add leading and trailing slash sanitization for params (#8276)

* add leading and trailing slash sanitization for params

* chore: fix lint

* refactor: use shared trimSlashes util

---------

Co-authored-by: Nate Moore <natemoo-re@users.noreply.github.com>
Co-authored-by: Nate Moore <nate@astro.build>

.changeset/chilled-hornets-press.md

@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Sanitize route params for leading and trailing slashes

packages/astro/src/core/routing/params.ts

@@ -1,5 +1,6 @@
 import type { GetStaticPathsItem, Params, RouteData } from '../../@types/astro';
 import { validateGetStaticPathsParameter } from './validation.js';
+import { trimSlashes } from '../path.js';
 
 /**
  * given an array of params like `['x', 'y', 'z']` for
@@ -32,7 +33,9 @@ export function stringifyParams(params: GetStaticPathsItem['params'], route: Rou
 	const validatedParams = Object.entries(params).reduce((acc, next) => {
 		validateGetStaticPathsParameter(next, route.component);
 		const [key, value] = next;
-		acc[key] = value?.toString();
+		if (value !== undefined) {
+			acc[key] = typeof value === 'string' ? trimSlashes(value) : value.toString()
+		}
 		return acc;
 	}, {} as Params);
 

packages/astro/test/units/routing/route-sanitization.test.js

@@ -0,0 +1,66 @@
+import {
+	createBasicSettings,
+	createFs,
+	createRequestAndResponse,
+	defaultLogger,
+} from '../test-utils.js';
+import { fileURLToPath } from 'node:url';
+import { expect } from 'chai';
+import { createContainer } from '../../../dist/core/dev/container.js';
+import * as cheerio from 'cheerio';
+import testAdapter from '../../test-adapter.js';
+
+const root = new URL('../../fixtures/alias/', import.meta.url);
+const fileSystem = {
+'/src/pages/[...testSlashTrim].astro': `
+	---
+	export function getStaticPaths() {
+		return [
+			{
+				params: {
+					testSlashTrim: "/a-route-param-with-leading-trailing-slash/",
+				},
+			},
+		];
+	}
+	---
+	<p>Success!</p>
+`,
+};
+
+describe('Route sanitization', () => {
+	let container;
+	let settings;
+
+	before(async () => {
+		const fs = createFs(fileSystem, root);
+		settings = await createBasicSettings({
+			root: fileURLToPath(root),
+			trailingSlash: 'never',
+			output: 'hybrid',
+			adapter: testAdapter(),
+		});
+		container = await createContainer({
+			fs,
+			settings,
+			logger: defaultLogger,
+		});
+	});
+
+	after(async () => {
+		await container.close();
+	});
+
+	describe('Request', () => {
+		it('should correctly match a route param with a trailing slash', async () => {
+			const { req, res, text } = createRequestAndResponse({
+				method: 'GET',
+				url: '/a-route-param-with-leading-trailing-slash',
+			});
+			container.handle(req, res);
+			const html = await text();
+			const $ = cheerio.load(html);
+			expect($('p').text()).to.equal('Success!');
+		});
+	});
+});