Adds support for IN TRANSACTIONS (#430)

Fixes #429

Author: cskardon

Neo4jClient.Tests/Cypher/CypherFluentQueryCallTests.cs

@@ -8,7 +8,55 @@
 
 namespace Neo4jClient.Tests.Cypher
 {
-    
+    public class CypherFluentQueryInTransactionsTests : IClassFixture<CultureInfoSetupFixture>
+    {
+        private static IRawGraphClient GraphClient_44
+        {
+            get
+            {
+                var client = Substitute.For<IRawGraphClient>();
+                client.CypherCapabilities.Returns(CypherCapabilities.Cypher44);
+                return client;
+            }
+        }
+
+        [Fact]
+        public void AddsInTransactionsWithNoRows_WhenRowsNotSpecified()
+        {
+            var client = GraphClient_44;
+            var query = new CypherFluentQuery(client)
+                .Call("{arlo()}")
+                .InTransactions()
+                .Query;
+
+            Assert.Equal("CALL {arlo()}\r\nIN TRANSACTIONS", query.QueryText);
+        }
+
+        [Fact]
+        public void AddsInTransactionsWithRows_WhenRowsSpecified()
+        {
+            var client = GraphClient_44;
+            var query = new CypherFluentQuery(client)
+                .Call("{arlo()}")
+                .InTransactions(1000)
+                .Query;
+
+            Assert.Equal("CALL {arlo()}\r\nIN TRANSACTIONS OF 1000 ROWS", query.QueryText);
+        }
+
+        [Fact]
+        public void AddsInTransactionsWithNoRows_WhenRowsAreNull()
+        {
+            var client = GraphClient_44;
+            var query = new CypherFluentQuery(client)
+                .Call("{arlo()}")
+                .InTransactions(null)
+                .Query;
+
+            Assert.Equal("CALL {arlo()}\r\nIN TRANSACTIONS", query.QueryText);
+        }
+    }
+
     public class CypherFluentQueryCallTests : IClassFixture<CultureInfoSetupFixture>
     {
         private class Foo

Neo4jClient/BoltGraphClient.cs

@@ -285,10 +285,12 @@ public async Task ConnectAsync(NeoServerConfiguration configuration = null)
                 var version = record["versions"].As<List<object>>();
                 ServerVersion = RootApiResponse.GetVersion(version?.First()?.ToString());
 
-                if (ServerVersion > new Version(3, 0))
+                if (ServerVersion >= new Version(3, 0))
                     CypherCapabilities = CypherCapabilities.Cypher30;
                 if(ServerVersion >= new Version(4,0))
                     CypherCapabilities = CypherCapabilities.Cypher40;
+                if(ServerVersion >= new Version(4,4))
+                    CypherCapabilities = CypherCapabilities.Cypher44;
             }
 
             await session.CloseAsync().ConfigureAwait(false);

Neo4jClient/Cypher/CypherCapabilities.cs

@@ -14,6 +14,7 @@ public CypherCapabilities(CypherCapabilities cypherCapabilities)
             SupportsStoredProcedures = cypherCapabilities.SupportsStoredProcedures;
             SupportsHasFunction = cypherCapabilities.SupportsHasFunction;
             SupportsMultipleTenancy = cypherCapabilities.SupportsMultipleTenancy;
+            SupportsStoredProceduresWithTransactionalBatching = cypherCapabilities.SupportsStoredProceduresWithTransactionalBatching;
         }
 
         public static readonly CypherCapabilities Cypher19 = new CypherCapabilities
@@ -34,7 +35,7 @@ public CypherCapabilities(CypherCapabilities cypherCapabilities)
         public static readonly CypherCapabilities Cypher23 = new CypherCapabilities(Cypher226) {SupportsStartsWith = true};
         public static readonly CypherCapabilities Cypher30 = new CypherCapabilities(Cypher23) { SupportsStoredProcedures = true, SupportsHasFunction = false };
         public static readonly CypherCapabilities Cypher40 = new CypherCapabilities(Cypher30) { SupportsMultipleTenancy = true, SupportsShow = true };
-        
+        public static readonly CypherCapabilities Cypher44 = new CypherCapabilities(Cypher40) { SupportsStoredProceduresWithTransactionalBatching = true };
         public static readonly CypherCapabilities Default = Cypher20;
 
         /// <summary>
@@ -46,6 +47,7 @@ public CypherCapabilities(CypherCapabilities cypherCapabilities)
         public bool SupportsPropertySuffixesForControllingNullComparisons { get; set; }
         public bool SupportsNullComparisonsWithIsOperator { get; set; }
         public bool SupportsStartsWith { get; set; }
+        public bool SupportsStoredProceduresWithTransactionalBatching { get; set; }
 
         /// <summary>
         /// Cypher 3.0 provides support for Stored Procedures via the CALL keyword.

Neo4jClient/Cypher/CypherFluentQuery.cs

@@ -62,6 +62,17 @@ public ICypherFluentQuery Call<T>(Func<ICypherFluentQuery<T>> subQuery)
             return Call($"{{ {query.QueryText} }}", query.QueryParameters);
         }
 
+        public ICypherFluentQuery InTransactions(int? rows = null)
+        {
+            if (!Client.CypherCapabilities.SupportsStoredProceduresWithTransactionalBatching)
+                throw new InvalidOperationException("IN TRANSACTIONS not supported in Neo4j versions older than 4.4");
+
+            return Mutate(w =>
+            {
+                w.AppendClause($"IN TRANSACTIONS{(rows.HasValue ? $" OF {rows.Value} ROWS" : string.Empty)}{Environment.NewLine}");
+            });
+        }
+
 
 
         public ICypherFluentQuery Read

Neo4jClient/Cypher/ICypherFluentQuery.cs

@@ -77,6 +77,13 @@ public partial interface ICypherFluentQuery
         /// <exception cref="InvalidOperationException">Thrown if an attempt is made to call this against a server version prior to 3.0.</exception>
         ICypherFluentQuery Call<T>(Func<ICypherFluentQuery<T>> subQuery);
 
+        /// <summary>
+        /// [Neo4j 4.4+] Batches subqueries 
+        /// </summary>
+        /// <param name="rows"></param>
+        /// <returns></returns>
+        ICypherFluentQuery InTransactions(int? rows = null);
+
         /// <summary>
         /// [Neo4j 3.0+] Yields the values from the response of a <see cref="Call"/> method
         /// </summary>

Neo4jClient/GraphClient.cs

@@ -119,6 +119,8 @@ void StopTimerAndNotifyCompleted()
 
                 if (version >= new Version(4, 0))
                     CypherCapabilities = CypherCapabilities.Cypher40;
+                if(ServerVersion >= new Version(4,4))
+                    CypherCapabilities = CypherCapabilities.Cypher44;
             }
             catch (AggregateException ex)
             {