Add test for publishing and consuming files with unicode characters in name (#3785)

test/lish/unicode_file_names_test.dart

diff --git a/test/lish/unicode_file_names_test.dart b/test/lish/unicode_file_names_test.dart
new file mode 100644
index 0000000..4e1ef36
--- /dev/null
+++ b/test/lish/unicode_file_names_test.dart
@@ -0,0 +1,50 @@
+// Copyright (c) 2023, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'dart:convert';
+
+import 'package:pub/src/exit_codes.dart' as exit_codes;
+import 'package:shelf/shelf.dart' as shelf;
+import 'package:test/test.dart';
+
+import '../descriptor.dart' as d;
+import '../test_pub.dart';
+import 'utils.dart';
+
+void main() {
+  test('archives and uploads a package with unicode filenames', () async {
+    await d.validPackage.create();
+    await d.dir(appPath, [d.file('🦄.yml')]).create();
+
+    await servePackages();
+    await d.credentialsFile(globalServer, 'access-token').create();
+    var pub = await startPublish(globalServer);
+
+    await confirmPublish(pub);
+    handleUploadForm(globalServer);
+    handleUpload(globalServer);
+
+    globalServer.expect('GET', '/create', (request) {
+      return shelf.Response.ok(
+        jsonEncode({
+          'success': {'message': 'Package test_pkg 1.0.0 uploaded!'}
+        }),
+      );
+    });
+
+    expect(pub.stdout, emits(startsWith('Uploading...')));
+    expect(pub.stdout, emits('Package test_pkg 1.0.0 uploaded!'));
+    await pub.shouldExit(exit_codes.SUCCESS);
+  });
+
+  test('Can download and unpack package with unicode in file-name', () async {
+    final server = await servePackages();
+    server.serve('foo', '1.0.0', contents: [d.file('🦄.yml')]);
+    await d.appDir(dependencies: {'foo': '1.0.0'}).create();
+    await pubGet();
+    await d.hostedCache([
+      d.dir('foo-1.0.0', [d.file('🦄.yml')]),
+    ]).validate();
+  });
+}