/// <summary>
/// Tests that handler does not have to remove an item from the collection
/// and that the handled item is the item on which the handler completed.
/// </summary>
private async Task HandleableCollectionHandleNoRemovalTestCore(bool useAsync)
{
using var collection = new HandleableCollection <int>();
Assert.Empty(collection);
var shim = new HandleableCollectionApiShim <int>(collection, useAsync);
AddRangeAndVerifyItems(collection, endInclusive: 4);
const int expectedItem = 2;
HandleableCollection <int> .Handler handler = (int item, out bool removeItem) =>
{
// Do not remove any item (the purpose of this test is to handle an
// item without removing it).
removeItem = false;
// Terminate handler on some item in the middle of the collection
return(expectedItem == item);
};
// Wait for handled item to be returned
int handledItem = await shim.Handle(handler, DefaultPositiveVerificationTimeout);
Assert.Equal(expectedItem, handledItem);
Assert.Equal(new int[] { 0, 1, 2, 3, 4 }, collection);
}
/// <summary>
/// Tests that a non-default handler can remove items independently from
/// handling an item and that the handled item is the item on which
/// the handler completed.
/// </summary>
private async Task HandleableCollectionComplexHandlerTestCore(bool useAsync)
{
using var collection = new HandleableCollection <int>();
Assert.Empty(collection);
var shim = new HandleableCollectionApiShim <int>(collection, useAsync);
const int expectedItem = 7;
AddRangeAndVerifyItems(collection, endInclusive: expectedItem);
HandleableCollection <int> .Handler handler = (int item, out bool removeItem) =>
{
removeItem = false;
// Remove every third item
if (item % 3 == 0)
{
removeItem = true;
}
// Terminate handler on last item
return(expectedItem == item);
};
int handledItem = await shim.Handle(handler, DefaultPositiveVerificationTimeout);
Assert.Equal(expectedItem, handledItem);
Assert.Equal(new int[] { 1, 2, 4, 5, 7 }, collection);
}
/// <summary>
/// Tests that the default handler handles one item at a time and
/// removes each item after each successful handling.
/// </summary>
private async Task HandleableCollectionDefaultHandlerTestCore(bool useAsync)
{
using var collection = new HandleableCollection <int>();
Assert.Empty(collection);
var shim = new HandleableCollectionApiShim <int>(collection, useAsync);
AddRangeAndVerifyItems(collection, endInclusive: 14);
int expectedCollectionCount = collection.Count();
for (int item = 0; item < 15; item++)
{
int handledItem = await shim.Handle(DefaultPositiveVerificationTimeout);
expectedCollectionCount--;
Assert.Equal(item, handledItem);
Assert.Equal(expectedCollectionCount, collection.Count());
}
Assert.Empty(collection);
await shim.Handle(DefaultNegativeVerificationTimeout, expectTimeout : true);
}
/// <summary>
/// Tests that handler can be added before an item is provided to the collection.
/// </summary>
private async Task HandleableCollectionHandleBeforeAddTestCore(bool useAsync)
{
using var collection = new TestHandleableCollection <int>();
Assert.Empty(collection);
var shim = new HandleableCollectionApiShim <int>(collection, useAsync);
// Register to be notified when handler is beginning to be processed
Task handlerBeginTask = collection.WaitForHandlerBeginAsync(DefaultPositiveVerificationTimeout);
const int expectedItem = 3;
HandleableCollection <int> .Handler handler = (int item, out bool removeItem) =>
{
// Terminate handler on some item in the middle of the collection
if (expectedItem == item)
{
removeItem = true;
return(true);
}
removeItem = false;
return(false);
};
// Create task that will start handling BEFORE an item is added
Task <int> handleItemTask = Task.Run(() => shim.Handle(handler, DefaultPositiveVerificationTimeout));
// Wait for handler to begin processing
Task delayTask = Task.Delay(5 * DefaultPositiveVerificationTimeout);
Task completedTask = await Task.WhenAny(delayTask, handlerBeginTask);
Assert.Equal(handlerBeginTask, completedTask);
IList <(int, int)> itemsAndCounts = new List <(int, int)>()
{
(0, 1),
(1, 2),
(2, 3),
(3, 3), // Item is consumed immediately, thus collection count does not change
(4, 4),
(5, 5)
};
AddAndVerifyItems(collection, itemsAndCounts);
// Wait for handled item to be returned
int handledItem = await handleItemTask;
Assert.Equal(expectedItem, handledItem);
Assert.Equal(new int[] { 0, 1, 2, 4, 5 }, collection);
}
/// <summary>
/// Tests that handler does not have to remove an item from the collection
/// and that the handled item is the item on which the handler completed.
/// </summary>
private async Task HandleableCollectionHandlerThrowsTestCore(bool useAsync)
{
using var collection = new HandleableCollection <int>();
Assert.Empty(collection);
var shim = new HandleableCollectionApiShim <int>(collection, useAsync);
AddRangeAndVerifyItems(collection, endInclusive: 4);
HandleableCollection <int> .Handler handler = (int item, out bool removeItem) =>
{
if (6 == item)
{
throw new InvalidOperationException();
}
removeItem = false;
return(false);
};
Task <int> handleTask = Task.Run(() => shim.Handle(handler, DefaultPositiveVerificationTimeout));
// Task.Delay intentionally shorter than default timeout to check that Handle*
// calls did not complete quickly.
Task delayTask = Task.Delay(TimeSpan.FromSeconds(1));
Task completedTask = await Task.WhenAny(delayTask, handleTask);
// Check that the handle task didn't complete
Assert.Equal(delayTask, completedTask);
IList <(int, int)> itemsAndCounts = new List <(int, int)>();
itemsAndCounts.Add((5, 6));
itemsAndCounts.Add((6, 7)); // Handler should fault on this task
itemsAndCounts.Add((7, 8));
AddAndVerifyItems(collection, itemsAndCounts);
// Task.Delay intentionally longer than default timeout to check that Handle*
// does complete by handling a value. The delay Task is used in case the handler doesn't
// handle a value and doesn't respect cancellation so as to not stall the test indefinitely.
delayTask = Task.Delay(2 * DefaultPositiveVerificationTimeout);
completedTask = await Task.WhenAny(delayTask, handleTask);
// Check that the handle task faulted and the collection did not change
Assert.Equal(handleTask, completedTask);
await Assert.ThrowsAsync <InvalidOperationException>(() => handleTask);
Assert.Equal(new int[] { 0, 1, 2, 3, 4, 5, 6, 7 }, collection);
}
