Fix loading of non-index routes that end with index.html (#10979)

* Add test

* Fix alt pathname

* Add changeset

.changeset/tiny-dodos-melt.md

@@ -0,0 +1,5 @@
+---
+"astro": patch
+---
+
+Fix loading of non-index routes that end with `index.html`

packages/astro/src/vite-plugin-astro-server/route.ts

@@ -81,7 +81,10 @@ export async function matchRoute(
  // Try without `.html` extensions or `index.html` in request URLs to mimic
  // routing behavior in production builds. This supports both file and directory
  // build formats, and is necessary based on how the manifest tracks build targets.
- const altPathname = pathname.replace(/(?:index)?\.html$/, '');
+ const altPathname = pathname
+ .replace(/\/index\.html$/, '/')
+ .replace(/\.html$/, '');
+
  if (altPathname !== pathname) {
  return await matchRoute(altPathname, manifestData, pipeline);
  }

packages/astro/test/dev-routing.test.js

@@ -321,6 +321,11 @@ describe('Development Routing', () => {
  assert.equal(response.status, 200);
  });
 
+ it('200 when loading /base-index.html', async () => {
+ const response = await fixture.fetch('/base-index.html');
+ assert.equal(response.status, 200);
+ });
+
  it('200 when loading /', async () => {
  const response = await fixture.fetch('/');
  assert.equal(response.status, 200);

packages/astro/test/fixtures/without-site-config/src/pages/base-index.astro

@@ -0,0 +1 @@
+<div>testing</div>