add tests for checking filename, working dir and validation of presence of environmental variables

src/dotnet/commands/dotnet-build/Program.cs

@@ -113,7 +113,7 @@ namespace Microsoft.DotNet.Tools.Build
             int exitCode = app.Execute(args);
             if (ret._forwardingApp == null)
             {
-                throw new CodeNotExecutedException(exitCode);
+                throw new CommandCreationException(exitCode);
             }
 
             return ret;
@@ -128,7 +128,7 @@ namespace Microsoft.DotNet.Tools.Build
             {
                 cmd = FromArgs(args);
             }
-            catch (CodeNotExecutedException e)
+            catch (CommandCreationException e)
             {
                 return e.ExitCode;
             }
@@ -146,11 +146,11 @@ namespace Microsoft.DotNet.Tools.Build
             return GetProcessStartInfo().Execute();
         }
 
-        private class CodeNotExecutedException : Exception
+        private class CommandCreationException : Exception
         {
             public int ExitCode { get; private set; }
 
-            public CodeNotExecutedException(int exitCode)
+            public CommandCreationException(int exitCode)
             {
                 ExitCode = exitCode;
             }

test/Microsoft.DotNet.Tools.Tests.Utilities/NonWindowsOnlyFactAttribute.cs

@@ -1,3 +1,6 @@
+// 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.PlatformAbstractions;
 using Xunit;
 
@@ -9,7 +12,7 @@ namespace Microsoft.DotNet.Tools.Test.Utilities
         {
             if (RuntimeEnvironment.OperatingSystemPlatform == Platform.Windows)
             {
-                this.Skip = "This test requires windows to run";
+                this.Skip = "This test requires non-Windows to run";
             }
         }
     }

test/Microsoft.DotNet.Tools.Tests.Utilities/NonWindowsOnlyTheoryAttribute.cs

@@ -0,0 +1,19 @@
+// 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.PlatformAbstractions;
+using Xunit;
+
+namespace Microsoft.DotNet.Tools.Test.Utilities
+{
+    public class NonWindowsOnlyTheoryAttribute : TheoryAttribute
+    {
+        public NonWindowsOnlyTheoryAttribute()
+        {
+            if (RuntimeEnvironment.OperatingSystemPlatform == Platform.Windows)
+            {
+                this.Skip = "This test requires non-Windows to run";
+            }
+        }
+    }
+}

test/Microsoft.DotNet.Tools.Tests.Utilities/WindowsOnlyFactAttribute.cs

@@ -12,7 +12,7 @@ namespace Microsoft.DotNet.Tools.Test.Utilities
         {
             if (RuntimeEnvironment.OperatingSystemPlatform != Platform.Windows)
             {
-                this.Skip = "This test requires windows to run";
+                this.Skip = "This test requires Windows to run";
             }
         }
     }

test/Microsoft.DotNet.Tools.Tests.Utilities/WindowsOnlyTheoryAttribute.cs

@@ -1,4 +1,7 @@
-using Microsoft.DotNet.PlatformAbstractions;
+// 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.PlatformAbstractions;
 using Xunit;
 
 namespace Microsoft.DotNet.Tools.Test.Utilities
@@ -9,7 +12,7 @@ namespace Microsoft.DotNet.Tools.Test.Utilities
         {
             if (RuntimeEnvironment.OperatingSystemPlatform != Platform.Windows)
             {
-                this.Skip = "This test requires windows to run";
+                this.Skip = "This test requires Windows to run";
             }
         }
     }

test/dotnet-msbuild.Tests/GivenDotnetBuildInvocation.cs

@@ -1,6 +1,9 @@
 using Microsoft.DotNet.Tools.Build;
 using FluentAssertions;
 using Xunit;
+using WindowsOnlyFactAttribute = Microsoft.DotNet.Tools.Test.Utilities.WindowsOnlyFactAttribute;
+using NonWindowsOnlyFactAttribute = Microsoft.DotNet.Tools.Test.Utilities.NonWindowsOnlyFactAttribute;
+using System.Collections.Generic;
 
 namespace Microsoft.DotNet.Cli.MSBuild.Tests
 {
@@ -29,5 +32,48 @@ namespace Microsoft.DotNet.Cli.MSBuild.Tests
             BuildCommand.FromArgs(args, msbuildPath)
                 .GetProcessStartInfo().Arguments.Should().Be(expectedCommand);
         }
+
+        [WindowsOnlyFact]
+        public void WhenInvokingBuildCommandOnWindowsTheDotnetIsExecuted()
+        {
+            var msbuildPath = "<msbuildpath>";
+            BuildCommand.FromArgs(new string[0], msbuildPath)
+                .GetProcessStartInfo().FileName.Should().Be("dotnet.exe");
+        }
+
+        [NonWindowsOnlyFact]
+        public void WhenInvokingBuildCommandOnNonWindowsTheDotnetIsExecuted()
+        {
+            var msbuildPath = "<msbuildpath>";
+            BuildCommand.FromArgs(new string[0], msbuildPath)
+                .GetProcessStartInfo().FileName.Should().Be("dotnet");
+        }
+
+        [Fact]
+        public void WhenInvokingBuildCommandItSetsEnvironmentVariables()
+        {
+            var expectedEnvironmentalVariables = new HashSet<string> {
+                "MSBuildExtensionsPath",
+                "CscToolExe",
+                "MSBuildSDKsPath",
+                "DOTNET_CLI_TELEMETRY_SESSIONID"
+            };
+
+            var msbuildPath = "<msbuildpath>";
+            var startInfo = BuildCommand.FromArgs(new string[0], msbuildPath).GetProcessStartInfo();
+
+            foreach (var envVarName in expectedEnvironmentalVariables)
+            {
+                startInfo.Environment.ContainsKey(envVarName).Should().BeTrue();
+            }
+        }
+
+        [Fact]
+        public void WhenInvokingBuildCommandItDoesNotSetCurrentWorkingDirectory()
+        {
+            var msbuildPath = "<msbuildpath>";
+            var startInfo = BuildCommand.FromArgs(new string[0], msbuildPath)
+                .GetProcessStartInfo().WorkingDirectory.Should().Be("");
+        }
     }
 }