Detect flow source / target changes

[nikku]

Proposed Changes

The PR does not use plain object diffing for moddle elements, but rather uses the moddle meta-data to figure what is supposed to be diffed.

This ensures we're able to diff otherwise hidden references, too, such as Flow#target.

Closes https://github.com/bpmn-io/bpmn-js-differ/issues/18.

Checklist

To ensure you provided everything we need to look at your PR:

• [x] Brief textual description of the changes present
• [ ] Visual demo attached
• [ ] Steps to try out present, i.e. using the @bpmn-io/sr tool
• [x] Related issue linked via Closes {LINK_TO_ISSUE} or Related to {LINK_TO_ISSUE}

[nikku]

CC @nithinssabu

[nikku]

@nithinssabu via https://github.com/bpmn-io/bpmn-js-differ/pull/22/commits/7ffa85264743b9560683f815476ff97fd5a42b31 I sketched how a special differ, aware of moddle elements can be added to the diff utility. As discussed we may then want to use the moddle introspection utilities to iterate through all available properties.

[nikku]

Via https://github.com/bpmn-io/bpmn-js-differ/pull/22/commits/142c8b1dea79d5e9491cf15dc1f52e62443f81cf I sketch how the actual diffing would work; still two rough edges to sort out.

[nikku]

I moved this to review as it works good on my machine. Feedback welcome.

[nikku]

As discussed @philippfromme, please have a look.

[nikku]

This is relased as v3.0.0.

[nithinssabu]

This could have introduced a bug in the library. See https://github.com/camunda/web-modeler/pull/10621#issuecomment-2311946929

[nithinssabu]

This could have introduced a bug in the library. See camunda/web-modeler#10621 (comment)

Created a minimal reproducer. Just change the bpmn-js-differ versions between 2.0.2 and 3.0.0 to see the difference in changes count.

[nikku]

Thanks for the report and steps to reproduce @nithinssabu.

As always, let's create a new bug report and take it from there :arrow_right: https://github.com/bpmn-io/bpmn-js-differ/issues/24.