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It is possible to receive progress updates about a URLSessionTask by implementing the URLSessionDataDelegate.urlSession(_:dataTask:didReceive:) delegate method, and using the delegate-style "task, task.resume()" style of invocation.

With the Combine flavor of the API, this does not appear to be possible. Using URLSession.dataTaskPublisher(for:) returns a publisher that publishes the (Data, URLResponse) tuple upon completion, but never invokes the delegate method. In that way, it is very similar to the URLSession.dataTask(with:completionHandler:) method, which invokes completionHandler with the final result, and not in-process Progress reports.

Am I missing any API or pattern to allow progress reporting, or does the Combine flavor of URLSession task handling not offer a way to retrieve progress?

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No, you're not missing anything. To retrieve the progress information you would need to construct your own Future and not use the built-in data task publisher.

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Thanks for confirming. Have you seen any useful patterns for publishing more than one stream from an API? I'm currently looking at returning an object with various *publisher properties (e.g., resultPublisher, progressPublisher), which feels icky. The other thing I'm considering is accepting a PassthroughSubject<Progress, Never> on the API for interested folks to be notified, but again...icky.
Actually I don't see why result publisher and progress publisher are icky.
Also there's already some good discussion stackoverflow.com/questions/61102801/… and stackoverflow.com/questions/57836518/…

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