CSHARP-1978, CSHARP-2045: added hint and comment support to aggregate.

Author: craiggwilson

src/MongoDB.Driver.Core/Core/Misc/Feature.cs

@@ -26,11 +26,13 @@ public class Feature
         private static readonly Feature __aggregate = new Feature("Aggregate", new SemanticVersion(2, 2, 0));
         private static readonly Feature __aggregateAllowDiskUse = new Feature("AggregateAllowDiskUse", new SemanticVersion(2, 6, 0));
         private static readonly Feature __aggregateBucketStage = new Feature("AggregateBucketStage", new SemanticVersion(3, 3, 11));
+        private static readonly Feature __aggregateComment = new Feature("AggregateComment", new SemanticVersion(3, 6, 0, "rc0"));
         private static readonly Feature __aggregateCountStage = new Feature("AggregateCountStage", new SemanticVersion(3, 3, 11));
         private static readonly Feature __aggregateCursorResult = new Feature("AggregateCursorResult", new SemanticVersion(2, 6, 0));
         private static readonly Feature __aggregateExplain = new Feature("AggregateExplain", new SemanticVersion(2, 6, 0));
         private static readonly Feature __aggregateFacetStage = new Feature("AggregateFacetStage", new SemanticVersion(3, 4, 0, "rc0"));
         private static readonly Feature __aggregateGraphLookupStage = new Feature("AggregateGraphLookupStage", new SemanticVersion(3, 4, 0, "rc0"));
+        private static readonly Feature __aggregateHint = new Feature("AggregateHint", new SemanticVersion(3, 6, 0, "rc0"));
         private static readonly Feature __aggregateOut = new Feature("Aggregate", new SemanticVersion(2, 6, 0));
         private static readonly ArrayFiltersFeature __arrayFilters = new ArrayFiltersFeature("ArrayFilters", new SemanticVersion(3, 5, 11));
         private static readonly Feature __bypassDocumentValidation = new Feature("BypassDocumentValidation", new SemanticVersion(3, 2, 0));
@@ -72,6 +74,11 @@ public class Feature
         /// </summary>
         public static Feature AggregateBucketStage => __aggregateBucketStage;
 
+        /// <summary>
+        /// Gets the aggregate comment feature.
+        /// </summary>
+        public static Feature AggregateComment => __aggregateComment;
+
         /// <summary>
         /// Gets the aggregate count stage feature.
         /// </summary>
@@ -97,6 +104,11 @@ public class Feature
         /// </summary>
         public static Feature AggregateGraphLookupStage => __aggregateGraphLookupStage;
 
+        /// <summary>
+        /// Gets the aggregate hint feature.
+        /// </summary>
+        public static Feature AggregateHint => __aggregateHint;
+
         /// <summary>
         /// Gets the aggregate out feature.
         /// </summary>

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

@@ -35,6 +35,8 @@ public class AggregateExplainOperation : IReadOperation<BsonDocument>
         private bool? _allowDiskUse;
         private Collation _collation;
         private CollectionNamespace _collectionNamespace;
+        private string _comment;
+        private BsonValue _hint;
         private TimeSpan? _maxTime;
         private MessageEncoderSettings _messageEncoderSettings;
         private IReadOnlyList<BsonDocument> _pipeline;
@@ -89,6 +91,30 @@ public CollectionNamespace CollectionNamespace
             get { return _collectionNamespace; }
         }
 
+        /// <summary>
+        /// Gets or sets the comment.
+        /// </summary>
+        /// <value>
+        /// The comment.
+        /// </value>
+        public string Comment
+        {
+            get { return _comment; }
+            set { _comment = value; }
+        }
+
+        /// <summary>
+        /// Gets or sets the hint. This must either be a BsonString representing the index name or a BsonDocument representing the key pattern of the index.
+        /// </summary>
+        /// <value>
+        /// The hint.
+        /// </value>
+        public BsonValue Hint
+        {
+            get { return _hint; }
+            set { _hint = value; }
+        }
+
         /// <summary>
         /// Gets or sets the maximum time the server should spend on this operation.
         /// </summary>
@@ -135,7 +161,9 @@ internal BsonDocument CreateCommand(SemanticVersion serverVersion)
                 { "pipeline", new BsonArray(_pipeline) },
                 { "allowDiskUse", () => _allowDiskUse.Value, _allowDiskUse.HasValue },
                 { "maxTimeMS", () => _maxTime.Value.TotalMilliseconds, _maxTime.HasValue },
-                { "collation", () => _collation.ToBsonDocument(), _collation != null }
+                { "collation", () => _collation.ToBsonDocument(), _collation != null },
+                { "hint", () => _hint, _hint != null },
+                { "comment", () => _comment, _comment != null }
             };
         }
 

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

@@ -41,6 +41,8 @@ public class AggregateOperation<TResult> : IReadOperation<IAsyncCursor<TResult>>
         private int? _batchSize;
         private Collation _collation;
         private readonly CollectionNamespace _collectionNamespace;
+        private string _comment;
+        private BsonValue _hint;
         private TimeSpan? _maxAwaitTime;
         private TimeSpan? _maxTime;
         private readonly MessageEncoderSettings _messageEncoderSettings;
@@ -110,6 +112,30 @@ public CollectionNamespace CollectionNamespace
             get { return _collectionNamespace; }
         }
 
