public void CompareIntsUsingSignComparer()
{
var array1 = new[] { 1, 2, 3 };
var array2 = new[] { 2, 3, 5 };
var array3 = new[] { 1, 3, -3 };
var array4 = new[] { 1, 2, 3, 4 };
var comparer = EqualityComparerEx.Collection <int[], int>(EqualityComparerEx.Func <int>((x, y) => Math.Sign(x) == Math.Sign(y), Math.Sign));
var hashCode1 = comparer.GetHashCode(array1);
var hashCode2 = comparer.GetHashCode(array2);
var hashCode3 = comparer.GetHashCode(array3);
var hashCode4 = comparer.GetHashCode(array4);
Assert.Equal(hashCode1, hashCode2);
Assert.NotEqual(hashCode1, hashCode3);
Assert.NotEqual(hashCode1, hashCode4);
Assert.True(comparer.Equals(array1, array1));
Assert.True(comparer.Equals(array1, array2));
Assert.False(comparer.Equals(array1, array3));
Assert.False(comparer.Equals(array1, array4));
}
private static IEqualityComparer <T[]> GetCollectionComparer <T>()
{
return(EqualityComparerEx.Collection <T[], T>());
}