fix(astro): Astro.url.pathname respects trailingSlash: 'never' with base path (#14260)

jp-knj · web-flow · commit 86a1e40ce21b · 2025-08-27T06:05:35.000+01:00
* fix: Astro.url.pathname respects trailingSlash: 'never' with base path

  Fixes that Astro.url.pathname incorrectly returned '/base/' instead
  of '/base' for root path when trailingSlash was set to 'never'.

* feat: add .changeset
diff --git a/.changeset/plenty-colts-hammer.md b/.changeset/plenty-colts-hammer.md
@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Fixes `Astro.url.pathname` to respect `trailingSlash: 'never'` configuration when using a base path. Previously, the root path with a base would incorrectly return `/base/` instead of `/base` when `trailingSlash` was set to 'never'.
diff --git a/packages/astro/src/vite-plugin-astro-server/request.ts b/packages/astro/src/vite-plugin-astro-server/request.ts
@@ -1,5 +1,6 @@
 import type http from 'node:http';
-import { removeTrailingForwardSlash } from '../core/path.js';
+import { hasFileExtension } from '@astrojs/internal-helpers/path';
+import { appendForwardSlash, removeTrailingForwardSlash } from '../core/path.js';
 import type { RoutesList } from '../types/astro.js';
 import type { DevServerController } from './controller.js';
 import { runWithErrorHandling } from './controller.js';
@@ -41,6 +42,13 @@ export async function handleRequest({
 
 	// Add config.base back to url before passing it to SSR
 	url.pathname = removeTrailingForwardSlash(config.base) + url.pathname;
+	
+	// Apply trailing slash configuration consistently
+	if (config.trailingSlash === 'never') {
+		url.pathname = removeTrailingForwardSlash(url.pathname);
+	} else if (config.trailingSlash === 'always' && !hasFileExtension(url.pathname)) {
+		url.pathname = appendForwardSlash(url.pathname);
+	}
 
 	let body: ArrayBuffer | undefined = undefined;
 	if (!(incomingRequest.method === 'GET' || incomingRequest.method === 'HEAD')) {
diff --git a/packages/astro/test/fixtures/ssr-trailing-slash/astro.config.mjs b/packages/astro/test/fixtures/ssr-trailing-slash/astro.config.mjs
@@ -0,0 +1,9 @@
+import { defineConfig } from 'astro/config';
+import node from '@astrojs/node';
+
+export default defineConfig({
+  base: '/mybase',
+  trailingSlash: 'never',
+  output: 'server',
+  adapter: node({ mode: 'standalone' })
+});
diff --git a/packages/astro/test/fixtures/ssr-trailing-slash/package.json b/packages/astro/test/fixtures/ssr-trailing-slash/package.json
@@ -0,0 +1,13 @@
+{
+  "name": "test-ssr-trailing-slash",
+  "type": "module",
+  "scripts": {
+    "dev": "astro dev",
+    "build": "astro build",
+    "start": "node dist/server/entry.mjs"
+  },
+  "dependencies": {
+    "astro": "file:../../",
+    "@astrojs/node": "^8.0.0"
+  }
+}
diff --git a/packages/astro/test/fixtures/ssr-trailing-slash/src/pages/index.astro b/packages/astro/test/fixtures/ssr-trailing-slash/src/pages/index.astro
@@ -0,0 +1,10 @@
+---
+export const prerender = false;
+const pathname = Astro.url.pathname;
+---
+<html>
+<body>
+  <h1>Test: {pathname}</h1>
+  <code>{pathname}</code>
+</body>
+</html>
diff --git a/packages/astro/test/ssr-trailing-slash.test.js b/packages/astro/test/ssr-trailing-slash.test.js
@@ -231,6 +231,51 @@ describe('Redirecting trailing slashes in SSR', () => {
 		});
 	});
 
+	describe('trailingSlash: never with base path', () => {
+		before(async () => {
+			fixture = await loadFixture({
+				root: './fixtures/ssr-response/',
+				adapter: testAdapter(),
+				output: 'server',
+				trailingSlash: 'never',
+				base: '/mybase',
+			});
+			await fixture.build();
+		});
+
+		it('Redirects to remove a trailing slash on base path', async () => {
+			const app = await fixture.loadTestAdapterApp();
+			const request = new Request('http://example.com/mybase/');
+			const response = await app.render(request);
+			assert.equal(response.status, 301);
+			assert.equal(response.headers.get('Location'), '/mybase');
+		});
+
+		it('Does not redirect when base path has no trailing slash', async () => {
+			const app = await fixture.loadTestAdapterApp();
+			const request = new Request('http://example.com/mybase');
+			const response = await app.render(request);
+			// Should not redirect, but will 404 since we don't have an index page
+			assert.notEqual(response.status, 301);
+			assert.notEqual(response.status, 308);
+		});
+
+		it('Redirects to remove trailing slash on sub-paths with base', async () => {
+			const app = await fixture.loadTestAdapterApp();
+			const request = new Request('http://example.com/mybase/another/');
+			const response = await app.render(request);
+			assert.equal(response.status, 301);
+			assert.equal(response.headers.get('Location'), '/mybase/another');
+		});
+
+		it('Does not redirect sub-paths without trailing slash with base', async () => {
+			const app = await fixture.loadTestAdapterApp();
+			const request = new Request('http://example.com/mybase/another');
+			const response = await app.render(request);
+			assert.equal(response.status, 200);
+		});
+	});
+
 	describe('trailingSlash: ignore', () => {
 		before(async () => {
 			fixture = await loadFixture({
diff --git a/packages/astro/test/units/routing/trailing-slash.test.js b/packages/astro/test/units/routing/trailing-slash.test.js
@@ -10,14 +10,17 @@ import {
 } from '../test-utils.js';
 
