This is a breaking change to Workflow that removes ReactiveSwift from the public interface of Workflow and Workflow UI.
There are 3 changes:

1. In WorkflowHost rendering is now a Combine publisher that has a value property for the current rendering. In searching the register code base there were very few places we were using a Signal/SignalProducer from the rendering property. The plan would be to change those consumers to use sink. The value property is the same so all references to rendering.value will work.
2. In WorkflowHost output has been renamed to outputPublisher. It is now a Combine Publisher that can be used to subscribe to Workflow output. Per Andrew's suggestion I added a new protocol WorkflowOutputPubisher that exposes the outputPublisher. The output property is used in a lot of places in register. To fix those places I added an extension on WorkflowOutputPubisher in WorkflowReactiveSwift that re-exposes output as a Signal. All the places that use output will just need to import WorkflowReactiveSwift and they will continue to work.
3. WorkflowHostingController in WorkflowUI now implements WorkflowOutputPublisher. Consumers using output will just need to import WorkflowReactiveSwift to continue to work.

Note: Even though this removes ReactiveSwift as a dependency from the Workflow and WorkflowUI targets the Workflow Package has to continue to have ReactiveSwift as a dependency since it's used by WorkflowReactiveSwift. But because register uses bazel if you import Workflow/WorkflowUI in your module it does not import (directly or transitively) ReactiveSwift.

Checklist

• Unit Tests
• UI Tests
• Snapshot Tests (iOS only)
• I have made corresponding changes to the documentation