Hi,
Whilst optimizing the NotStep I came across what looks to me like a bug
in TraversalHelper.replaceStep or perhaps rather in CountStrategy.
The test below shows the bug.
@Test
public void g_VX1X_repeatXoutX_untilXoutE_count_isX0XX_name() {
Graph graph = TinkerFactory.createModern();
final Traversal<Vertex, String> traversal1 = graph.traversal()
.V(convertToVertexId(graph, "marko"))
.repeat(__.out())
.until(__.not(__.outE()))
.values("name");
checkResults(Arrays.asList("lop", "lop", "ripple", "vadas"),
traversal1);
List<VertexStep> vertexSteps =
TraversalHelper.getStepsOfAssignableClassRecursively(VertexStep.class,
traversal1.asAdmin());
VertexStep vertexStep = vertexSteps.stream().filter(s ->
s.returnsEdge()).findAny().get();
Assert.assertEquals(EmptyStep.instance(),
vertexStep.getPreviousStep());
final Traversal<Vertex, String> traversal2 = graph.traversal()
.V(convertToVertexId(graph, "marko"))
.repeat(__.out())
.until(__.outE().count().is(0))
.values("name");
checkResults(Arrays.asList("lop", "lop", "ripple", "vadas"),
traversal2);
vertexSteps =
TraversalHelper.getStepsOfAssignableClassRecursively(VertexStep.class,
traversal2.asAdmin());
vertexStep = vertexSteps.stream().filter(s ->
s.returnsEdge()).findAny().get();
//This fails because the vertexStep's previous step is the
NotStepwhen it should be an EmptyStep.
Assert.assertEquals(EmptyStep.instance(),
vertexStep.getPreviousStep());
}
traversal1 and traversal2 should be the same as the CountStrategy will
replace the __.outE().count().is(0) with __.not(__.outE())
The CountStrategy does what its suppose to do however then it calls
TraversalHelper.replaceStep(prev, new NotStep<>(traversal, inner),
traversal); the traversal's VertexStep gets its previousStep set to the
NotStep. This is because of the way TraversalHelper.replaceStep is
implemented.
I am not sure whether the fix should be in replaceStep or rather in
CountStrategy.
Thanks
Pieter
