[fix] symlink routes (#6796)

* [fix] symlink routes

Fixes #6303

* add test

* support symlinks

* lint

* allow symlinked endpoints

* try this

* ugh

Co-authored-by: Rich Harris <hello@rich-harris.dev>

Author: dummdidumm

.changeset/silent-jeans-vanish.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/kit': patch
+---
+
+[fix] symlink routes

packages/kit/src/core/generate_manifest/index.js

@@ -1,5 +1,6 @@
 import { s } from '../../utils/misc.js';
 import { get_mime_lookup } from '../utils.js';
+import { resolve_symlinks } from '../../exports/vite/build/utils.js';
 
 /**
  * Generates the data used to write the server-side manifest.js file. This data is used in the Vite
@@ -65,7 +66,7 @@ export function generate_manifest({ build_data, relative_path, routes, format =
 					names: ${s(route.names)},
 					types: ${s(route.types)},
 					page: ${route.page ? `{ layouts: ${get_nodes(route.page.layouts)}, errors: ${get_nodes(route.page.errors)}, leaf: ${route.page.leaf} }` : 'null'},
-					endpoint: ${route.endpoint ? loader(`${relative_path}/${build_data.server.vite_manifest[route.endpoint.file].file}`) : 'null'}
+					endpoint: ${route.endpoint ? loader(`${relative_path}/${resolve_symlinks(build_data.server.vite_manifest, route.endpoint.file).chunk.file}`) : 'null'}
 				}`;
 				}).filter(Boolean).join(',\n\t\t\t\t')}
 			],

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

@@ -164,13 +164,16 @@ function create_routes_and_nodes(cwd, config, fallback) {
 
 			const dir = path.join(cwd, routes_base, id);
 
-			const files = fs.readdirSync(dir, {
-				withFileTypes: true
-			});
+			// We can't use withFileTypes because of a NodeJs bug which returns wrong results
+			// with isDirectory() in case of symlinks: https://github.com/nodejs/node/issues/30646
+			const files = fs.readdirSync(dir).map((name) => ({
+				is_dir: fs.statSync(path.join(dir, name)).isDirectory(),
+				name
+			}));
 
 			// process files first
 			for (const file of files) {
-				if (file.isDirectory()) continue;
+				if (file.is_dir) continue;
 				if (!file.name.startsWith('+')) continue;
 				if (!valid_extensions.find((ext) => file.name.endsWith(ext))) continue;
 
@@ -213,7 +216,7 @@ function create_routes_and_nodes(cwd, config, fallback) {
 
 			// then handle children
 			for (const file of files) {
-				if (file.isDirectory()) {
+				if (file.is_dir) {
 					walk(depth + 1, path.posix.join(id, file.name), file.name, route);
 				}
 			}

packages/kit/src/exports/vite/build/build_server.js

@@ -4,7 +4,13 @@ import { mkdirp, posixify, resolve_entry } from '../../../utils/filesystem.js';
 import { get_vite_config, merge_vite_configs } from '../utils.js';
 import { load_error_page, load_template } from '../../../core/config/index.js';
 import { runtime_directory } from '../../../core/utils.js';
-import { create_build, find_deps, get_default_build_config, is_http_method } from './utils.js';
+import {
+	create_build,
+	find_deps,
+	get_default_build_config,
+	is_http_method,
+	resolve_symlinks
+} from './utils.js';
 import { s } from '../../../utils/misc.js';
 
 /**
@@ -285,7 +291,7 @@ export async function build_server(options, client) {
 
 			exports.push(
 				`export const component = async () => (await import('../${
-					vite_manifest[node.component].file
+					resolve_symlinks(vite_manifest, node.component).chunk.file
 				}')).default;`,
 				`export const file = '${entry.file}';` // TODO what is this?
 			);

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

@@ -1,3 +1,5 @@
+import fs from 'fs';
+import path from 'path';
 import * as vite from 'vite';
 import { get_aliases } from '../utils.js';
 
@@ -44,14 +46,14 @@ export function find_deps(manifest, entry, add_dynamic_css) {
 	const stylesheets = new Set();
 
 	/**
-	 * @param {string} file
+	 * @param {string} current
 	 * @param {boolean} add_js
 	 */
-	function traverse(file, add_js) {
-		if (seen.has(file)) return;
-		seen.add(file);
+	function traverse(current, add_js) {
+		if (seen.has(current)) return;
+		seen.add(current);
 
-		const chunk = manifest[file];
+		const { chunk } = resolve_symlinks(manifest, current);
 
 		if (add_js) imports.add(chunk.file);
 
@@ -68,15 +70,31 @@ export function find_deps(manifest, entry, add_dynamic_css) {
 		}
 	}
 
-	traverse(entry, true);
+	const { chunk, file } = resolve_symlinks(manifest, entry);
+
+	traverse(file, true);
 
 	return {
-		file: manifest[entry].file,
+		file: chunk.file,
 		imports: Array.from(imports),
 		stylesheets: Array.from(stylesheets)
 	};
 }
 
+/**
+ * @param {import('vite').Manifest} manifest
+ * @param {string} file
+ */
+export function resolve_symlinks(manifest, file) {
+	while (!manifest[file]) {
+		file = path.relative('.', fs.realpathSync(file));
+	}
+
+	const chunk = manifest[file];
+
+	return { chunk, file };
+}
+
 /**
  * The Vite configuration that we use by default.
  * @param {{

packages/kit/test/apps/basics/.gitignore

@@ -1,2 +1,3 @@
 /test/errors.json
 !/.env
+/src/routes/routing/symlink-from

packages/kit/test/apps/basics/package.json

@@ -7,7 +7,7 @@
 		"build": "vite build",
 		"preview": "vite preview",
 		"check": "svelte-kit sync && tsc && svelte-check",
-		"test": "npm run test:dev && npm run test:build",
+		"test": "node test/setup.js && npm run test:dev && npm run test:build",
 		"test:dev": "rimraf test/errors.json && cross-env DEV=true playwright test",
 		"test:build": "rimraf test/errors.json && playwright test"
 	},

packages/kit/test/apps/basics/src/routes/routing/+page.svelte

@@ -6,6 +6,7 @@
 
 <a href="/routing/a">a</a>
 <a href="/routing/ambiguous/ok.json" rel="external">ok</a>
+<a href="/routing/symlink-from">symlinked</a>
 <a href="http://localhost:{$page.url.searchParams.get('port')}">elsewhere</a>
 <a href="/static.json">static.json</a>
 

packages/kit/test/apps/basics/src/routes/routing/symlink-to/+page.svelte

@@ -0,0 +1 @@
+<h1>symlinked</h1>

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

@@ -0,0 +1,7 @@
+import fs from 'fs';
+
+if (process.platform !== 'win32') {
+	process.chdir('src/routes/routing');
+	fs.rmSync('symlink-from', { recursive: true, force: true });
+	fs.symlinkSync('symlink-to', 'symlink-from', 'dir');
+}