public void GivenRandomStringGeneratorWhenRandomStringsGeneratedThenAllCharactersAreUsed()
{
ISet <char> alphaChars = new HashSet <char> {
'0', '1', '2', '3', '4', '5'
};
ISet <char> foundChars = new HashSet <char>();
string alpha = string.Join("", alphaChars);
int maxIterations = 100;
int rndStringLength = 4;
IRandomStringGenerator generator = NewGenerator();
for (int index = 0; index < maxIterations; index++)
{
string rnd = generator.RandomString(rndStringLength, alpha);
char[] rndChars = rnd.ToCharArray();
foreach (char c in rndChars)
{
foundChars.Add(c);
}
if (alphaChars.Count == foundChars.Count)
{
Assert.Pass("All chars found at index: " + index);
}
}
Assert.Fail(string.Format("Not all characters found in random strings. Found: '{0}'", string.Join(", ", alphaChars)));
}
public void GivenRandomStringGeneratorWhenRandomStringsGeneratedThenAllCharactersHaveEvenDistributionWithin10Percent()
{
ISet <char> alphaChars = new HashSet <char> {
'0', '1', '2', '3', '4', '5'
};
IDictionary <char, int> charCount = new Dictionary <char, int>();
string alpha = string.Join("", alphaChars);
int maxIterations = 10000;
int rndStringLength = 1;
IRandomStringGenerator generator = NewGenerator();
for (int index = 0; index < maxIterations; index++)
{
string rnd = generator.RandomString(rndStringLength, alpha);
char[] rndChars = rnd.ToCharArray();
foreach (char c in rndChars)
{
if (charCount.ContainsKey(c))
{
charCount[c]++;
}
else
{
charCount.Add(c, 1);
}
}
}
double expectedCharCount = (maxIterations * rndStringLength) / alphaChars.Count;
double delta = expectedCharCount * 0.1;
foreach (var pair in charCount)
{
Assert.AreEqual(expectedCharCount, pair.Value, delta, "Character distribution for char '{0}' not even", pair.Key);
}
}