@Test
    public void shouldSuccessfullyEvaluateSingleIterationTraversals() throws Exception {
        final String outputLocation = TestHelper.makeTestDataDirectory(SparkSingleIterationStrategyTest.class, UUID.randomUUID().toString());
        Configuration configuration = getBaseConfiguration();
        configuration.setProperty(Constants.GREMLIN_HADOOP_INPUT_LOCATION, TestFiles.PATHS.get("tinkerpop-modern-v3.kryo"));
        configuration.setProperty(Constants.GREMLIN_HADOOP_GRAPH_READER, GryoInputFormat.class.getCanonicalName());
        configuration.setProperty(Constants.GREMLIN_HADOOP_GRAPH_WRITER, PersistedOutputRDD.class.getCanonicalName());
        configuration.setProperty(Constants.GREMLIN_HADOOP_OUTPUT_LOCATION, outputLocation);
        configuration.setProperty(Constants.GREMLIN_HADOOP_DEFAULT_GRAPH_COMPUTER, SparkGraphComputer.class.getCanonicalName());
        configuration.setProperty(Constants.GREMLIN_SPARK_PERSIST_CONTEXT, true);
        configuration.setProperty(GryoPool.CONFIG_IO_GRYO_VERSION, version.name());

        /////////// WITHOUT SINGLE-ITERATION STRATEGY LESS SINGLE-PASS OPTIONS ARE AVAILABLE

        Graph graph = GraphFactory.open(configuration);
        GraphTraversalSource g = graph.traversal().withComputer().withoutStrategies(SparkInterceptorStrategy.class, MessagePassingReductionStrategy.class);
        assertFalse(g.getStrategies().getStrategy(SparkInterceptorStrategy.class).isPresent());
        assertFalse(g.V().count().explain().getStrategyTraversals().stream().filter(pair -> pair.getValue0() instanceof SparkInterceptorStrategy).findAny().isPresent());
        assertFalse(g.getStrategies().getStrategy(MessagePassingReductionStrategy.class).isPresent());
        assertFalse(g.V().count().explain().getStrategyTraversals().stream().filter(pair -> pair.getValue0() instanceof MessagePassingReductionStrategy).findAny().isPresent());
        assertTrue(g.getStrategies().getStrategy(SparkSingleIterationStrategy.class).isPresent());
        assertTrue(g.V().count().explain().getStrategyTraversals().stream().filter(pair -> pair.getValue0() instanceof SparkSingleIterationStrategy).findAny().isPresent());

        test(true, g.V().limit(10));
        test(true, g.V().values("age").groupCount());
        test(true, g.V().groupCount().by(__.out().count()));
        test(true, g.V().outE());
        test(true, 6L, g.V().count());
        test(true, 6L, g.V().out().count());
        test(true, 6L, g.V().outE().inV().count());
        ////
        test(false, 6L, g.V().local(__.inE()).count());
        test(false, g.V().outE().inV());
        test(false, g.V().both());
        test(false, 12L, g.V().both().count());
        test(false, g.V().out().id());
        test(false, 2L, g.V().out().out().count());
        test(false, 6L, g.V().in().count());
        test(false, 6L, g.V().inE().count());

        /////////// WITH SINGLE-ITERATION STRATEGY MORE SINGLE-PASS OPTIONS ARE AVAILABLE

        graph = GraphFactory.open(configuration);
        g = graph.traversal().withComputer().withoutStrategies(SparkInterceptorStrategy.class).withStrategies(MessagePassingReductionStrategy.instance());
        assertFalse(g.getStrategies().getStrategy(SparkInterceptorStrategy.class).isPresent());
        assertFalse(g.V().count().explain().getStrategyTraversals().stream().filter(pair -> pair.getValue0() instanceof SparkInterceptorStrategy).findAny().isPresent());
        assertTrue(g.getStrategies().getStrategy(MessagePassingReductionStrategy.class).isPresent());
        assertTrue(g.V().count().explain().getStrategyTraversals().stream().filter(pair -> pair.getValue0() instanceof MessagePassingReductionStrategy).findAny().isPresent());
        assertTrue(g.getStrategies().getStrategy(SparkSingleIterationStrategy.class).isPresent());
        assertTrue(g.V().count().explain().getStrategyTraversals().stream().filter(pair -> pair.getValue0() instanceof SparkSingleIterationStrategy).findAny().isPresent());

