fix(@angular-devkit/build-angular): normalize asset source locations in Vite-based development server

The Vite-based development server uses an allow list to permit access to configured assets. This list
is checked internally to Vite by uses its normalized path form. To ensure that assets provided by the
build are checked correctly on all platforms, the asset list is now normalized with Vite's path
normalization prior to being used.

Author: clydin

packages/angular_devkit/build_angular/src/builders/dev-server/vite-server.ts

@@ -191,7 +191,7 @@ export async function* serveWithVite(
     assetFiles.clear();
     if (result.assetFiles) {
       for (const asset of result.assetFiles) {
-        assetFiles.set('/' + normalizePath(asset.destination), asset.source);
+        assetFiles.set('/' + normalizePath(asset.destination), normalizePath(asset.source));
       }
     }
 

tests/legacy-cli/e2e/tests/commands/serve/assets.ts

@@ -0,0 +1,23 @@
+import assert from 'assert';
+import { ngServe } from '../../../utils/project';
+
+export default async function () {
+  const port = await ngServe();
+
+  let response = await fetch(`http://localhost:${port}/`, { headers: { 'Accept': 'text/html' } });
+  assert.strictEqual(response.status, 200);
+  assert.match(await response.text(), /<app-root><\/app-root>/);
+
+  response = await fetch(`http://localhost:${port}/test`, { headers: { 'Accept': 'text/html' } });
+  assert.strictEqual(response.status, 200);
+  assert.match(await response.text(), /<app-root><\/app-root>/);
+
+  response = await fetch(`http://localhost:${port}/test/abc`, {
+    headers: { 'Accept': 'text/html' },
+  });
+  assert.strictEqual(response.status, 200);
+  assert.match(await response.text(), /<app-root><\/app-root>/);
+
+  response = await fetch(`http://localhost:${port}/favicon.ico`);
+  assert.strictEqual(response.status, 200);
+}