Read dotnet.config file to use MTP or VSTest in dotnet test (#46717)

Author: Evangelink

src/Cli/dotnet/commands/dotnet-test/TestCommandParser.cs

@@ -3,6 +3,7 @@
 
 using System.CommandLine;
 using Microsoft.DotNet.Tools.Test;
+using Microsoft.Extensions.Configuration;
 using LocalizableStrings = Microsoft.DotNet.Tools.Test.LocalizableStrings;
 
 namespace Microsoft.DotNet.Cli
@@ -151,28 +152,67 @@ public static CliCommand GetCommand()
             return Command;
         }
 
-        private static bool IsTestingPlatformEnabled()
+        public static string GetTestRunnerName()
         {
-            var testingPlatformEnabledEnvironmentVariable = Environment.GetEnvironmentVariable("DOTNET_CLI_TESTINGPLATFORM_ENABLE");
-            var isTestingPlatformEnabled = testingPlatformEnabledEnvironmentVariable == "1" || string.Equals(testingPlatformEnabledEnvironmentVariable, "true", StringComparison.OrdinalIgnoreCase);
-            return isTestingPlatformEnabled;
+            var builder = new ConfigurationBuilder();
+
+            string dotnetConfigPath = GetDotnetConfigPath(Environment.CurrentDirectory);
+
+            if (!File.Exists(dotnetConfigPath))
+            {
+                return CliConstants.VSTest;
+            }
+
+            builder.AddIniFile(dotnetConfigPath);
+
+            IConfigurationRoot config = builder.Build();
+            var testSection = config.GetSection("dotnet.test");
+
+            if (!testSection.Exists())
+            {
+                return CliConstants.VSTest;
+            }
+
+            string runnerNameSection = testSection["runner:name"];
+
+            if (string.IsNullOrEmpty(runnerNameSection))
+            {
+                return CliConstants.VSTest;
+            }
+
+            return runnerNameSection;
+        }
+
+        private static string? GetDotnetConfigPath(string? startDir)
+        {
+            string? directory = startDir;
+            while (directory != null)
+            {
+                string dotnetConfigPath = Path.Combine(directory, "dotnet.config");
+                if (File.Exists(dotnetConfigPath))
+                {
+                    return dotnetConfigPath;
+                }
+
+                directory = Path.GetDirectoryName(directory);
+            }
+            return null;
         }
 
         private static CliCommand ConstructCommand()
         {
-            bool isTestingPlatformEnabled = IsTestingPlatformEnabled();
-            string testingSdkName = isTestingPlatformEnabled ? "testingplatform" : "vstest";
+            string testRunnerName = GetTestRunnerName();
 
-            if (isTestingPlatformEnabled)
+            if (testRunnerName.Equals(CliConstants.VSTest, StringComparison.OrdinalIgnoreCase))
             {
-                return GetTestingPlatformCliCommand();
+                return GetVSTestCliCommand();
             }
-            else
+            else if (testRunnerName.Equals(CliConstants.MicrosoftTestingPlatform, StringComparison.OrdinalIgnoreCase))
             {
-                return GetVSTestCliCommand();
+                return GetTestingPlatformCliCommand();
             }
 
-            throw new InvalidOperationException($"Testing sdk not supported: {testingSdkName}");
+            throw new InvalidOperationException(string.Format(LocalizableStrings.CmdUnsupportedTestRunnerDescription, testRunnerName));
         }
 
         private static CliCommand GetTestingPlatformCliCommand()

test/TestAssets/TestProjects/EmptyFolder/dotnet.config

@@ -0,0 +1,2 @@
+[dotnet.test:runner]
+name= "MicrosoftTestingPlatform"

test/TestAssets/TestProjects/HybridTestRunnerTestProjects/dotnet.config

@@ -0,0 +1,2 @@
+[dotnet.test:runner]
+name= "MicrosoftTestingPlatform"

test/TestAssets/TestProjects/MSTestMetaPackageProjectWithMultipleTFMsSolution/dotnet.config

@@ -0,0 +1,2 @@
+[dotnet.test:runner]
+name= "MicrosoftTestingPlatform"

test/TestAssets/TestProjects/MultiTestProjectSolutionWithDifferentFailures/dotnet.config

@@ -0,0 +1,2 @@
+[dotnet.test:runner]
+name= "MicrosoftTestingPlatform"

test/TestAssets/TestProjects/MultiTestProjectSolutionWithDiscoveredTests/dotnet.config

@@ -0,0 +1,2 @@
+[dotnet.test:runner]
+name= "MicrosoftTestingPlatform"

test/TestAssets/TestProjects/MultiTestProjectSolutionWithTests/dotnet.config

@@ -0,0 +1,2 @@
+[dotnet.test:runner]
+name= "MicrosoftTestingPlatform"

test/TestAssets/TestProjects/MultipleTestProjectSolution/dotnet.config

@@ -0,0 +1,2 @@
+[dotnet.test:runner]
+name= "MicrosoftTestingPlatform"

test/TestAssets/TestProjects/MultipleTestProjectsWithoutSolution/dotnet.config

@@ -0,0 +1,2 @@
+[dotnet.test:runner]
+name= "MicrosoftTestingPlatform"

test/TestAssets/TestProjects/ProjectSolutionForMultipleTFMs/dotnet.config

@@ -0,0 +1,2 @@
+[dotnet.test:runner]
+name= "MicrosoftTestingPlatform"