gremlin-dotnet/test/Gremlin.Net.IntegrationTest/Process/Traversal/DriverRemoteConnection/GraphTraversalTests.cs

#region License

/*
 * 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.
 */

#endregion

using System.Linq;
using System.Collections.Generic;
using System.Threading;
using System.Threading.Tasks;
using Gremlin.Net.Driver;
using Gremlin.Net.Driver.Exceptions;
using Gremlin.Net.Process.Traversal;
using Gremlin.Net.Structure;
using Xunit;
using Gremlin.Net.Process.Traversal.Strategy.Decoration;

namespace Gremlin.Net.IntegrationTest.Process.Traversal.DriverRemoteConnection
{
    public class GraphTraversalTests
    {
        private readonly RemoteConnectionFactory _connectionFactory = new RemoteConnectionFactory();

        [Fact]
        public void g_V_Count()
        {
            var connection = _connectionFactory.CreateRemoteConnection();
            var g = AnonymousTraversalSource.Traversal().With(connection);

            var count = g.V().Count().Next();

            Assert.Equal(6, count);
        }

        [Fact]
        public void g_V_Has_Count()
        {
            var connection = _connectionFactory.CreateRemoteConnection();
            var g = AnonymousTraversalSource.Traversal().With(connection);

            var count = g.V().Has("person", "age", P.Lt(30)).Count().Next();

            Assert.Equal(2, count);
        }

        [Fact]
        public void g_V_Count_Clone()
        {
            var connection = _connectionFactory.CreateRemoteConnection();
            var g = AnonymousTraversalSource.Traversal().With(connection);

            var t = g.V().Count();

            Assert.Equal(6, t.Next());
            Assert.Equal(6, t.Clone().Next());
            Assert.Equal(6, t.Clone().Next());
        }

        [Fact]
        public void g_VX1X_Next()
        {
            var connection = _connectionFactory.CreateRemoteConnection();
            var g = AnonymousTraversalSource.Traversal().With(connection);

            var vertex = g.V(1).Next();

            Assert.Equal(new Vertex(1), vertex);
            Assert.Equal(1, vertex!.Id);
        }

        [Fact]
        public void g_VX1X_NextTraverser()
        {
            var connection = _connectionFactory.CreateRemoteConnection();
            var g = AnonymousTraversalSource.Traversal().With(connection);

            var traverser = g.V(1).NextTraverser();

            Assert.Equal(new Traverser(new Vertex(1)), traverser);
        }

        [Fact]
        public void g_VX1X_ToList()
        {
            var connection = _connectionFactory.CreateRemoteConnection();
            var g = AnonymousTraversalSource.Traversal().With(connection);

            var list = g.V(1).ToList();

            Assert.Equal(1, list.Count);
        }

        [Fact]
        public void g_V_RepeatXBothX_TimesX5X_NextX10X()
        {
            var connection = _connectionFactory.CreateRemoteConnection();
            var g = AnonymousTraversalSource.Traversal().With(connection);

            var result = g.V().Repeat(__.Both()).Times(5).Next(10);

            Assert.Equal(10, result.Count());
        }

        [Fact]
        public void g_V_RepeatXOutX_TimesX2X_ValuesXNameX()
        {
            var connection = _connectionFactory.CreateRemoteConnection();
            var g = AnonymousTraversalSource.Traversal().With(connection);

            var t = g.V().Repeat(__.Out()).Times(2).Values<string>("name");
            var names = t.ToList();

            Assert.Equal((long) 2, names.Count);
            Assert.Contains("lop", names);
            Assert.Contains("ripple", names);
        }

        [Fact]
        public void ShortestPathTest()
        {
            var connection = _connectionFactory.CreateRemoteConnection();
            var g = AnonymousTraversalSource.Traversal().With(connection);

            var shortestPath =
                g.V(5).Repeat(__.Both().SimplePath()).Until(__.HasId(6)).Limit<Vertex>(1).Path().Next();

            Assert.Equal(4, shortestPath!.Count);
            Assert.Equal(new Vertex(6), shortestPath[3]);
        }

