public void CacheUsesCachedValuesAfterTheyAreComputed()
{
var computeCounts = new Dictionary <int, int>();
object factory(int value)
{
if (!computeCounts.ContainsKey(value))
{
computeCounts[value] = 0;
}
++computeCounts[value];
return(computeCounts[value]);
}
var projection = Projection.CacheOnFirstUse(3, Projection.CreateUsingFuncAdaptor(factory));
Assert.AreEqual(1, projection[0]);
Assert.AreEqual(1, projection[0]);
Assert.AreEqual(1, projection[0]);
Assert.AreEqual(1, projection[1]);
Assert.AreEqual(1, projection[1]);
Assert.AreEqual(1, projection[1]);
Assert.AreEqual(1, projection[2]);
Assert.AreEqual(1, projection[2]);
Assert.AreEqual(1, projection[2]);
}
public void CacheDoesNotInvokeProjectionOnCreation()
{
var invoked = false;
object factory(int value)
{
invoked = true;
return(value);
};
var projection = Projection.CacheOnFirstUse(
3,
Projection.CreateUsingFuncAdaptor(factory));
Assert.IsFalse(invoked);
}
public void CacheThrowsWithNegativeArgument()
{
Assert.ThrowsException <ArgumentOutOfRangeException>(
() => Projection.CacheOnFirstUse(-1, Projection.Identity <int>()));
}
public void CacheThrowsWithNullArgument()
{
Assert.ThrowsException <ArgumentNullException>(
() => Projection.CacheOnFirstUse <object>(1, null));
}