public async Task All_Requested_Keys_Should_Be_Cached()
{
var loader = new CollectionBatchDataLoader <int, Order>((ids, ct) => Orders.GetOrdersByUserIdAsync(ids));
// Start async tasks to load by User ID
var task1 = loader.LoadAsync(1);
var task2 = loader.LoadAsync(2);
// Dispatch loading
loader.Dispatch();
var user1Orders = await task1;
var user2Orders = await task2;
user1Orders.ShouldNotBeNull();
user2Orders.ShouldNotBeNull();
user1Orders.Count().ShouldBe(2);
user2Orders.Count().ShouldBe(0);
// Request keys 1 and 2 again. Result should be cached.
// Key 3 should NOT be cached
var task1b = loader.LoadAsync(1);
var task2b = loader.LoadAsync(2);
var task3 = loader.LoadAsync(3);
task1b.Status.ShouldBe(TaskStatus.RanToCompletion, "Result should already be cached");
task2b.Status.ShouldBe(TaskStatus.RanToCompletion, "Result should already be cached");
task3.Status.ShouldNotBe(TaskStatus.RanToCompletion, "Result should already be cached");
// Dispatch loading
loader.Dispatch();
var user1bOrders = await task1b;
var user2bOrders = await task2b;
var user3Orders = await task3;
user1bOrders.ShouldNotBeNull();
user2bOrders.ShouldNotBeNull();
user3Orders.ShouldNotBeNull();
user1Orders.Count().ShouldBe(2);
user2Orders.Count().ShouldBe(0);
user3Orders.Count().ShouldBe(0);
// This should have been called only once to load in a single batch
Orders.GetOrdersByUserIdCalledCount.ShouldBe(2, "Operations should be batched");
}
public async Task Keys_Are_DeDuped()
{
var loader = new CollectionBatchDataLoader <int, Order>((ids, ct) => Orders.GetOrdersByUserIdAsync(ids));
// Start async tasks to load duplicate keys
var task1 = loader.LoadAsync(1);
var task2 = loader.LoadAsync(1);
// Dispatch loading
loader.Dispatch();
// Now await tasks
var user1Orders = await task1;
var user1bOrders = await task2;
Orders.GetOrdersByUserIdCalledCount.ShouldBe(1);
Orders.GetOrdersByUserId_UserIds.Count().ShouldBe(1, "The keys passed to the fetch delegate should be de-duplicated");
}
public async Task NonExistent_Key_Should_Return_Empty()
{
var loader = new CollectionBatchDataLoader <int, Order>((ids, ct) => Orders.GetOrdersByUserIdAsync(ids));
// Start async tasks to load by User ID
var task1 = loader.LoadAsync(1);
var task2 = loader.LoadAsync(2);
// Dispatch loading
loader.Dispatch();
var user1Orders = await task1;
var user2Orders = await task2;
user1Orders.ShouldNotBeNull();
user2Orders.ShouldNotBeNull();
user1Orders.Count().ShouldBe(2);
user2Orders.Count().ShouldBe(0);
// This should have been called only once to load in a single batch
Orders.GetOrdersByUserIdCalledCount.ShouldBe(1, "Operations should be batched");
}