Add test for publish --skip-validation (#3935)

diff --git a/test/lish/skip_validation_test.dart b/test/lish/skip_validation_test.dart
new file mode 100644
index 0000000..3757dbc
--- /dev/null
+++ b/test/lish/skip_validation_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 'dart:io';
+
+import 'package:path/path.dart' as p;
+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(
+      'with --skip-validation dependency resolution and validations are skipped.',
+      () async {
+    await servePackages();
+    await d.validPackage().create();
+    await d.dir(appPath, [
+      d.validPubspec(
+        extras: {
+          // Dependency cannot be resolved.
+          'dependencies': {'foo': 'any'}
+        },
+      )
+    ]).create();
+    // It is an error to publish without a LICENSE file.
+    File(d.path(p.join(appPath, 'LICENSE'))).deleteSync();
+    await d.credentialsFile(globalServer, 'access-token').create();
+
+    await servePackages();
+    var pub = await startPublish(globalServer, args: ['--skip-validation']);
+
+    handleUploadForm(globalServer);
+    handleUpload(globalServer);
+
+    globalServer.expect('GET', '/create', (request) {
+      return shelf.Response.ok(
+        jsonEncode({
+          'success': {'message': 'Package test_pkg 1.0.0 uploaded!'}
+        }),
+      );
+    });
+    await pub.shouldExit(exit_codes.SUCCESS);
+  });
+}