Use Moq framework instead of a concrete class to mock ICommandFactory in dotnet-run.UnitTests.

test/dotnet-run.UnitTests/GivenARunCommand.cs

@@ -1,13 +1,12 @@
 // 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.Collections.Generic;
-using System.IO;
 using FluentAssertions;
 using Microsoft.DotNet.Cli.Utils;
 using Microsoft.DotNet.TestFramework;
 using Microsoft.DotNet.Tools.Test.Utilities;
+using Moq;
 using NuGet.Frameworks;
 using Xunit;
 
@@ -28,95 +27,27 @@ namespace Microsoft.DotNet.Tools.Run.Tests
                 .Should()
                 .Pass();
 
-            RunCommand runCommand = new RunCommand(new FailOnRedirectOutputCommandFactory());
+            // use MockBehavior.Strict to ensure the RunCommand doesn't call CaptureStdOut, ForwardStdOut, etc.
+            Mock<ICommand> failOnRedirectOutputCommand = new Mock<ICommand>(MockBehavior.Strict);
+            failOnRedirectOutputCommand
+                .Setup(c => c.Execute())
+                .Returns(new CommandResult(null, RunExitCode, null, null));
+
+            Mock<ICommandFactory> commandFactoryMock = new Mock<ICommandFactory>();
+            commandFactoryMock
+                .Setup(c => c.Create(
+                                It.IsAny<string>(),
+                                It.IsAny<IEnumerable<string>>(),
+                                It.IsAny<NuGetFramework>(),
+                                It.IsAny<string>()))
+                .Returns(failOnRedirectOutputCommand.Object);
+
+            RunCommand runCommand = new RunCommand(commandFactoryMock.Object);
             runCommand.Project = instance.TestRoot;
 
             runCommand.Start()
                 .Should()
                 .Be(RunExitCode);
         }
-
-        private class FailOnRedirectOutputCommandFactory : ICommandFactory
-        {
-            public ICommand Create(string commandName, IEnumerable<string> args, NuGetFramework framework = null, string configuration = "Debug")
-            {
-                return new FailOnRedirectOutputCommand();
-            }
-
-            /// <summary>
-            /// A Command that will fail if a caller tries redirecting StdOut or StdErr.
-            /// </summary>
-            private class FailOnRedirectOutputCommand : ICommand
-            {
-                public CommandResult Execute()
-                {
-                    return new CommandResult(null, RunExitCode, null, null);
-                }
-
-                public ICommand CaptureStdErr()
-                {
-                    throw new NotSupportedException();
-                }
-
-                public ICommand CaptureStdOut()
-                {
-                    throw new NotSupportedException();
-                }
-
-                public ICommand ForwardStdErr(TextWriter to = null, bool onlyIfVerbose = false, bool ansiPassThrough = true)
-                {
-                    throw new NotSupportedException();
-                }
-
-                public ICommand ForwardStdOut(TextWriter to = null, bool onlyIfVerbose = false, bool ansiPassThrough = true)
-                {
-                    throw new NotSupportedException();
-                }
-
-                public ICommand OnErrorLine(Action<string> handler)
-                {
-                    throw new NotSupportedException();
-                }
-
-                public ICommand OnOutputLine(Action<string> handler)
-                {
-                    throw new NotSupportedException();
-                }
-
-                public string CommandArgs
-                {
-                    get
-                    {
-                        throw new NotImplementedException();
-                    }
-                }
-
-                public string CommandName
-                {
-                    get
-                    {
-                        throw new NotImplementedException();
-                    }
-                }
-
-                public CommandResolutionStrategy ResolutionStrategy
-                {
-                    get
-                    {
-                        throw new NotImplementedException();
-                    }
-                }
-
-                public ICommand EnvironmentVariable(string name, string value)
-                {
-                    throw new NotImplementedException();
-                }
-
-                public ICommand WorkingDirectory(string projectDirectory)
-                {
-                    throw new NotImplementedException();
-                }
-            }
-        }
     }
 }

test/dotnet-run.UnitTests/project.json

@@ -13,6 +13,7 @@
       "target": "project"
     },
     "xunit": "2.1.0",
+    "moq.netcore": "4.4.0-beta8",
     "dotnet-test-xunit": "1.0.0-rc2-173361-36"
   },
   "frameworks": {