public void Given_a_hash_checksum_transcoder_When_written_to_the_transcoder_Then_the_inner_stream_contains_the_written_data_followed_by_its_hash()
{
var hashAlgorithm = SHA256.Create();
var streamHashGenerator = new CryptoStreamHashGenerator(hashAlgorithm);
var hashChecksumTranscodingStreamFactory =
new HashChecksumTranscodingStreamFactory(streamHashGenerator);
const int HashByteCount = 32;
const string TestText = "Test";
using (var innerStream = new MemoryStream())
using (var hashChecksumTranscodingStream = hashChecksumTranscodingStreamFactory.CreateTrancodingStream(innerStream))
{
var writer = new StreamWriter(hashChecksumTranscodingStream);
writer.Write(TestText);
writer.Flush();
hashChecksumTranscodingStream.Flush();
innerStream.Position = 0;
var reader = new StreamReader(innerStream);
var stringBuffer = new char[4];
reader.ReadBlock(stringBuffer, 0, 4);
var expectedInnerStreamLength = TestText.Length + HashByteCount;
Assert.AreEqual(expectedInnerStreamLength, innerStream.Length);
const string ExpectedString = TestText;
var actualString = new string(stringBuffer);
Assert.AreEqual(ExpectedString, actualString);
const string ExpectedHash =
"53-2E-AA-BD-95-74-88-0D-BF-76-B9-B8-CC-00-83-2C-20-A6-EC-11-3D-68-22-99-55-0D-7A-6E-0F-34-5E-25";
innerStream.Position = 4;
var hashBuffer = new byte[innerStream.Length - innerStream.Position];
innerStream.Read(hashBuffer, 0, HashByteCount);
var actualHash = BitConverter.ToString(hashBuffer);
Assert.AreEqual(ExpectedHash, actualHash);
}
}
private static ITranscodingStreamFactory ConstructTranscodingStreamFactories()
{
var hashAlgorithm = SHA256.Create();
var streamHashGenerator = new CryptoStreamHashGenerator(hashAlgorithm);
var hashByteCount = streamHashGenerator.GetHashSize();
var previousEventStreamProvider = new DirectoryPreviousEventStreamProvider(
EventStorePath, EventFilenameGenerator.DefaultFileExtension);
var previousEventHashReader = new PreviousEventStreamHashReader(
previousEventStreamProvider, hashByteCount);
var sequenceValidationTranscodingStreamFactor =
new SequenceValidationTranscodingStreamFactory(previousEventHashReader);
var hashChecksumTranscodingStreamFactory =
new HashChecksumTranscodingStreamFactory(streamHashGenerator, sequenceValidationTranscodingStreamFactor);
return hashChecksumTranscodingStreamFactory;
}