Add TryVerifyConnectivity (#693)

* Add IDriver.TryVerifyConnectivity

Neo4j.Driver/Neo4j.Driver.Tests/DriverTests.cs

@@ -149,6 +149,32 @@ public async void ShouldVerifyConnection()
             mock.Verify(x => x.VerifyConnectivityAndGetInfoAsync(), Times.Once);
         }
 
+        [Fact]
+        public async void ShouldTryVerifyConnection()
+        {
+            var mock = new Mock<IConnectionProvider>();
+            mock.Setup(x => x.VerifyConnectivityAndGetInfoAsync())
+                .Returns(Task.FromResult(new Mock<IServerInfo>().Object));
+
+            var driver = (IDriver)new Internal.Driver(new Uri("bolt://localhost"), false, mock.Object, null);
+            var connects = await driver.TryVerifyConnectivityAsync();
+
+            connects.Should().BeTrue();
+        }
+
+        [Fact]
+        public async void ShouldCatchInTryVerifyConnection()
+        {
+            var mock = new Mock<IConnectionProvider>();
+            mock.Setup(x => x.VerifyConnectivityAndGetInfoAsync())
+                .ThrowsAsync(new Exception("broken"));
+
+            var driver = (IDriver)new Internal.Driver(new Uri("bolt://localhost"), false, mock.Object, null);
+            var connects = await driver.TryVerifyConnectivityAsync();
+
+            connects.Should().BeFalse();
+        }
+
         [Fact]
         public async void ShouldGetInfoConnection()
         {

Neo4j.Driver/Neo4j.Driver/IDriver.cs

@@ -66,6 +66,15 @@ public interface IDriver : IDisposable, IAsyncDisposable
     /// <returns>A task that represents the asynchronous operation. The task result contains the connected server's info.</returns>
     Task<IServerInfo> GetServerInfoAsync();
 
+    /// <summary>
+    /// Asynchronously verify if the driver can connect to the remote server.
+    /// </summary>
+    ///  <remarks>Even if this method returns false, the driver still need to be closed via
+    /// <see cref="CloseAsync"/> or disposed to free up all resources.</remarks>
+    /// <returns>A task that represents the asynchronous operation.<br/>
+    /// The task result contains if the driver successfully connected to the remote server.</returns>
+    Task<bool> TryVerifyConnectivityAsync();
+
     /// <summary>
     /// Asynchronously verify if the driver can connect to the remote server by establishing a network connection with
     /// the remote. If the driver fails to connect to the remote server, an error will be thrown, which can be used to further

Neo4j.Driver/Neo4j.Driver/Internal/Driver.cs

@@ -109,6 +109,20 @@ public Task<IServerInfo> GetServerInfoAsync()
         return _connectionProvider.VerifyConnectivityAndGetInfoAsync();
     }
 
+    public async Task<bool> TryVerifyConnectivityAsync()
+    {
+        try
+        {
+            await _connectionProvider.VerifyConnectivityAndGetInfoAsync().ConfigureAwait(false);
+            return true;
+        }
+        catch (Exception)
+        {
+            return false;
+        }
+    }
+
+
     public Task VerifyConnectivityAsync()
     {
         return GetServerInfoAsync();