stop showing progress when exception happens deep inside the language server

[martinlippert]

Under certain conditions (I will try to reproduce the code snippet that I used when I ran into this), selecting a bean completion proposal causes this on the language server side:

13:54:30.383 [ForkJoinPool.commonPool-worker-1] ERROR o.s.i.v.c.rewrite.java.ORAstUtils - 
java.lang.ClassCastException: class com.sun.tools.javac.tree.JCTree$JCExpressionStatement cannot be cast to class com.sun.tools.javac.tree.JCTree$JCVariableDecl (com.sun.tools.javac.tree.JCTree$JCExpressionStatement and com.sun.tools.javac.tree.JCTree$JCVariableDecl are in unnamed module of loader org.openrewrite.java.JavaUnrestrictedClassLoader @62839bf)
	at org.openrewrite.java.isolated.ReloadableJava21ParserVisitor.visitVariables(ReloadableJava21ParserVisitor.java:1554)
	at org.openrewrite.java.isolated.ReloadableJava21ParserVisitor.convertStatements(ReloadableJava21ParserVisitor.java:1910)
	at org.openrewrite.java.isolated.ReloadableJava21ParserVisitor.convertStatements(ReloadableJava21ParserVisitor.java:1879)
	at org.openrewrite.java.isolated.ReloadableJava21ParserVisitor.visitBlock(ReloadableJava21ParserVisitor.java:326)
	at org.openrewrite.java.isolated.ReloadableJava21ParserVisitor.visitBlock(ReloadableJava21ParserVisitor.java:77)
	at com.sun.tools.javac.tree.JCTree$JCBlock.accept(JCTree.java:1104)
	at com.sun.source.util.TreePathScanner.scan(TreePathScanner.java:92)
	at org.openrewrite.java.isolated.ReloadableJava21ParserVisitor.convert(ReloadableJava21ParserVisitor.java:1699)
	at org.openrewrite.java.isolated.ReloadableJava21ParserVisitor.convertOrNull(ReloadableJava21ParserVisitor.java:1780)
	at org.openrewrite.java.isolated.ReloadableJava21ParserVisitor.visitMethod(ReloadableJava21ParserVisitor.java:1020)
	at org.openrewrite.java.isolated.ReloadableJava21ParserVisitor.visitMethod(ReloadableJava21ParserVisitor.java:77)
	at com.sun.tools.javac.tree.JCTree$JCMethodDecl.accept(JCTree.java:948)
	at com.sun.source.util.TreePathScanner.scan(TreePathScanner.java:92)
	at org.openrewrite.java.isolated.ReloadableJava21ParserVisitor.convert(ReloadableJava21ParserVisitor.java:1699)
	at org.openrewrite.java.isolated.ReloadableJava21ParserVisitor.convert(ReloadableJava21ParserVisitor.java:1735)
	at org.openrewrite.java.isolated.ReloadableJava21ParserVisitor.convertStatements(ReloadableJava21ParserVisitor.java:1901)
	at org.openrewrite.java.isolated.ReloadableJava21ParserVisitor.convertStatements(ReloadableJava21ParserVisitor.java:1879)
	at org.openrewrite.java.isolated.ReloadableJava21ParserVisitor.visitClass(ReloadableJava21ParserVisitor.java:520)
	at org.openrewrite.java.isolated.ReloadableJava21ParserVisitor.visitClass(ReloadableJava21ParserVisitor.java:77)
	at com.sun.tools.javac.tree.JCTree$JCClassDecl.accept(JCTree.java:855)
	at com.sun.source.util.TreePathScanner.scan(TreePathScanner.java:92)
	at org.openrewrite.java.isolated.ReloadableJava21ParserVisitor.convert(ReloadableJava21ParserVisitor.java:1699)
	at org.openrewrite.java.isolated.ReloadableJava21ParserVisitor.convertAll(ReloadableJava21ParserVisitor.java:1790)
	at org.openrewrite.java.isolated.ReloadableJava21ParserVisitor.visitCompilationUnit(ReloadableJava21ParserVisitor.java:564)
	at org.openrewrite.java.isolated.ReloadableJava21ParserVisitor.visitCompilationUnit(ReloadableJava21ParserVisitor.java:77)
	at com.sun.tools.javac.tree.JCTree$JCCompilationUnit.accept(JCTree.java:623)
	at com.sun.source.util.TreePathScanner.scan(TreePathScanner.java:92)
	at org.openrewrite.java.isolated.ReloadableJava21Parser.lambda$parseInputs$0(ReloadableJava21Parser.java:166)
	at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197)
	at java.base/java.util.Iterator.forEachRemaining(Iterator.java:133)
	at java.base/java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1939)
	at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:509)
	at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499)
	at java.base/java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:921)
	at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
	at java.base/java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:682)
	at org.springframework.ide.vscode.commons.rewrite.java.ORAstUtils.parseInputs(ORAstUtils.java:332)
	at org.springframework.ide.vscode.boot.java.rewrite.RewriteRefactorings.lambda$4(RewriteRefactorings.java:143)
	at java.base/java.util.concurrent.CompletableFuture$UniCompose.tryFire(CompletableFuture.java:1150)
	at java.base/java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:510)
	at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1773)
	at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.exec(CompletableFuture.java:1760)
	at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:387)
	at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1312)
	at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1843)
	at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1808)
	at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:188)
13:54:30.383 [ForkJoinPool.commonPool-worker-1] ERROR o.e.lsp4j.jsonrpc.RemoteEndpoint - Internal error: java.lang.ClassCastException: Cannot cast org.openrewrite.tree.ParseError to org.openrewrite.java.tree.J$CompilationUnit
java.util.concurrent.CompletionException: java.lang.ClassCastException: Cannot cast org.openrewrite.tree.ParseError to org.openrewrite.java.tree.J$CompilationUnit
	at java.base/java.util.concurrent.CompletableFuture.encodeRelay(CompletableFuture.java:368)
	at java.base/java.util.concurrent.CompletableFuture.completeRelay(CompletableFuture.java:377)
	at java.base/java.util.concurrent.CompletableFuture$UniRelay.tryFire(CompletableFuture.java:1097)
	at java.base/java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:510)
	at java.base/java.util.concurrent.CompletableFuture.completeExceptionally(CompletableFuture.java:2194)
	at reactor.core.publisher.MonoToCompletableFuture.onError(MonoToCompletableFuture.java:77)
	at reactor.core.publisher.FluxOnAssembly$OnAssemblySubscriber.onError(FluxOnAssembly.java:544)
	at reactor.core.publisher.MonoFlatMap$FlatMapMain.onError(MonoFlatMap.java:180)
	at reactor.core.publisher.FluxOnAssembly$OnAssemblySubscriber.onError(FluxOnAssembly.java:544)
	at reactor.core.publisher.MonoCompletionStage$MonoCompletionStageSubscription.apply(MonoCompletionStage.java:115)
	at reactor.core.publisher.MonoCompletionStage$MonoCompletionStageSubscription.apply(MonoCompletionStage.java:67)
	at java.base/java.util.concurrent.CompletableFuture.uniHandle(CompletableFuture.java:934)
	at java.base/java.util.concurrent.CompletableFuture$UniHandle.tryFire(CompletableFuture.java:911)
	at java.base/java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:510)
	at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1773)
	at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.exec(CompletableFuture.java:1760)
	at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:387)
	at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1312)
	at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1843)
	at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1808)
	at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:188)
Caused by: java.lang.ClassCastException: Cannot cast org.openrewrite.tree.ParseError to org.openrewrite.java.tree.J$CompilationUnit
	at java.base/java.lang.Class.cast(Class.java:4067)
	Suppressed: reactor.core.publisher.FluxOnAssembly$OnAssemblyException: 
Assembly trace from producer [reactor.core.publisher.MonoCompletionStage] :
	reactor.core.publisher.Mono.fromFuture(Mono.java:629)
	org.springframework.ide.vscode.boot.java.rewrite.RewriteRefactorings.createEdits(RewriteRefactorings.java:91)
Error has been observed at the following site(s):
	*__Mono.fromFuture ⇢ at org.springframework.ide.vscode.boot.java.rewrite.RewriteRefactorings.createEdits(RewriteRefactorings.java:91)
	|_    Mono.flatMap ⇢ at org.springframework.ide.vscode.commons.languageserver.util.SimpleLanguageServer.executeCommand(SimpleLanguageServer.java:321)
Original Stack Trace:
		at java.base/java.lang.Class.cast(Class.java:4067)
		at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197)
		at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197)
		at java.base/java.util.Iterator.forEachRemaining(Iterator.java:133)
		at java.base/java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1939)
		at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:509)
		at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499)
		at java.base/java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:921)
		at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
		at java.base/java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:682)
		at org.springframework.ide.vscode.commons.rewrite.java.ORAstUtils.parseInputs(ORAstUtils.java:332)
		at org.springframework.ide.vscode.boot.java.rewrite.RewriteRefactorings.lambda$4(RewriteRefactorings.java:143)
		at java.base/java.util.concurrent.CompletableFuture$UniCompose.tryFire(CompletableFuture.java:1150)
		at java.base/java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:510)
		at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1773)
		at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.exec(CompletableFuture.java:1760)
		at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:387)
		at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1312)
		at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1843)
		at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1808)
		at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:188)

