Add transaction configuration constructors; add test to ensure it can be used with ExecutableQuery (#857)

* Add transaction configuration constructor with optional parameters, add test to ensure it can be used with ExecutableQuery

* Make Metadata setter public to allow external modification of transaction metadata

Author: RichardIrons-neo4j

Neo4j.Driver/Neo4j.Driver.Tests/ExecutableQuery/ExecutableQueryTests.cs

@@ -453,10 +453,33 @@ await subject
             .BeEquivalentTo(person);
     }
 
-
     public class Person
     {
         public string Name { get; set; }
         public int Age { get; set; }
     }
+
+    [Fact]
+    public async Task ShouldGetCorrectTransactionConfig()
+    {
+        var tc = new TransactionConfig(timeout: TimeSpan.FromSeconds(10));
+
+        var qc = new QueryConfig(transactionConfig: tc);
+        var autoMock = new AutoMocker(MockBehavior.Loose);
+        var driverMock = autoMock.GetMock<IDriverRowSource<int>>();
+
+        driverMock
+            .Setup(x => x.GetRowsAsync(It.IsAny<Action<int>>(), It.IsAny<CancellationToken>()))
+            .ReturnsAsync(new ExecutionSummary(null, null));
+
+        TransactionConfig configPassed = null;
+        driverMock
+            .Setup(x => x.SetConfig(It.IsAny<QueryConfig>()))
+            .Callback<QueryConfig>(qc => configPassed = qc.TransactionConfig);
+
+        var subject = new ExecutableQuery<int, int>(driverMock.Object, i => i);
+        await subject.WithConfig(qc).ExecuteAsync();
+
+        configPassed.Should().Be(tc);
+    }
 }

Neo4j.Driver/Neo4j.Driver/Public/TransactionConfig.cs

@@ -29,6 +29,13 @@ public sealed class TransactionConfig
     private IDictionary<string, object> _metadata = new Dictionary<string, object>();
     private TimeSpan? _timeout;
 
+    // constructor with two optional parameters
+    public TransactionConfig(IDictionary<string, object> metadata = null, TimeSpan? timeout = null)
+    {
+        Metadata = metadata ?? new Dictionary<string, object>();
+        Timeout = timeout;
+    }
+
     /// <summary>
     /// Transaction timeout. Transactions that execute longer than the configured timeout will be terminated by the
     /// database. This functionality allows user code to limit query/transaction execution time. The specified timeout
@@ -47,7 +54,7 @@ public sealed class TransactionConfig
     public TimeSpan? Timeout
     {
         get => _timeout;
-        internal set
+        set
         {
             if (!value.HasValue || value.Value == TimeSpan.MaxValue)
             {
@@ -84,7 +91,7 @@ internal set
     public IDictionary<string, object> Metadata
     {
         get => _metadata;
-        internal set => _metadata =
+        set => _metadata =
             value ?? throw new ArgumentNullException(nameof(value), "Transaction metadata should not be null");
     }