Possible stack overflow when invoking "Expand All" on a domain

[pcdavid]

Since the addition of support virtual nodes in the Explorer, and in particular support for EStructuralFeature.Setting, it is possible to create virtually infinite trees.

For example create a Domain definition with two entities A and B; set B as superType of A, and A as superType of B:

Then try to invoke "Expand All" on either A or B:

java.util.concurrent.CompletionException: java.lang.StackOverflowError
	at java.base/java.util.concurrent.CompletableFuture.encodeThrowable(CompletableFuture.java:315) ~[na:na]
	at java.base/java.util.concurrent.CompletableFuture.uniComposeStage(CompletableFuture.java:1194) ~[na:na]
	at java.base/java.util.concurrent.CompletableFuture.thenCompose(CompletableFuture.java:2309) ~[na:na]
	at graphql.GraphQL.parseValidateAndExecute(GraphQL.java:471) ~[graphql-java-22.0.jar:na]
	at graphql.GraphQL.lambda$executeAsync$9(GraphQL.java:429) ~[graphql-java-22.0.jar:na]
	at java.base/java.util.concurrent.CompletableFuture.uniComposeStage(CompletableFuture.java:1187) ~[na:na]
	at java.base/java.util.concurrent.CompletableFuture.thenCompose(CompletableFuture.java:2309) ~[na:na]
	at graphql.GraphQL.executeAsync(GraphQL.java:418) ~[graphql-java-22.0.jar:na]
	at graphql.GraphQL.execute(GraphQL.java:359) ~[graphql-java-22.0.jar:na]
	at org.eclipse.sirius.components.graphql.ws.handlers.StartMessageHandler.handle(StartMessageHandler.java:94) ~[classes/:na]
    [...]
Caused by: java.lang.StackOverflowError: null
	at java.base/java.util.HashMap.putVal(HashMap.java:627) ~[na:na]
	at java.base/java.util.HashMap.putMapEntries(HashMap.java:514) ~[na:na]
	at java.base/java.util.HashMap.<init>(HashMap.java:484) ~[na:na]
	at org.eclipse.sirius.components.representations.VariableManager.getVariables(VariableManager.java:66) ~[classes/:na]
	at org.eclipse.sirius.components.representations.VariableManager.getVariables(VariableManager.java:62) ~[classes/:na]
	at org.eclipse.sirius.components.representations.VariableManager.getVariables(VariableManager.java:62) ~[classes/:na]

[pcdavid]

Actually, "Expand All" is not even needed:

Capture.video.du.2024-09-03.19-00-42.mp4

[adaussy]

I reproduce this problem using UML workflow.

I would try to contribute a fix for this composed of two features:

First add an "ancestorIds" in the variable manager that keeps tracks of all parent ids of the current rendering TreeItem. This variable could be used to generate truly unique id for TreeItem. That would give the opportunity for the specifier to create such loop.

Add a security in Sirius Web that prevents the creating of a child if its id is contained in the "ancestorId" list. To make the user aware of the problem I would suggest to return a "Virtual" Tree item that show the possible infinite loop.

This item will have the same icon than the TreeItem causing the problem plus a warning sign. A prefix will be added to the label to identify the problem.

Do you think that could do the trick?

This contribution do not fix the "Expand All" action only the stackoverflow during the render phase.

[adaussy]

In domain it would give