Loading native dll's correctly for UWP release mode

src/Microsoft.TestPlatform.ObjectModel/Navigation/NativeMethods.cs

@@ -556,19 +556,11 @@ internal static class DiaSourceObject
 
         public static IDiaDataSource GetDiaSourceObject()
         {
-            var currentDirectory = new ProcessHelper().GetCurrentProcessLocation();
+            var nativeDllDirectory = new ProcessHelper().GetNativeDllDirectory();
 
-            IntPtr modHandle = IntPtr.Zero;
-            if (IntPtr.Size == 8)
-            {
-                modHandle = LoadLibraryEx(Path.Combine(currentDirectory, "x64\\msdia140.dll"), IntPtr.Zero, 0);
-            }
-            else
-            {
-                modHandle = LoadLibraryEx(Path.Combine(currentDirectory, "x86\\msdia140.dll"), IntPtr.Zero, 0);
-            }
+            IntPtr modHandle = LoadLibraryEx(Path.Combine(nativeDllDirectory, "msdia140.dll"), IntPtr.Zero, 0);
 
-            if(modHandle == IntPtr.Zero)
+            if (modHandle == IntPtr.Zero)
             {
                 throw new COMException(string.Format(Resources.Resources.FailedToLoadMsDia));
             }

src/Microsoft.TestPlatform.PlatformAbstractions/Interfaces/System/IProcessHelper.cs

@@ -41,6 +41,18 @@ public interface IProcessHelper
         /// <returns>Location of test engine.</returns>
         string GetTestEngineDirectory();
 
+        /// <summary>
+        /// Gets the location of native dll's, depending on current process architecture..
+        /// </summary>
+        /// <returns>Location of native dll's</returns>
+        string GetNativeDllDirectory();
+
+        /// <summary>
+        /// Gets current process architecture
+        /// </summary>
+        /// <returns>Process Architecture</returns>
+        PlatformArchitecture GetCurrentProcessArchitecture();
+
         /// <summary>
         /// Gets the process id of test engine.
         /// </summary>

src/Microsoft.TestPlatform.PlatformAbstractions/common/System/ProcessHelper.cs

@@ -16,6 +16,8 @@ namespace Microsoft.VisualStudio.TestPlatform.PlatformAbstractions
     /// </summary>
     public partial class ProcessHelper : IProcessHelper
     {
+        private static readonly string ARM = "arm";
+
         /// <inheritdoc/>
         public object LaunchProcess(string processPath, string arguments, string workingDirectory, IDictionary<string, string> envVariables, Action<object, string> errorCallback, Action<object> exitCallBack)
         {
@@ -162,5 +164,23 @@ public int GetProcessId(object process)
             var proc = process as Process;
             return proc?.Id ?? -1;
         }
+
+        /// <inheritdoc/>
+        public PlatformArchitecture GetCurrentProcessArchitecture()
+        {
+            if (IntPtr.Size == 8)
+            {
+                return PlatformArchitecture.X64;
+            }
+
+            return PlatformArchitecture.X86;
+        }
+
+        /// <inheritdoc/>
+        public string GetNativeDllDirectory()
+        {
+            var isArm = Environment.GetEnvironmentVariable("PROCESSOR_ARCHITECTURE").Contains("ARM");
+            return Path.Combine(this.GetCurrentProcessLocation(), this.GetCurrentProcessArchitecture().ToString(), isArm ? ARM : string.Empty);
+        }
     }
 }

src/Microsoft.TestPlatform.PlatformAbstractions/netstandard1.0/System/ProcessHelper.cs

@@ -78,5 +78,17 @@ public int GetProcessId(object process)
         {
             throw new NotImplementedException();
         }
+
+        /// <inheritdoc/>
+        public string GetNativeDllDirectory()
+        {
+            throw new NotImplementedException();
+        }
+
+        /// <inheritdoc/>
+        public PlatformArchitecture GetCurrentProcessArchitecture()
+        {
+            throw new NotImplementedException();
+        }
     }
 }

src/Microsoft.TestPlatform.PlatformAbstractions/uap10.0/System/ProcessHelper.cs

@@ -77,5 +77,23 @@ public int GetProcessId(object process)
         {
             return -1;
         }
+
+        /// <inheritdoc/>
+        public PlatformArchitecture GetCurrentProcessArchitecture()
+        {
+            if (IntPtr.Size == 8)
+            {
+                return PlatformArchitecture.X64;
+            }
+
+            return PlatformArchitecture.X86;
+        }
+
+        /// <inheritdoc/>
+        public string GetNativeDllDirectory()
+        {
+            // For UWP the native dll's are to be kept in same directory
+            return this.GetCurrentProcessLocation();
+        }
     }
 }