BUG: 9.0 - Translating document nodes leads to wrong ordering

[skurfuerst]

Currently the ordering behavior of the CR is undefined for the following scenarios:

• CreateNodeAggregateWithNode with fallbacks
• Create Peer Variant
• Create Generalization

This leads to the problem that different projections implement ordering differently then; leading to subtle bugs.

For instance, the DocumentUriPathProjection needs the ordering as well to find the first child node for FirstChild-shortcuts -- and it currently does it differently than the Content Graph.

That is what I originally wanted to fix; when I stumbled into this rabbit hole ;)

Current Behavior

On the demo site, let's say you have the following english nodes:

• a
• b
• c
• d

=> now, you translate b to german; leading to the following structure:

• b

=> now, you translate a to german, leading to the following structure:

• b
• a

=> this is wrong, expected would be:

- a
- b

Fixing Plan

• NodePeerVariantWasCreated
  • highest priority, because it is relevant when simply having a language dimension and starting to translate
  •  extend event to have s.th. like PositionMapping (modeled after MoveNodeMapping)
  • in command handler, use same logic to determine positionMapping as in MoveNode
  • write testcase
  • ensure ordering is respected in graph projection
  • ensure ordering is respected in Routing projection
• NodeGeneralizationVariantWasCreated
• NodeAggregateWithNodeWasCreated with fallbacks

NOTE: NodeSpecializationVariantWasCreated does not need to be adjusted, because it only leads to re-wiring of edges, and not to new edges.

[nezaniel]

FYI: I can't detect any issues with only CreateNodeAggregateWithNode alone, which commands are needed for this to fail?
Edit: Edge case found, tested and fixed

[nezaniel]

the content graph part will be fixed in #4961
still missing is the uri path projection part, which will happen in a follow-up

[nezaniel]

follow-up is ready: #4975

[nezaniel]

Also: NodeSpecializationVariantWasCreated needed to be adjusted for edge cases where a succeeding sibling is deleted in a variant that is to be created by variation.