, value, type } = error
@@ -388,7 +388,7 @@ export class ValidationError extends Error {
 			// @ts-ignore private field
 			const schema = validator?.schema ?? validator
 
-			if (!isProduction && !allowUnsafeValidationDetails) {
+			if (!isProduction && !allowUnsafeValidationDetails)
 				try {
 					expected = Value.Create(schema)
 				} catch (error) {
@@ -399,7 +399,6 @@ export class ValidationError extends Error {
 						error
 					}
 				}
-			}
 
 			customError =
 				error?.schema?.message || error?.schema?.error !== undefined
@@ -418,7 +417,7 @@ export class ValidationError extends Error {
 											property: accessor,
 											message: error?.message,
 											summary:
-												mapValueError(error).summary,
+												mapValueError(error)?.summary,
 											found: value,
 											expected,
 											errors:
@@ -458,7 +457,7 @@ export class ValidationError extends Error {
 						on: type,
 						property: accessor,
 						message: error?.message,
-						summary: mapValueError(error).summary,
+						summary: mapValueError(error)?.summary,
 						expected,
 						found: value,
 						errors:
@@ -596,9 +595,7 @@ export class ValidationError extends Error {
 					on: this.type,
 					property: this.valueError?.path || 'root',
 					message,
-					summary: this.valueError
-						? mapValueError(this.valueError).summary
-						: undefined,
+					summary: mapValueError(this.valueError)?.summary,
 					found: value,
 					expected,
 					errors

test/validator/response.test.ts

@@ -370,7 +370,7 @@ describe('Response Validator', () => {
 	})
 
 	it('return static undefined with status based schema', async () => {
-		const app = new Elysia().get('/', undefined, {
+		const app = new Elysia().get('/', undefined as any, {
 			response: {
 				200: t.Union([
 					t.Void(),
@@ -562,4 +562,24 @@ describe('Response Validator', () => {
 
 		expect(result.join('')).toContain('data: {"name":"Name"}')
 	})
+
+	it('handle distinct union', () => {
+		const app = new Elysia()
+			.get('/health', () => ({ status: 'healthy' }) as const, {
+				response: {
+					200: t.Union([
+						t.Object({
+							status: t.Literal('a'),
+							a: t.Object({ b: t.Integer() })
+						}),
+						t.Object({ status: t.Literal('healthy') })
+					])
+				}
+			})
+			.listen(3000)
+
+		const status = app.handle(req('/health')).then((x) => x.status)
+
+		expect(status).resolves.toBe(200)
+	})
 })