fix: silently 404 Chrome DevTools workspaces request in dev and preview

.changeset/quiet-devtools-mute.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/kit': patch
+---
+
+fix: silently 404 Chrome DevTools workspaces request in dev and preview

packages/kit/src/exports/vite/dev/index.js

@@ -15,7 +15,7 @@ import { SVELTE_KIT_ASSETS } from '../../../constants.js';
 import * as sync from '../../../core/sync/sync.js';
 import { get_mime_lookup, runtime_base } from '../../../core/utils.js';
 import { compact } from '../../../utils/array.js';
-import { not_found } from '../utils.js';
+import { is_chrome_devtools_request, not_found } from '../utils.js';
 import { SCHEME } from '../../../utils/url.js';
 import { check_feature } from '../../../utils/features.js';
 import { escape_html } from '../../../utils/escape.js';
@@ -467,6 +467,10 @@ export async function dev(vite, vite_config, svelte_config, get_remotes) {
 					return;
 				}
 
+				if (is_chrome_devtools_request(decoded, res)) {
+					return;
+				}
+
 				if (!decoded.startsWith(svelte_config.kit.paths.base)) {
 					return not_found(req, res, svelte_config.kit.paths.base);
 				}

packages/kit/src/exports/vite/preview/index.js

@@ -7,7 +7,7 @@ import { loadEnv, normalizePath } from 'vite';
 import { createReadableStream, getRequest, setResponse } from '../../../exports/node/index.js';
 import { installPolyfills } from '../../../exports/node/polyfills.js';
 import { SVELTE_KIT_ASSETS } from '../../../constants.js';
-import { not_found } from '../utils.js';
+import { is_chrome_devtools_request, not_found } from '../utils.js';
 
 /** @typedef {import('http').IncomingMessage} Req */
 /** @typedef {import('http').ServerResponse} Res */
@@ -102,6 +102,10 @@ export async function preview(vite, vite_config, svelte_config) {
 				return;
 			}
 
+			if (is_chrome_devtools_request(pathname, res)) {
+				return;
+			}
+
 			if (pathname.startsWith(base)) {
 				next();
 			} else {

packages/kit/src/exports/vite/utils.js

@@ -76,6 +76,24 @@ export function get_env(env_config, mode) {
 	};
 }
 
+/**
+ * Silently respond with 404 for Chrome DevTools workspaces request.
+ * Chrome always requests this at the root, regardless of base path.
+ * Users who want workspaces can install `vite-plugin-devtools-json`,
+ * which takes precedence as Vite plugin middleware runs first.
+ * @param {string} pathname
+ * @param {import('http').ServerResponse} res
+ * @returns {boolean} `true` if the request was handled
+ */
+export function is_chrome_devtools_request(pathname, res) {
+	if (pathname === '/.well-known/appspecific/com.chrome.devtools.json') {
+		res.writeHead(404);
+		res.end('not found');
+		return true;
+	}
+	return false;
+}
+
 /**
  * @param {import('http').IncomingMessage} req
  * @param {import('http').ServerResponse} res

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

@@ -55,8 +55,6 @@ const page_methods = new Set(['GET', 'HEAD', 'POST']);
 
 const allowed_page_methods = new Set(['GET', 'HEAD', 'OPTIONS']);
 
-let warned_on_devtools_json_request = false;
-
 export const respond = propagate_context(internal_respond);
 
 /**
@@ -676,21 +674,6 @@ export async function internal_respond(request, options, manifest, state) {
 			// if this request came direct from the user, rather than
 			// via our own `fetch`, render a 404 page
 			if (state.depth === 0) {
-				// In local development, Chrome requests this file for its 'automatic workspace folders' feature,
-				// causing console spam. If users want to serve this file they can install
-				// https://svelte.dev/docs/cli/devtools-json
-				if (DEV && event.url.pathname === '/.well-known/appspecific/com.chrome.devtools.json') {
-					if (!warned_on_devtools_json_request) {
-						console.log(
-							`\nGoogle Chrome is requesting ${event.url.pathname} to automatically configure devtools project settings. To learn why, and how to prevent this message, see https://svelte.dev/docs/cli/devtools-json\n`
-						);
-
-						warned_on_devtools_json_request = true;
-					}
-
-					return new Response(undefined, { status: 404 });
-				}
-
 				return await respond_with_error({
 					event,
 					event_state,

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

@@ -775,6 +775,12 @@ test.describe('Static files', () => {
 			expect(await response.text()).toBe('hello');
 		});
 	}
+
+	test('returns 404 for Chrome DevTools workspaces request', async ({ request }) => {
+		const response = await request.get('/.well-known/appspecific/com.chrome.devtools.json');
+		expect(response.status()).toBe(404);
+		expect(await response.text()).toBe('not found');
+	});
 });
 
 test.describe('setHeaders', () => {