+        /// <summary>
+        /// Gets or sets the comment.
+        /// </summary>
+        /// <value>
+        /// The comment.
+        /// </value>
+        public string Comment
+        {
+            get { return _comment; }
+            set { _comment = value; }
+        }
+
+        /// <summary>
+        /// Gets or sets the hint. This must either be a BsonString representing the index name or a BsonDocument representing the key pattern of the index.
+        /// </summary>
+        /// <value>
+        /// The hint.
+        /// </value>
+        public BsonValue Hint
+        {
+            get { return _hint; }
+            set { _hint = value; }
+        }
+
         /// <summary>
         /// Gets or sets the maximum await time.
         /// </summary>
@@ -252,7 +278,9 @@ internal BsonDocument CreateCommand(ConnectionDescription connectionDescription,
                 { "pipeline", new BsonArray(_pipeline) },
                 { "allowDiskUse", () => _allowDiskUse.Value, _allowDiskUse.HasValue },
                 { "maxTimeMS", () => _maxTime.Value.TotalMilliseconds, _maxTime.HasValue },
-                { "collation", () => _collation.ToBsonDocument(), _collation != null }
+                { "collation", () => _collation.ToBsonDocument(), _collation != null },
+                { "hint", () => _hint, _hint != null },
+                { "comment", () => _comment, _comment != null }
             };
 
             ReadConcernHelper.AppendReadConcern(command, _readConcern, connectionDescription, session);

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

@@ -36,6 +36,8 @@ public class AggregateToCollectionOperation : IWriteOperation<BsonDocument>
         private bool? _bypassDocumentValidation;
         private Collation _collation;
         private readonly CollectionNamespace _collectionNamespace;
+        private string _comment;
+        private BsonValue _hint;
         private TimeSpan? _maxTime;
         private readonly MessageEncoderSettings _messageEncoderSettings;
         private readonly IReadOnlyList<BsonDocument> _pipeline;
@@ -105,6 +107,30 @@ public CollectionNamespace CollectionNamespace
             get { return _collectionNamespace; }
         }
 
+        /// <summary>
+        /// Gets or sets the comment.
+        /// </summary>
+        /// <value>
+        /// The comment.
+        /// </value>
+        public string Comment
+        {
+            get { return _comment; }
+            set { _comment = value; }
+        }
+
+        /// <summary>
+        /// Gets or sets the hint. This must either be a BsonString representing the index name or a BsonDocument representing the key pattern of the index.
+        /// </summary>
+        /// <value>
+        /// The hint.
+        /// </value>
+        public BsonValue Hint
+        {
+            get { return _hint; }
+            set { _hint = value; }
+        }
+
         /// <summary>
         /// Gets or sets the maximum time the server should spend on this operation.
         /// </summary>
@@ -197,7 +223,9 @@ internal BsonDocument CreateCommand(SemanticVersion serverVersion)
                 { "maxTimeMS", () => _maxTime.Value.TotalMilliseconds, _maxTime.HasValue },
                 { "collation", () => _collation.ToBsonDocument(), _collation != null },
                 { "writeConcern", () => _writeConcern.ToBsonDocument(), Feature.CommandsThatWriteAcceptWriteConcern.ShouldSendWriteConcern(serverVersion, _writeConcern) },
-                { "cursor", new BsonDocument(), serverVersion >= new SemanticVersion(3, 5, 0) }
+                { "cursor", new BsonDocument(), serverVersion >= new SemanticVersion(3, 5, 0) },
+                { "hint", () => _hint, _hint != null },
+                { "comment", () => _comment, _comment != null }
             };
         }
 

src/MongoDB.Driver/AggregateOptions.cs

@@ -14,6 +14,7 @@
 */
 
 using System;
+using MongoDB.Bson;
 using MongoDB.Driver.Core.Misc;
 
 namespace MongoDB.Driver
@@ -28,6 +29,8 @@ public class AggregateOptions
         private int? _batchSize;
         private bool? _bypassDocumentValidation;
         private Collation _collation;
+        private string _comment;
+        private BsonValue _hint;
         private TimeSpan? _maxAwaitTime;
         private TimeSpan? _maxTime;
         private ExpressionTranslationOptions _translationOptions;
@@ -70,6 +73,24 @@ public Collation Collation
             set { _collation = value; }
         }
 
