feat: type resolve with the correct trailing slash option

.changeset/cold-streets-refuse.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/kit': patch
+---
+
+fix: `resolve` will narrow types to follow trailing slash page settings

eslint.config.js

@@ -32,6 +32,7 @@ export default [
 			'**/.custom-out-dir',
 			'packages/adapter-*/files',
 			'packages/kit/src/core/config/fixtures/multiple', // dir contains svelte config with multiple extensions tripping eslint
+			'packages/kit/types/index.d.ts', // generated file
 			'packages/package/test/fixtures/typescript-svelte-config/expected',
 			'packages/package/test/errors/**/*',
 			'packages/package/test/fixtures/**/*'

packages/kit/src/core/postbuild/analyse.js

@@ -65,21 +65,8 @@ async function analyse({
 	internal.set_manifest(manifest);
 	internal.set_read_implementation((file) => createReadableStream(`${server_root}/server/${file}`));
 
-	/** @type {Map<string, { page_options: Record<string, any> | null, children: string[] }>} */
-	const static_exports = new Map();
-
 	// first, build server nodes without the client manifest so we can analyse it
-	await build_server_nodes(
-		out,
-		config,
-		manifest_data,
-		server_manifest,
-		null,
-		null,
-		null,
-		output_config,
-		static_exports
-	);
+	build_server_nodes(out, config, manifest_data, server_manifest, null, null, null, output_config);
 
 	/** @type {import('types').ServerMetadata} */
 	const metadata = {
@@ -188,7 +175,7 @@ async function analyse({
 		metadata.remotes.set(remote.hash, exports);
 	}
 
-	return { metadata, static_exports };
+	return { metadata };
 }
 
 /**

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

@@ -8,6 +8,10 @@ import { posixify, resolve_entry } from '../../../utils/filesystem.js';
 import { parse_route_id } from '../../../utils/routing.js';
 import { sort_routes } from './sort.js';
 import { isSvelte5Plus } from '../utils.js';
+import {
+	create_node_analyser,
+	get_page_options
+} from '../../../exports/vite/static_analysis/index.js';
 
 /**
  * Generates the manifest data used for the client-side manifest and types generation.
@@ -342,7 +346,8 @@ function create_routes_and_nodes(cwd, config, fallback) {
 					}
 
 					route.endpoint = {
-						file: project_relative
+						file: project_relative,
+						page_options: null // will be filled later
 					};
 				}
 			}
@@ -415,6 +420,8 @@ function create_routes_and_nodes(cwd, config, fallback) {
 
 	const indexes = new Map(nodes.map((node, i) => [node, i]));
 
+	const node_analyser = create_node_analyser();
+
 	for (const route of routes) {
 		if (!route.leaf) continue;
 
@@ -459,6 +466,16 @@ function create_routes_and_nodes(cwd, config, fallback) {
 		}
 	}
 
+	for (const node of nodes) {
+		node.page_options = node_analyser.get_page_options(node);
+	}
+
+	for (const route of routes) {
+		if (route.endpoint) {
+			route.endpoint.page_options = get_page_options(route.endpoint.file);
+		}
+	}
+
 	return {
 		nodes,
 		routes: sort_routes(routes)

