Allow VSTestConsole path to be specified

src/Microsoft.TestPlatform.Build/Microsoft.TestPlatform.targets

@@ -13,6 +13,7 @@ Copyright (c) .NET Foundation. All rights reserved.
   <!-- Load Microsoft.TestPlatform.Build.Tasks.dll, this can be overridden to use a different version with $(VSTestTaskAssemblyFile) -->
   <PropertyGroup>
     <VSTestTaskAssemblyFile Condition="$(VSTestTaskAssemblyFile) == ''">Microsoft.TestPlatform.Build.dll</VSTestTaskAssemblyFile>
+    <VSTestConsoleFile Condition="$(VSTestConsoleFile) == ''">vstest.console.dll</VSTestConsoleFile>
     <MSBuildAllProjects>$(MSBuildAllProjects);$(MSBuildThisFileFullPath)</MSBuildAllProjects>
   </PropertyGroup>
   <UsingTask TaskName="Microsoft.TestPlatform.Build.Tasks.VSTestTask" AssemblyFile="$(VSTestTaskAssemblyFile)" />
@@ -40,6 +41,7 @@ Copyright (c) .NET Foundation. All rights reserved.
       VSTestListTests="$(VSTestListTests)"
       VSTestDiag="$(VSTestDiag)"
       VSTestCLIRunSettings="$(VSTestCLIRunSettings)"
+      VSTestConsolePath="$(VSTestConsoleFile)"
     />
   </Target>
 

src/Microsoft.TestPlatform.Build/Tasks/VSTestForwardingApp.cs

@@ -12,18 +12,17 @@ namespace Microsoft.TestPlatform.Build.Tasks
     public class VSTestForwardingApp
     {
         private const string hostExe = "dotnet";
-        private const string vsTestAppName = "vstest.console.dll";
         private readonly List<string> allArgs = new List<string>();
         private int activeProcessId;
 
-        public VSTestForwardingApp(IEnumerable<string> argsToForward)
+        public VSTestForwardingApp(string vsTestExePath, IEnumerable<string> argsToForward)
         {
             this.allArgs.Add("exec");
 
             // Ensure that path to vstest.console is whitespace friendly. User may install
             // dotnet-cli to any folder containing whitespace (e.g. VS installs to program files).
             // Arguments are already whitespace friendly.
-            this.allArgs.Add("\"" + GetVSTestExePath() + "\"");
+            this.allArgs.Add("\"" + vsTestExePath + "\"");
             this.allArgs.AddRange(argsToForward);
         }
 
@@ -69,10 +68,5 @@ public void Cancel()
                 Tracing.Trace(string.Format("VSTest: Killing process throws ArgumentException with the following message {0}. It may be that process is not running", ex.Message));
             }
         }
-
-        private static string GetVSTestExePath()
-        {
-            return Path.Combine(AppContext.BaseDirectory, vsTestAppName);
-        }
     }
 }

src/Microsoft.TestPlatform.Build/Tasks/VSTestTask.cs

@@ -18,6 +18,8 @@ public class VSTestTask : Task, ICancelableTask
         // The process which is invoking vstest.console
         private VSTestForwardingApp vsTestForwardingApp;
 
+        private const string vsTestAppName = "vstest.console.dll";
+
         public string TestFileFullPath
         {
             get;
@@ -77,12 +79,19 @@ public string[] VSTestCLIRunSettings
             set;
         }
 
+        [Required]
+        public string VSTestConsolePath
+        {
+            get; 
+            set;
+        }
+
         public override bool Execute()
         {
             var traceEnabledValue = Environment.GetEnvironmentVariable("VSTEST_BUILD_TRACE");
             Tracing.traceEnabled = !string.IsNullOrEmpty(traceEnabledValue) && traceEnabledValue.Equals("1", StringComparison.OrdinalIgnoreCase);
 
-            vsTestForwardingApp = new VSTestForwardingApp(this.CreateArgument());
+            vsTestForwardingApp = new VSTestForwardingApp(this.VSTestConsolePath, this.CreateArgument());
             if (!string.IsNullOrEmpty(this.VSTestFramework))
             {
                 Console.WriteLine("Test run for {0}({1})", this.TestFileFullPath, this.VSTestFramework);