public void Cache_reportsIfItemWasRetrievedFromCache()
{
Func <int, string> creator = key => {
return(key.ToString());
};
bool wasRetrievedFromCache;
var cache = new RecentItemsCache <int, string>(7);
cache.GetItem(0, creator, out wasRetrievedFromCache);
Assert.AreEqual(false, wasRetrievedFromCache, "Adding a new item to cache should not report it as retrieved from cache.");
cache.GetItem(0, creator, out wasRetrievedFromCache);
Assert.AreEqual(true, wasRetrievedFromCache, "Retrieving a cached item should report that it was retrieved from cache.");
}
public void NullInput_key()
{
// Attempt to cache a key,value pair with null key
var cache = new RecentItemsCache <string, string>(7);
cache.GetItem(null, key => { return("value"); });
}
public void NullInput_value()
{
// Cache a key,value pair with null value.
var cache = new RecentItemsCache <int, string>(7);
Assert.DoesNotThrow(() => {
cache.GetItem(0, key => { return(null); });
}, "Null value should not throw exception");
}
/// <summary>
/// Add key,value pair to cache, checking if it was newly added.
/// Will assert if computed if not expected, or did not compute if expected to.
/// </summary>
/// <param name="cache"></param>
/// <param name="key"></param>
/// <param name="creator">Delegate to create the value from key</param>
/// <param name="expectToCompute">
/// Whether should expect to need to compute the value from key using creator
/// </param>
private void AddItem <K, V>(RecentItemsCache <K, V> cache, K key, Func <K, V> creator,
bool expectToCompute)
{
bool didCompute = false;
Assert.AreEqual(creator(key), cache.GetItem(key, key1 =>
{
didCompute = true;
return(creator(key1));
}), String.Format("wrong value for {0} cached key given", didCompute?"newly":"previously"));
string errorMessage;
if (expectToCompute)
{
errorMessage = "Expected to compute value from key since it was not expected to be in the cache, but it was in the cache.";
}
else
{
errorMessage = "Did not expect to compute value from key since expected it to be in the cache, but it was not in the cache.";
}
Assert.AreEqual(expectToCompute, didCompute, errorMessage);
}