[tests, build] multi-target Xamarin.Android.Build.Tests

There are various tests in `Xamarin.Android.Build.Tests` that execute
MSBuild tasks directly. This means the changes in dotnet#4820 are not quite
complete. We need to actually *run* the tests under .NET Core to see
if these tests would pass under a One .NET context.

The solution (you would think), would be to make the test assembly
`netstandard2.0` so you could run either:

    > nunit3-console Xamarin.Android.Build.Tests.dll
    > dotnet test Xamarin.Android.Build.Tests.dll

`nunit3-console` would execute the tests under .NET framework/Mono and
`dotnet test` would run under .NET Core or .NET 5+.

Unfortunately, `nunit3-console` can't run tests from a
`netstandard2.0` library!

So we multi-target:

    <TargetFrameworks>net472;net5.0</TargetFrameworks>

Unfortunately, the `net5.0` causes MSBuild to fail with:

    > msbuild Xamarin.Android.sln
    ...
    (GetReferenceAssemblyPaths target) ->
      C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets(1177,5): error MSB3644: The reference assemblies for .NETFramework,Version=v5.0 were not found. To resolve this, install the Developer Pack (SDK/Targeting Pack) for this framework version or retarget your application. You can download .NET Framework Developer Packs at https://aka.ms/msbuild/developerpacks

I think there is some expectation to use `dotnet build` for .NET 5
instead. We don't want to move our *entire* build over to `dotnet
build` yet (we probably can't!), so instead we can do:

    <TargetFrameworks>net472;netcoreapp3.1</TargetFrameworks>

This allows `msbuild Xamarin.Android.sln` to continue to work. This
might also be something that gets fixed in a future MSBuild version.

I updated various `.yaml` definitions so we can run NUnit tests via
`nunit3-console` or `dotnet test` as needed.

Other things that broke here:

* We need `Microsoft.NET.Test.Sdk` for `dotnet test` to work.
* `Builder.UseDotNet` can now be set based on a `#if` instead of an
  NUnit parameter.
* `Xamarin.Android.Tools.Aidl` needs to be `netstandard2.0`. This
  required including a `System.CodeDom` package.
* `Xamarin.Android.Build.Tasks` can't use `FSharp.Core` in
  `netcoreapp3.1`. I just removed it, since it is not used.
* Updated various paths to `Xamarin.Android.Build.Tests.dll`.
* Usage of System.Drawing crashed on macOS. I replaced this with
  ImageSharp: https://www.nuget.org/packages/SixLabors.ImageSharp/

.vscode/launch.json

@@ -8,7 +8,7 @@
             "name": "Launch",
             "type": "mono",
             "request": "launch",
-            "program": "${workspaceRoot}packages/nunit.consolerunner/3.11.1/tools/nunit3-console.exe ${workspaceRoot}bin/TestDebug/Xamarin.Android.Build.Tests.dll",
+            "program": "${workspaceRoot}packages/nunit.consolerunner/3.11.1/tools/nunit3-console.exe ${workspaceRoot}bin/TestDebug/net472/Xamarin.Android.Build.Tests.dll",
             "cwd": "${workspaceRoot}bin/TestDebug/"
         },
         {

.vscode/settings.json

@@ -2,7 +2,7 @@
     "nxunitExplorer.nunit": "packages/nunit.consolerunner/3.11.1/tools/nunit3-console.exe",
     "nxunitExplorer.modules": [
         "bin/TestDebug/MSBuildDeviceIntegration/MSBuildDeviceIntegration.dll",
-        "bin/TestDebug/Xamarin.Android.Build.Tests.dll",
+        "bin/TestDebug/net472/Xamarin.Android.Build.Tests.dll",
         "bin/TestDebug/Xamarin.Android.Build.Tests.Commercial.dll",
     ],
     "cmake.configureOnOpen": false

