Test both APIs under .NET Framework; switch APIs automatically

NUnitConsole.sln

@@ -139,6 +139,16 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "WpfTest", "src\TestData\wpf
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "WpfApp", "src\TestData\WpfApp\WpfApp.csproj", "{93D182B7-2F63-4661-BB32-94F1716CF03F}"
 EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "OlderNUnit", "OlderNUnit", "{D31607D2-D689-488B-9F9F-92F47AC1D7F6}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "NUnit3.0", "src\TestData\NUnit3.0\NUnit3.0.csproj", "{2448CE80-59AA-41B7-83A0-768BE5520F7A}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "NUnit3.0.1", "src\TestData\NUnit3.0.1\NUnit3.0.1.csproj", "{56416AD9-8E7B-4F72-B0E1-E75A024431F8}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "NUnit3.2", "src\TestData\NUnit3.2\NUnit3.2.csproj", "{8AFBB856-700A-4CCC-AE0E-9B622178E1E0}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "NUnit3.10", "src\TestData\NUnit3.10\NUnit3.10.csproj", "{0555B97D-E918-455B-951C-74EFCDA8790A}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -241,6 +251,22 @@ Global
 		{93D182B7-2F63-4661-BB32-94F1716CF03F}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{93D182B7-2F63-4661-BB32-94F1716CF03F}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{93D182B7-2F63-4661-BB32-94F1716CF03F}.Release|Any CPU.Build.0 = Release|Any CPU
+		{2448CE80-59AA-41B7-83A0-768BE5520F7A}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{2448CE80-59AA-41B7-83A0-768BE5520F7A}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{2448CE80-59AA-41B7-83A0-768BE5520F7A}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{2448CE80-59AA-41B7-83A0-768BE5520F7A}.Release|Any CPU.Build.0 = Release|Any CPU
+		{56416AD9-8E7B-4F72-B0E1-E75A024431F8}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{56416AD9-8E7B-4F72-B0E1-E75A024431F8}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{56416AD9-8E7B-4F72-B0E1-E75A024431F8}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{56416AD9-8E7B-4F72-B0E1-E75A024431F8}.Release|Any CPU.Build.0 = Release|Any CPU
+		{8AFBB856-700A-4CCC-AE0E-9B622178E1E0}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{8AFBB856-700A-4CCC-AE0E-9B622178E1E0}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{8AFBB856-700A-4CCC-AE0E-9B622178E1E0}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{8AFBB856-700A-4CCC-AE0E-9B622178E1E0}.Release|Any CPU.Build.0 = Release|Any CPU
+		{0555B97D-E918-455B-951C-74EFCDA8790A}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{0555B97D-E918-455B-951C-74EFCDA8790A}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{0555B97D-E918-455B-951C-74EFCDA8790A}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{0555B97D-E918-455B-951C-74EFCDA8790A}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -280,6 +306,11 @@ Global
 		{48DF1E40-93BA-436A-B460-5D1130316ADA} = {37D508B2-91E0-4B32-869B-DFF9E68EA213}
 		{2F9D8932-2186-464F-BED6-7D7979C8FFA6} = {37D508B2-91E0-4B32-869B-DFF9E68EA213}
 		{93D182B7-2F63-4661-BB32-94F1716CF03F} = {37D508B2-91E0-4B32-869B-DFF9E68EA213}
+		{D31607D2-D689-488B-9F9F-92F47AC1D7F6} = {37D508B2-91E0-4B32-869B-DFF9E68EA213}
+		{2448CE80-59AA-41B7-83A0-768BE5520F7A} = {D31607D2-D689-488B-9F9F-92F47AC1D7F6}
+		{56416AD9-8E7B-4F72-B0E1-E75A024431F8} = {D31607D2-D689-488B-9F9F-92F47AC1D7F6}
+		{8AFBB856-700A-4CCC-AE0E-9B622178E1E0} = {D31607D2-D689-488B-9F9F-92F47AC1D7F6}
+		{0555B97D-E918-455B-951C-74EFCDA8790A} = {D31607D2-D689-488B-9F9F-92F47AC1D7F6}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {D8E4FC26-5422-4C51-8BBC-D1AC0A578711}

package-tests.cake

@@ -142,6 +142,46 @@ StandardRunnerTests.Add(new PackageTest(
     "testdata/net462/mock-assembly.dll testdata/net6.0/mock-assembly.dll",
     new MockAssemblyExpectedResult("net-4.6.2", "netcore-6.0")));
 
