add linux test project

Rx.NET/Integration/LinuxTests.sln

@@ -0,0 +1,25 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 16
+VisualStudioVersion = 16.0.28407.52
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "LinuxTests", "LinuxTests\LinuxTests.csproj", "{E5607740-EAAC-4A42-B59C-3B2387582559}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{E5607740-EAAC-4A42-B59C-3B2387582559}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{E5607740-EAAC-4A42-B59C-3B2387582559}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{E5607740-EAAC-4A42-B59C-3B2387582559}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{E5607740-EAAC-4A42-B59C-3B2387582559}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {2ABA1A1F-6AEE-4AB5-A710-4D7474576023}
+	EndGlobalSection
+EndGlobal

Rx.NET/Integration/LinuxTests/LinuxTests.csproj

@@ -2,14 +2,31 @@
   <PropertyGroup>
     <TargetFrameworks>netcoreapp3.0;netcoreapp2.1</TargetFrameworks>
     <NoWarn>$(NoWarn);CS0618</NoWarn>
+    <LangVersion>latest</LangVersion>
+    <AssemblyName>Tests.System.Reactive</AssemblyName>
+    <RootNamespace>Tests.System.Reactive</RootNamespace>
+    <SignAssembly>true</SignAssembly>
+    <AssemblyOriginatorKeyFile>..\..\Source\ReactiveX.snk</AssemblyOriginatorKeyFile>
+  </PropertyGroup>
+
+  <PropertyGroup Condition="'$(TargetFramework)' == 'netcoreapp3.0' ">
+    <UseWPF>true</UseWPF>
+    <UseWindowsForms>true</UseWindowsForms>
+  </PropertyGroup>
+
+  
+  <PropertyGroup Condition="'$(TargetFramework)' == 'netstandard2.0' or '$(TargetFramework)' == 'netcoreapp2.1'">
+    <DefineConstants>$(DefineConstants);HAS_TRACE;HAS_WINRT;PREFER_ASYNC;HAS_TPL46;NO_REMOTING</DefineConstants>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(TargetFramework)' == 'netcoreapp3.0'">
+    <DefineConstants>$(DefineConstants);HAS_TRACE;HAS_WINRT;HAS_WINFORMS;HAS_DISPATCHER;PREFER_ASYNC;HAS_TPL46;NO_REMOTING;DESKTOPCLR;LINUX</DefineConstants>
   </PropertyGroup>
 
   <ItemGroup>
     <Content Include="..\..\Source\tests\Tests.System.Reactive\xunit.runner.json">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </Content>
-    <Compile Include="..\..\Source\tests\Tests.System.Reactive\**\*.cs" 
-             Exclude="..\..\Source\tests\Tests.System.Reactive\obj\**" />
+    <Compile Include="..\..\Source\tests\Tests.System.Reactive\**\*.cs" Exclude="..\..\Source\tests\Tests.System.Reactive\obj\**" />
   </ItemGroup>
 
   <ItemGroup>
@@ -18,6 +35,6 @@
     <PackageReference Include="xunit.runner.visualstudio" Version="2.4.1" />
     <PackageReference Include="System.Reactive" Version="4.2.0-preview.63" />
     <PackageReference Include="Microsoft.Reactive.Testing" Version="4.2.0-preview.63" />
-    <PackageReference Include="System.Reactive.Observable.Aliases Version="4.2.0-preview.63" />
+    <PackageReference Include="System.Reactive.Observable.Aliases" Version="4.2.0-preview.63" />
   </ItemGroup>
 </Project>

Rx.NET/Integration/global.json

@@ -0,0 +1,8 @@
+{
+  "sdk": {
+    "version": "3.0.100-preview"
+  },
+  "msbuild-sdks": {
+    "MSBuild.Sdk.Extras": "2.0.0-preview.14"
+  }
+}