On the client side (Eclipse in this case), just nothing happens, just the task is continue to run (endlessly) in the progress view.

[BoykoAlex]

The stack trace hints at an issue with parsing java source with errors... Likely a case we are missing with erroneous node.

[martinlippert]

🤔 Seems to be difficult to reproduce, tried various things but wasn't able to get to this exception reliably. I've seen it again, but wasn't able to capture the exact code that produced it. Need to investigate this further.

[martinlippert]

One thing that I observed though is that once this exception happens, VSCode shows an error popup and the progress continues to be displayed (so the client things that this operation hasn't finished yet), so it would be good to avoid that endless progress display if things like this happen.

[martinlippert]

I tried again, but I can't reproduce this anymore. So we should focus on the generic "avoid showing the progress endlessly if something like this happens" aspect here - in case this is possible to solve without reproducing the issue. Maybe we can inject an artificial exception somewhere to reproduce at least the rest of the behavior (the endless progress).

[BoykoAlex]

We can try add a utility method to progress service:

	default <T> CompletableFuture<T> futureWithIndefiniteProgress(CompletableFuture<T> f, String title, String message, T onError) {
		IndefiniteProgressTask progress = createIndefiniteProgressTask(UUID.randomUUID().toString(), title, message);
		return f.exceptionally(t -> {
			progress.done();
			return onError;
		});
	}

Or just deal with each case individually... as task might be needed while future is exdecuted to update the message etc. This case in RewriteRefactorings is rather straight-forward and can be dealt with at the RewriteRefactorings class level...