[fix] goto self can incorrectly result in 404 #4316 (#4318)

* fix:  last match route  fallthrough return 404

* fix

* make test relate more directly to the missing method

* remove renamed test files

* lint

Co-authored-by: tom <[email protected]>
Co-authored-by: Rich Harris <[email protected]>

Author: 3 people

.changeset/spicy-suits-relax.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/kit': patch
+---
+
+Allow page endpoint without GET handler

packages/kit/src/runtime/client/client.js

@@ -561,7 +561,7 @@ export function create_client({ target, session, base, trailing_slash }) {
 	 * @param {import('./types').NavigationIntent} intent
 	 * @param {boolean} no_cache
 	 */
-	async function load_route(route, { id, url, path }, no_cache) {
+	async function load_route(route, { id, url, path, routes }, no_cache) {
 		if (!no_cache) {
 			const cached = cache.get(id);
 			if (cached) return cached;
@@ -570,7 +570,7 @@ export function create_client({ target, session, base, trailing_slash }) {
 		const [pattern, a, b, get_params, shadow_key] = route;
 		const params = get_params
 			? // the pattern is for the route which we've already matched to this path
-			  get_params(/** @type {RegExpExecArray}  */ (pattern.exec(path)))
+			  get_params(/** @type {RegExpExecArray} */ (pattern.exec(path)))
 			: {};
 
 		const changed = current.url && {
@@ -642,10 +642,14 @@ export function create_client({ target, session, base, trailing_slash }) {
 							}
 
 							if (res.status === 204) {
-								// fallthrough
-								return;
+								if (route !== routes[routes.length - 1]) {
+									// fallthrough
+									return;
+								}
+								props = {};
+							} else {
+								props = await res.json();
 							}
-							props = await res.json();
 						} else {
 							status = res.status;
 							error = new Error('Failed to load data');

packages/kit/test/apps/basics/src/routes/shadowed/index.svelte

@@ -4,6 +4,7 @@
 <a href="/shadowed/error-get">error-get</a>
 <a href="/shadowed/no-get">no-get</a>
 <a href="/shadowed/dynamic/foo">dynamic/foo</a>
+<a href="/shadowed/missing-get">missing-get</a>
 
 <form action="/shadowed/redirect-post" method="post">
 	<button type="submit" id="redirect-post">redirect</button>

packages/kit/test/apps/basics/src/routes/shadowed/missing-get/index.js

@@ -0,0 +1 @@
+export const post = () => {};

packages/kit/test/apps/basics/src/routes/shadowed/missing-get/index.svelte

@@ -0,0 +1 @@
+<h1>post without get</h1>

packages/kit/test/apps/basics/test/test.js

@@ -522,6 +522,23 @@ test.describe.parallel('Shadowed pages', () => {
 		await clicknav('[href="/shadowed/redirect/a"]');
 		expect(await page.textContent('h1')).toBe('done');
 	});
+
+	test('Endpoint without GET', async ({ page, clicknav, baseURL, javaScriptEnabled }) => {
+		await page.goto('/shadowed');
+
+		/** @type {string[]} */
+		const requests = [];
+		page.on('request', (r) => requests.push(r.url()));
+
+		await clicknav('[href="/shadowed/missing-get"]');
+
+		expect(await page.textContent('h1')).toBe('post without get');
+
+		// check that the router didn't fall back to the server
+		if (javaScriptEnabled) {
+			expect(requests).not.toContain(`${baseURL}/shadowed/missing-get`);
+		}
+	});
 });
 
 test.describe.parallel('Endpoints', () => {