        test(true, g.V().limit(10));
        test(true, g.V().values("age").groupCount());
        test(true, g.V().groupCount().by(__.out().count()));
        test(true, g.V().outE());
        test(true, 6L, g.V().outE().values("weight").count());
        test(true, 6L, g.V().inE().values("weight").count());
        test(true, 12L, g.V().bothE().values("weight").count());
        test(true, g.V().bothE().values("weight"));
        test(true, g.V().bothE().values("weight").limit(2));
        test(true, 6L, g.V().count());
        test(true, 6L, g.V().id().count());
        test(true, 6L, g.V().identity().outE().identity().count());
        test(true, 6L, g.V().identity().outE().has("weight").count());
        test(true, 6L, g.V().out().count());
        test(true, 6L, g.V().outE().inV().count());
        test(true, 6L, g.V().outE().inV().id().count());
        test(true, 2L, g.V().outE().inV().id().groupCount().select(Column.values).unfold().dedup().count());
        test(true, g.V().out().id());
        test(true, 6L, g.V().outE().valueMap().count());
        test(true, g.V().outE().valueMap());
        test(true, 6L, g.V().inE().valueMap().count());
        test(true, g.V().inE().valueMap());
        test(true, 12L, g.V().bothE().valueMap().count());
        test(true, g.V().bothE().valueMap());
        test(true, 6L, g.V().inE().id().count());
        test(true, 6L, g.V().outE().count());
        test(true, 4L, g.V().outE().inV().id().dedup().count());
        test(true, 4L, g.V().filter(__.in()).count());
        test(true, 6L, g.V().sideEffect(__.in()).count());
        test(true, 6L, g.V().map(__.constant("hello")).count());
        test(true, g.V().groupCount());
        test(true, g.V().groupCount("x"));
        test(true, g.V().groupCount("x").cap("x"));
        test(true, g.V().id().groupCount("x").cap("x"));
        test(true, g.V().outE().groupCount());
        test(true, g.V().outE().groupCount().by("weight"));
        test(true, g.V().inE().id().groupCount());
        test(true, g.V().inE().values("weight").groupCount());
        test(true, 6L, g.V().outE().outV().count());
        test(true, g.V().out().id().groupCount("x"));
        test(true, g.V().inE().values("weight").groupCount("x"));
        test(true, 6L, g.V().in().count());
        test(true, 12L, g.V().both().count());
        test(true, 6L, g.V().flatMap(__.in()).count());
        test(true, 4L, g.V().map(__.in()).count());
        test(true, 6L, g.V().inE().count());
        test(true, 4L, g.V().outE().inV().dedup().count());
        /////
        test(false, 6L, g.V().as("a").outE().inV().as("b").id().dedup("a", "b").by(T.id).count());
        test(false, 6L, g.V().local(__.inE()).count());
        test(false, 4L, g.V().outE().inV().dedup().by("name").count());
        test(false, 6L, g.V().local(__.in()).count());
        test(false, g.V().outE().inV());
        test(false, g.V().both());
        test(false, g.V().outE().inV().dedup());
        test(false, 2L, g.V().out().out().count());
        test(false, 6L, g.V().as("a").map(__.both()).select("a").count());
        test(false, g.V().out().values("name"));
        test(false, g.V().out().properties("name"));
        test(false, g.V().out().valueMap());
        test(false, 6L, g.V().as("a").outE().inV().values("name").as("b").dedup("a", "b").count());
        test(false, 2L, g.V().outE().inV().groupCount().select(Column.values).unfold().dedup().count());
        test(false, g.V().out().groupCount("x"));
        test(false, g.V().out().groupCount("x").cap("x"));
        test(false, 6L, g.V().both().groupCount("x").cap("x").select(keys).unfold().count());
        test(false, g.V().outE().inV().groupCount());
        test(false, g.V().outE().unfold().inV().groupCount());
        test(false, g.V().outE().inV().groupCount().by("name"));
        test(false, g.V().outE().inV().tree());
        test(false, g.V().outE().inV().id().tree());
        test(false, g.V().inE().groupCount());
        test(false, g.V().inE().groupCount().by("weight"));
        test(false, g.V().in().values("name").groupCount());
        test(false, g.V().out().groupCount("x"));
        test(false, g.V().in().groupCount("x"));
        test(false, g.V().both().groupCount("x").cap("x"));
    }
@author Marko A. Rodriguez (http://markorodriguez.com)
spark-gremlin/src/test/java/org/apache/tinkerpop/gremlin/spark/process/computer/traversal/strategy/optimization/SparkSingleIterationStrategyTest.java