Ordering of replicated relationships in deployment environment is non-deterministic

[goto1134]

Description

Running tests in https://github.com/goto1134/structurizr-d2-exporter, I face multiple false-negative results.

The tests are end-to-end: given a structurizr workspace.dsl the code produces a d2 output and check if it is the same as expected.

The diffs for failed tests usually contain the same data but a different order of relationships added:

See an example here: https://github.com/goto1134/structurizr-d2-exporter/pull/143/checks?check_run_id=33778947846

Please provide a deterministic order of relationships in the workspace to be exported.

Priority

I have no budget and there's no rush, please add this feature for free

More information

No response

[simonbrowndotje]

RelationshipView instances are stored in a TreeSet, so I'm not sure how you're seeing non-deterministic ordering. If this was the case, my own exporter tests should exhibit the same failing behaviour, but they don't.

• https://github.com/structurizr/java/blob/master/structurizr-core/src/main/java/com/structurizr/view/ModelView.java#L38

Perhaps it's related to view.relationships.associateBy { it.id }, which seems to use a LinkedHashMap?

• https://github.com/goto1134/structurizr-d2-exporter/blob/main/lib/src/main/kotlin/io/github/goto1134/structurizr/export/d2/D2Exporter.kt#L97

[goto1134]

@simonbrowndotje, thank you; I will check that!

[goto1134]

@simonbrowndotje, the code you referenced is only used for animations, and the workspace in the provided test does not use any animation in it. So it can't be the LinkedHashMap.

Do you think I could gather some example data for you?

[simonbrowndotje]

I've just released v3.2.1 that should resolve this for you ... it turns out that it was the process of replicating relationships when software system/container instances were added to deployment nodes that was non-deterministic, rather than calling ModelView.getRelationships().