public void TestStreamReadWriteDuality()
{
const int N_SAMPLES = 100;
var rnd = new Random();
var bufferLength = rnd.Next(100, 1000);
var testBytes = new byte[bufferLength];
var resultBytes = new byte[bufferLength];
for (var i = 0; i < N_SAMPLES; i++)
{
var shift = rnd.Next(0, byte.MaxValue*3);
rnd.NextBytes(testBytes);
using (MemoryStream sourceStream = new MemoryStream(testBytes),
destStream = new MemoryStream())
using (CaesarStream caeToRead = new CaesarStream(sourceStream, shift),
caeToWrite = new CaesarStream(destStream, -shift))
{
caeToRead.Read(resultBytes, 0, bufferLength);
caeToWrite.Write(resultBytes, 0, bufferLength);
destStream.Seek(0, SeekOrigin.Begin);
destStream.Read(resultBytes, 0, bufferLength);
CollectionAssert.AreEqual(resultBytes, testBytes);
}
}
}
public void TestStreamWritePositiveShift()
{
const int N_SAMPLES = 100;
var rnd = new Random();
var bufferLength = rnd.Next(100, 1000);
var testBytes = new byte[bufferLength];
var resultBytes = new byte[bufferLength];
for (var i = 0; i < N_SAMPLES; i++)
{
var shift = rnd.Next(0, byte.MaxValue*3);
rnd.NextBytes(testBytes);
var expectedBytes = testBytes.Select(b => (byte) ((b + shift)%(byte.MaxValue + 1))).ToArray();
using (var mStream = new MemoryStream())
using (var caesar = new CaesarStream(mStream, shift))
{
caesar.Write(testBytes, 0, bufferLength);
mStream.Seek(0, SeekOrigin.Begin);
mStream.Read(resultBytes, 0, bufferLength);
CollectionAssert.AreEqual(resultBytes, expectedBytes);
}
}
}