fix: ignore nested outDir files outside generated

.changeset/curly-wolves-watch.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/kit': patch
+---
+
+fix: ignore nested outDir files outside generated

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

@@ -410,8 +410,9 @@ function kit({ svelte_config }) {
 						sourcemapIgnoreList,
 						watch: {
 							ignored: [
-								// Ignore all siblings of config.outDir/generated
-								`${out_dir}/!(generated)`
+								// Ignore all siblings of config.outDir/generated, at any depth
+								`${out_dir}/!(generated)`,
+								`${out_dir}/!(generated)/**`
 							]
 						}
 					},

packages/kit/test/apps/options/unit-test/vite.spec.js

@@ -1,11 +1,28 @@
 import { test, expect } from 'vitest';
 import { spawnSync } from 'node:child_process';
 import path from 'node:path';
+import { createFilter, resolveConfig } from 'vite';
 
 const timeout = 60_000;
 
 const cwd = path.resolve(import.meta.dirname, '..');
 
+test('ignores all outDir files except generated files', async () => {
+	const config = await resolveConfig(
+		{ configFile: path.join(cwd, 'vite.custom.config.js') },
+		'serve'
+	);
+	const is_ignored = createFilter(config.server.watch.ignored);
+	const out_dir = path.resolve(cwd, '.custom-out-dir').replaceAll('\\', '/');
+
+	expect(is_ignored(`${out_dir}/tsconfig.json`)).toBe(true);
+	expect(is_ignored(`${out_dir}/.svelte-check/tsconfig.json`)).toBe(true);
+	expect(is_ignored(`${out_dir}/types/a/$types.d.ts`)).toBe(true);
+	expect(is_ignored(`${out_dir}/generated`)).toBe(false);
+	expect(is_ignored(`${out_dir}/generated/root.js`)).toBe(false);
+	expect(is_ignored(`${out_dir}/generated/client/app.js`)).toBe(false);
+});
+
 test('no overridden options warning', { timeout }, () => {
 	const result = spawnSync(
 		'pnpm',