Merge pull request #397 from zhenlineo/michael-simons/feature/databas…

…e_example

Create a database selection example.

Neo4j.Driver/Neo4j.Driver.Tests.Integration/Direct/BoltV4IT.cs

@@ -15,12 +15,11 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-using System.Runtime.CompilerServices;
 using System.Threading.Tasks;
 using FluentAssertions;
 using Xunit.Abstractions;
 using static Neo4j.Driver.IntegrationTests.VersionComparison;
-using static Neo4j.Driver.SessionConfigBuilder;
+using static Neo4j.Driver.IntegrationTests.DatabaseExtensions;
 
 namespace Neo4j.Driver.IntegrationTests.Direct
 {
@@ -228,33 +227,5 @@ private async Task VerifyDatabaseNameOnSummaryTxFunc(string name, string expecte
                 await session.CloseAsync();
             }
         }
-
-        private static async Task CreateDatabase(IDriver driver, string name)
-        {
-            var session = driver.AsyncSession(ForDatabase("system"));
-            try
-            {
-                var cursor = await session.RunAsync($"CREATE DATABASE {name}");
-                await cursor.ConsumeAsync();
-            }
-            finally
-            {
-                await session.CloseAsync();
-            }
-        }
-
-        private static async Task DropDatabase(IDriver driver, string name)
-        {
-            var session = driver.AsyncSession(ForDatabase("system"));
-            try
-            {
-                var cursor = await session.RunAsync($"DROP DATABASE {name}");
-                await cursor.ConsumeAsync();
-            }
-            finally
-            {
-                await session.CloseAsync();
-            }
-        }
     }
 }

Neo4j.Driver/Neo4j.Driver.Tests.Integration/Examples.cs

@@ -24,6 +24,7 @@
 using Neo4j.Driver;
 using Neo4j.Driver.IntegrationTests;
 using Neo4j.Driver.IntegrationTests.Internals;
+using static Neo4j.Driver.IntegrationTests.DatabaseExtensions;
 using Xunit;
 using Xunit.Abstractions;
 
@@ -706,6 +707,85 @@ public void TestTransactionFunctionExample()
                 CountPerson("Alice").Should().Be(1);
             }
         }
+
+        public class DatabaseSelectionExampleTest : BaseExample
+        {
+            public DatabaseSelectionExampleTest(ITestOutputHelper output, StandAloneIntegrationTestFixture fixture)
+                : base(output, fixture)
+            {
+            }
+
+            [RequireEnterpriseEdition("4.0.0", VersionComparison.GreaterThanOrEqualTo)]
+            public async void TestUseAnotherDatabaseExample()
+            {
+                try
+                {
+                    await DropDatabase(Driver, "examples");
+                }
+                catch (FatalDiscoveryException ex)
+                {
+                    // Its a new server instance, the database didn't exist yet
+                }
+
+                await CreateDatabase(Driver, "examples");
+
+                // Given
+                using (var example = new DatabaseSelectionExample(Uri, User, Password))
+                {
+                    // When
+                    example.UseAnotherDatabaseExample();
+
+                    // Then
+                    var greetingCount = ReadInt("examples", "MATCH (a:Greeting) RETURN count(a)");
+                    greetingCount.Should().Be(1);
+                }
+            }
+
+            private int ReadInt(string database, string query)
+            {
+                using (var session = Driver.Session(SessionConfigBuilder.ForDatabase(database)))
+                {
+                    return session.Run(query).Single()[0].As<int>();
+                }
+            }
+
+            private class DatabaseSelectionExample : IDisposable
+            {
+                private readonly IDriver _driver;
+
+                public DatabaseSelectionExample(string uri, string user, string password)
+                {
+                    _driver = GraphDatabase.Driver(uri, AuthTokens.Basic(user, password));
+                }
+
+                public void UseAnotherDatabaseExample()
+                {
+                    // tag::database-selection[]
+                    using (var session = _driver.Session(SessionConfigBuilder.ForDatabase("examples")))
+                    {
+                        session.Run("CREATE (a:Greeting {message: 'Hello, Example-Database'}) RETURN a").Consume();
+                    }
+
+                    void SessionConfig(SessionConfigBuilder configBuilder) =>
+                        configBuilder.WithDatabase("examples")
+                            .WithDefaultAccessMode(AccessMode.Read)
+                            .Build();
+
+                    using (var session = _driver.Session(SessionConfig))
+                    {
+                        var result = session.Run("MATCH (a:Greeting) RETURN a.message as msg");
+                        var msg = result.Single()[0].As<string>();
+                        Console.WriteLine(msg);
+                    }
+                    // end::database-selection[]
+                }
+
+                public void Dispose()
+                {
+                    _driver?.Dispose();
+                }
+            }
+        }
 
         [SuppressMessage("ReSharper", "xUnit1013")]
         public class PassBookmarksExample : BaseExample

Neo4j.Driver/Neo4j.Driver.Tests.Integration/Extensions/DatabaseExtensions.cs

@@ -0,0 +1,53 @@
+// Copyright (c) 2002-2020 "Neo4j,"
+// Neo4j Sweden AB [http://neo4j.com]
+// 
+// This file is part of Neo4j.
+// 
+// Licensed 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.
+
+using System.Threading.Tasks;
+using static Neo4j.Driver.SessionConfigBuilder;
+
+namespace Neo4j.Driver.IntegrationTests
+{
+    public class DatabaseExtensions
+    {
+        public static async Task CreateDatabase(IDriver driver, string name)
+        {
+            var session = driver.AsyncSession(ForDatabase("system"));
+            try
+            {
+                var cursor = await session.RunAsync($"CREATE DATABASE {name}");
+                await cursor.ConsumeAsync();
+            }
+            finally
+            {
+                await session.CloseAsync();
+            }
+        }
+
+        public static async Task DropDatabase(IDriver driver, string name)
+        {
+            var session = driver.AsyncSession(ForDatabase("system"));
+            try
+            {
+                var cursor = await session.RunAsync($"DROP DATABASE {name}");
+                await cursor.ConsumeAsync();
+            }
+            finally
+            {
+                await session.CloseAsync();
+            }
+        }
+    }
+}

Neo4j.Driver/Neo4j.Driver.Tests.Integration/Internals/BoltkitHelper.cs

@@ -158,7 +158,7 @@ private static BoltkitStatus TestBoltkitAvailability()
             return BoltkitStatus.Installed;
         }
 
-        private static bool IsEnterprise()
+        public static bool IsEnterprise()
         {
             var strings = BoltkitArgs.Split(null);
             return strings.Contains("-e");

Neo4j.Driver/Neo4j.Driver.Tests.Integration/Internals/IntegrationTestAttribute.cs

@@ -107,6 +107,23 @@ public RequireServerFactAttribute(string versionText = null,
             Skip = skipText.ToString();
         }
     }
+
+    public class RequireEnterpriseEdition : RequireServerFactAttribute
+    {
+        public RequireEnterpriseEdition(string versionText = null,
+            VersionComparison versionCompare = VersionComparison.EqualTo)
+            : base(versionText, versionCompare)
+        {
+            if (string.IsNullOrEmpty(Skip))
+            {
+
+                if (!BoltkitHelper.IsEnterprise())
+                {
+                    Skip = "Test requires Neo4j enterprise edition.";
+                }
+            }
+        }
+    }
 
     public class RequireServerWithIPv6FactAttribute : RequireServerFactAttribute
     {