CSHARP-5697: Fix Client.BulkWrite failure in case complex type is being used as Document's Id

src/MongoDB.Driver/BulkWriteInsertOneResult.cs

@@ -13,6 +13,7 @@
 * limitations under the License.
 */
 
+using System;
 using MongoDB.Bson;
 
 namespace MongoDB.Driver
@@ -25,6 +26,19 @@ public class BulkWriteInsertOneResult
         /// <summary>
         /// The id of the inserted document.
         /// </summary>
-        public BsonValue InsertedId { get; init; }
+        [Obsolete("InsertedId is deprecated and will be removed in future versions. Use DocumentId instead.")]
+        public BsonValue InsertedId
+        {
+            get => BsonValue.Create(DocumentId);
+            init
+            {
+                DocumentId = value;
+            }
+        }
+
+        /// <summary>
+        /// The id of the inserted document.
+        /// </summary>
+        public object DocumentId { get; init; }
     }
 }

src/MongoDB.Driver/Core/Operations/ClientBulkWriteOperation.cs

@@ -33,7 +33,7 @@ internal sealed class ClientBulkWriteOperation : RetryableWriteCommandOperationB
     {
         private readonly bool? _bypassDocumentValidation;
         private readonly bool _errorsOnly;
-        private readonly Dictionary<int, BsonValue> _idsMap = new();
+        private readonly Dictionary<int, object> _idsMap = new();
         private readonly BsonDocument _let;
         private readonly RenderArgs<BsonDocument> _renderArgs;
         private readonly IBatchableSource<BulkWriteModel> _writeModels;
@@ -331,7 +331,7 @@ private void PopulateIndividualResponses(IEnumerable<BsonDocument> individualRes
                         _idsMap.TryGetValue(operationIndex, out var insertedId);
                         bulkWriteResult.InsertResults.Add(operationIndex, new()
                         {
-                            InsertedId = insertedId
+                            DocumentId = insertedId
                         });
                     }
                     else if (writeModelType == typeof(BulkWriteUpdateOneModel<>) || writeModelType == typeof(BulkWriteUpdateManyModel<>) || writeModelType == typeof(BulkWriteReplaceOneModel<>))

src/MongoDB.Driver/Core/WireProtocol/Messages/CommandMessageSection.cs

@@ -133,7 +133,7 @@ internal sealed class ClientBulkWriteOpsCommandMessageSection : BatchableCommand
     {
         public ClientBulkWriteOpsCommandMessageSection(
             IBatchableSource<BulkWriteModel> operations,
-            Dictionary<int, BsonValue> idsMap,
+            Dictionary<int, object> idsMap,
             int? maxBatchCount,
             int? maxDocumentSize,
             RenderArgs<BsonDocument> renderArgs)
@@ -144,7 +144,7 @@ public ClientBulkWriteOpsCommandMessageSection(
                 RenderArgs = renderArgs;
             }
 
-        public Dictionary<int, BsonValue> IdsMap { get; }
+        public Dictionary<int, object> IdsMap { get; }
         public new IBatchableSource<BulkWriteModel> Documents { get; }
         public RenderArgs<BsonDocument> RenderArgs { get; }
     }

src/MongoDB.Driver/Core/WireProtocol/Messages/Encoders/BinaryEncoders/ClientBulkWriteOpsSectionFormatter.cs

@@ -32,7 +32,7 @@ internal sealed class ClientBulkWriteOpsSectionFormatter : ICommandMessageSectio
         private MemoryStream _nsInfoMemoryStream;
         private BsonBinaryWriter _nsInfoWriter;
         private IBsonSerializerRegistry _serializerRegistry;
-        private Dictionary<int, BsonValue> _idsMap;
+        private Dictionary<int, object> _idsMap;
         private int _currentIndex;
 