build-tools/automation/azure-pipelines.yaml

@@ -63,7 +63,7 @@ variables:
   # - This is a non-fork branch with name containing "mono-" (for Mono bumps)
   IsMonoBranch: $[and(eq(variables['XA.Commercial.Build'], 'true'), ne(variables['System.PullRequest.IsFork'], 'True'), or(contains(variables['Build.SourceBranchName'], 'mono-'), contains(variables['System.PullRequest.SourceBranch'], 'mono-')))]
   RunAllTests: $[or(eq(variables['XA.RunAllTests'], true), eq(variables['IsMonoBranch'], true))]
-  DotNetNUnitCategories: '&& cat != DotNetIgnore && cat != AOT && cat != FSharp && cat != LibraryProjectZip && cat != MkBundle && cat != MonoSymbolicate && cat != PackagesConfig && cat != StaticProject'
+  DotNetNUnitCategories: '& TestCategory != DotNetIgnore & TestCategory != AOT & TestCategory != FSharp & TestCategory != LibraryProjectZip & TestCategory != MkBundle & TestCategory != MonoSymbolicate & TestCategory != PackagesConfig & TestCategory != StaticProject'
 
 # Stage and Job "display names" are shortened because they are combined to form the name of the corresponding GitHub check.
 stages:
@@ -366,7 +366,7 @@ stages:
     - template: yaml-templates\run-nunit-tests.yaml
       parameters:
         testRunTitle: Smoke MSBuild Tests - Windows Build Tree
-        testAssembly: $(System.DefaultWorkingDirectory)\bin\Test$(XA.Build.Configuration)\Xamarin.Android.Build.Tests.dll
+        testAssembly: $(System.DefaultWorkingDirectory)\bin\Test$(XA.Build.Configuration)\net472\Xamarin.Android.Build.Tests.dll
         testResultsFile: TestResult-SmokeMSBuildTests-WinBuildTree-$(XA.Build.Configuration).xml
         nunitConsoleExtraArgs: --where "cat == SmokeTests" --workers=4
 
@@ -1054,23 +1054,23 @@ stages:
       job_name: mac_dotnet_tests_1
       job_suffix: One .NET
       nunit_categories: $(DotNetNUnitCategories)
-      nunit_extra: --testparam dotnet=true
+      target_framework: 'netcoreapp3.1'
 
   - template: yaml-templates\run-msbuild-mac-tests.yaml
     parameters:
       node_id: 2
       job_name: mac_dotnet_tests_2
       job_suffix: One .NET
       nunit_categories: $(DotNetNUnitCategories)
-      nunit_extra: --testparam dotnet=true
+      target_framework: 'netcoreapp3.1'
 
   - template: yaml-templates\run-msbuild-mac-tests.yaml
     parameters:
       node_id: 3
       job_name: mac_dotnet_tests_3
       job_suffix: One .NET
       nunit_categories: $(DotNetNUnitCategories)
-      nunit_extra: --testparam dotnet=true
+      target_framework: 'netcoreapp3.1'
 
   # Xamarin.Android (Test MSBuild - Windows - One .NET)
   - template: yaml-templates\run-msbuild-win-tests.yaml
@@ -1079,23 +1079,23 @@ stages:
       job_name: win_dotnet_tests_1
       job_suffix: One .NET
       nunit_categories: $(DotNetNUnitCategories)
-      nunit_extra: --testparam dotnet=true
+      target_framework: 'netcoreapp3.1'
 
   - template: yaml-templates\run-msbuild-win-tests.yaml
     parameters:
       node_id: 2
       job_name: win_dotnet_tests_2
       job_suffix: One .NET
       nunit_categories: $(DotNetNUnitCategories)
-      nunit_extra: --testparam dotnet=true
+      target_framework: 'netcoreapp3.1'
 
   - template: yaml-templates\run-msbuild-win-tests.yaml
     parameters:
       node_id: 3
       job_name: win_dotnet_tests_3
       job_suffix: One .NET
       nunit_categories: $(DotNetNUnitCategories)
-      nunit_extra: --testparam dotnet=true
+      target_framework: 'netcoreapp3.1'
 
