NullPointerException when property is not present in context json

[fjtirado]

I think the best way to ilustrate the issue is through a JQplay snapshpt

When trying to evalute that using the library, the code throws a null pointer exception

java.lang.NullPointerException: Cannot invoke "com.fasterxml.jackson.databind.JsonNode.isIntegralNumber()" because "lhs" is null
	at net.thisptr.jackson.jq.internal.operators.PlusOperator.apply(PlusOperator.java:19)
	at net.thisptr.jackson.jq.internal.tree.binaryop.assignment.ComplexAssignment.lambda$null$1(ComplexAssignment.java:41)
	at net.thisptr.jackson.jq.path.ObjectFieldPath.mutate(ObjectFieldPath.java:69)
	at net.thisptr.jackson.jq.path.ObjectFieldPath.lambda$mutate$1(ObjectFieldPath.java:52)
	at net.thisptr.jackson.jq.path.RootPath.mutate(RootPath.java:30)
	at net.thisptr.jackson.jq.path.ObjectFieldPath.mutate(ObjectFieldPath.java:51)
	at net.thisptr.jackson.jq.path.Path.mutate(Path.java:20)
	at net.thisptr.jackson.jq.internal.tree.binaryop.assignment.ComplexAssignment.lambda$apply$2(ComplexAssignment.java:41)
	at net.thisptr.jackson.jq.Output.emit(Output.java:14)
	at net.thisptr.jackson.jq.internal.tree.ArrayConstruction.apply(ArrayConstruction.java:28)
	at net.thisptr.jackson.jq.Expression.apply(Expression.java:11)
	at net.thisptr.jackson.jq.internal.tree.binaryop.assignment.ComplexAssignment.apply(ComplexAssignment.java:29)
	at net.thisptr.jackson.jq.Expression.apply(Expression.java:11)
	at io.serverlessworkflow.impl.expressions.JQExpression.eval(JQExpression.java:184)
	at io.serverlessworkflow.impl.executors.AbstractTaskExecutor.lambda$2(AbstractTaskExecutor.java:94)
	at java.base/java.util.Optional.ifPresent(Optional.java:178)
	at io.serverlessworkflow.impl.executors.AbstractTaskExecutor.apply(AbstractTaskExecutor.java:93)
	at io.serverlessworkflow.impl.WorkflowUtils.processTaskList(WorkflowUtils.java:155)
	at io.serverlessworkflow.impl.executors.ForExecutor.internalExecute(ForExecutor.java:55)
	at io.serverlessworkflow.impl.executors.AbstractTaskExecutor.apply(AbstractTaskExecutor.java:92)
	at io.serverlessworkflow.impl.WorkflowUtils.processTaskList(WorkflowUtils.java:155)
	at io.serverlessworkflow.impl.WorkflowInstance.<init>(WorkflowInstance.java:36)
	at io.serverlessworkflow.impl.WorkflowDefinition.execute(WorkflowDefinition.java:100)
	at io.serverlessworkflow.impl.WorkflowDefinitionTest.testWorkflowExecution(WorkflowDefinitionTest.java:44)
	at java.base/java.lang.reflect.Method.invoke(Method.java:569)
	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183)
	at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197)
	at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:179)
	at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197)
	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183)
	at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197)
	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183)
	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183)
	at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197)
	at java.base/java.util.Spliterators$ArraySpliterator.forEachRemaining(Spliterators.java:992)
	at java.base/java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:762)
	at java.base/java.util.stream.ReferencePipeline$7$1.accept(ReferencePipeline.java:276)
	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.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197)
	at java.base/java.util.Spliterators$ArraySpliterator.forEachRemaining(Spliterators.java:992)
	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.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150)
	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173)
	at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
	at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:596)
	at java.base/java.util.stream.ReferencePipeline$7$1.accept(ReferencePipeline.java:276)
	at java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1625)
	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.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150)
	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173)
	at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
	at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:596)
	at java.base/java.util.stream.ReferencePipeline$7$1.accept(ReferencePipeline.java:276)
	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.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197)
	at java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1625)
	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.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150)
	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173)
	at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
	at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:596)
	at java.base/java.util.stream.ReferencePipeline$7$1.accept(ReferencePipeline.java:276)
	at java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1625)
	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.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150)
	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173)
	at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
	at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:596)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)