Fix directory separator on Linux

Author: xplicit

NuGet.Core/ServiceStack.Text.Core/servicestack.text.core.nuspec

@@ -27,7 +27,8 @@
         <dependency id="Microsoft.CSharp" version="[4.0.1, )" />
         <dependency id="System.Reflection.Emit" version="[4.0.1, )" />
         <dependency id="System.Reflection.Extensions" version="[4.0.1, )" />
-         <dependency id="NETStandard.Library" version="[1.6.0, )" />
+        <dependency id="System.Runtime.InteropServices.RuntimeInformation" version="[4.0.0, )" />
+        <dependency id="NETStandard.Library" version="[1.6.0, )" />
       </group>
       <group targetFramework=".NETStandard1.3">
         <dependency id="System.Runtime.Serialization.Primitives" version="[4.1.1, )" />

src/ServiceStack.Text/PclExport.NetStandard.cs

@@ -12,6 +12,7 @@
 using System.Globalization;
 using System.Reflection;
 using System.Reflection.Emit;
+using System.Runtime.InteropServices;
 
 #if NETSTANDARD1_3
 using System.Collections.Specialized;
@@ -56,6 +57,11 @@ public class NetStandardPclExport : PclExport
         public NetStandardPclExport()
         {
             this.PlatformName = Platforms.NetStandard;
+#if NETSTANDARD1_3
+            this.DirSep = Path.DirectorySeparatorChar;
+#else 
+            this.DirSep = RuntimeInformation.IsOSPlatform(OSPlatform.Windows) ? '\\' : '/';
+#endif
         }
 
         public override string ReadAllText(string filePath)

src/ServiceStack.Text/project.json

@@ -31,7 +31,8 @@
         "System.Reflection.Emit": "4.0.1",
         "System.Reflection.Emit.LightWeight" : "4.0.1",
         "System.Reflection.Extensions": "4.0.1",
-        "System.Linq.Expressions": "4.1.0"
+        "System.Linq.Expressions": "4.1.0",
+        "System.Runtime.InteropServices.RuntimeInformation" : "4.0.0"
       }
     },
     "netstandard1.3": {

tests/ServiceStack.Text.Tests/StringExtensionsTests.cs

@@ -101,7 +101,7 @@ public void Can_LastLeftPart_and_LastRightPart_string_needle()
         }
 
         private static readonly char DirSep = Path.DirectorySeparatorChar;
-        private static readonly char AltDirSep = Path.DirectorySeparatorChar == '/' ? '\\' : '/';
+        private static readonly char AltDirSep = '/';
 
         [Test]
         public void Does_get_ParentDirectory()