public void GetHashCode_InvokedOverKey()
{
IEqualityComparer <string> subject = new SelectorEqualizer <string, string>(s => s.ToLower());
Assert.That(subject.GetHashCode("DANIEL"), Is.EqualTo("daniel".GetHashCode()));
Assert.That(subject.GetHashCode("DANIEL"), Is.Not.EqualTo("someoneElse".GetHashCode()));
}
public void Equals_BothKeysNull_True()
{
IEqualityComparer <string> subject = new SelectorEqualizer <string, string>(s => null);
Assert.That(subject.Equals("x", "x"), Is.True);
Assert.That(subject.Equals("x", "y"), Is.True);
}
public void Equals_NoKeyIsNull_KeysCompared()
{
IEqualityComparer <string> subject = new SelectorEqualizer <string, string>(s => s.ToLower());
Assert.That(subject.Equals("AB", "ab"), Is.True);
Assert.That(subject.Equals("AB", "CD"), Is.False);
}
public void Equals_OneKeyNull_False(string first, string second)
{
Func <string, string> notNullIfStartsWithCapital = x => char.IsUpper(x[0]) ? x : null;
IEqualityComparer <string> subject = new SelectorEqualizer <string, string>(notNullIfStartsWithCapital);
Assert.That(subject.Equals(first, second), Is.False);
}
public void GetHashCode_NullKey_GetHashCodeInvocationNotNeeded()
{
var spy = new EqualitySpy();
IEqualityComparer <EqualitySpy> subject = new SelectorEqualizer <EqualitySpy, string>(s => s.FakeASelector <string>(null));
subject.GetHashCode(spy);
Assert.That(spy.GetHashCodeCalled, Is.False);
}
public void Clients_DoNotHaveToCareAboutNulls()
{
var notNull = new EqualitySubject("a", 1, 1m);
var chainable = new SelectorEqualizer <EqualitySubject, int>(s => s.I);
Assert.That(chainable.Equals(notNull, null), Is.False);
Assert.That(chainable.Equals(null, notNull), Is.False);
Assert.That(chainable.Equals(null, null), Is.True);
}
public void Equals_NoKeyIsNull_EqualsInvoked()
{
EqualitySpy spyForX = new EqualitySpy(), spyForY = new EqualitySpy();
Func <string, EqualitySpy> eachSpyToEachLetter = s => s.Equals("x") ? spyForX : spyForY;
IEqualityComparer <string> subject = new SelectorEqualizer <string, EqualitySpy>(eachSpyToEachLetter);
subject.Equals("x", "y");
Assert.That(spyForX.EqualsCalled, Is.True);
Assert.That(spyForY.EqualsCalled, Is.True);
}
public void Chaining_IsDestructive()
{
EqualitySubject x1 = new EqualitySubject("x", 1, 1m), x2 = new EqualitySubject("x", 1, 2m);
ChainableEqualizer <EqualitySubject> sAndI = new SelectorEqualizer <EqualitySubject, string>(s => s.S)
.Then(s => s.I);
Assert.That(sAndI.Equals(x1, x2), Is.True);
var allProp = sAndI.Then(Eq <EqualitySubject> .By(s => s.D));
Assert.That(allProp.Equals(x1, x2), Is.False);
Assert.That(sAndI.Equals(x1, x2), Is.False);
}
public void Equals_OneKeyNull_SelectedEqualsNotCalled()
{
EqualitySpy spyForX = new EqualitySpy(), spyForY = new EqualitySpy();
Func <string, EqualitySpy> spyXForX = s => s.Equals("x") ? spyForX : null;
Func <string, EqualitySpy> spyYForY = s => s.Equals("y") ? spyForY : null;
IEqualityComparer <string> subject = new SelectorEqualizer <string, EqualitySpy>(spyXForX);
subject.Equals("x", "y");
Assert.That(spyForX.EqualsCalled, Is.False);
subject = new SelectorEqualizer <string, EqualitySpy>(spyYForY);
subject.Equals("x", "y");
Assert.That(spyForY.EqualsCalled, Is.False);
}
public void Explore()
{
IEqualityComparer <EqualitySubject> subject = new SelectorEqualizer <EqualitySubject, int>(s => s.I);
Assert.That(subject.Equals(new EqualitySubject {
I = 1
}, new EqualitySubject {
I = 2
}), Is.False);
Assert.That(subject.GetHashCode(new EqualitySubject {
I = 1
}), Is.EqualTo(1.GetHashCode()));
IEqualityComparer <EqualitySubject> byDAndI = new SelectorEqualizer <EqualitySubject, decimal>(s => s.D)
.Then(s => s.I);
byDAndI = Eq <EqualitySubject> .By(s => s.D)
.Then(s => s.I);
}
public void GetHashCode_NullKey_Zero()
{
IEqualityComparer <string> subject = new SelectorEqualizer <string, string>(s => null);
Assert.That(subject.GetHashCode("whatever"), Is.EqualTo(0));
}
