public void Initialize()
{
this.requesterSecurity = new Mock <IRequesterSecurity>();
this.requesterSecurity.SetupFor(Requester);
// Mock potentially side-effecting components with strict behaviour.
this.connectionFactory = new Mock <IFifthweekDbConnectionFactory>(MockBehavior.Strict);
this.target = new ReorderQueueCommandHandler(this.requesterSecurity.Object, this.connectionFactory.Object);
}
private async Task <ExpectedSideEffects> TestExpectedQueueOrderAsync(TestDatabaseContext testDatabase, IReadOnlyList <Post> validSuperset, ReorderQueueCommand command)
{
this.target = new ReorderQueueCommandHandler(this.requesterSecurity.Object, testDatabase);
await testDatabase.TakeSnapshotAsync();
await this.target.HandleAsync(command);
if (validSuperset.Count == 0)
{
return(ExpectedSideEffects.None);
}
// Posts that are both valid for update, and have been requested to be updated by the command.
var allowedUpdates = validSuperset.Where(_ => command.NewPartialQueueOrder.Any(id => id.Value == _.Id)).ToArray();
// Descending range of live dates for these posts.
var expectedDateRange = allowedUpdates.Select(_ => _.LiveDate).OrderByDescending(_ => _).ToArray();
// Re-assign live dates in order specified by command.
var dateIndex = 0;
var expectedUpdates = new List <Post>();
foreach (var postId in command.NewPartialQueueOrder)
{
// Request may contain IDs that are not valid for update, so we ignore these, as the implementation should.
var allowedUpdate = allowedUpdates.SingleOrDefault(_ => _.Id == postId.Value);
if (allowedUpdate != null)
{
var newLiveDate = expectedDateRange[dateIndex++];
if (allowedUpdate.LiveDate == newLiveDate)
{
continue;
}
// Sometimes the live date may not have changed.
allowedUpdate.LiveDate = newLiveDate;
expectedUpdates.Add(allowedUpdate);
}
}
if (expectedUpdates.Count == 0)
{
throw new Exception(
"It is unlikely that all posts will keep their original live date after being shuffled. " +
"Please check test code. If all is good and this is coincidental, then simply change the random seed number.");
}
return(new ExpectedSideEffects
{
Updates = expectedUpdates
});
}
public async Task ItShouldBeIdempotent()
{
await this.DatabaseTestAsync(async testDatabase =>
{
this.target = new ReorderQueueCommandHandler(this.requesterSecurity.Object, testDatabase);
var validPosts = await this.CreateValidQueueCandidatesAsync(testDatabase);
var attemptedNewQueueOrder = GetRandomSubset(validPosts);
var command = new ReorderQueueCommand(Requester, QueueId, attemptedNewQueueOrder);
await this.target.HandleAsync(command);
await testDatabase.TakeSnapshotAsync();
await this.target.HandleAsync(command);
return(ExpectedSideEffects.None);
});
}