Use overrideOn2Xx when dowloading files. (#1800)

Author: peombwa

src/readme.graph.md

@@ -648,12 +648,12 @@ directive:
         let outFileParameterRegex = /(^\s*)public\s*global::System\.String\s*OutFile\s*/gmi
         let streamResponseRegex = /global::System\.Threading\.Tasks\.Task<global::System\.IO\.Stream>\s*response/gmi
         let octetStreamSchemaResponseRegex = /global::System\.Threading\.Tasks\.Task<.*(OctetStreamSchema|GraphReport)>\s*response/gmi
-        let overrideOnOkCallRegex = /(^\s*)(overrideOnOk\(\s*responseMessage\s*,\s*response\s*,\s*ref\s*_returnNow\s*\);)/gmi
+        let overrideOn2XxCallRegex = /(^\s*)(overrideOn2Xx\(\s*responseMessage\s*,\s*response\s*,\s*ref\s*_returnNow\s*\);)/gmi
         if($.match(outFileParameterRegex) && $.match(streamResponseRegex)) {
           // Handle file download.
-          $ = $.replace(overrideOnOkCallRegex, '$1$2\n$1using(var stream = await response){ this.WriteToFile(responseMessage, stream, this.GetProviderPath(OutFile, false), _cancellationTokenSource.Token); _returnNow = global::System.Threading.Tasks.Task<bool>.FromResult(true);}\n$1');
+          $ = $.replace(overrideOn2XxCallRegex, '$1$2\n$1using(var stream = await response){ this.WriteToFile(responseMessage, stream, this.GetProviderPath(OutFile, false), _cancellationTokenSource.Token); _returnNow = global::System.Threading.Tasks.Task<bool>.FromResult(true);}\n$1');
         } else if ($.match(outFileParameterRegex) && $.match(octetStreamSchemaResponseRegex)){
-          $ = $.replace(overrideOnOkCallRegex, '$1$2\n$1using(var stream = await responseMessage.Content.ReadAsStreamAsync()){ this.WriteToFile(responseMessage, stream, this.GetProviderPath(OutFile, false), _cancellationTokenSource.Token); _returnNow = global::System.Threading.Tasks.Task<bool>.FromResult(true);}\n$1');
+          $ = $.replace(overrideOn2XxCallRegex, '$1$2\n$1using(var stream = await responseMessage.Content.ReadAsStreamAsync()){ this.WriteToFile(responseMessage, stream, this.GetProviderPath(OutFile, false), _cancellationTokenSource.Token); _returnNow = global::System.Threading.Tasks.Task<bool>.FromResult(true);}\n$1');
         }
         return $;
       }

tools/Custom/PSCmdletExtensions.cs

@@ -16,6 +16,8 @@ namespace NamespacePrefixPlaceholder.PowerShell
 
     internal static class PSCmdletExtensions
     {
+        private static readonly char[] PathSeparators = new char[] { Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar };
+
         /// <summary>
         /// Gets a resolved or unresolved path from PSPath.
         /// </summary>
@@ -121,20 +123,24 @@ private static void WriteToStream(this PSCmdlet cmdlet, Stream inputStream, Stre
         private static bool IsPathDirectory(string path)
         {
             if (path == null) throw new ArgumentNullException("path");
+            bool isDirectory = false;
             path = path.Trim();
 
             if (Directory.Exists(path))
-                return true;
+                isDirectory = true;
 
             if (File.Exists(path))
-                return false;
+                isDirectory = false;
 
             // If path has a trailing slash then it's a directory.
-            if (new[] { Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar }.Any(x => path.EndsWith(x.ToString())))
-                return true;
+            if (PathSeparators.Contains(path.Last()))
+                isDirectory = true;
+
+            // If path has an extension then its a file.
+            if (Path.HasExtension(path))
+                isDirectory = false;
 
-            // If path has an extension then its a file; directory otherwise.
-            return string.IsNullOrWhiteSpace(Path.GetExtension(path));
+            return isDirectory;
         }
 
         private static string GetFileName(HttpResponseMessage responseMessage)