[C#][AWS][S3][MsTest] A sample of AWS S3's File Repository.

GuestBookImageRepository.cs

using System;
using System.IO;

using Amazon.S3.Model;
using Amazon.S3.Transfer;

namespace GuestBook.Repository.Aws.S3
{
    class GuestBookImageRepository : S3RepositoryBase, IGuestBookImageRepository
    {
        // Adjust the BUCKET_NAME to match yours
        public const string BUCKET_NAME = "guestbookdemo-bucket-aws";

        public GuestBookImageRepository()
            : base(CommonHelpers.GetRegionEndpointFromConfig(), BUCKET_NAME) { }

        public string UploadImageFile(string imageType, Stream imageStream)
        {
            var uniqueKey = Guid.NewGuid().ToString();            
            //var transferUtiliyConfig = new TransferUtilityConfig { DefaultTimeout = 10 * 60 * 1000 };
            //var transferUtility = new TransferUtility(S3, transferUtiliyConfig);
            var transferUtility = new TransferUtility(S3);
            var uploadRequest = new TransferUtilityUploadRequest
                {
                    BucketName = BUCKET_NAME,
                    Key = uniqueKey,
                    ContentType = imageType,
                    InputStream = imageStream

                }.WithAutoCloseStream(false);

            transferUtility.Upload(uploadRequest);

            return uniqueKey;
        }

        public void Remove(string objectKey)
        {
            S3.DeleteObject(new DeleteObjectRequest { Key = objectKey, BucketName = BUCKET_NAME });
        }
    }
}

GuestBookImageRepositoryTest.cs

using System.Drawing.Imaging;
using System.IO;
using System.Net.Mime;

using GuestBook.Repository;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using Xtremecode.Infrastructure.Library.Di;

namespace Demo.S3.Test
{
    [TestClass]
    public class GuestBookImageRepositoryTest
    {
        private readonly IGuestBookImageRepository _guestBookImageRepository = DependencyInjector.Get<IGuestBookImageRepository>();
        private Stream _uploadedImageFileStream;
        private string _uniqueBlobName;

        [TestMethod]
        public void Can_store_uploaded_image_file()
        {
            // Arrange
            _uploadedImageFileStream = new MemoryStream();
            Resource.Huang5.Save(_uploadedImageFileStream, ImageFormat.Jpeg);
            // This is an IMPORTANT ONE TO DO! Or else, calling the S3's Upload Utility method would return IOException later.
            _uploadedImageFileStream.Seek(0, SeekOrigin.Begin); 
            
            // Act
            _uniqueBlobName = _guestBookImageRepository.UploadImageFile(MediaTypeNames.Image.Jpeg, _uploadedImageFileStream);

            // Assert
            Assert.IsFalse(string.IsNullOrWhiteSpace(_uniqueBlobName));
        }

        [TestCleanup]
        public void Teardown()
        {
            // Wipe out the stored image
            if (_uploadedImageFileStream != null)
            {
                _uploadedImageFileStream.Dispose();
                _uploadedImageFileStream = null;
            }

            _guestBookImageRepository.Remove(_uniqueBlobName);
        }
    }
}

S3Helpers.cs

using Amazon;
using Amazon.S3;

namespace GuestBook.Repository.Aws.S3
{
    static class S3Helpers
    {
        public static S3Region AsS3Region(this RegionEndpoint regionEndpoint)
        {
            if (regionEndpoint == RegionEndpoint.APNortheast1)
            {
                return S3Region.APN1;
            }
            if (regionEndpoint == RegionEndpoint.APSoutheast1)
            {
                return S3Region.APS1;
            }
            if (regionEndpoint == RegionEndpoint.APSoutheast2)
            {
                return S3Region.APS2;
            }
            if (regionEndpoint == RegionEndpoint.EUWest1)
            {
                return S3Region.EU;
            }
            if (regionEndpoint == RegionEndpoint.SAEast1)
            {
                return S3Region.SAE1;
            }
            if (regionEndpoint == RegionEndpoint.USEast1)
            {
                return S3Region.US;
            }
            if (regionEndpoint == RegionEndpoint.USWest1)
            {
                return S3Region.USW1;
            }
            if (regionEndpoint == RegionEndpoint.USWest2)
            {
                return S3Region.USW2;
            }

            return S3Region.SFO;
        }
    }
}

S3RepositoryBase.cs

using System.Linq;

using Amazon;
using Amazon.S3;
using Amazon.S3.Model;

namespace GuestBook.Repository.Aws.S3
{
    abstract class S3RepositoryBase
    {
        private readonly string _bucketName;
        private readonly S3Region _region;

        protected S3RepositoryBase(RegionEndpoint regionEndpoint, string bucketName)
        {
            _bucketName = bucketName;
            S3 = new AmazonS3Client(regionEndpoint);
            _region = regionEndpoint.AsS3Region();
            initialiseBucket();
        }

        private void initialiseBucket()
        {
            var response = S3.ListBuckets();
            if (!response.Buckets.Any(bucket => bucket.BucketName.Equals(_bucketName)))
            {
                S3.PutBucket(new PutBucketRequest { BucketName = _bucketName, BucketRegion = _region });
            }            
        }

        protected AmazonS3Client S3 { private set; get; }
    }
}