 - stage: integrated_regression_test
   displayName: Regression Tests

build-tools/automation/yaml-templates/run-msbuild-mac-tests.yaml

@@ -5,7 +5,7 @@ parameters:
   job_name: ''
   job_suffix: ''
   nunit_categories: ''
-  nunit_extra: ''
+  target_framework: 'net472'
   run_extra_tests: false
 
 jobs:
@@ -16,6 +16,8 @@ jobs:
     cancelTimeoutInMinutes: 5
     workspace:
       clean: all
+    variables:
+      UseDotNet: ${{ eq(parameters.target_framework, 'netcoreapp3.1') }}
     steps:
     - template: setup-test-environment.yaml
 
@@ -31,24 +33,29 @@ jobs:
 
     - template: run-nunit-tests.yaml
       parameters:
+        useDotNet: $(UseDotNet)
         testRunTitle: Xamarin.Android.Build.Tests - macOS-${{ parameters.node_id }} - ${{ parameters.job_suffix }}
-        testAssembly: $(System.DefaultWorkingDirectory)/bin/Test$(XA.Build.Configuration)/Xamarin.Android.Build.Tests.dll
-        nunitConsoleExtraArgs: --where "cat == Node-${{ parameters.node_id }} ${{ parameters.nunit_categories }}" ${{ parameters.nunit_extra }}
+        testAssembly: $(System.DefaultWorkingDirectory)/bin/Test$(XA.Build.Configuration)/${{ parameters.target_framework }}/Xamarin.Android.Build.Tests.dll
+        nunitConsoleExtraArgs: --where "cat == Node-${{ parameters.node_id }} ${{ parameters.nunit_categories }}"
+        dotNetTestExtraArgs: --filter "TestCategory = Node-${{ parameters.node_id }} ${{ parameters.nunit_categories }}"
         testResultsFile: TestResult-MSBuildTests-${{ parameters.job_name }}-$(XA.Build.Configuration).xml
 
     # Only run these tests on node 2
     - ${{ if eq(parameters.run_extra_tests, true) }}:
       - template: run-nunit-tests.yaml
         parameters:
+          useDotNet: $(UseDotNet)
           testRunTitle: Xamarin.Android.Build.Tests.Commercial - macOS
           testAssembly: $(System.DefaultWorkingDirectory)/bin/Test$(XA.Build.Configuration)/Xamarin.Android.Build.Tests.Commercial.dll
           testResultsFile: TestResult-MSBuildTestsCommercial-macOS-$(XA.Build.Configuration).xml
 
       - template: run-nunit-tests.yaml
         parameters:
+          useDotNet: $(UseDotNet)
           testRunTitle: Xamarin.Android.Build.Tests - macOS - No Node
-          testAssembly: $(System.DefaultWorkingDirectory)/bin/Test$(XA.Build.Configuration)/Xamarin.Android.Build.Tests.dll
+          testAssembly: $(System.DefaultWorkingDirectory)/bin/Test$(XA.Build.Configuration)/${{ parameters.target_framework }}/Xamarin.Android.Build.Tests.dll
           nunitConsoleExtraArgs: --where "cat != Node-1 && cat != Node-2 && cat != Node-3"
+          dotNetTestExtraArgs: --filter "TestCategory != Node-1 & TestCategory != Node-2 & TestCategory != Node-3"
           testResultsFile: TestResult-MSBuildTests-macOS-NoNode-$(XA.Build.Configuration).xml
 
     - template: upload-results.yaml

build-tools/automation/yaml-templates/run-msbuild-win-tests.yaml

@@ -5,7 +5,7 @@ parameters:
   job_name: ''
   job_suffix: ''
   nunit_categories: ''
-  nunit_extra: ''
+  target_framework: 'net472'
   run_extra_tests: false
 
 jobs:
@@ -16,6 +16,7 @@ jobs:
     cancelTimeoutInMinutes: 5
     variables:
       VSINSTALLDIR: C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise
+      UseDotNet: ${{ eq(parameters.target_framework, 'netcoreapp3.1') }}
     steps:
 
