Fix for headers being overwritten by query

src/openapi.ts

@@ -345,7 +345,7 @@ export function toOpenAPISchema(
 
 		// Handle header parameters
 		if (hooks.headers) {
-			const headers = unwrapReference(unwrapSchema(hooks.query, vendors), definitions)
+			const headers = unwrapReference(unwrapSchema(hooks.headers, vendors), definitions)
 
 			if (headers && headers.type === 'object' && headers.properties) {
 				const required = headers.required || []

test/openapi.test.ts

@@ -1,5 +1,6 @@
 import { describe, it, expect } from 'bun:test'
-import { getPossiblePath } from '../src/openapi'
+import { Elysia, t } from 'elysia'
+import { getPossiblePath, toOpenAPISchema } from '../src/openapi'
 
 describe('OpenAPI utilities', () => {
 	it('getPossiblePath', () => {
@@ -12,3 +13,54 @@ describe('OpenAPI utilities', () => {
 		])
 	})
 })
+
+describe('Convert Elysia routes to OpenAPI 3.0.3 paths schema', () => {
+	describe('with path, header, query and cookie params', () => {
+		const app = new Elysia().get('/', () => 'hi', {
+			response: t.String({ description: 'sample description' }),
+			headers: t.Object({
+				testheader: t.String()
+			}),
+			params: t.Object({
+				testparam: t.String()
+			}),
+			query: t.Object({
+				testquery: t.String()
+			}),
+			cookie: t.Cookie({
+				testcookie: t.String()
+			})
+		})
+
+		const {
+			paths: { ['/']: path }
+		} = toOpenAPISchema(app)
+
+		const parameters = path?.get?.parameters ?? []
+
+		it('includes all expected parameters', () => {
+			const names = parameters.map((p: any) => p.name)
+			expect(names).toEqual(
+				expect.arrayContaining([
+					'testheader',
+					'testparam',
+					'testquery',
+					'testcookie'
+				])
+			)
+			expect(names).toHaveLength(4)
+		})
+
+		it('marks each parameter with the correct OpenAPI parameter location', () => {
+			const map = Object.fromEntries(
+				parameters.map((p: any) => [p.name, p.in])
+			)
+			expect(map).toMatchObject({
+				testheader: 'header',
+				testparam: 'path',
+				testquery: 'query',
+				testcookie: 'cookie'
+			})
+		})
+	})
+})