Configuration for Message Node Strategies

[mikeminutillo]

There are a number of different ways that messages of the same type can be treated by the diagram.

• Collapse into a single node if sent by the same sender: The current default. This makes it easy to track published events as there is a single instance of the event for each publisher with outgoing lines to all of the subscribers.
• Collapse into a single node if received by the same receiver: When the same commands are sent from multiple places this makes it much easier to see them.

There are other options that have been trialled but were difficult to follow. Collapse just by message type results in each message type only appearing once. If routing config is off this can lead to inaccurate visualizations (i.e. where one endpoint publishes a message and another appears to receive it but in reality did not).

Collapse by sender and receiver results in an explosion of edges that is difficult to follow in a sufficiently complex solution.

We could also change behavior based on intent. For instance, we could Collapse By Receiver by default and for Publishes we could Collapse By Sender.

It should be possible to specify these options via configuration or via the command line. To do that we'd want to be able to configure a default strategy and overrides per Intent.