     - template: kill-processes.yaml
@@ -42,24 +43,29 @@ jobs:
     # Using all available cores seems to occasionally bog down our machines and cause parallel test execution to slow down dramatically.
     - template: run-nunit-tests.yaml
       parameters:
+        useDotNet: $(UseDotNet)
         testRunTitle: Xamarin.Android.Build.Tests - Windows-${{ parameters.node_id }} - ${{ parameters.job_suffix }}
-        testAssembly: $(System.DefaultWorkingDirectory)\bin\Test$(XA.Build.Configuration)\Xamarin.Android.Build.Tests.dll
-        nunitConsoleExtraArgs: --workers=4 --where "cat == Node-${{ parameters.node_id }} ${{ parameters.nunit_categories }}" ${{ parameters.nunit_extra }}
+        testAssembly: $(System.DefaultWorkingDirectory)\bin\Test$(XA.Build.Configuration)\${{ parameters.target_framework }}\Xamarin.Android.Build.Tests.dll
+        nunitConsoleExtraArgs: --workers=4 --where "cat == Node-${{ parameters.node_id }} ${{ parameters.nunit_categories }}"
+        dotNetTestExtraArgs: --filter "TestCategory = Node-${{ parameters.node_id }} ${{ parameters.nunit_categories }}"
         testResultsFile: TestResult-MSBuildTests-${{ parameters.job_name }}-$(XA.Build.Configuration).xml
 
     # Only run these tests on node 2
     - ${{ if eq(parameters.run_extra_tests, true) }}:
       - template: run-nunit-tests.yaml
         parameters:
+          useDotNet: $(UseDotNet)
           testRunTitle: Xamarin.Android.Build.Tests.Commercial - Windows
           testAssembly: $(System.DefaultWorkingDirectory)\bin\Test$(XA.Build.Configuration)\Xamarin.Android.Build.Tests.Commercial.dll
           testResultsFile: TestResult-MSBuildTestsCommercial-Windows-$(XA.Build.Configuration).xml
 
       - template: run-nunit-tests.yaml
         parameters:
+          useDotNet: $(UseDotNet)
           testRunTitle: Xamarin.Android.Build.Tests - Windows - No Node
-          testAssembly: $(System.DefaultWorkingDirectory)\bin\Test$(XA.Build.Configuration)\Xamarin.Android.Build.Tests.dll
+          testAssembly: $(System.DefaultWorkingDirectory)\bin\Test$(XA.Build.Configuration)\${{ parameters.target_framework }}\Xamarin.Android.Build.Tests.dll
           nunitConsoleExtraArgs: --workers=4 --where "cat != Node-1 && cat != Node-2 && cat != Node-3"
+          dotNetTestExtraArgs: --filter "TestCategory != Node-1 & TestCategory != Node-2 & TestCategory != Node-3"
           testResultsFile: TestResult-MSBuildTests-Windows-NoNode-$(XA.Build.Configuration).xml
 
     - template: upload-results.yaml

build-tools/automation/yaml-templates/run-nunit-tests.yaml

@@ -3,15 +3,21 @@ parameters:
   testRunTitle: Xamarin Android Tests
   testAssembly: []
   testResultsFile: TestResult.xml
-  testResultsFormat: NUnit
   nunitConsoleExtraArgs: ''
+  dotNetTestExtraArgs: ''
+  useDotNet: false
   condition: succeeded()
 
