gremlin-core/src/test/java/org/apache/tinkerpop/gremlin/process/traversal/strategy/optimization/MatchPredicateStrategyTest.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
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package org.apache.tinkerpop.gremlin.process.traversal.strategy.optimization;

import org.apache.tinkerpop.gremlin.process.traversal.P;
import org.apache.tinkerpop.gremlin.process.traversal.Traversal;
import org.apache.tinkerpop.gremlin.process.traversal.TraversalEngine;
import org.apache.tinkerpop.gremlin.process.traversal.TraversalStrategies;
import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.__;
import org.apache.tinkerpop.gremlin.process.traversal.util.DefaultTraversalStrategies;
import org.junit.Before;
import org.junit.Test;
import org.junit.experimental.runners.Enclosed;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;

import java.util.Arrays;

import static org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.__.as;
import static org.junit.Assert.assertEquals;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;

/**
 * @author Marko A. Rodriguez (http://markorodriguez.com)
 */
@RunWith(Enclosed.class)
public class MatchPredicateStrategyTest {

    @RunWith(Parameterized.class)
    public static class StandardTest extends AbstractMatchPredicateStrategyTest {

        @Parameterized.Parameters(name = "{0}")
        public static Iterable<Object[]> data() {
            return generateTestParameters();
        }

        @Parameterized.Parameter(value = 0)
        public Traversal original;

        @Parameterized.Parameter(value = 1)
        public Traversal optimized;

        @Before
        public void setup() {
            this.traversalEngine = mock(TraversalEngine.class);
            when(this.traversalEngine.getType()).thenReturn(TraversalEngine.Type.STANDARD);
        }

        @Test
        public void shouldApplyStrategy() {
            doTest(original, optimized);
        }
    }

    @RunWith(Parameterized.class)
    public static class ComputerTest extends AbstractMatchPredicateStrategyTest {

        @Parameterized.Parameters(name = "{0}")
        public static Iterable<Object[]> data() {
            return generateTestParameters();
        }

        @Parameterized.Parameter(value = 0)
        public Traversal original;

        @Parameterized.Parameter(value = 1)
        public Traversal optimized;

        @Before
        public void setup() {
            this.traversalEngine = mock(TraversalEngine.class);
            when(this.traversalEngine.getType()).thenReturn(TraversalEngine.Type.COMPUTER);
        }

        @Test
        public void shouldApplyStrategy() {
            doTest(original, optimized);
        }
    }

    private static abstract class AbstractMatchPredicateStrategyTest {

        protected TraversalEngine traversalEngine;

        void applyMatchWhereStrategy(final Traversal traversal) {
            final TraversalStrategies strategies = new DefaultTraversalStrategies();
            strategies.addStrategies(MatchPredicateStrategy.instance(), IdentityRemovalStrategy.instance());
            traversal.asAdmin().setStrategies(strategies);
            traversal.asAdmin().setEngine(this.traversalEngine);
            traversal.asAdmin().applyStrategies();
        }

        public void doTest(final Traversal traversal, final Traversal optimized) {
            applyMatchWhereStrategy(traversal);
            assertEquals(optimized, traversal);
        }

        static Iterable<Object[]> generateTestParameters() {

            return Arrays.asList(new Traversal[][]{
                    {__.out().match(as("a").has("name", "marko"), as("a").out().as("b")), __.out().as("a").has("name", "marko").match(as("a").out().as("b"))}, // has() pull out
                    {__.out().as("a").match(as("a").has("name", "marko"), as("a").out().as("b")), __.out().as("a").has("name", "marko").match(as("a").out().as("b"))}, // has() pull out
                    {__.out().as("a").out().match(as("a").has("name", "marko"), as("a").out().as("b")), __.out().as("a").out().match(as("a").has("name", "marko"), as("a").out().as("b"))}, // no has() pull out
                    {__.map(__.match(as("a").has("name", "marko"), as("a").out().as("b"))), __.map(__.match(as("a").has("name", "marko"), as("a").out().as("b")))}, // no has() pull out
                    {__.out().as("c").match(as("a").has("name", "marko"), as("a").out().as("b")), __.out().as("c").match(as("a").has("name", "marko"), as("a").out().as("b"))}, // no has() pull out
                    /////////
                    {__.match(as("a").out().as("b"), __.where(as("b").out("knows").as("c"))), __.match(as("a").out().as("b"), as("b").where(__.out("knows").as("c")))}, // make as().where()
                    {__.match(as("a").out().as("b"), __.where("a", P.gt("b"))), __.match(as("a").out().as("b"), __.as("a").where(P.gt("b")))},  // make as().where()
                    /////////
                    //{__.match(as("a").out().as("b")).where(as("b").out("knows").as("c")), __.match(as("a").out().as("b"), as("b").where(__.out("knows").as("c")))}, // make as().where()
                    //{__.match(as("a").out().as("b")).where("a", P.gt("b")), __.match(as("a").out().as("b"), __.as("a").where(P.gt("b")))},  // make as().where()
            });
        }
    }
}