public void NonGenericIComparableComparisonsShouldTryToCallLeftHandCompareToFirst()
{
var left = new MutatingComparable(0);
var right = new object();
var comparer = Comparer <object> .Default;
Assert.Equal(0, comparer.Compare(left, right));
Assert.Equal(1, comparer.Compare(left, right));
// If the lhs does not implement IComparable, the rhs should be checked
// Additionally the result from rhs.CompareTo should be negated
Assert.Equal(-2, comparer.Compare(right, left));
}
public void IComparableComparisonsShouldTryToCallLeftHandCompareToFirst()
{
var left = new MutatingComparable(0);
var right = new MutatingComparable(0);
var comparer = Comparer <MutatingComparable> .Default;
// Every CompareTo() call yields the comparable's current
// state and then increments it
Assert.Equal(0, comparer.Compare(left, right));
Assert.Equal(1, comparer.Compare(left, right));
Assert.Equal(0, comparer.Compare(right, left));
}
public void NullableOfIComparableComparisonsShouldTryToCallLeftHandCompareToFirst()
{
// If two non-null nullables are passed in, Default<T?>.Compare
// should try to call the left-hand side's CompareTo() first
// Would have liked to reuse MutatingComparable here, but it is
// a class and can't be nullable, so it's necessary to wrap it
// in a struct
var leftValue = new MutatingComparable(0);
var rightValue = new MutatingComparable(0);
var left = new ValueComparable <MutatingComparable>?(ValueComparable.Create(leftValue));
var right = new ValueComparable <MutatingComparable>?(ValueComparable.Create(rightValue));
var comparer = Comparer <ValueComparable <MutatingComparable>?> .Default;
Assert.Equal(0, comparer.Compare(left, right));
Assert.Equal(1, comparer.Compare(left, right));
Assert.Equal(0, comparer.Compare(right, left));
}