 steps:
 - powershell: |
-    if ([Environment]::OSVersion.Platform -eq "Unix") {
+    if ("${{ parameters.useDotNet }}" -eq $true) {
+        Write-Host '##vso[task.setvariable variable=TestResultsFormat]VSTest'
+        dotnet test ${{ parameters.testAssembly }} --results-directory . --logger "trx;LogFileName=${{ parameters.testResultsFile }}" ${{ parameters.dotNetTestExtraArgs }}
+    } elseif ([Environment]::OSVersion.Platform -eq "Unix") {
+        Write-Host '##vso[task.setvariable variable=TestResultsFormat]NUnit'
         mono ${{ parameters.nunitConsole }} ${{ parameters.testAssembly }} --result ${{ parameters.testResultsFile }} ${{ parameters.nunitConsoleExtraArgs }}
     } else {
+        Write-Host '##vso[task.setvariable variable=TestResultsFormat]NUnit'
         ${{ parameters.nunitConsole }} ${{ parameters.testAssembly }} --result ${{ parameters.testResultsFile }}  ${{ parameters.nunitConsoleExtraArgs }}
     }
     if ($LASTEXITCODE -ne 0) {
@@ -27,7 +33,7 @@ steps:
 
 - task: PublishTestResults@2
   inputs:
-    testResultsFormat: ${{ parameters.testResultsFormat }}
+    testResultsFormat: $(TestResultsFormat)
     testResultsFiles: ${{ parameters.testResultsFile }}
     testRunTitle: ${{ parameters.testRunTitle }}
   condition: ${{ parameters.condition }}

build-tools/installers/create-installers.targets

@@ -121,7 +121,6 @@
     <_MSBuildFiles Include="$(MSBuildSrcDir)\cil-strip.pdb"   Condition=" '$(PackageId)' != 'Microsoft.Android.Sdk' " />
     <_MSBuildFiles Include="$(MSBuildSrcDir)\class-parse.exe" Condition=" '$(PackageId)' != 'Microsoft.Android.Sdk' " />
     <_MSBuildFiles Include="$(MSBuildSrcDir)\class-parse.pdb" Condition=" '$(PackageId)' != 'Microsoft.Android.Sdk' " />
-    <_MSBuildFiles Include="$(MSBuildSrcDir)\FSharp.Core.dll" />
     <_MSBuildFiles Include="$(MSBuildSrcDir)\generator.exe"   Condition=" '$(PackageId)' != 'Microsoft.Android.Sdk' " />
     <_MSBuildFiles Include="$(MSBuildSrcDir)\generator.pdb"   Condition=" '$(PackageId)' != 'Microsoft.Android.Sdk' " />
     <_MSBuildFiles Include="$(MSBuildSrcDir)\HtmlAgilityPack.dll" />
@@ -401,6 +400,7 @@
     <_MSBuildFiles Include="$(MSBuildSrcDir)\lib\x86\installer" />
     <_MSBuildFiles Include="$(MSBuildSrcDir)\lib\x86_64\installer" />
     <_MSBuildFiles Include="$(MSBuildSrcDir)\protobuf-net.dll" />
+    <_MSBuildFiles Include="$(MSBuildSrcDir)\System.CodeDom.dll" />
     <_MSBuildFiles Include="$(MSBuildSrcDir)\System.Collections.Immutable.dll" />
     <_MSBuildFiles Include="$(MSBuildSrcDir)\Xamarin.AndroidTools.dll" />
     <_MSBuildFiles Include="$(MSBuildSrcDir)\Xamarin.AndroidTools.pdb" />

build-tools/scripts/RunTests.targets

@@ -15,7 +15,7 @@
     <_XABuildProperties>$(_XABuildDiag)/p:Configuration=$(Configuration)</_XABuildProperties>
   </PropertyGroup>
   <ItemGroup>
-    <_TestAssembly Include="$(_TopDir)\bin\Test$(Configuration)\Xamarin.Android.Build.Tests.dll" />
+    <_TestAssembly Include="$(_TopDir)\bin\Test$(Configuration)\net472\Xamarin.Android.Build.Tests.dll" />
     <_ApkTestProject Include="$(_TopDir)\src\Mono.Android\Test\Mono.Android-Tests.csproj" />
     <_ApkTestProject Include="$(_TopDir)\tests\CodeGen-Binding\Xamarin.Android.JcwGen-Tests\Xamarin.Android.JcwGen-Tests.csproj" />
     <_ApkTestProject Include="$(_TopDir)\tests\CodeGen-MkBundle\Xamarin.Android.MakeBundle-Tests\Xamarin.Android.MakeBundle-Tests.csproj" />

src/Xamarin.Android.Build.Tasks/Tests/Xamarin.Android.Build.Tests/BindingBuildTest.cs