 const fileSystem = {
-	'/src/pages/api.ts': `export const GET = () => Response.json({ success: true })`,
-	'/src/pages/dot.json.ts': `export const GET = () => Response.json({ success: true })`,
+	'/src/pages/api.ts': `export const GET = () => new Response(JSON.stringify({ success: true }), { headers: { 'content-type': 'application/json' } })`,
+	'/src/pages/dot.json.ts': `export const GET = () => new Response(JSON.stringify({ success: true }), { headers: { 'content-type': 'application/json' } })`,
+	'/src/pages/pathname.ts': `export const GET = (ctx) => new Response(JSON.stringify({ pathname: ctx.url.pathname }), { headers: { 'content-type': 'application/json' } })`,
+	'/src/pages/subpage.ts': `export const GET = (ctx) => new Response(JSON.stringify({ pathname: ctx.url.pathname }), { headers: { 'content-type': 'application/json' } })`,
 };
 
 describe('trailingSlash', () => {
 	let fixture;
 	let container;
 	let baseContainer;
+	let rootPathContainer;
 
 	before(async () => {
 		fixture = await createFixture(fileSystem);
@@ -80,11 +83,39 @@ describe('trailingSlash', () => {
 			settings: baseSettings,
 			logger: defaultLogger,
 		});
+
+		// Create a container specifically for testing root path with base
+		const rootPathSettings = await createBasicSettings({
+			root: fixture.path,
+			trailingSlash: 'never',
+			base: '/mybase',
+			output: 'server',
+			adapter: testAdapter(),
+			integrations: [
+				{
+					name: 'test',
+					hooks: {
+						'astro:config:setup': ({ injectRoute }) => {
+							// Inject a route at the root that returns Astro.url.pathname
+							injectRoute({
+								pattern: '/',
+								entrypoint: './src/pages/pathname.ts',
+							});
+						},
+					},
+				},
+			],
+		});
+		rootPathContainer = await createContainer({
+			settings: rootPathSettings,
+			logger: defaultLogger,
+		});
 	});
 
 	after(async () => {
 		await container.close();
 		await baseContainer.close();
+		await rootPathContainer.close();
 	});
 
 	// Tests for trailingSlash: 'always'
@@ -181,4 +212,42 @@ describe('trailingSlash', () => {
 		assert.equal(html.includes(`<span class="statusMessage">Not found</span>`), true);
 		assert.equal(res.statusCode, 404);
 	});
+
+	// Test for issue #13736: Astro.url.pathname should respect trailingSlash config with base
+	it('Astro.url.pathname should not have trailing slash on root path when base is set and trailingSlash is never', async () => {
+		const { req, res, text } = createRequestAndResponse({
+			method: 'GET',
+			url: '/mybase',
+		});
+		rootPathContainer.handle(req, res);
+		const json = await text();
+		const data = JSON.parse(json);
+		// The pathname should be /mybase without trailing slash (the core issue from #13736)
+		assert.equal(data.pathname, '/mybase');
+		assert.equal(res.statusCode, 200);
+	});
+
+	it('should return correct Astro.url.pathname for pages with base and trailingSlash never', async () => {
+		const { req, res, text } = createRequestAndResponse({
+			method: 'GET',
+			url: '/base/pathname',
+		});
+		baseContainer.handle(req, res);
+		const json = await text();
+		const data = JSON.parse(json);
+		// The pathname should be /base/pathname without trailing slash
+		assert.equal(data.pathname, '/base/pathname');
+	});
+
+	it('should return correct Astro.url.pathname for subpage with base and trailingSlash never', async () => {
+		const { req, res, text } = createRequestAndResponse({
+			method: 'GET',
+			url: '/base/subpage',
+		});
+		baseContainer.handle(req, res);
+		const json = await text();
+		const data = JSON.parse(json);
+		// The pathname should be /base/subpage without trailing slash
+		assert.equal(data.pathname, '/base/subpage');
+	});
 });
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml

-Original file line number
+Diff line change
@@ @@ -0,0 +1,5 @@ @@
 +---
 +'astro': patch
 +---
++
 +Fixes `Astro.url.pathname` to respect `trailingSlash: 'never'` configuration when using a base path. Previously, the root path with a base would incorrectly return `/base/` instead of `/base` when `trailingSlash` was set to 'never'.