+//////////////////////////////////////////////////////////////////////
+// TEST OLDER VERSIONS OF NUNIT SWITCHING API IF NEEDED
+//////////////////////////////////////////////////////////////////////
+
+StandardRunnerTests.Add(new PackageTest(
+    1, "NUnit30Test",
+    "Run a test under NUnit 3.0 using 2009 API",
+    "testdata/NUnit3.0/net462/NUnit3.0.dll",
+    new ExpectedResult("Passed")
+    {
+        Assemblies = new[] { new ExpectedAssemblyResult("NUnit3.0.dll", "net462") }
+    }));
+
+StandardRunnerTests.Add(new PackageTest(
+    1, "NUnit301Test",
+    "Run a test under NUnit 3.0.1 using 2009 API",
+    "testdata/NUnit3.0/net462/NUnit3.0.1.dll",
+    new ExpectedResult("Passed")
+    {
+        Assemblies = new[] { new ExpectedAssemblyResult("NUnit3.0.1.dll", "net462") }
+    }));
+
+StandardRunnerTests.Add(new PackageTest(
+    1, "NUnit32Test",
+    "Run a test under NUnit 3.2 using 20018 API",
+    "testdata/NUnit3.0/net462/NUnit3.2.dll",
+    new ExpectedResult("Passed")
+    {
+        Assemblies = new[] { new ExpectedAssemblyResult("NUnit3.2.dll", "net462") }
+    }));
+
+StandardRunnerTests.Add(new PackageTest(
+    1, "NUnit310Test",
+    "Run a test under NUnit 3.10 using 2018 API",
+    "testdata/NUnit3.0/net462/NUnit3.10.dll",
+    new ExpectedResult("Passed")
+    {
+        Assemblies = new[] { new ExpectedAssemblyResult("NUnit3.10.dll", "net462") }
+    }));
+
 //////////////////////////////////////////////////////////////////////
 // ASP.NETCORE TESTS
 //////////////////////////////////////////////////////////////////////

src/NUnitEngine/nunit.engine.core.tests/Drivers/NUnitFrameworkDriverTests.cs

@@ -12,6 +12,10 @@
 namespace NUnit.Engine.Drivers
 {
     // Functional tests of the NUnitFrameworkDriver calling into the framework.
+#if NETFRAMEWORK
+    [TestFixture("2009")]
+    [TestFixture("2018")]
+#endif
     public class NUnitFrameworkDriverTests
     {
         private const string MOCK_ASSEMBLY = "mock-assembly.dll";
@@ -22,13 +26,22 @@ public class NUnitFrameworkDriverTests
         private NUnitFrameworkDriver _driver;
         private string _mockAssemblyPath;
 
+#if NETFRAMEWORK
+        private string _whichApi;
+        public NUnitFrameworkDriverTests(string whichApi)
+        {
+            _whichApi = whichApi;
+        }
+#endif
+
         [SetUp]
         public void CreateDriver()
         {
-            var nunitRef = typeof(NUnit.Framework.TestAttribute).Assembly.GetName();
+            var nunitRef = typeof(TestAttribute).Assembly.GetName();
             _mockAssemblyPath = System.IO.Path.Combine(TestContext.CurrentContext.TestDirectory, MOCK_ASSEMBLY);
+
 #if NETFRAMEWORK
-            _driver = new NUnitFrameworkDriver(AppDomain.CurrentDomain, "99", nunitRef);
+            _driver = new NUnitFrameworkDriver(AppDomain.CurrentDomain, _whichApi, "99", nunitRef);
 #else
             _driver = new NUnitFrameworkDriver("99", nunitRef);
 #endif

src/NUnitEngine/nunit.engine.core/Drivers/NUnitFrameworkApi2009.cs

@@ -27,7 +27,7 @@ class NUnitFrameworkApi2009 : NUnitFrameworkApi
 
             const string CONTROLLER_TYPE = "NUnit.Framework.Api.FrameworkController";
 
