Bring Host build into separate project

build_projects/Microsoft.DotNet.Cli.Build.Framework/CommandResult.cs

@@ -0,0 +1,50 @@
+// 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 System;
+using System.Text;
+using System.Diagnostics;
+
+namespace Microsoft.DotNet.Cli.Build.Framework
+{
+    public struct CommandResult
+    {
+        public static readonly CommandResult Empty = new CommandResult();
+
+        public ProcessStartInfo StartInfo { get; }
+        public int ExitCode { get; }
+        public string StdOut { get; }
+        public string StdErr { get; }
+
+        public CommandResult(ProcessStartInfo startInfo, int exitCode, string stdOut, string stdErr)
+        {
+            StartInfo = startInfo;
+            ExitCode = exitCode;
+            StdOut = stdOut;
+            StdErr = stdErr;
+        }
+
+        public void EnsureSuccessful(bool suppressOutput = false)
+        {
+            if(ExitCode != 0)
+            {
+                StringBuilder message = new StringBuilder($"Command failed with exit code {ExitCode}: {StartInfo.FileName} {StartInfo.Arguments}");
+
+                if (!suppressOutput)
+                {
+                    if (!string.IsNullOrEmpty(StdOut))
+                    {
+                        message.AppendLine($"{Environment.NewLine}Standard Output:{Environment.NewLine}{StdOut}");
+                    }
+
+                    if (!string.IsNullOrEmpty(StdErr))
+                    {
+                        message.AppendLine($"{Environment.NewLine}Standard Error:{Environment.NewLine}{StdErr}");
+                    }
+                }
+
+                throw new BuildFailureException(message.ToString());
+            }
+        }
+    }
+}