From 49891b96c12567109d6086a23ca7c117dd40bdc7 Mon Sep 17 00:00:00 2001
From: sfoslund <sfoslund@microsoft.com>
Date: Fri, 14 Feb 2020 15:05:24 -0800
Subject: [PATCH] Resolving and adding test coverage for stack dump on dotnet
 -d

---
 .../LocalToolsCommandResolver.cs              |  3 +-
 src/Cli/dotnet/Program.cs                     |  4 +++
 .../GivenALocalToolsCommandResolver.cs        | 13 ++++++++
 .../CommandTests/CommandIntegrationTests.cs   | 31 +++++++++++++++++++
 4 files changed, 50 insertions(+), 1 deletion(-)
 create mode 100644 src/Tests/dotnet.Tests/CommandTests/CommandIntegrationTests.cs

diff --git a/src/dotnet/CommandFactory/CommandResolution/LocalToolsCommandResolver.cs b/src/dotnet/CommandFactory/CommandResolution/LocalToolsCommandResolver.cs
index fae180cbde..59af704755 100644
--- a/src/dotnet/CommandFactory/CommandResolution/LocalToolsCommandResolver.cs
+++ b/src/dotnet/CommandFactory/CommandResolution/LocalToolsCommandResolver.cs
@@ -57,7 +57,8 @@ public CommandSpec Resolve(CommandResolverArguments arguments)
                 return null;
             }
 
-            if (!arguments.CommandName.StartsWith(LeadingDotnetPrefix, StringComparison.OrdinalIgnoreCase))
+            if (!arguments.CommandName.StartsWith(LeadingDotnetPrefix, StringComparison.OrdinalIgnoreCase) ||
+                string.IsNullOrWhiteSpace(arguments.CommandName.Substring(LeadingDotnetPrefix.Length)))
             {
                 return null;
             }
diff --git a/src/dotnet/Program.cs b/src/dotnet/Program.cs
index 8b9cccfe0b..67e784bbf3 100644
--- a/src/dotnet/Program.cs
+++ b/src/dotnet/Program.cs
@@ -216,6 +216,10 @@ internal static int ProcessArgs(string[] args, ITelemetry telemetryClient = null
 
                 exitCode = builtIn.Command(appArgs.ToArray());
             }
+            else if (string.IsNullOrEmpty(topLevelCommandParserResult.Command))
+            {
+                exitCode = 0;
+            }
             else
             {
                 CommandResult result = CommandFactoryUsingResolver.Create(
diff --git a/test/Microsoft.DotNet.CommandFactory.Tests/GivenALocalToolsCommandResolver.cs b/test/Microsoft.DotNet.CommandFactory.Tests/GivenALocalToolsCommandResolver.cs
index 4235f2055e..07bd774c97 100644
--- a/test/Microsoft.DotNet.CommandFactory.Tests/GivenALocalToolsCommandResolver.cs
+++ b/test/Microsoft.DotNet.CommandFactory.Tests/GivenALocalToolsCommandResolver.cs
@@ -79,6 +79,19 @@ public void WhenResolveItCanFindToolExecutable(string toolCommand)
             commandPath.Should().Be(fakeExecutable.Value);
         }
 
+        [Fact]
+        public void WhenResolveWithNoArgumentsItReturnsNull()
+        {
+            (FilePath fakeExecutable, LocalToolsCommandResolver localToolsCommandResolver) = DefaultSetup("-d");
+
+            var result = localToolsCommandResolver.Resolve(new CommandResolverArguments()
+            {
+                CommandName = "-d",
+            });
+
+            result.Should().BeNull();
+        }
+
         private (FilePath, LocalToolsCommandResolver) DefaultSetup(string toolCommand)
         {
             NuGetVersion packageVersionA = NuGetVersion.Parse("1.0.4");
diff --git a/test/dotnet.Tests/CommandTests/CommandIntegrationTests.cs b/test/dotnet.Tests/CommandTests/CommandIntegrationTests.cs
new file mode 100644
index 0000000000..30e5bfdbb7
--- /dev/null
+++ b/test/dotnet.Tests/CommandTests/CommandIntegrationTests.cs
@@ -0,0 +1,31 @@
+// 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.NET.TestFramework;
+using Microsoft.NET.TestFramework.Commands;
+using Xunit;
+using Xunit.Abstractions;
+
+namespace Microsoft.DotNet.Tests.Commands
+{
+    public class CommandIntegrationTests : SdkTest
+    {
+        public CommandIntegrationTests(ITestOutputHelper log) : base(log) {}
+
+        [Fact]
+        public void GivenNoArgumentsProvided()
+        {
+            var cmd = new DotnetCommand(Log).Execute(string.Empty);
+            cmd.StdErr.Should().BeEmpty();
+        }
+
+        [Fact]
+        public void GivenOnlyArgumentProvidedIsDiagnosticsFlag()
+        {
+            var cmd = new DotnetCommand(Log).Execute("-d");
+            cmd.ExitCode.Should().Be(0);
+            cmd.StdErr.Should().BeEmpty();
+        }
+    }
+}