-            NUnitFrameworkDriver _driver;
+            string _driverId;
 
             AppDomain _testDomain;
             AssemblyName _nunitRef;
@@ -37,10 +37,14 @@ class NUnitFrameworkApi2009 : NUnitFrameworkApi
             object? _frameworkController;
             Type? _frameworkControllerType;
 
-            public NUnitFrameworkApi2009(NUnitFrameworkDriver driver, AppDomain testDomain, AssemblyName nunitRef)
+            public NUnitFrameworkApi2009(AppDomain testDomain, string driverId, AssemblyName nunitRef)
             {
-                _driver = driver;
+                Guard.ArgumentNotNull(testDomain, nameof(testDomain));
+                Guard.ArgumentNotNull(driverId, nameof(driverId));
+                Guard.ArgumentNotNull(nunitRef, nameof(nunitRef));
+
                 _testDomain = testDomain;
+                _driverId = driverId;
                 _nunitRef = nunitRef;
             }
 
@@ -56,7 +60,8 @@ public string Load(string testAssemblyPath, IDictionary<string, object> settings
                 var requestedRuntime = settings.ContainsKey(EnginePackageSettings.RequestedRuntimeFramework)
                     ? settings[EnginePackageSettings.RequestedRuntimeFramework] : null;
 
-                var idPrefix = string.IsNullOrEmpty(_driver.ID) ? "" : _driver.ID + "-";
+                var idPrefix = string.IsNullOrEmpty(_driverId) ? "" : _driverId + "-";
+
                 try
                 {
                     _frameworkController = CreateObject(CONTROLLER_TYPE, _testAssemblyPath, idPrefix, settings);

src/NUnitEngine/nunit.engine.core/Drivers/NUnitFrameworkDriver.cs

@@ -7,6 +7,7 @@
 using NUnit.Common;
 using NUnit.Engine.Internal;
 using NUnit.Engine.Extensibility;
+using NUnit.Engine.Runners;
 
 namespace NUnit.Engine.Drivers
 {
@@ -27,25 +28,34 @@ public class NUnitFrameworkDriver : IFrameworkDriver
         /// <param name="testDomain">The application domain in which to create the FrameworkController</param>
         /// <param name="nunitRef">An AssemblyName referring to the test framework.</param>
         public NUnitFrameworkDriver(AppDomain testDomain, string id, AssemblyName nunitRef)
+            : this(testDomain, nunitRef.Version >= new Version(3,2,0) ? "2018" : "2009", id, nunitRef) { }
+
+        /// <summary>
+        /// Internal generic constructor used directly by our tests.
+        /// </summary>
+        /// <param name="testDomain">The application domain in which to create the FrameworkController</param>
+        /// <param name="nunitRef">An AssemblyName referring to the test framework.</param>
+        internal NUnitFrameworkDriver(AppDomain testDomain, string api, string id, AssemblyName nunitRef)
         {
             Guard.ArgumentNotNull(testDomain, nameof(testDomain));
+            Guard.ArgumentNotNull(api, nameof(api));
+            Guard.ArgumentValid(api == "2009" || api == "2018", $"Invalid API specified: {api}", nameof(api));
             Guard.ArgumentNotNullOrEmpty(id, nameof(id));
             Guard.ArgumentNotNull(nunitRef, nameof(nunitRef));
 
             ID = id;
 
