IllegalArgumentException: Duplicate Key thrown for two relationships with different direction

[ma-ku]

We have a simple model that contains Failure nodes than CAUSE other Failure nodes when a particular Condition is met. To avoid circular dependencies and potential full loading of the graph, we only provide relations on the condition node rather than having the inverse relation defined at the Failure node.

Since we are interested into upstream and downstream failures, we have two relationships defined which of course use the same type CAUSE but have opposite directions.

After a completely detached change in another portion of the codebase we started receiving above error for the relationship between Condition and Failure:

IllegalArgumentException: Duplicate key 'ConditionNode_CAUSES_FailureNode'

After debugging the issue we found out that the type of Cypher statement that is created depends upon the fact if the graph could contain cycles. After our latest change, the graph became cycle-free and the generated uses a different generator strategy that leads to above error. We have implemented a tiny change that would overcome the issue. In class RelationshipDescription of SDN, the method below must return different names depending on the direction of the relationship:

@NonNull
default String generateRelatedNodesCollectionName(NodeDescription<?> mostAbstractNodeDescription) {

       if (this.isOutgoing()) {
		return this.getSource().getMostAbstractParentLabel(mostAbstractNodeDescription) + "_" + this.getType() + "_" + this.getTarget().getPrimaryLabel();
	} else {
		return this.getTarget().getPrimaryLabel() + "_" + this.getType() + "_" + this.getSource().getMostAbstractParentLabel(mostAbstractNodeDescription);
	}
}

I have created a branch in my fork of SDN that provides a test cases that covers that issue.

[michael-simons]

Hej @ma-ku I'll investigate this week, but I am alone atm, will take a bit.

[michael-simons]

Oh well, there was little to triage, thanks for the excellent reproducer and fix. I attributed your contribution proper and this makes it into the pending release this weeks. Cheers.

[ma-ku]

Thank you very much. Trying to help where I can ;-)