Factor WinRT GetFolderPath into static accessible via reflection (#34873)

Signed-off-by: dotnet-bot <dotnet-bot@microsoft.com>

2 files changed, 146 insertions, 127 deletions

diff --git a/src/System.Private.CoreLib/shared/System/Environment.WinRT.cs b/src/System.Private.CoreLib/shared/System/Environment.WinRT.cs
index c757bea779..72d66c44a6 100644
--- a/src/System.Private.CoreLib/shared/System/Environment.WinRT.cs
+++ b/src/System.Private.CoreLib/shared/System/Environment.WinRT.cs
@@ -2,8 +2,6 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Windows.Foundation.Metadata;
-using Windows.Storage;
 using System.IO;
 
 namespace System
@@ -12,130 +10,7 @@ namespace System
     {
         public static string UserName => "Windows User";
         public static string UserDomainName => "Windows Domain";
-
-        private static string GetFolderPathCore(SpecialFolder folder, SpecialFolderOption option)
-        {
-            // For testing we'll fall back if the needed APIs aren't present.
-            //
-            // We're not honoring the special folder options (noverify/create) for a few reasons. One, most of the
-            // folders always exist (e.g. it is moot). Two, most locations are inaccessible from an appcontainer
-            // currently - making it impossible to answer the question of existence or create if necessary. Thirdly,
-            // the Win32 API would create these folders with very specific ACLs, which even in the cases we can create
-            // are a significant compat risk (trying to replicate internal Windows behavior- it is documented that they
-            // set specific ACLs, but not which ones).
-            if (ApiInformation.IsTypePresent("Windows.Storage.UserDataPaths"))
-            {
-                return GetFolderPathCoreCurrent(folder);
-            }
-            else
-            {
-                return GetFolderPathCoreFallBack(folder);
-            }
-        }
-
-        private static string GetFolderPathCoreCurrent(SpecialFolder folder)
-        {
-            // While all of these give back real paths, most of them are not accessible
-            // from an appcontainer currently (they will give access denied)
-            switch (folder)
-            {
-                case SpecialFolder.ApplicationData:
-                    return UserDataPaths.GetDefault().RoamingAppData;
-                case SpecialFolder.CommonApplicationData:
-                    return AppDataPaths.GetDefault().ProgramData;
-                case SpecialFolder.LocalApplicationData:
-                    return AppDataPaths.GetDefault().LocalAppData;
-                case SpecialFolder.Cookies:
-                    return AppDataPaths.GetDefault().Cookies;
-                case SpecialFolder.Desktop:
-                    return AppDataPaths.GetDefault().Desktop;
-                case SpecialFolder.Favorites:
-                    return AppDataPaths.GetDefault().Favorites;
-                case SpecialFolder.History:
-                    return AppDataPaths.GetDefault().History;
-                case SpecialFolder.InternetCache:
-                    return AppDataPaths.GetDefault().InternetCache;
-                case SpecialFolder.MyMusic:
-                    return UserDataPaths.GetDefault().Music;
-                case SpecialFolder.MyPictures:
-                    return UserDataPaths.GetDefault().Pictures;
-                case SpecialFolder.MyVideos:
-                    return UserDataPaths.GetDefault().Videos;
-                case SpecialFolder.Recent:
-                    return UserDataPaths.GetDefault().Recent;
-                case SpecialFolder.System:
-                    return SystemDataPaths.GetDefault().System;
-                case SpecialFolder.Templates:
-                    return UserDataPaths.GetDefault().Templates;
-                case SpecialFolder.DesktopDirectory:
-                    return UserDataPaths.GetDefault().Desktop;
-                case SpecialFolder.Personal:
-                    return UserDataPaths.GetDefault().Documents;
-                case SpecialFolder.CommonDocuments:
-                    return SystemDataPaths.GetDefault().PublicDocuments;
-                case SpecialFolder.CommonMusic:
-                    return SystemDataPaths.GetDefault().PublicMusic;
-                case SpecialFolder.CommonPictures:
-                    return SystemDataPaths.GetDefault().PublicPictures;
-                case SpecialFolder.CommonDesktopDirectory:
-                    return SystemDataPaths.GetDefault().PublicDesktop;
-                case SpecialFolder.CommonVideos:
-                    return SystemDataPaths.GetDefault().PublicVideos;
-                case SpecialFolder.UserProfile:
-                    return UserDataPaths.GetDefault().Profile;
-                case SpecialFolder.SystemX86:
-                    return SystemDataPaths.GetDefault().SystemX86;
-                case SpecialFolder.Windows:
-                    return SystemDataPaths.GetDefault().Windows;
-
-                // The following aren't available on WinRT. Our default behavior
-                // is string.Empty for paths that aren't available.