-            // Under .NET Framework, the Api class must be injected in the test domain
-            //testDomain.AssemblyResolve += TestDomain_AssemblyResolve;
-
-            _api = (NUnitFrameworkApi2018)testDomain.CreateInstanceFromAndUnwrap(
-                Assembly.GetExecutingAssembly().Location,
-                typeof(NUnitFrameworkApi2018).FullName!,
-                false,
-                0,
-                null,
-                new object[] { ID, nunitRef },
-                null,
-                null).ShouldNotBeNull();
+            _api = api == "2018"
+                ? (NUnitFrameworkApi)testDomain.CreateInstanceFromAndUnwrap(
+                    Assembly.GetExecutingAssembly().Location,
+                    $"NUnit.Engine.Drivers.NUnitFrameworkApi{api}",
+                    false,
+                    0,
+                    null,
+                    new object[] { ID, nunitRef },
+                    null,
+                    null).ShouldNotBeNull()
+                : new NUnitFrameworkApi2009(testDomain, ID, nunitRef);
         }
 
         private Assembly? TestDomain_AssemblyResolve(object? sender, ResolveEventArgs args)

src/TestData/NUnit3.0.1/Class1.cs

@@ -0,0 +1,13 @@
+// Copyright (c) Charlie Poole, Rob Prouse and Contributors. MIT License - see LICENSE.txt
+
+using System;
+using NUnit.Framework;
+
+namespace NUnit.Engine.TestData
+{
+    public class NUnit_3_0_1_Test
+    {
+        [Test]
+        public void Test() { Assert.Pass("test passes"); }
+    }
+}

src/TestData/NUnit3.0.1/NUnit3.0.1.csproj

@@ -0,0 +1,13 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <RootNamespace>NUnit.TestData</RootNamespace>
+    <TargetFramework>net462</TargetFramework>
+    <OutputPath>../../../bin/$(Configuration)/testdata/nunit3.0</OutputPath>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="NUnit" Version="3.0.0" />
+  </ItemGroup>
+
+</Project>

src/TestData/NUnit3.0/NUnit3.0.csproj

@@ -0,0 +1,13 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <RootNamespace>NUnit.TestData</RootNamespace>
+    <TargetFramework>net462</TargetFramework>
+    <OutputPath>../../../bin/$(Configuration)/testdata/nunit3.0</OutputPath>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="NUnit" Version="3.0.0" />
+  </ItemGroup>
+
+</Project>

src/TestData/NUnit3.0/NUnit_3_0_Test.cs

@@ -0,0 +1,13 @@
+// Copyright (c) Charlie Poole, Rob Prouse and Contributors. MIT License - see LICENSE.txt
+
+using System;
+using NUnit.Framework;
+
+namespace NUnit.Engine.TestData
+{
+    public class NUnit_3_0_Test
+    {
+        [Test]
+        public void Test() { Assert.Pass("test passes"); }
+    }
+}

src/TestData/NUnit3.10/NUnit3.10.csproj

@@ -0,0 +1,13 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <RootNamespace>NUnit.TestData</RootNamespace>
+    <TargetFramework>net462</TargetFramework>
+    <OutputPath>../../../bin/$(Configuration)/testdata/nunit3.0</OutputPath>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="NUnit" Version="3.0.0" />
+  </ItemGroup>
+
+</Project>

src/TestData/NUnit3.10/NUnit_3_10_Test.cs

@@ -0,0 +1,13 @@
+// Copyright (c) Charlie Poole, Rob Prouse and Contributors. MIT License - see LICENSE.txt
+
+using System;
+using NUnit.Framework;
+
+namespace NUnit.Engine.TestData
+{
+    public class NUnit_3_10_Test
+    {
+        [Test]
+        public void Test() { Assert.Pass("test passes"); }
+    }
+}

src/TestData/NUnit3.2/NUnit3.2.csproj

@@ -0,0 +1,13 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <RootNamespace>NUnit.TestData</RootNamespace>
+    <TargetFramework>net462</TargetFramework>
+    <OutputPath>../../../bin/$(Configuration)/testdata/nunit3.0</OutputPath>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="NUnit" Version="3.0.0" />
+  </ItemGroup>
+
+</Project>

src/TestData/NUnit3.2/NUnit_3_2_Test.cs

@@ -0,0 +1,13 @@
+// Copyright (c) Charlie Poole, Rob Prouse and Contributors. MIT License - see LICENSE.txt
+
+using System;
+using NUnit.Framework;
+
+namespace NUnit.Engine.TestData
+{
+    public class NUnit_3_2_Test
+    {
+        [Test]
+        public void Test() { Assert.Pass("test passes"); }
+    }
+}