public void UsesProvidedComparerOfT()
{
SimpleEqualityComparer <int> comparer = new SimpleEqualityComparer <int>();
Assert.That(2 + 2, Is.EqualTo(4).Using(comparer));
Assert.That(comparer.Called, "Comparer was not called");
}
public void GetHashCodeTest()
{
var Comparer = new SimpleEqualityComparer <string>((x, y) => string.Equals(x, y), x => x.GetHashCode());
Assert.Equal("A".GetHashCode(), Comparer.GetHashCode("A"));
Assert.Equal("B".GetHashCode(), Comparer.GetHashCode("B"));
}
public void Compare()
{
var Comparer = new SimpleEqualityComparer <string>((x, y) => string.Equals(x, y), x => x.GetHashCode());
Assert.True(Comparer.Equals("A", "A"));
Assert.False(Comparer.Equals("A", "B"));
Assert.False(Comparer.Equals("B", "A"));
}
public void NullElementsArePassedToComparer()
{
IEqualityComparer <object> comparer = new SimpleEqualityComparer();
Assert.Throws <NullReferenceException>(() => comparer.GetHashCode(null));
Assert.Throws <NullReferenceException>(() => comparer.Equals(null, "xyz"));
string[] source = { "xyz", null, "xyz", null, "abc" };
var distinct = source.Distinct(comparer);
Assert.Throws <NullReferenceException>(() => distinct.Count());
}
public void NullElementsArePassedToComparer()
{
IEqualityComparer <object> comparer = new SimpleEqualityComparer();
Assert.AreEqual(0, comparer.GetHashCode(null));
Assert.IsFalse(comparer.Equals(null, "xyz"));
string[] source = { "xyz", null, "abc", null };
var distinct = source.Distinct(comparer);
Assert.AreEqual(3, distinct.Count());
}
public SimpleEqualityComparerTests()
{
TestObject = new SimpleEqualityComparer <string>((x, y) => string.Equals(x, y), x => x?.GetHashCode() ?? 0);
}
