Porting SaveAS API to HttpPostedFile

Author: Biroj Nayak

src/Microsoft.AspNetCore.SystemWebAdapters/HttpPostedFile.cs

@@ -23,7 +23,6 @@ public sealed class HttpPostedFile
 
     public void SaveAs(string filename)
     {
-
         if (!Path.IsPathRooted(filename))
         {
             throw new HttpException(string.Format(CultureInfo.InvariantCulture,
@@ -32,7 +31,6 @@ public void SaveAs(string filename)
 
         using (var fileStream = new FileStream(filename, FileMode.Create))
         {
-            InputStream.Seek(0, SeekOrigin.Begin);
             InputStream.CopyTo(fileStream);
         }
     }

test/Microsoft.AspNetCore.SystemWebAdapters.Tests/HttpPostedFileTests.cs

@@ -1,6 +1,8 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System;
+using System.Globalization;
 using System.IO;
 using System.Web;
 using AutoFixture;
@@ -102,13 +104,35 @@ public void InputStream()
     }
 
     [Fact]
-    public void SaveAs()
+    public void SaveAsForInvalidRootPath()
     {
+        // Arrange
         var file = new Mock<IFormFile>();
         var expectedStream = new Mock<Stream>();
         file.Setup(f => f.OpenReadStream()).Returns(expectedStream.Object);
-
         var posted = new HttpPostedFile(file.Object);
+
+        //Act and Assert
         Assert.Throws<HttpException>(() => posted.SaveAs("InvalidPath"));
     }
+
+    [Fact]
+    public void SaveAsWithValidRootPath()
+    {
+        // Arrange
+        var file = new Mock<IFormFile>();
+        var expectedStream = new Mock<Stream>();
+        file.Setup(f => f.OpenReadStream()).Returns(expectedStream.Object);
+        string validTempPath = string.Format(CultureInfo.InvariantCulture, @"{0}{1}.txt", Path.GetTempPath(), Guid.NewGuid());
+        var posted = new HttpPostedFile(file.Object);
+
+        //Act
+        posted.SaveAs(validTempPath);
+
+        //Assert
+        Assert.True(File.Exists(validTempPath), "Temp file should be created");
+
+        //Cleanup
+        File.Delete(validTempPath);
+    }
 }