public void when_instantiated_parses_string_into_address_prefix_and_suffix(string range, byte expectedMostSignificantByte, byte expectedSuffix)
{
//arrange
//act
var sut = new CidrRange(range);
//assert
Assert.AreEqual(expectedMostSignificantByte, sut.Prefix[3]);
Assert.AreEqual(expectedSuffix, sut.Suffix);
}
public void when_insignificant_prefix_bits_differ_should_consider_other_to_be_equal(string leftRange, string rightRange)
{
//arrange
var sut = new CidrRange(leftRange);
var other = new CidrRange(rightRange);
//act
//assert
Assert.AreEqual(sut, other);
}
public RangeIntersectionResult CompareTo(CidrRange other)
{
if (Equals(other))
return RangeIntersectionResult.Equals;
if (PrefixesEquals(other) && Suffix > other.Suffix)
return RangeIntersectionResult.Subset;
if (PrefixesEquals(other) && Suffix < other.Suffix)
return RangeIntersectionResult.Superset;
return RangeIntersectionResult.Disjoint;
}
public void when_prefixes_are_equal_and_left_suffix_is_less_should_consider_left_to_be_a_superset(string leftRange, string rightRange)
{
//arrange
var sut = new CidrRange(leftRange);
var right = new CidrRange(rightRange);
//act
var actual = sut.CompareTo(right);
var expected = sut.Prefix.Skip(1).SequenceEqual(right.Prefix.Skip(1)) && sut.Suffix < right.Suffix
? RangeIntersectionResult.Superset
: RangeIntersectionResult.Disjoint;
//assert
Assert.AreEqual(expected, actual);
}
public void when_prefixes_are_different_should_consider_left_to_be_a_disjoint(string leftRange, string rightRange)
{
//arrange
var sut = new CidrRange(leftRange);
var right = new CidrRange(rightRange);
//act
var actual = sut.CompareTo(right);
var expected = !sut.Prefix.SequenceEqual(right.Prefix)//this is not exactly correct specification, but it's OK for the sake of simplicity
? RangeIntersectionResult.Disjoint
: RangeIntersectionResult.Subset;
//assert
Assert.AreEqual(expected, actual);
}
private bool PrefixesEquals(CidrRange other)
{
var leftMask = new BitArray(Prefix);
var leftSuffix = new BitArray(32, false);
for (int i = 31; i >= 32 - Suffix; i--)
{
leftSuffix[i] = true;
}
leftMask = leftSuffix.And(leftMask);
var rightMask = new BitArray(other.Prefix);
var rightSuffix = new BitArray(32, false);
for (int i = 31; i >= 32 - other.Suffix; i--)
{
rightSuffix[i] = true;
}
rightMask = rightSuffix.And(rightMask);
var result = rightMask.Xor(leftMask);
return result.Cast<bool>().ToArray().Skip(32 - Math.Min(Suffix, other.Suffix)).All(x => !x);
}
public void when_prefix_and_suffix_are_equal_should_consider_other_to_be_equal(string range)
{
//arrange
var sut = new CidrRange(range);
var other = new CidrRange(range);
//act
//assert
Assert.AreEqual(sut, other);
}
protected bool Equals(CidrRange other)
{
return Suffix == other.Suffix && PrefixesEquals(other);
}
