Fix double prepended forward slash in certain cases (#7091)

* test: add test with no base

* fix: don't always prepend a forward slash

* chore: changeset

* `'/' + base`   ------> `prependForwardSlash(base)`

.changeset/swift-moons-drop.md

@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Fix double prepended forward slash in SSR

packages/astro/src/core/app/index.ts

@@ -14,7 +14,7 @@ import { call as callEndpoint, createAPIContext } from '../endpoint/index.js';
 import { consoleLogDestination } from '../logger/console.js';
 import { error, type LogOptions } from '../logger/core.js';
 import { callMiddleware } from '../middleware/callMiddleware.js';
-import { removeTrailingForwardSlash } from '../path.js';
+import { prependForwardSlash, removeTrailingForwardSlash } from '../path.js';
 import {
 	createEnvironment,
 	createRenderContext,
@@ -101,7 +101,7 @@ export class App {
 		if (this.#manifest.assets.has(url.pathname)) {
 			return undefined;
 		}
-		let pathname = '/' + this.removeBase(url.pathname);
+		let pathname = prependForwardSlash(this.removeBase(url.pathname));
 		let routeData = matchRoute(pathname, this.#manifestData);
 
 		if (routeData) {
@@ -178,7 +178,7 @@ export class App {
 		status = 200
 	): Promise<Response> {
 		const url = new URL(request.url);
-		const pathname = '/' + this.removeBase(url.pathname);
+		const pathname = prependForwardSlash(this.removeBase(url.pathname));
 		const info = this.#routeDataToRouteInfo.get(routeData!)!;
 		// may be used in the future for handling rel=modulepreload, rel=icon, rel=manifest etc.
 		const links = new Set<never>();

packages/integrations/node/test/prerender.test.js

@@ -9,61 +9,108 @@ describe('Prerendering', () => {
 	let fixture;
 	let server;
 
-	before(async () => {
-		process.env.ASTRO_NODE_AUTOSTART = 'disabled';
-		fixture = await loadFixture({
-			base: '/some-base',
-			root: './fixtures/prerender/',
-			output: 'server',
-			adapter: nodejs({ mode: 'standalone' }),
-		});
-		await fixture.build();
-		const { startServer } = await await load();
-		let res = startServer();
-		server = res.server;
-	});
-
-	after(async () => {
-		await server.stop();
-	});
-
 	async function load() {
 		const mod = await import('./fixtures/prerender/dist/server/entry.mjs');
 		return mod;
 	}
 
-	it('Can render SSR route', async () => {
-		const res = await fetch(`http://${server.host}:${server.port}/some-base/one`);
-		const html = await res.text();
-		const $ = cheerio.load(html);
+	describe('With base', () => {
+		before(async () => {
+			process.env.ASTRO_NODE_AUTOSTART = 'disabled';
+			fixture = await loadFixture({
+				base: '/some-base',
+				root: './fixtures/prerender/',
+				output: 'server',
+				adapter: nodejs({ mode: 'standalone' }),
+			});
+			await fixture.build();
+			const { startServer } = await await load();
+			let res = startServer();
+			server = res.server;
+		});
 
-		expect(res.status).to.equal(200);
-		expect($('h1').text()).to.equal('One');
-	});
+		after(async () => {
+			await server.stop();
+		});
 
-	it('Can render prerendered route', async () => {
-		const res = await fetch(`http://${server.host}:${server.port}/some-base/two`);
-		const html = await res.text();
-		const $ = cheerio.load(html);
+		it('Can render SSR route', async () => {
+			const res = await fetch(`http://${server.host}:${server.port}/some-base/one`);
+			const html = await res.text();
+			const $ = cheerio.load(html);
 
-		expect(res.status).to.equal(200);
-		expect($('h1').text()).to.equal('Two');
-	});
+			expect(res.status).to.equal(200);
+			expect($('h1').text()).to.equal('One');
+		});
+
+		it('Can render prerendered route', async () => {
+			const res = await fetch(`http://${server.host}:${server.port}/some-base/two`);
+			const html = await res.text();
+			const $ = cheerio.load(html);
+
+			expect(res.status).to.equal(200);
+			expect($('h1').text()).to.equal('Two');
+		});
 
-	it('Can render prerendered route with query params', async () => {
-		const res = await fetch(`http://${server.host}:${server.port}/some-base/two/?foo=bar`);
-		const html = await res.text();
-		const $ = cheerio.load(html);
+		it('Can render prerendered route with query params', async () => {
+			const res = await fetch(`http://${server.host}:${server.port}/some-base/two/?foo=bar`);
+			const html = await res.text();
+			const $ = cheerio.load(html);
 
-		expect(res.status).to.equal(200);
-		expect($('h1').text()).to.equal('Two');
+			expect(res.status).to.equal(200);
+			expect($('h1').text()).to.equal('Two');
+		});
+
+		it('Omitting the trailing slash results in a redirect that includes the base', async () => {
+			const res = await fetch(`http://${server.host}:${server.port}/some-base/two`, {
+				redirect: 'manual',
+			});
+			expect(res.status).to.equal(301);
+			expect(res.headers.get('location')).to.equal('/some-base/two/');
+		});
 	});
+	describe('Without base', () => {
+		before(async () => {
+			process.env.ASTRO_NODE_AUTOSTART = 'disabled';
+			fixture = await loadFixture({
+				root: './fixtures/prerender/',
+				output: 'server',
+				adapter: nodejs({ mode: 'standalone' }),
+			});
+			await fixture.build();
+			const { startServer } = await await load();
+			let res = startServer();
+			server = res.server;
+		});
+
+		after(async () => {
+			await server.stop();
+		});
+
+		it('Can render SSR route', async () => {
+			const res = await fetch(`http://${server.host}:${server.port}/one`);
+			const html = await res.text();
+			const $ = cheerio.load(html);
+
+			expect(res.status).to.equal(200);
+			expect($('h1').text()).to.equal('One');
+		});
+
+		it('Can render prerendered route', async () => {
+			const res = await fetch(`http://${server.host}:${server.port}/two`);
+			const html = await res.text();
+			const $ = cheerio.load(html);
+
+			expect(res.status).to.equal(200);
+			expect($('h1').text()).to.equal('Two');
+		});
+
+		it('Can render prerendered route with query params', async () => {
+			const res = await fetch(`http://${server.host}:${server.port}/two/?foo=bar`);
+			const html = await res.text();
+			const $ = cheerio.load(html);
 
-	it('Omitting the trailing slash results in a redirect that includes the base', async () => {
-		const res = await fetch(`http://${server.host}:${server.port}/some-base/two`, {
-			redirect: 'manual',
+			expect(res.status).to.equal(200);
+			expect($('h1').text()).to.equal('Two');
 		});
-		expect(res.status).to.equal(301);
-		expect(res.headers.get('location')).to.equal('/some-base/two/');
 	});
 });