Aggregate failed executions in chain?

[toni-schmitt]

Hello, really enjoying your job system!
Is it possible to aggregate failed executions and create a single job from it?

Lets assume I have to update a number of users because some other action required it.

• Each successful job gets chained into a send email job, that sends an individual success message to the user
• After all jobs from the batch are finished, all failed jobs get aggregated into a single send email job, that sends a single email to an administrator saying that the users could not be updated and manual intervention is needed

Now with the current implementation of chaining I would have to send an individual email for each failed job to an admin.
Is it possible to aggregate them and send when all jobs from that batch are finished?

Currently I am doing this:

users.Select(user => FluentChainTickerBuilder<TimeTickerEntity>.BeginWith(parent =>
{
    parent.SetFunction(JobNames.UpdateUser)
        .SetDescription(
            "Something action required an update for the user")
        .SetRequest(new UpdateUserJobRequest
        {
            UserId = user.UserId,
            ...
        }).SetRetries(/* a number of different retries */);
}).WithFirstChild(child =>
{
    child.SetFunction(JobNames.SendEmail).SetRunCondition(RunCondition.OnSuccess).SetRequest(
        new EmailSendJobRequest
        {
            Recipient = user.Email,
            Subject = "Update success"
        });
}).WithSecondChild(child =>
{
    child.SetFunction(JobNames.SendEmail).SetRunCondition(RunCondition.OnFailureOrCancelled).SetRequest(
        new EmailSendJobRequest
        {
            Recipient = admin.Email,
            Subject = "Could not update user"
        });
}).Build()).ToList();

It would be really cool to do something like:

.WithSecondAggregatedChild(
RunCondition.OnFailureOrCancelled, // all jobs need to be finished, but the child only executes for jobs with this status
(child, context[]) => // maybe we could access the contexts here and then indirectly the request?
{
    child.SetFunction(JobNames.SendEmail).SetRunCondition().SetRequest(
        new EmailSendJobRequest
        {
            Recipient = admin.Email,
            Subject = $"Could not update users",
            Body = $"""
            Could not update users with IDs {string.Join(',', context.Select(x => x.Request.UserId))}
            """
        });
})

Now of course I could replicate this without chaining in a single job method, but then I'd loose the whole retry ability for each update and would have to implement that myself, which would kind of defeat the purpose of this library.

This would be a really powerful and neat feature.

I'd also be willing to contribute some time in implementing or planning something like this, if you'd see this as a viable functionality for your library.

Thanks for taking the time to read this and of course for taking the time to build the library in the first place :D