        [Fact]
        public void ValueMapTest()
        {
            var connection = _connectionFactory.CreateRemoteConnection();
            var g = AnonymousTraversalSource.Traversal().With(connection);

            var result = g.V(1).ValueMap<string, IList<object>>().Next();
            Assert.True(result.Count >= 2); // .NET may receive an extra haltedTraversers key from the server which we currently just ignore
            Assert.Equal(new List<object> { 29 }, result["age"]);
            Assert.Equal(new List<object> { "marko" }, result["name"]);
        }

        [Fact]
        public void ValueMapWithListConversionTest()
        {
            var connection = _connectionFactory.CreateRemoteConnection();
            var g = AnonymousTraversalSource.Traversal().With(connection);

            var result = g.V(1).ValueMap<string, IList<int>>("age").Next();
            Assert.Equal(new Dictionary<string, IList<int>>
            {
                { "age", new List<int> { 29 } }
            }, result);
        }

        [Fact]
        public void GroupedEdgePropertyConversionTest()
        {
            var connection = _connectionFactory.CreateRemoteConnection();
            var g = AnonymousTraversalSource.Traversal().With(connection);
            var result = g.V().HasLabel("software").Group<string, double>().By("name")
                          .By(__.BothE().Values<double>("weight").Mean<double>()).Next();
            Assert.Equal(new Dictionary<string, double>
            {
                { "ripple", 1D },
                { "lop", 1d/3d }
            }, result);
        }

        [Fact]
        public void ShouldUseParametersInTraversal()
        {
            var connection = _connectionFactory.CreateRemoteConnection();
            var g = AnonymousTraversalSource.Traversal().With(connection);

            var count = g.V().Has("name", "marko").OutE().Count().Next();

            Assert.Equal(3, count);
        }  

        [Fact]
        public void ShouldUseOptionsInTraversal()
        {
            var connection = _connectionFactory.CreateRemoteConnection();
            var options = new Dictionary<string,object>
            {
                {"x", "test"},
                {"y", true}
            };
            var g = AnonymousTraversalSource.Traversal().With(connection);
            
            var countWithStrategy = g.WithStrategies(new OptionsStrategy(options)).V().Count().Next();
            Assert.Equal(6, countWithStrategy);
        }

        [Fact]
        public void ShouldUseSeedStrategyToReturnDeterministicResults()
        {
            var connection = _connectionFactory.CreateRemoteConnection();
            var g = AnonymousTraversalSource.Traversal().With(connection).WithStrategies(new SeedStrategy(664664));

            var shuffledResults = g.V().Values<string>("name").Order().By(Order.Shuffle).ToList();
            Assert.Equal(shuffledResults, g.V().Values<string>("name").Order().By(Order.Shuffle).ToList());
            Assert.Equal(shuffledResults, g.V().Values<string>("name").Order().By(Order.Shuffle).ToList());
            Assert.Equal(shuffledResults, g.V().Values<string>("name").Order().By(Order.Shuffle).ToList());
            Assert.Equal(shuffledResults, g.V().Values<string>("name").Order().By(Order.Shuffle).ToList());
            Assert.Equal(shuffledResults, g.V().Values<string>("name").Order().By(Order.Shuffle).ToList());
        }

        [Fact]
        public async Task ShouldExecuteAsynchronouslyWhenPromiseIsCalled()
        {
            var connection = _connectionFactory.CreateRemoteConnection();
            var g = AnonymousTraversalSource.Traversal().With(connection);

            var count = await g.V().Count().Promise(t => t.Next());

            Assert.Equal(6, count);
        }

        [Fact]
        public async Task ShouldSupportCancellationForPromise()
        {
            var connection = _connectionFactory.CreateRemoteConnection();
            var g = AnonymousTraversalSource.Traversal().With(connection);

            await Assert.ThrowsAsync<TaskCanceledException>(async () =>
                await g.V().Promise(t => t.Iterate(), new CancellationToken(true)));
        }
        
        [Fact]
        public async Task ShouldSupportFurtherTraversalsAfterOneWasCancelled()
        {
            var connection = _connectionFactory.CreateRemoteConnection(connectionPoolSize: 1);
            var g = AnonymousTraversalSource.Traversal().With(connection);
            var cts = new CancellationTokenSource();
            
            var cancelledTask = g.V().Promise(t => t.Iterate(), cts.Token);
            cts.Cancel();
            await Assert.ThrowsAsync<TaskCanceledException>(async () => await cancelledTask);
            
