private static void ShouldBeEqualAccordingToCompareToMethods(
SomeComparableObject first,
SomeComparableObject second)
{
first.CompareTo(second).Should().Be(0);
first.CompareToObject(second).Should().Be(0);
}
private static void ShouldBeGreaterAccordingToCompareToMethods(
SomeComparableObject greater,
SomeComparableObject smaller)
{
greater.CompareTo(smaller).Should().BePositive();
greater.CompareToObject(smaller).Should().BePositive();
}
private static void ShouldBeLesserThanAccordingToCompareToMethods(
SomeComparableObject smaller,
SomeComparableObject greater)
{
smaller.CompareTo(greater).Should().BeNegative();
smaller.CompareToObject(greater).Should().BeNegative();
}
public void cannot_compare_objects_of_two_different_types()
{
var first = new SomeComparableObject(1);
var second = "some string";
Action comparing = () => first.CompareToObject(second);
comparing.ShouldThrow <ArgumentException>();
}
public void any_object_compares_greater_than_null()
{
var some = new SomeComparableObject(1);
ShouldBeGreaterAccordingToCompareToMethods(some, null);
ShouldBeGreaterThanAccordingToOperators(some, null);
ShouldBeLesserThanAccordingToOperators(null, some);
}
private void ShouldBeLesserThanAccordingToOperators(SomeComparableObject first, SomeComparableObject second)
{
(first > second).Should().BeFalse();
(first >= second).Should().BeFalse();
(first == second).Should().BeFalse();
(first <= second).Should().BeTrue();
(first < second).Should().BeTrue();
(first != second).Should().BeTrue();
}
public void equality_comparing_objects_of_two_different_types_should_still_be_possible()
{
var first = new SomeComparableObject(1);
var second = "some string";
// ReSharper disable once SuspiciousTypeConversion.Global
// ReSharper disable once ReturnValueOfPureMethodIsNotUsed
Action equalityComparing = () => first.Equals(second);
equalityComparing.ShouldNotThrow();
}
public void greater_object_compares_greater_than_smaller_one()
{
var greater = new SomeComparableObject(2);
var smaller = new SomeComparableObject(1);
ShouldBeGreaterAccordingToCompareToMethods(greater, smaller);
ShouldBeLesserThanAccordingToCompareToMethods(smaller, greater);
ShouldBeGreaterThanAccordingToOperators(greater, smaller);
ShouldBeLesserThanAccordingToOperators(smaller, greater);
}
public void equal_objects_compare_equal()
{
var first = new SomeComparableObject(1);
var second = new SomeComparableObject(1);
ShouldBeEqualAccordingToCompareToMethods(first, second);
ShouldBeEqualAccordingToCompareToMethods(second, first);
ShouldBeEqualAccordingToOperators(first, second);
ShouldBeEqualAccordingToOperators(second, first);
}
protected override int CompareToNotNull(SomeComparableObject notNullOther) => _value.CompareTo(notNullOther._value);