-                //
-                // case SpecialFolder.Programs:
-                // case SpecialFolder.MyComputer:
-                // case SpecialFolder.SendTo:
-                // case SpecialFolder.StartMenu:
-                // case SpecialFolder.Startup:
-                // case SpecialFolder.ProgramFiles:
-                // case SpecialFolder.CommonProgramFiles:
-                // case SpecialFolder.AdminTools:
-                // case SpecialFolder.CDBurning:
-                // case SpecialFolder.CommonAdminTools:
-                // case SpecialFolder.CommonOemLinks:
-                // case SpecialFolder.CommonStartMenu:
-                // case SpecialFolder.CommonPrograms:
-                // case SpecialFolder.CommonStartup:
-                // case SpecialFolder.CommonTemplates:
-                // case SpecialFolder.Fonts:
-                // case SpecialFolder.NetworkShortcuts:
-                // case SpecialFolder.PrinterShortcuts:
-                // case SpecialFolder.CommonProgramFilesX86:
-                // case SpecialFolder.ProgramFilesX86:
-                // case SpecialFolder.Resources:
-                // case SpecialFolder.LocalizedResources:
-
-                default:
-                    return string.Empty;
-            }
-        }
-
-        private static string GetFolderPathCoreFallBack(SpecialFolder folder)
-        {
-            // For testing without the new WinRT APIs. We cannot use Win32 APIs for
-            // special folders as they are not in the WACK.
-            switch (folder)
-            {
-                case SpecialFolder.ApplicationData:
-                    return ApplicationData.Current.RoamingFolder?.Path;
-                case SpecialFolder.LocalApplicationData:
-                    return ApplicationData.Current.LocalFolder?.Path;
-                case SpecialFolder.System:
-                    return SystemDirectory;
-                case SpecialFolder.Windows:
-                    return Path.GetDirectoryName(SystemDirectory);
-                default:
-                    return string.Empty;
-            }
-        }
+        private static string GetFolderPathCore(SpecialFolder folder, SpecialFolderOption option) =>
+            WinRTFolderPaths.GetFolderPath(folder, option);
     }
 }
diff --git a/src/System.Private.CoreLib/shared/System/WinRTFolderPaths.cs b/src/System.Private.CoreLib/shared/System/WinRTFolderPaths.cs
new file mode 100644
index 0000000000..020898a8f1
--- /dev/null
+++ b/src/System.Private.CoreLib/shared/System/WinRTFolderPaths.cs
@@ -0,0 +1,144 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+#if SYSTEM_RUNTIME_WINDOWSRUNTIME_ASSEMBLY
+extern alias System_Runtime_Extensions;
+using static System_Runtime_Extensions::System.Environment;
+#else
+using static System.Environment;
+#endif
+using Windows.Foundation.Metadata;
+using Windows.Storage;
+using System.IO;
+
+namespace System
+{
+    internal static class WinRTFolderPaths
+    {
+        public static string GetFolderPath(SpecialFolder folder, SpecialFolderOption option)
+        {
+            // For testing we'll fall back if the needed APIs aren't present.
+            //
+            // We're not honoring the special folder options (noverify/create) for a few reasons. One, most of the
+            // folders always exist (e.g. it is moot). Two, most locations are inaccessible from an appcontainer
+            // currently - making it impossible to answer the question of existence or create if necessary. Thirdly,
+            // the Win32 API would create these folders with very specific ACLs, which even in the cases we can create
+            // are a significant compat risk (trying to replicate internal Windows behavior- it is documented that they
+            // set specific ACLs, but not which ones).