         public ClientBulkWriteOpsSectionFormatter(long? maxSize)
@@ -150,7 +150,7 @@ public void RenderInsertOne<TDocument>(RenderArgs<BsonDocument> renderArgs, Bson
             WriteStartModel(serializationContext, "insert", model);
             var documentSerializer = _serializerRegistry.GetSerializer<TDocument>();
             var documentId = documentSerializer.SetDocumentIdIfMissing(null, model.Document);
-            _idsMap[_currentIndex] = BsonValue.Create(documentId);
+            _idsMap[_currentIndex] = documentId;
             serializationContext.Writer.WriteName("document");
             documentSerializer.Serialize(serializationContext, model.Document);
             WriteEndModel(serializationContext);

tests/MongoDB.Driver.Tests/Jira/CSharp5697Tests.cs

@@ -0,0 +1,106 @@
+/* Copyright 2010-present MongoDB Inc.
+ *
+ * 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;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using FluentAssertions;
+using MongoDB.Bson.Serialization;
+using MongoDB.Driver.Core.Misc;
+using MongoDB.Driver.TestHelpers;
+using MongoDB.TestHelpers.XunitExtensions;
+using Xunit;
+
+namespace MongoDB.Driver.Tests.Jira;
+
+public class CSharp5697Tests : IntegrationTest<CSharp5697Tests.ClassFixture>
+{
+    public CSharp5697Tests(ClassFixture fixture)
+        : base(fixture, server => server.Supports(Feature.ClientBulkWrite))
+    {
+    }
+
+    [Theory]
+    [ParameterAttributeData]
+    public async Task ClientBulkWrite_supports_complex_id([Values(true, false)] bool async)
+    {
+        var id = async ? "1" : "2";
+        var options = new ClientBulkWriteOptions { VerboseResult = true };
+        BulkWriteModel[] models =
+        [
+            new BulkWriteInsertOneModel<Document>(
+                Fixture.Collection.CollectionNamespace,
+                new Document(new DocumentId(id)))
+        ];
+
+        var result = async ?
+            await Fixture.Client.BulkWriteAsync(models, options) :
+            Fixture.Client.BulkWrite(models, options);
+
+        result.InsertResults[0].DocumentId.Should().BeOfType<DocumentId>()
+            .Subject.Key.Should().Be(id);
+    }
+
+    public class Document
+    {
+        public Document(DocumentId id)
+        {
+            Id = id;
+        }
+
+        public DocumentId Id { get; }
+    }
+
+    public class DocumentId
+    {
+        public DocumentId(string key)
+        {
+            Key = key;
+        }
+
+        public string Key { get; }
+    }
+
+    public sealed class DocumentIdSerializer : IBsonSerializer<DocumentId>
+    {
+        public Type ValueType => typeof(DocumentId);
+
+        public DocumentId Deserialize(BsonDeserializationContext context, BsonDeserializationArgs args)
+            => new DocumentId(context.Reader.ReadString());
+
+        public void Serialize(BsonSerializationContext context, BsonSerializationArgs args, DocumentId value)
+            => context.Writer.WriteString(value.Key);
+
+        public void Serialize(BsonSerializationContext context, BsonSerializationArgs args, object value)
+        {
+            var id = (DocumentId)value;
+            Serialize(context, args, id);
+        }
+
+        object IBsonSerializer.Deserialize(BsonDeserializationContext context, BsonDeserializationArgs args)
+            => Deserialize(context, args);
+    }
+
+    public class ClassFixture : MongoCollectionFixture<Document>
+    {
+        public ClassFixture()
+        {
+            BsonSerializer.RegisterSerializer( new DocumentIdSerializer());
+        }
+
+        protected override IEnumerable<Document> InitialData => null;
+    }
+}
+

tests/MongoDB.Driver.Tests/UnifiedTestOperations/UnifiedClientBulkWriteOperation.cs

@@ -102,7 +102,7 @@ public static BsonDocument ConvertClientBulkWriteResult(ClientBulkWriteResult re
                 { "deletedCount", (int)result.DeletedCount },
                 {
                     "insertResults", ConvertResults(result.InsertResults,
-                        item => new() { { "insertedId", item.InsertedId } })
+                        item => new() { { "insertedId", BsonValue.Create(item.DocumentId) } })
                 },
                 {
                     "updateResults", ConvertResults(result.UpdateResults,