chore: remove empty type output directories for removed routes

.changeset/remove-empty-type-dirs.md

@@ -0,0 +1,5 @@
+---
+"@sveltejs/kit": patch
+---
+
+fix: remove empty type output directories for removed routes

packages/kit/src/core/sync/write_types/index.js

@@ -26,6 +26,28 @@ const is_whitespace = (/** @type {string} */ char) => /\s/.test(char);
  *  @typedef {Map<import('types').PageNode, {route: import('types').RouteData, proxies: Proxies}>} RoutesMap
  */
 
+/**
+ * Recursively remove empty directories under `root`, leaving `root` itself.
+ * @param {string} dir
+ * @param {string} root
+ */
+function remove_empty_directories(dir, root = dir) {
+	if (!fs.existsSync(dir)) return;
+
+	for (const name of fs.readdirSync(dir)) {
+		const child = path.join(dir, name);
+		if (fs.statSync(child).isDirectory()) {
+			remove_empty_directories(child, root);
+		}
+	}
+
+	if (path.resolve(dir) === path.resolve(root)) return;
+
+	if (fs.readdirSync(dir).length === 0) {
+		fs.rmdirSync(dir);
+	}
+}
+
 /**
  * Creates types for the whole manifest
  * @param {import('types').ValidatedConfig} config
@@ -52,6 +74,8 @@ export function write_all_types(config, manifest_data, root) {
 				fs.rmSync(path.join(types_dir, file), { force: true, recursive: true });
 			}
 		}
+		// Stale files are removed above; empty route directories are left behind.
+		remove_empty_directories(types_dir);
 	}
 
 	// Read/write meta data on each invocation, not once per node process,

packages/kit/src/core/sync/write_types/index.spec.js

@@ -3,7 +3,7 @@ import fs from 'node:fs';
 import os from 'node:os';
 import path from 'node:path';
 import process from 'node:process';
-import { assert, describe, expect, test } from 'vitest';
+import { afterEach, assert, beforeEach, describe, expect, test } from 'vitest';
 import create_manifest_data from '../create_manifest_data/index.js';
 import { tweak_types, write_all_types } from './index.js';
 import { write_app_types } from '../write_app_types.js';
@@ -311,6 +311,68 @@ test('Leaves satisfies operator untouched', () => {
 	assert.equal(rewritten?.code, source);
 });
 
+describe('Cleans up unused files', () => {
+	/** @type {string} */
+	let root;
+
+	beforeEach(() => {
+		root = fs.mkdtempSync(path.join(os.tmpdir(), 'kit-write-types-'));
+
+		for (const dir of ['', 'about']) {
+			const route_dir = path.join(root, 'src/routes', dir);
+			fs.mkdirSync(route_dir, { recursive: true });
+			fs.writeFileSync(path.join(route_dir, '+page.svelte'), '');
+		}
+	});
+
+	afterEach(() => {
+		fs.rmSync(root, { force: true, recursive: true });
+	});
+
+	function sync() {
+		const config = validate_config({});
+		config.files.assets = path.join(root, 'static');
+		config.files.params = path.join(root, 'src/params');
+		config.files.routes = path.join(root, 'src/routes');
+		config.outDir = path.join(root, '.svelte-kit');
+
+		write_all_types(config, create_manifest_data(config, root), root);
+
+		return path.join(config.outDir, 'types');
+	}
+
+	test('removes empty output directories for removed routes', () => {
+		const types_dir = sync();
+		const route_types_dir = path.join(types_dir, 'src/routes/about');
+		const types_file = path.join(route_types_dir, '$types.d.ts');
+		assert.ok(fs.existsSync(types_file));
+
+		fs.rmSync(path.join(root, 'src/routes/about'), { recursive: true });
+		sync();
+
+		assert.ok(!fs.existsSync(types_file));
+		assert.ok(!fs.existsSync(route_types_dir));
+	});
+
+	test('keeps parent directories that still have nested routes', () => {
+		const nested = path.join(root, 'src/routes/about/team');
+		fs.mkdirSync(nested, { recursive: true });
+		fs.writeFileSync(path.join(nested, '+page.svelte'), '');
+
+		const types_dir = sync();
+		const about_dir = path.join(types_dir, 'src/routes/about');
+		const team_types = path.join(about_dir, 'team/$types.d.ts');
+		assert.ok(fs.existsSync(team_types));
+
+		fs.rmSync(path.join(root, 'src/routes/about/team'), { recursive: true });
+		sync();
+
+		assert.ok(!fs.existsSync(team_types));
+		assert.ok(!fs.existsSync(path.join(about_dir, 'team')));
+		assert.ok(fs.existsSync(path.join(about_dir, '$types.d.ts')));
+	});
+});
+
 test('prunes stale entries from route_meta_data.json when routes are deleted', () => {
 	const tmp = fs.mkdtempSync(path.join(os.tmpdir(), 'sveltekit-prune-test-'));
 	try {