            Assert.True(await g.V().Promise(t => t.HasNext(), CancellationToken.None));
        }

        // TODO: update after tx is implemented in 4.0
        [Fact (Skip = "transaction-related tests are disabled until Tx implemented")]
        public async Task ShouldThrowExceptionOnCommitWhenGraphNotSupportTx()
        {
            var connection = _connectionFactory.CreateRemoteConnection();
            var g = AnonymousTraversalSource.Traversal().With(connection);
            var tx = g.Tx();
            var exception = await Assert.ThrowsAsync<ResponseException>(async () => await tx.CommitAsync());
            Assert.Equal("ServerError: Graph does not support transactions", exception.Message);
        }

        [Fact (Skip = "transaction-related tests are disabled until Tx implemented")]
        public async Task ShouldThrowExceptionOnRollbackWhenGraphNotSupportTx()
        {
            var connection = _connectionFactory.CreateRemoteConnection();
            var g = AnonymousTraversalSource.Traversal().With(connection);
            var tx = g.Tx();
            var exception = await Assert.ThrowsAsync<ResponseException>(async () => await tx.RollbackAsync());
            Assert.Equal("ServerError: Graph does not support transactions", exception.Message);
        }
        
        [Fact]
        public void ShouldUseMaterializedPropertiesTokenInV()
        {
            var connection = _connectionFactory.CreateRemoteConnection();
            var g = AnonymousTraversalSource.Traversal().With(connection);
            var vertices = g.With("materializeProperties", "tokens").V().ToList();
            foreach (var v in vertices)
            {
                Assert.NotNull(v);
                Assert.Empty(v.Properties);
            }
        }
        
        [Fact]
        public void ShouldUseMaterializedPropertiesTokenInE()
        {
            var connection = _connectionFactory.CreateRemoteConnection();
            var g = AnonymousTraversalSource.Traversal().With(connection);
            var edges = g.With("materializeProperties", "tokens").E().ToList();
            foreach (var e in edges)
            {
                Assert.NotNull(e);
                Assert.Empty(e.Properties);
            }
        }
        
        [Fact]
        public void ShouldUseMaterializedPropertiesTokenInVP()
        {
            var connection = _connectionFactory.CreateRemoteConnection();
            var g = AnonymousTraversalSource.Traversal().With(connection);
            var vps = g.With("materializeProperties", "tokens").V().Properties<VertexProperty>().ToList();
            foreach (var vp in vps)
            {
                Assert.NotNull(vp);
                Assert.Empty(vp.Properties);
            }
        }
        
        [Fact]
        public void ShouldUseMaterializedPropertiesTokenInPath()
        {
            var connection = _connectionFactory.CreateRemoteConnection();
            var g = AnonymousTraversalSource.Traversal().With(connection);
            var p = g.With("materializeProperties", "tokens").V().Has("name", "marko").OutE().InV().HasLabel("software").Path().Next();
            
            Assert.NotNull(p);
            Assert.Equal(3, p.Count);
            
            var a = p[0] as Vertex;
            var b = p[1] as Edge;
            var c = p[2] as Vertex;
            
            Assert.NotNull(a);
            Assert.NotNull(b);
            Assert.NotNull(c);
            
            Assert.Empty(a.Properties);
            Assert.Empty(b.Properties);
            Assert.Empty(c.Properties);
        }
        
        [Fact]
        public void ShouldMaterializePropertiesAllInPath()
        {
            var connection = _connectionFactory.CreateRemoteConnection();
            var g = AnonymousTraversalSource.Traversal().With(connection);
            var p = g.With("materializeProperties", "all").V().Has("name", "marko").OutE().InV().HasLabel("software").Path().Next();

            Assert.NotNull(p);
            Assert.Equal(3, p.Count);

            var a = p[0] as Vertex;
            var b = p[1] as Edge;
            var c = p[2] as Vertex;

            Assert.NotNull(a);
            Assert.NotNull(b);
            Assert.NotNull(c);

            Assert.True(a.Properties != null && a.Properties.Length > 0);
            Assert.True(b.Properties != null && b.Properties.Length > 0);
            Assert.True(c.Properties != null && c.Properties.Length > 0);
        }
    }
}