[fix] handle undefined body on endpoint output

.changeset/fluffy-cheetahs-remain.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/kit': patch
+---
+
+handle undefined body on endpoint output

packages/kit/src/runtime/server/endpoint.js

@@ -33,7 +33,7 @@ export default async function render_route(request, route) {
 				);
 			}
 
-			let { status = 200, body, headers = {} } = response;
+			let { status = 200, body = {}, headers = {} } = response;
 
 			headers = lowercase_keys(headers);
 			const type = headers['content-type'];

packages/kit/test/apps/basics/src/routes/endpoint-output/_tests.js

@@ -0,0 +1,26 @@
+import * as assert from 'uvu/assert';
+
+/** @type {import('test').TestMaker} */
+export default function (test) {
+	test('not ok on void endpoint', null, async ({ fetch }) => {
+		const res = await fetch('/endpoint-output/empty', { method: 'DELETE' });
+		assert.equal(res.ok, false);
+	});
+	test('200 status on empty endpoint', null, async ({ fetch }) => {
+		const res = await fetch('/endpoint-output/empty');
+		assert.equal(res.status, 200);
+		assert.equal(await res.json(), {});
+	});
+
+	test('set-cookie without body', null, async ({ fetch }) => {
+		const res = await fetch('/endpoint-output/headers');
+		assert.equal(res.status, 200);
+		assert.equal(res.headers.has('set-cookie'), true);
+	});
+
+	test('200 status by default', null, async ({ fetch }) => {
+		const res = await fetch('/endpoint-output/body');
+		assert.equal(res.status, 200);
+		assert.equal(await res.text(), '{}');
+	});
+}

packages/kit/test/apps/basics/src/routes/endpoint-output/body.js

@@ -0,0 +1,4 @@
+/** @type {import('@sveltejs/kit').RequestHandler} */
+export function get() {
+	return { body: {} };
+}

packages/kit/test/apps/basics/src/routes/endpoint-output/empty.js

@@ -0,0 +1,7 @@
+/** @type {import('@sveltejs/kit').RequestHandler} */
+export function get() {
+	return {};
+}
+
+/** @type {import('@sveltejs/kit').RequestHandler} */
+export function del() {}

packages/kit/test/apps/basics/src/routes/endpoint-output/headers.js

@@ -0,0 +1,8 @@
+/** @type {import('@sveltejs/kit').RequestHandler} */
+export function get() {
+	return {
+		headers: {
+			'Set-Cookie': 'foo=bar'
+		}
+	};
+}