fix: hydration for null body http status response

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

@@ -0,0 +1 @@
+export const NULL_BODY_STATUS = [101, 103, 204, 205, 304];

packages/kit/src/runtime/server/page/load_data.js

@@ -3,6 +3,7 @@ import { disable_search, make_trackable } from '../../../utils/url.js';
 import { validate_depends } from '../../shared.js';
 import { b64_encode } from '../../utils.js';
 import { with_event } from '../../app/server/event.js';
+import { NULL_BODY_STATUS } from '../constants.js';
 
 /**
  * Calls the user's server `load` function.
@@ -278,7 +279,7 @@ export function create_universal_fetch(event, state, fetched, csr, resolve_opts)
 		const proxy = new Proxy(response, {
 			get(response, key, _receiver) {
 				/**
-				 * @param {string} body
+				 * @param {string | undefined} body
 				 * @param {boolean} is_b64
 				 */
 				async function push_fetched(body, is_b64) {
@@ -325,6 +326,11 @@ export function create_universal_fetch(event, state, fetched, csr, resolve_opts)
 				async function text() {
 					const body = await response.text();
 
+          if (NULL_BODY_STATUS.includes(response.status) && typeof body === 'string' && body === '') {
+            await push_fetched(undefined, false);
+            return undefined;
+          }
+
 					if (!body || typeof body === 'string') {
 						await push_fetched(body, false);
 					}
@@ -342,7 +348,8 @@ export function create_universal_fetch(event, state, fetched, csr, resolve_opts)
 
 				if (key === 'json') {
 					return async () => {
-						return JSON.parse(await text());
+						const body = await text();
+            return body ? JSON.parse(body) : undefined;
 					};
 				}
 

packages/kit/src/runtime/server/page/types.d.ts

@@ -6,7 +6,7 @@ export interface Fetched {
 	method: string;
 	request_body?: string | ArrayBufferView | null;
 	request_headers?: HeadersInit | undefined;
-	response_body: string;
+	response_body: string | undefined;
 	response: Response;
 	is_b64?: boolean;
 }