public void EmptyAlphabetNonEmptyStringDecryptionTest()
{
string empty = string.Empty;
var unzipper = new LZWDecompress(empty);
unzipper.Decrypt("0");
}
public void EmptyStringTest()
{
string empty = string.Empty;
var zipper = new LZWCompress(empty);
var zipperPT = new LZWCompressPT(empty);
var unzipper = new LZWDecompress(empty);
Assert.AreEqual(empty, zipper.Encrypt(empty));
Assert.AreEqual(empty, zipperPT.Encrypt(empty));
Assert.AreEqual(empty, unzipper.Decrypt(empty));
}
public void AllStringsTest()
{
string fullAlphabet = "abcdefghijklmnopqrstuvwxyz";
int maxAlphabetLength = 12;
int maxLength = 6;
StringBuilder builder = new StringBuilder();
// For alphabets of different sizes
for (int alphabetSize = 1; alphabetSize <= maxAlphabetLength; ++alphabetSize)
{
string alphabet = fullAlphabet.Substring(0, alphabetSize);
var zipper = new LZWCompress(alphabet);
var zipperPT = new LZWCompressPT(alphabet);
var unzipper = new LZWDecompress(alphabet);
// For strings in current alphabet of different size
for (int strlen = 0; strlen <= maxLength; ++strlen)
{
// Number of all possible strings in current alphabet of current size
int strings = (int)Math.Pow(alphabet.Length, strlen);
for (int i = 0; i < strings; ++i)
{
builder.Clear();
int mask = i;
for (int shift = 0; shift < strlen; ++shift)
{
builder.Append(alphabet[mask % alphabet.Length]);
mask >>= 1;
}
string message = builder.ToString();
string encrypted = zipper.Encrypt(message);
string encryptedPT = zipperPT.Encrypt(message);
Assert.AreEqual(encrypted, encryptedPT);
Assert.AreEqual(message, unzipper.Decrypt(encrypted));
}
}
}
}
