dotnet restore using new parser

test/dotnet.Tests/ParserTests/ArgumentForwardingExtensionsTests.cs

@@ -0,0 +1,47 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using FluentAssertions;
+using Microsoft.DotNet.Cli;
+using Microsoft.DotNet.Cli.CommandLine;
+using Xunit;
+using static Microsoft.DotNet.Cli.CommandLine.Accept;
+using static Microsoft.DotNet.Cli.CommandLine.Create;
+
+namespace Microsoft.DotNet.Tests.ParserTests
+{
+    public class ArgumentForwardingExtensionsTests
+    {
+        [Fact]
+        public void An_outgoing_command_line_can_be_generated_based_on_a_parse_result()
+        {
+            var command = Command("the-command", "",
+                Option("-o|--one", "",
+                    ZeroOrOneArgument.ForwardAs("/i:{0}")),
+                Option("-t|--two", "",
+                    ZeroOrOneArgument.ForwardAs("/s:{0}")));
+
+            var result = command.Parse("the-command -t argument-two-value -o 123");
+
+            result["the-command"]
+                .ArgsToBeForwarded()
+                .Should()
+                .BeEquivalentTo("/i:123", "/s:argument-two-value");
+        }
+
+        [Fact]
+        public void MultipleArgumentsCanBeJoinedWhenForwarding()
+        {
+            var command = Command("the-command", "",
+                Option("-x", "",
+                    ZeroOrMoreArguments.ForwardAs(o => $"/x:{string.Join("&", o.Arguments)}")));
+
+            var result = command.Parse("the-command -x one -x two");
+
+            result["the-command"]
+                .ArgsToBeForwarded()
+                .Should()
+                .BeEquivalentTo("/x:one&two");
+        }
+    }
+}