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

@@ -87,7 +87,7 @@ test('creates routes', () => {
 		{
 			id: '/blog.json',
 			pattern: '/^/blog.json/?$/',
-			endpoint: { file: 'samples/basic/blog.json/+server.js' }
+			endpoint: { file: 'samples/basic/blog.json/+server.js', page_options: null }
 		},
 		{
 			id: '/blog',
@@ -98,7 +98,8 @@ test('creates routes', () => {
 			id: '/blog/[slug].json',
 			pattern: '/^/blog/([^/]+?).json/?$/',
 			endpoint: {
-				file: 'samples/basic/blog/[slug].json/+server.ts'
+				file: 'samples/basic/blog/[slug].json/+server.ts',
+				page_options: null
 			}
 		},
 		{
@@ -308,7 +309,8 @@ test('allows rest parameters inside segments', () => {
 			id: '/[...rest].json',
 			pattern: '/^/([^]*?).json/?$/',
 			endpoint: {
-				file: 'samples/rest-prefix-suffix/[...rest].json/+server.js'
+				file: 'samples/rest-prefix-suffix/[...rest].json/+server.js',
+				page_options: null
 			}
 		}
 	]);
@@ -346,7 +348,7 @@ test('optional parameters', () => {
 		{
 			id: '/[[foo]]bar',
 			pattern: '/^/([^/]*)?bar/?$/',
-			endpoint: { file: 'samples/optional/[[foo]]bar/+server.js' }
+			endpoint: { file: 'samples/optional/[[foo]]bar/+server.js', page_options: null }
 		},
 		{ id: '/nested', pattern: '/^/nested/?$/' },
 		{
@@ -478,7 +480,8 @@ test('allows multiple slugs', () => {
 			id: '/[file].[ext]',
 			pattern: '/^/([^/]+?).([^/]+?)/?$/',
 			endpoint: {
-				file: 'samples/multiple-slugs/[file].[ext]/+server.js'
+				file: 'samples/multiple-slugs/[file].[ext]/+server.js',
+				page_options: null
 			}
 		}
 	]);
@@ -502,7 +505,8 @@ test('ignores things that look like lockfiles', () => {
 			id: '/foo',
 			pattern: '/^/foo/?$/',
 			endpoint: {
-				file: 'samples/lockfiles/foo/+server.js'
+				file: 'samples/lockfiles/foo/+server.js',
+				page_options: null
 			}
 		}
 	]);
@@ -537,7 +541,8 @@ test('works with custom extensions', () => {
 			id: '/blog.json',
 			pattern: '/^/blog.json/?$/',
 			endpoint: {
-				file: 'samples/custom-extension/blog.json/+server.js'
+				file: 'samples/custom-extension/blog.json/+server.js',
+				page_options: null
 			}
 		},
 		{
@@ -549,7 +554,8 @@ test('works with custom extensions', () => {
 			id: '/blog/[slug].json',
 			pattern: '/^/blog/([^/]+?).json/?$/',
 			endpoint: {
-				file: 'samples/custom-extension/blog/[slug].json/+server.js'
+				file: 'samples/custom-extension/blog/[slug].json/+server.js',
+				page_options: null
 			}
 		},
 		{

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

@@ -45,6 +45,8 @@ export function create(config) {
  * @param {string} file
  */
 export function update(config, manifest_data, file) {
+	// TODO: statically analyse page options for the file and update the manifest_data
+
 	write_types(config, manifest_data, file);
 }
 

packages/kit/src/core/sync/write_non_ambient.js

@@ -13,6 +13,40 @@ const remove_group_segments = (/** @type {string} */ id) => {
 	return '/' + get_route_segments(id).join('/');
 };
 
+/**
+ * Get pathnames to add based on trailingSlash settings
+ * @param {string} pathname
+ * @param {import('types').RouteData} route
+ * @returns {string[]}
+ */
+function get_pathnames_for_trailing_slash(pathname, route) {
+	if (pathname === '/') {
+		return [pathname];
+	}
+
+	/** @type {({ trailingSlash?: import('types').TrailingSlash } | null)[]} */
+	const routes = [];
+
+	if (route.leaf) routes.push(route.leaf.page_options ?? null);
+	if (route.endpoint) routes.push(route.endpoint.page_options);
+
+	/** @type {Set<string>} */
+	const pathnames = new Set();
+
+	for (const page_options of routes) {
+		if (page_options === null || page_options.trailingSlash === 'ignore') {
+			pathnames.add(pathname);
+			pathnames.add(pathname + '/');
+		} else if (page_options.trailingSlash === 'always') {
+			pathnames.add(pathname + '/');
+		} else {
+			pathnames.add(pathname);
+		}
+	}
+
+	return Array.from(pathnames);
+}
+
 // `declare module "svelte/elements"` needs to happen in a non-ambient module, and dts-buddy generates one big ambient module,
 // so we can't add it there - therefore generate the typings ourselves here.
 // We're not using the `declare namespace svelteHTML` variant because that one doesn't augment the HTMLAttributes interface
@@ -67,19 +101,14 @@ function generate_app_types(manifest_data) {
 
 			const pathname = remove_group_segments(route.id);
 			const replaced_pathname = replace_required_params(replace_optional_params(pathname));
-			pathnames.add(`\`${replaced_pathname}\` & {}`);
 
-			if (pathname !== '/') {
-				// Support trailing slash
-				pathnames.add(`\`${replaced_pathname + '/'}\` & {}`);
+			for (const p of get_pathnames_for_trailing_slash(replaced_pathname, route)) {
+				pathnames.add(`\`${p}\` & {}`);
 			}
 		} else {
 			const pathname = remove_group_segments(route.id);
-			pathnames.add(s(pathname));
-
-			if (pathname !== '/') {
-				// Support trailing slash
-				pathnames.add(s(pathname + '/'));
+			for (const p of get_pathnames_for_trailing_slash(pathname, route)) {
+				pathnames.add(s(p));
 			}
 		}
 

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

@@ -362,6 +362,10 @@ function update_types(config, routes, route, to_delete = new Set()) {
 		exports.push('export type RequestEvent = Kit.RequestEvent<RouteParams, RouteId>;');
 	}
 