+            if (ApiInformation.IsTypePresent("Windows.Storage.UserDataPaths"))
+            {
+                return GetFolderPathCoreCurrent(folder);
+            }
+            else
+            {
+                return GetFolderPathCoreFallBack(folder);
+            }
+        }
+
+        private static string GetFolderPathCoreCurrent(SpecialFolder folder)
+        {
+            // While all of these give back real paths, most of them are not accessible
+            // from an appcontainer currently (they will give access denied)
+            switch (folder)
+            {
+                case SpecialFolder.ApplicationData:
+                    return UserDataPaths.GetDefault().RoamingAppData;
+                case SpecialFolder.CommonApplicationData:
+                    return AppDataPaths.GetDefault().ProgramData;
+                case SpecialFolder.LocalApplicationData:
+                    return AppDataPaths.GetDefault().LocalAppData;
+                case SpecialFolder.Cookies:
+                    return AppDataPaths.GetDefault().Cookies;
+                case SpecialFolder.Desktop:
+                    return AppDataPaths.GetDefault().Desktop;
+                case SpecialFolder.Favorites:
+                    return AppDataPaths.GetDefault().Favorites;
+                case SpecialFolder.History:
+                    return AppDataPaths.GetDefault().History;
+                case SpecialFolder.InternetCache:
+                    return AppDataPaths.GetDefault().InternetCache;
+                case SpecialFolder.MyMusic:
+                    return UserDataPaths.GetDefault().Music;
+                case SpecialFolder.MyPictures:
+                    return UserDataPaths.GetDefault().Pictures;
+                case SpecialFolder.MyVideos:
+                    return UserDataPaths.GetDefault().Videos;
+                case SpecialFolder.Recent:
+                    return UserDataPaths.GetDefault().Recent;
+                case SpecialFolder.System:
+                    return SystemDataPaths.GetDefault().System;
+                case SpecialFolder.Templates:
+                    return UserDataPaths.GetDefault().Templates;
+                case SpecialFolder.DesktopDirectory:
+                    return UserDataPaths.GetDefault().Desktop;
+                case SpecialFolder.Personal:
+                    return UserDataPaths.GetDefault().Documents;
+                case SpecialFolder.CommonDocuments:
+                    return SystemDataPaths.GetDefault().PublicDocuments;
+                case SpecialFolder.CommonMusic:
+                    return SystemDataPaths.GetDefault().PublicMusic;
+                case SpecialFolder.CommonPictures:
+                    return SystemDataPaths.GetDefault().PublicPictures;
+                case SpecialFolder.CommonDesktopDirectory:
+                    return SystemDataPaths.GetDefault().PublicDesktop;
+                case SpecialFolder.CommonVideos:
+                    return SystemDataPaths.GetDefault().PublicVideos;
+                case SpecialFolder.UserProfile:
+                    return UserDataPaths.GetDefault().Profile;
+                case SpecialFolder.SystemX86:
+                    return SystemDataPaths.GetDefault().SystemX86;
+                case SpecialFolder.Windows:
+                    return SystemDataPaths.GetDefault().Windows;
+
+                // The following aren't available on WinRT. Our default behavior
+                // is string.Empty for paths that aren't available.
+                //
+                // case SpecialFolder.Programs:
+                // case SpecialFolder.MyComputer:
+                // case SpecialFolder.SendTo:
+                // case SpecialFolder.StartMenu:
+                // case SpecialFolder.Startup:
+                // case SpecialFolder.ProgramFiles:
+                // case SpecialFolder.CommonProgramFiles:
+                // case SpecialFolder.AdminTools:
+                // case SpecialFolder.CDBurning:
+                // case SpecialFolder.CommonAdminTools:
+                // case SpecialFolder.CommonOemLinks:
+                // case SpecialFolder.CommonStartMenu:
+                // case SpecialFolder.CommonPrograms:
+                // case SpecialFolder.CommonStartup:
+                // case SpecialFolder.CommonTemplates:
+                // case SpecialFolder.Fonts:
+                // case SpecialFolder.NetworkShortcuts:
+                // case SpecialFolder.PrinterShortcuts:
+                // case SpecialFolder.CommonProgramFilesX86:
+                // case SpecialFolder.ProgramFilesX86:
+                // case SpecialFolder.Resources:
+                // case SpecialFolder.LocalizedResources:
+
+                default:
+                    return string.Empty;
+            }
+        }
+
+        private static string GetFolderPathCoreFallBack(SpecialFolder folder)
+        {
+            // For testing without the new WinRT APIs. We cannot use Win32 APIs for
+            // special folders as they are not in the WACK.
+            switch (folder)
+            {
+                case SpecialFolder.ApplicationData:
+                    return ApplicationData.Current.RoamingFolder?.Path;
+                case SpecialFolder.LocalApplicationData:
+                    return ApplicationData.Current.LocalFolder?.Path;
+                case SpecialFolder.System:
+                    return SystemDirectory;
+                case SpecialFolder.Windows:
+                    return Path.GetDirectoryName(SystemDirectory);
+                default:
+                    return string.Empty;
+            }
+        }
+    }
+}