@@ -86,11 +86,13 @@ public void CleanBasicBindingLibrary (string classParser)
 				var files = Directory.GetFiles (Path.Combine (Root, b.ProjectDirectory, proj.IntermediateOutputPath), "*", SearchOption.AllDirectories)
 					.Where (x => !ignoreFiles.Any (i => !Path.GetFileName (x).Contains (i)));
 				var directories = Directory.GetDirectories (Path.Combine (Root, b.ProjectDirectory, proj.IntermediateOutputPath), "*", SearchOption.AllDirectories)
-					.Where (x => Path.GetFileName (x) != "designtime");
-				Assert.AreEqual (0, directories.Count (),
-					"All directories in {0} should have been removed", proj.IntermediateOutputPath);
-				Assert.AreEqual (0, files.Count (), "{0} should be empty. Found {1}",
-					proj.IntermediateOutputPath, string.Join (Environment.NewLine, files));
+					// designtime folder is left behind, so Intellisense continues to work after a Clean
+					.Where (x => Path.GetFileName (x) != "designtime")
+					// .NET 5+ sets $(ProduceReferenceAssembly) by default
+					// https://github.com/dotnet/sdk/blob/18ee4eac8b3abe6d554d2e0c39d8952da0f23ce5/src/Tasks/Microsoft.NET.Build.Tasks/targets/Microsoft.NET.TargetFrameworkInference.targets#L242-L244
+					.Where (x => Path.GetFileName (x) != "ref");
+				CollectionAssert.IsEmpty (directories, $"{proj.IntermediateOutputPath} should have no directories.");
+				CollectionAssert.IsEmpty (files, $"{proj.IntermediateOutputPath} should have no files.");
 			}
 		}
 
@@ -554,11 +556,11 @@ public void BindDefaultInterfaceMethods (string classParser)
 			proj.SetProperty ("_EnableInterfaceMembers", "True");
 			proj.SetProperty ("LangVersion", "preview");
 
-			using (var b = CreateDllBuilder (Path.Combine ("temp", TestName), false, false)) {
+			using (var b = CreateDllBuilder ()) {
 				proj.NuGetRestore (b.ProjectDirectory);
 				Assert.IsTrue (b.Build (proj), "Build should have succeeded.");
 
-				string asmpath = Path.GetFullPath (Path.Combine (Path.GetDirectoryName (new Uri (GetType ().Assembly.CodeBase).LocalPath), b.ProjectDirectory, b.Output.OutputPath, (proj.AssemblyName ?? proj.ProjectName) + ".dll"));
+				string asmpath = Path.Combine (Root, b.ProjectDirectory, proj.OutputPath, $"{proj.ProjectName}.dll");
 				Assert.IsTrue (File.Exists (asmpath), "assembly does not exist");
 
 				var cs = b.Output.GetIntermediaryAsText (Path.Combine ("generated", "src", "Com.Xamarin.Test.IDefaultInterfaceMethods.cs"));

src/Xamarin.Android.Build.Tasks/Tests/Xamarin.Android.Build.Tests/Tasks/ManagedResourceParserTests.cs

@@ -631,6 +631,7 @@ public void CompareAaptAndManagedParserOutputWithCustomIds ()
 		}
 
 		[Test]
+		[NonParallelizable] // Test measures performance
 		public void CheckPerformanceOfManagedParser ()
 		{
 			var path = Path.Combine ("temp", TestName);

src/Xamarin.Android.Build.Tasks/Tests/Xamarin.Android.Build.Tests/Tasks/ResolveSdksTaskTests.cs

