TaskWindowTest running as a flaky test due to concurrency issues

[laim2003]

Actual behavior

The TaskWindowTest turns out to be flaky due to some list operations that can cause issues when GitHub Actions runs the test in a concurrent manner:

com.devonfw.ide.gui.progress.TaskWindowTest.listContentsAreCoherent -- Time elapsed: 0.311 s <<< ERROR!
java.util.ConcurrentModificationException
	at java.base/java.util.AbstractList$RandomAccessSpliterator.checkAbstractListModCount(AbstractList.java:745)
	at java.base/java.util.AbstractList$RandomAccessSpliterator.tryAdvance(AbstractList.java:709)
	at java.base/java.util.stream.ReferencePipeline.forEachWithCancel(ReferencePipeline.java:147)
	at java.base/java.util.stream.AbstractPipeline.copyIntoWithCancel(AbstractPipeline.java:588)
	at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:574)
	at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:560)
	at java.base/java.util.stream.MatchOps$MatchOp.evaluateSequential(MatchOps.java:230)
	at java.base/java.util.stream.MatchOps$MatchOp.evaluateSequential(MatchOps.java:196)
	at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:265)
	at java.base/java.util.stream.ReferencePipeline.anyMatch(ReferencePipeline.java:668)
	at com.devonfw.ide.gui.context.TaskManager.addTask(TaskManager.java:28)
	at com.devonfw.ide.gui.progress.TaskWindowTest.listContentsAreCoherent(TaskWindowTest.java:111)
	at java.base/java.lang.reflect.Method.invoke(Method.java:565)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1604)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1604)

Reproduce

As this is a flaky test it will sometimes occur during PR builds. Reproduction is therefore very hard, but you can see this error occurring in this PR build: https://github.com/devonfw/IDEasy/actions/runs/30631287562/job/91157973779

Expected behavior

Test should not get a ConcurrentModificationException.

IDEasy status

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IDE_ROOT is set to C:\Users\lfaber\projects
IDE_HOME is set to C:\Users\lfaber\projects\ideasy
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Successfully completed ide (status)

Please use (git-)bash (integrated in Windows Terminal) for full IDEasy support:
https://github.com/devonfw/IDEasy/blob/main/documentation/advanced-tooling-windows.adoc#tabs-for-shells

Related/Dependent issues

No response

Comments/Hints

No response

[laim2003]

Seems like the issue is inside TaskManagers' addTask() method. Looking into it.

[laim2003]

We maybe need to review the implementation of ObservableList in the taskmanager or at least how we are exposing the list of tasks to members that are not part of TaskManager class.