allow prefixes and suffixes around rest parameters

.changeset/silly-ants-battle.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/kit': patch
+---
+
+Allow prefixes and suffixes around rest parameters

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

@@ -103,10 +103,6 @@ export default function create_manifest_data({ config, output, cwd = process.cwd
 				throw new Error(`Invalid route ${file} — brackets are unbalanced`);
 			}
 
-			if (/.+\[\.\.\.[^\]]+\]/.test(segment) || /\[\.\.\.[^\]]+\].+/.test(segment)) {
-				throw new Error(`Invalid route ${file} — rest parameter must be a standalone segment`);
-			}
-
 			const parts = get_parts(segment, file);
 			const is_index = is_dir ? false : basename.startsWith('index.');
 			const is_page = config.extensions.indexOf(ext) !== -1;
@@ -367,31 +363,37 @@ function get_parts(part, file) {
 function get_pattern(segments, add_trailing_slash) {
 	const path = segments
 		.map((segment) => {
-			return segment[0].rest
-				? '(?:\\/(.*))?'
-				: '\\/' +
-						segment
-							.map((part) => {
-								return part.dynamic
-									? '([^/]+?)'
-									: // allow users to specify characters on the file system in an encoded manner
-									  part.content
-											.normalize()
-											// We use [ and ] to denote parameters, so users must encode these on the file
-											// system to match against them. We don't decode all characters since others
-											// can already be epressed and so that '%' can be easily used directly in filenames
-											.replace(/%5[Bb]/g, '[')
-											.replace(/%5[Dd]/g, ']')
-											// '#', '/', and '?' can only appear in URL path segments in an encoded manner.
-											// They will not be touched by decodeURI so need to be encoded here, so
-											// that we can match against them.
-											// We skip '/' since you can't create a file with it on any OS
-											.replace(/#/g, '%23')
-											.replace(/\?/g, '%3F')
-											// escape characters that have special meaning in regex
-											.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
-							})
-							.join('');
+			if (segment.length === 1 && segment[0].rest) {
+				// special case — `src/routes/foo/[...bar]/baz` matches `/foo/baz`
+				// so we need to make the leading slash optional
+				return '(?:\\/(.*))?';
+			}
+
+			const parts = segment.map((part) => {
+				if (part.rest) return '(.*?)';
+				if (part.dynamic) return '([^/]+?)';
+
+				return (
+					part.content
+						// allow users to specify characters on the file system in an encoded manner
+						.normalize()
+						// We use [ and ] to denote parameters, so users must encode these on the file
+						// system to match against them. We don't decode all characters since others
+						// can already be epressed and so that '%' can be easily used directly in filenames
+						.replace(/%5[Bb]/g, '[')
+						.replace(/%5[Dd]/g, ']')
+						// '#', '/', and '?' can only appear in URL path segments in an encoded manner.
+						// They will not be touched by decodeURI so need to be encoded here, so
+						// that we can match against them.
+						// We skip '/' since you can't create a file with it on any OS
+						.replace(/#/g, '%23')
+						.replace(/\?/g, '%3F')
+						// escape characters that have special meaning in regex
+						.replace(/[.*+?^${}()|[\]\\]/g, '\\$&')
+				);
+			});
+
+			return '\\/' + parts.join('');
 		})
 		.join('');
 

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

@@ -215,18 +215,38 @@ test('sorts routes with rest correctly', () => {
 });
 
 test('disallows rest parameters inside segments', () => {
-	assert.throws(
-		() => {
-			create('samples/invalid-rest');
+	const { routes } = create('samples/rest-prefix-suffix');
+
+	assert.equal(routes, [
+		{
+			type: 'page',
+			segments: [
+				{
+					dynamic: true,
+					rest: true,
+					content: 'prefix-[...rest]'
+				}
+			],
+			pattern: /^\/prefix-(.*?)\/?$/,
+			params: ['...rest'],
+			path: '',
+			a: ['components/layout.svelte', 'samples/rest-prefix-suffix/prefix-[...rest].svelte'],
+			b: ['components/error.svelte']
 		},
-		/** @param {Error} e */
-		(e) => {
-			return (
-				e.message ===
-				'Invalid route samples/invalid-rest/foo-[...rest]-bar.svelte — rest parameter must be a standalone segment'
-			);
+		{
+			type: 'endpoint',
+			segments: [
+				{
+					dynamic: true,
+					rest: true,
+					content: '[...rest].json'
+				}
+			],
+			pattern: /^\/(.*?)\.json$/,
+			file: 'samples/rest-prefix-suffix/[...rest].json.js',
+			params: ['...rest']
 		}
-	);
+	]);
 });
 
 test('ignores files and directories with leading underscores', () => {

packages/kit/test/apps/basics/src/routes/routing/rest/complex/[...parts].json.js

@@ -0,0 +1,8 @@
+/** @type {import('@sveltejs/kit').RequestHandler} */
+export function get({ params }) {
+	return {
+		body: {
+			parts: params.parts
+		}
+	};
+}

packages/kit/test/apps/basics/src/routes/routing/rest/complex/prefix-[...parts].svelte

@@ -0,0 +1,18 @@
+<script context="module">
+	/** @type {import('@sveltejs/kit').Load} */
+	export async function load({ fetch, params }) {
+		const res = await fetch(`/routing/rest/complex/${params.parts}.json`);
+		const { parts } = await res.json();
+
+		return {
+			props: { parts }
+		};
+	}
+</script>
+
+<script>
+	/** @type {string} */
+	export let parts;
+</script>
+
+<h1>parts: {parts}</h1>

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

@@ -1608,6 +1608,11 @@ test.describe.parallel('Routing', () => {
 		await clicknav('[href="/routing/rest/path/three"]');
 		expect(await page.textContent('h1')).toBe('path: /routing/rest/path/three');
 	});
+
+	test('allows rest routes to have prefixes and suffixes', async ({ page }) => {
+		await page.goto('/routing/rest/complex/prefix-one/two/three');
+		expect(await page.textContent('h1')).toBe('parts: one/two/three');
+	});
 });
 
 test.describe.parallel('Session', () => {