🔧 fix(type-generator): handle union type

Author: SaltyAom

CHANGELOG.md

@@ -1,3 +1,8 @@
+# 1.3.5 - 3 Sep 2025
+Bug fix:
+- type generator: merge references with existing response status
+- type generator: handle union type
+
 # 1.3.4 - 3 Sep 2025
 Bug fix:
 - type generator: exclude unknown type

example/gen.ts

@@ -1,5 +1,5 @@
 import { Elysia, t } from 'elysia'
-import { openapi } from '../src/index'
+import { openapi, withHeaders } from '../src/index'
 import { fromTypes } from '../src/gen'
 
 export const app = new Elysia()
@@ -8,7 +8,26 @@ export const app = new Elysia()
 			references: fromTypes('example/gen.ts')
 		})
 	)
-	.get('/', { test: 'hello' as const })
+	.get(
+		'/',
+		() =>
+			({ test: 'hello' as const }) as any as
+				| { test: 'hello' }
+				| undefined,
+		{
+			response: {
+				204: withHeaders(
+					t.Void({
+						title: 'Thing',
+						description: 'Void response'
+					}),
+					{
+						'X-Custom-Header': t.Literal('Elysia')
+					}
+				)
+			}
+		}
+	)
 	.post(
 		'/json',
 		({ body, status }) => (Math.random() > 0.5 ? status(418) : body),

package.json

@@ -1,6 +1,6 @@
 {
     "name": "@elysiajs/openapi",
-    "version": "1.3.4",
+    "version": "1.3.5",
     "description": "Plugin for Elysia to auto-generate API documentation",
     "author": {
         "name": "saltyAom",

src/openapi.ts

@@ -2,7 +2,7 @@ import { t, type AnyElysia, type TSchema, type InputSchema } from 'elysia'
 import type { HookContainer } from 'elysia/types'
 
 import type { OpenAPIV3 } from 'openapi-types'
-import type { TProperties } from '@sinclair/typebox'
+import { Kind, type TProperties } from '@sinclair/typebox'
 
 import type {
 	AdditionalReference,
@@ -53,6 +53,13 @@ export const getPossiblePath = (path: string): string[] => {
 	return paths
 }
 
+const isValidSchema = (schema: any): schema is TSchema =>
+	typeof schema === 'object' &&
+	((Kind in schema && schema[Kind] !== 'Unknown') ||
+		schema.type ||
+		schema.properties ||
+		schema.items)
+
 /**
  * Converts Elysia routes to OpenAPI 3.0.3 paths schema
  * @param routes Array of Elysia route objects
@@ -111,21 +118,33 @@ export function toOpenAPISchema(
 				const refer = reference[route.path]?.[method]
 				if (!refer) continue
 
-				if (!hooks.body && refer.body?.type) hooks.body = refer.body
-				if (!hooks.query && refer.query?.type) hooks.query = refer.query
-				if (!hooks.params && refer.params?.type)
+				if (!hooks.body && isValidSchema(refer.body))
+					hooks.body = refer.body
+
+				if (!hooks.query && isValidSchema(refer.query))
+					hooks.query = refer.query
+
+				if (!hooks.params && isValidSchema(refer.params))
 					hooks.params = refer.params
-				if (!hooks.headers && refer.headers?.type)
+
+				if (!hooks.headers && isValidSchema(refer.headers))
 					hooks.headers = refer.headers
-				if (!hooks.response && refer.response) {
-					hooks.response = {}
 
+				if (refer.response)
 					for (const [status, schema] of Object.entries(
 						refer.response
 					))
-						if (!hooks.response[status as any] && schema?.type)
-							hooks.response[status as any] = schema
-				}
+						if (isValidSchema(schema)) {
+							if (!hooks.response) hooks.response = {}
+
+							if (
+								!hooks.response[
+									status as keyof (typeof hooks)['response']
+								]
+							)
+								// @ts-ignore
+								hooks.response[status] = schema
+						}
 			}
 
 		if (