[WiP] enable /m by default (#4543)

* MSBuild integration project + refactoring

* Feature Complete

* Change default target to an existing one

TestAssets/TestProjects/MSBuildIntegration/build.proj

@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="14.0" DefaultTargets="Validate" 
+         xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+
+  <Target Name="Build"
+          DependsOnTargets="Validate" />
+
+  <Target Name="Clean"
+          DependsOnTargets="Validate" />
+
+  <Target Name="Pack"
+          DependsOnTargets="Validate" />
+
+  <Target Name="Publish"
+          DependsOnTargets="Validate" />
+  <Target Name="Restore"
+          DependsOnTargets="Validate" />
+  
+  <Target Name="VSTest"
+          DependsOnTargets="Validate" />
+
+  <Target Name="Validate">  
+    <Error Condition=" $(MSBuildNodeCount) &lt; 2 " 
+           Text="Expect MSBuildNodeCount to be greater than 1, but found $(MSBuildNodeCount). Is this a single proc machine?" />
+
+    <Error Condition=" '$(MSBuildExtensionsPath)' == '' " 
+           Text="Expect MSBuildExtensionsPath to be set, but it is not." />
+    
+    <Error Condition=" '$(CscToolExe)' == '' " 
+           Text="Expect CscToolExe to be set, but it is not." />
+  </Target>
+</Project>

src/dotnet/commands/dotnet-msbuild/MSBuildForwardingApp.cs

@@ -4,6 +4,7 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+using System.Linq;
 using System.Runtime.InteropServices;
 using Microsoft.DotNet.Cli;
 
@@ -12,14 +13,25 @@ namespace Microsoft.DotNet.Tools.MSBuild
     public class MSBuildForwardingApp
     {
         private const string s_msbuildExeName = "MSBuild.dll";
+
         private readonly ForwardingApp _forwardingApp;
 
+        private readonly Dictionary<string, string> _msbuildRequiredEnvironmentVariables =
+            new Dictionary<string, string>
+            {
+                { "MSBuildExtensionsPath", AppContext.BaseDirectory },
+                { "CscToolExe", GetRunCscPath() }
+            };
+        
+        private readonly IEnumerable<string> _msbuildRequiredParameters = 
+            new List<string> { "/m" };
+
         public MSBuildForwardingApp(IEnumerable<string> argsToForward)
         {
             _forwardingApp = new ForwardingApp(
                 GetMSBuildExePath(),
-                argsToForward,
+                _msbuildRequiredParameters.Concat(argsToForward),
-                environmentVariables: GetEnvironmentVariables());
+                environmentVariables: _msbuildRequiredEnvironmentVariables);
         }
 
         public int Execute()
@@ -27,15 +39,6 @@ namespace Microsoft.DotNet.Tools.MSBuild
             return _forwardingApp.Execute();
         }
 
-        private static Dictionary<string, string> GetEnvironmentVariables()
-        {
-            return new Dictionary<string, string>
-            {
-                { "MSBuildExtensionsPath", AppContext.BaseDirectory },
-                { "CscToolExe", GetRunCscPath() }
-            };
-        }
-
         private static string GetMSBuildExePath()
         {
             return Path.Combine(

test/msbuild.IntegrationTests/GivenDotnetInvokesMSBuild.cs

@@ -0,0 +1,35 @@
+// 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 Microsoft.DotNet.Tools.Test.Utilities;
+using Xunit;
+using System;
+using System.IO;
+using FluentAssertions;
+using Microsoft.DotNet.TestFramework;
+using Microsoft.DotNet.Cli.Utils;
+
+namespace Microsoft.DotNet.Cli.MSBuild.IntegrationTests
+{
+    public class GivenDotnetInvokesMSBuild : TestBase
+    {
+        [Theory]
+        [InlineData("build")]
+        [InlineData("clean")]
+        [InlineData("msbuild")]
+        [InlineData("pack")]
+        [InlineData("publish")]
+        [InlineData("test")]
+        public void When_dotnet_command_invokes_msbuild_Then_env_vars_and_m_are_passed(string command)
+        {
+            var testInstance = TestAssets.Get("MSBuildIntegration")
+                .CreateInstance(identifier: command)
+                .WithSourceFiles();
+
+            new DotnetCommand()
+                .WithWorkingDirectory(testInstance.Root)
+                .Execute(command)
+                .Should().Pass();
+        }
+    }
+}

test/msbuild.IntegrationTests/project.json

@@ -0,0 +1,23 @@
+{
+  "version": "1.0.0-*",
+  "dependencies": {
+    "Microsoft.NETCore.App": {
+      "type": "platform",
+      "version": "1.0.0"
+    },
+    "Microsoft.DotNet.Tools.Tests.Utilities": {
+      "target": "project"
+    },
+    "xunit": "2.2.0-beta3-build3330",
+    "dotnet-test-xunit": "1.0.0-rc2-330423-54"
+  },
+  "frameworks": {
+    "netcoreapp1.0": {
+      "imports": [
+        "dotnet5.4",
+        "portable-net451+win8"
+      ]
+    }
+  },
+  "testRunner": "xunit"
+}