Objects may be created using multiple strategies which can create incompatible objects in a single model

[sbegaudeau]

When we are creating the root objects of a resource, we are loading on the fly the EPackages from scratch without considering existing EPackages loaded in the package registry of the editing domain.

When we are creating objects using a dedicated tool from the view DSL with some model operations, they are created using the EPackages available in the package registry of the editing domain.

Let's consider a click on New Operational Entity which comes with a dedicated node tool using the view DSL.

As a result, it is quite easy to create a model in which the root object and objects created using the view DSL do not share the same EPackage. For some reason, this does not seems to create any issue in my case.

The problem becomes obvious since, when we are creating objects using the view DSL thanks to a canonical tool, the EPackage used is the EPackage of self and thus the source of the metamodel to use may change depending on the target of the tool.

Let's consider a click on New Operational Actor which rely on the canonical behavior.

Now we will end up with two subgraphs of objects in our domain using the same concepts from two versions of our EPackage.

[pcdavid]

Example stack trace (to make it easier to search for the issue):

java.util.concurrent.ExecutionException: java.lang.ClassCastException: The value of type 'org.eclipse.emf.ecore.impl.EClassImpl@31245735 (name: Component) (instanceClassName: null) (abstract: false, interface: false)' must be of type 'org.eclipse.emf.ecore.impl.EClassImpl@4ccbab80 (name: Component) (instanceClassName: null) (abstract: false, interface: false)'
	at java.base/java.util.concurrent.FutureTask.report(FutureTask.java:122) ~[na:na]
	at java.base/java.util.concurrent.FutureTask.get(FutureTask.java:191) ~[na:na]
	at org.eclipse.sirius.components.collaborative.editingcontext.EditingContextEventProcessor.handle(EditingContextEventProcessor.java:217) ~[classes/:na]
	at org.eclipse.sirius.components.collaborative.editingcontext.EditingContextEventProcessorRegistry.lambda$1(EditingContextEventProcessorRegistry.java:76) ~[classes/:na]
	at java.base/java.util.Optional.map(Optional.java:260) ~[na:na]
	at org.eclipse.sirius.components.collaborative.editingcontext.EditingContextEventProcessorRegistry.dispatchEvent(EditingContextEventProcessorRegistry.java:76) ~[classes/:na]
	at org.eclipse.sirius.components.starter.services.EditingContextDispatcher.dispatchMutation(EditingContextDispatcher.java:54) ~[classes/:na]
	at org.eclipse.sirius.components.diagrams.graphql.datafetchers.mutation.MutationInvokeSingleClickOnTwoDiagramElementsToolDataFetcher.lambda$0(MutationInvokeSingleClickOnTwoDiagramElementsToolDataFetcher.java:57) ~[classes/:na]
	at org.eclipse.sirius.components.starter.services.ExceptionWrapper.wrapMono(ExceptionWrapper.java:61) ~[classes/:na]
	at org.eclipse.sirius.components.diagrams.graphql.datafetchers.mutation.MutationInvokeSingleClickOnTwoDiagramElementsToolDataFetcher.get(MutationInvokeSingleClickOnTwoDiagramElementsToolDataFetcher.java:57) ~[classes/:na]
	at org.eclipse.sirius.components.diagrams.graphql.datafetchers.mutation.MutationInvokeSingleClickOnTwoDiagramElementsToolDataFetcher.get(MutationInvokeSingleClickOnTwoDiagramElementsToolDataFetcher.java:1) ~[classes/:na]
	at graphql.execution.instrumentation.dataloader.DataLoaderDispatcherInstrumentation.lambda$instrumentDataFetcher$0(DataLoaderDispatcherInstrumentation.java:87) ~[graphql-java-18.3.jar:na]
	at graphql.execution.ExecutionStrategy.fetchField(ExecutionStrategy.java:279) ~[graphql-java-18.3.jar:na]
	at graphql.execution.ExecutionStrategy.resolveFieldWithInfo(ExecutionStrategy.java:210) ~[graphql-java-18.3.jar:na]
	at graphql.execution.ExecutionStrategy.resolveField(ExecutionStrategy.java:182) ~[graphql-java-18.3.jar:na]
	at graphql.execution.AsyncSerialExecutionStrategy.lambda$execute$1(AsyncSerialExecutionStrategy.java:43) ~[graphql-java-18.3.jar:na]
	at graphql.execution.Async.eachSequentiallyImpl(Async.java:80) ~[graphql-java-18.3.jar:na]
	at graphql.execution.Async.eachSequentially(Async.java:69) ~[graphql-java-18.3.jar:na]
	at graphql.execution.AsyncSerialExecutionStrategy.execute(AsyncSerialExecutionStrategy.java:38) ~[graphql-java-18.3.jar:na]
	at graphql.execution.Execution.executeOperation(Execution.java:159) ~[graphql-java-18.3.jar:na]
	at graphql.execution.Execution.execute(Execution.java:105) ~[graphql-java-18.3.jar:na]