+	if (route.leaf || route.endpoint) {
+		//  TODO: update Pathname app type
+	}
+
 	const output = [imports.join('\n'), declarations.join('\n'), exports.join('\n')]
 		.filter(Boolean)
 		.join('\n\n');

packages/kit/src/core/sync/write_types/test/app-types/(group)/path-a/trailing-slash/always/+page.server.js

@@ -0,0 +1 @@
+export const trailingSlash = 'always';

packages/kit/src/core/sync/write_types/test/app-types/(group)/path-a/trailing-slash/always/endpoint/+server.js

@@ -0,0 +1 @@
+export const trailingSlash = 'always';

packages/kit/src/core/sync/write_types/test/app-types/(group)/path-a/trailing-slash/always/layout/+layout.js

@@ -0,0 +1 @@
+export const trailingSlash = 'always';

packages/kit/src/core/sync/write_types/test/app-types/(group)/path-a/trailing-slash/ignore/+page.server.js

@@ -0,0 +1 @@
+export const trailingSlash = 'ignore';

packages/kit/src/core/sync/write_types/test/app-types/(group)/path-a/trailing-slash/ignore/endpoint/+server.js

@@ -0,0 +1 @@
+export const trailingSlash = 'ignore';

packages/kit/src/core/sync/write_types/test/app-types/(group)/path-a/trailing-slash/ignore/layout/+layout.js

@@ -0,0 +1 @@
+export const trailingSlash = 'ignore';

packages/kit/src/core/sync/write_types/test/app-types/(group)/path-a/trailing-slash/mixed/+server.js

@@ -0,0 +1 @@
+export const trailingSlash = 'always';

packages/kit/src/core/sync/write_types/test/app-types/(group)/path-a/trailing-slash/never/+page.server.js

@@ -0,0 +1 @@
+export const trailingSlash = 'never';

packages/kit/src/core/sync/write_types/test/app-types/(group)/path-a/trailing-slash/never/endpoint/+server.js

@@ -0,0 +1 @@
+export const trailingSlash = 'never';

packages/kit/src/core/sync/write_types/test/app-types/(group)/path-a/trailing-slash/never/layout/+layout.js

@@ -0,0 +1 @@
+export const trailingSlash = 'never';

packages/kit/src/core/sync/write_types/test/app-types/+page.js

@@ -0,0 +1,64 @@
+/** @type {import('$app/types').RouteId} */
+let id;
+
+// okay
+id = '/';
+id = '/foo/[bar]/[baz]';
+id = '/(group)/path-a';
+
+// @ts-expect-error
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
+id = '/nope';
+
+/** @type {import('$app/types').RouteParams<'/foo/[bar]/[baz]'>} */
+const params = {
+	bar: 'A',
+	baz: 'B'
+};
+
+// @ts-expect-error foo is not a param
+params.foo;
+params.bar; // okay
+params.baz; // okay
+
+/** @type {import('$app/types').Pathname} */
+let pathname;
+
+// @ts-expect-error route doesn't exist
+pathname = '/nope';
+// @ts-expect-error route doesn't exist
+pathname = '/foo';
+// @ts-expect-error route doesn't exist
+pathname = '/foo/';
+pathname = '/foo/1/2'; // okay
+pathname = '/foo/1/2/'; // okay
+
+// Test layout groups
+pathname = '/path-a';
+// @ts-expect-error default trailing slash is never, so we should not have it here
+pathname = '/path-a/';
+// @ts-expect-error layout group names are NOT part of the pathname type
+pathname = '/(group)/path-a';
+
+// Test trailing-slash - always
+pathname = '/path-a/trailing-slash/always/';
+pathname = '/path-a/trailing-slash/always/endpoint/';
+pathname = '/path-a/trailing-slash/always/layout/inside/';
+
+// Test trailing-slash - ignore
+pathname = '/path-a/trailing-slash/ignore';
+pathname = '/path-a/trailing-slash/ignore/';
+pathname = '/path-a/trailing-slash/ignore/endpoint';
+pathname = '/path-a/trailing-slash/ignore/endpoint/';
+pathname = '/path-a/trailing-slash/ignore/layout/inside';
+pathname = '/path-a/trailing-slash/ignore/layout/inside/';
+
+// Test trailing-slash - never (default)
+pathname = '/path-a/trailing-slash/never';
+pathname = '/path-a/trailing-slash/never/endpoint';
+pathname = '/path-a/trailing-slash/never/layout/inside';
+
+// Test trailing-slash - always (endpoint) and never (page)
+pathname = '/path-a/trailing-slash/mixed';
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
+pathname = '/path-a/trailing-slash/mixed/';