public void should_generate_4_digits()
{
var generator = new BuiltinRandomNumberGenerator();
var randomNumbers = generator.NextNumber();
Assert.Equal(4, randomNumbers.Length);
Assert.Matches(new Regex(@"^\d{4}$"), randomNumbers);
}
public void should_generate_different_numbers_upon_multiple_invocations()
{
var generator = new BuiltinRandomNumberGenerator();
var numbers = new List <string>();
var times = new Random().Next(2, 20);
for (int i = 0; i < times; i++)
{
numbers.Add(generator.NextNumber());
}
Assert.True(numbers.Distinct().Count().Equals(numbers.Count));
}
public void should_generate_unrepeated_digits()
{
var generator = new BuiltinRandomNumberGenerator();
var randomNumbers = generator.NextNumber();
var chars = randomNumbers.ToCharArray();
foreach (var ch in chars)
{
var index = Array.IndexOf(chars, ch);
var lastIndex = Array.LastIndexOf(chars, ch);
Assert.True(index == lastIndex);
}
}