@@ -256,7 +256,7 @@ public void ResolveSdkTiming ()
 			Assert.NotNull (resolveSdks.ReferenceAssemblyPaths, "ReferenceAssemblyPaths should not be null.");
 			Assert.AreEqual (resolveSdks.ReferenceAssemblyPaths.Length, 1, "ReferenceAssemblyPaths should have 1 entry.");
 			Assert.AreEqual (resolveSdks.ReferenceAssemblyPaths[0], Path.Combine (referencePath, "MonoAndroid"), $"ReferenceAssemblyPaths should be {Path.Combine (referencePath, "MonoAndroid")}.");
-			var expected = Path.Combine (Root);
+			var expected = Path.GetDirectoryName (GetType ().Assembly.Location);
 			Assert.AreEqual (resolveSdks.MonoAndroidToolsPath, expected, $"MonoAndroidToolsPath should be {expected}");
 			expected += Path.DirectorySeparatorChar;
 			if (resolveSdks.MonoAndroidBinPath != expected) {

src/Xamarin.Android.Build.Tasks/Tests/Xamarin.Android.Build.Tests/Utilities/BaseTest.cs

@@ -40,7 +40,11 @@ public static string AndroidMSBuildDirectory {
 
 			static SetUp ()
 			{
-				Builder.UseDotNet = string.Equals (TestContext.Parameters ["dotnet"], bool.TrueString, StringComparison.OrdinalIgnoreCase);
+#if NETCOREAPP3_1
+				Builder.UseDotNet = true;
+#else
+				Builder.UseDotNet = false;
+#endif
 
 				using (var builder = new Builder ()) {
 					CommercialBuildAvailable = File.Exists (Path.Combine (builder.AndroidMSBuildDirectory, "Xamarin.Android.Common.Debugging.targets"));

src/Xamarin.Android.Build.Tasks/Tests/Xamarin.Android.Build.Tests/Xamarin.Android.Build.Tests.csproj

@@ -1,9 +1,8 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net472</TargetFramework>
+    <TargetFrameworks>net472;netcoreapp3.1</TargetFrameworks>
     <LibZipSharpBundleAllNativeLibraries>true</LibZipSharpBundleAllNativeLibraries>
-    <AppendTargetFrameworkToOutputPath>false</AppendTargetFrameworkToOutputPath>
     <OutputPath>..\..\..\..\bin\Test$(Configuration)</OutputPath>
   </PropertyGroup>
 
@@ -17,6 +16,12 @@
     </Reference>
   </ItemGroup>
 
+  <!-- Required packages for .NET Core -->
+  <ItemGroup Condition=" '$(TargetFramework)' == 'netcoreapp3.1' ">
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.6.1" />
+    <PackageReference Include="System.Configuration.ConfigurationManager" Version="4.7.0" />
+  </ItemGroup>
+
   <ItemGroup>
     <ProjectReference Include="..\Xamarin.ProjectTools\Xamarin.ProjectTools.csproj" />
     <ProjectReference Include="..\..\Xamarin.Android.Build.Tasks.csproj" />
@@ -26,12 +31,15 @@
   <ItemGroup>
     <Compile Remove="Expected\**" />
     <Content Include="Expected\GenerateDesignerFileExpected.cs">
+      <Link>..\Expected\GenerateDesignerFileExpected.cs</Link>
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </Content>
     <Content Include="Expected\GenerateDesignerFileWithElevenStyleableAttributesExpected.cs">
+      <Link>..\Expected\GenerateDesignerFileWithElevenStyleableAttributesExpected.cs</Link>
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </Content>
     <Content Include="Expected\GenerateDesignerFileWithLibraryReferenceExpected.cs">
+      <Link>..\Expected\GenerateDesignerFileWithLibraryReferenceExpected.cs</Link>
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </Content>
   </ItemGroup>