+        /// <summary>
+        /// Gets or sets the comment.
+        /// </summary>
+        public string Comment
+        {
+            get { return _comment; }
+            set { _comment = value; }
+        }
+
+        /// <summary>
+        /// Gets or sets the hint. This must either be a BsonString representing the index name or a BsonDocument representing the key pattern of the index.
+        /// </summary>
+        public BsonValue Hint
+        {
+            get { return _hint; }
+            set { _hint = value; }
+        }
+
         /// <summary>
         /// Gets or sets the maximum await time.
         /// </summary>

src/MongoDB.Driver/MongoCollectionImpl.cs

@@ -652,6 +652,8 @@ private AggregateOperation<TResult> CreateAggregateOperation<TResult>(RenderedPi
                 AllowDiskUse = options.AllowDiskUse,
                 BatchSize = options.BatchSize,
                 Collation = options.Collation,
+                Comment = options.Comment,
+                Hint = options.Hint,
                 MaxAwaitTime = options.MaxAwaitTime,
                 MaxTime = options.MaxTime,
                 ReadConcern = _settings.ReadConcern,
@@ -685,6 +687,8 @@ private AggregateToCollectionOperation CreateAggregateToCollectionOperation<TRes
                 AllowDiskUse = options.AllowDiskUse,
                 BypassDocumentValidation = options.BypassDocumentValidation,
                 Collation = options.Collation,
+                Comment = options.Comment,
+                Hint = options.Hint,
                 MaxTime = options.MaxTime,
                 WriteConcern = _settings.WriteConcern
             };

tests/MongoDB.Driver.Core.Tests/Core/Operations/AggregateExplainOperationTests.cs

@@ -93,6 +93,30 @@ public void Collation_get_and_set_should_work()
             result.Should().BeSameAs(value);
         }
 
+        [Fact]
+        public void Comment_get_and_set_should_work()
+        {
+            var subject = new AggregateExplainOperation(_collectionNamespace, __pipeline, _messageEncoderSettings);
+            var value = "test";
+
+            subject.Comment = value;
+            var result = subject.Comment;
+
+            result.Should().BeSameAs(value);
+        }
+
+        [Fact]
+        public void Hint_get_and_set_should_work()
+        {
+            var subject = new AggregateExplainOperation(_collectionNamespace, __pipeline, _messageEncoderSettings);
+            var value = new BsonDocument("x", 1);
+
+            subject.Hint = value;
+            var result = subject.Hint;
+
+            result.Should().BeSameAs(value);
+        }
+
         [Fact]
         public void MaxTime_get_and_set_should_work()
         {
@@ -168,6 +192,53 @@ public void CreateCommand_should_return_expected_result_when_Collation_is_set(
             result.Should().Be(expectedResult);
         }
 
+        [Theory]
+        [ParameterAttributeData]
+        public void CreateCommand_should_return_expected_result_when_Comment_is_set(
+            [Values(null, "test")]
+            string comment)
+        {
+            var subject = new AggregateExplainOperation(_collectionNamespace, __pipeline, _messageEncoderSettings)
+            {
+                Comment = comment,
+            };
+
+            var result = subject.CreateCommand(null);
+
+            var expectedResult = new BsonDocument
+            {
+                { "aggregate", _collectionNamespace.CollectionName },
+                { "explain", true },
+                { "pipeline", new BsonArray(__pipeline) },
+                { "comment", () => comment, comment != null }
+            };
+            result.Should().Be(expectedResult);
+        }
+
+        [Theory]
+        [ParameterAttributeData]
+        public void CreateCommand_should_return_the_expected_result_when_Hint_is_set(
+            [Values(null, "{x: 1}")]
+            string hintJson)
+        {
+            var hint = hintJson == null ? null : BsonDocument.Parse(hintJson);
+            var subject = new AggregateExplainOperation(_collectionNamespace, __pipeline, _messageEncoderSettings)
+            {
+                Hint = hint
+            };
+
+            var result = subject.CreateCommand(null);
+
+            var expectedResult = new BsonDocument
+            {
+                { "aggregate", _collectionNamespace.CollectionName },
+                { "explain", true },
+                { "pipeline", new BsonArray(__pipeline) },
+                { "hint", () => hint, hint != null }
+            };
+            result.Should().Be(expectedResult);
+        }
+
         [SkippableTheory]
         [ParameterAttributeData]
         public void CreateCommand_should_return_expected_result_when_MaxTime_is_set(
@@ -270,6 +341,49 @@ public void Execute_should_throw_when_Collation_is_set_but_not_supported(
             exception.Should().BeOfType<NotSupportedException>();
         }
 
+        [SkippableTheory]
+        [ParameterAttributeData]
+        public void Execute_should_return_expected_result_when_Comment_is_set(
+            [Values(false, true)]
+            bool async)
+        {
+            RequireServer.Check()
+                .ClusterTypes(ClusterType.Standalone, ClusterType.ReplicaSet)
+                .Supports(Feature.AggregateExplain, Feature.AggregateComment);
+            var subject = new AggregateExplainOperation(_collectionNamespace, __pipeline, _messageEncoderSettings)
+            {
+                Comment = "test"
+            };
+
+            using (var profile = Profile(_collectionNamespace.DatabaseNamespace))
+            {
+                var result = ExecuteOperation(subject, async);
+
+                result.Should().NotBeNull();
+
+                var profileEntries = profile.Find(new BsonDocument("command.aggregate", new BsonDocument("$exists", true)));
+                profileEntries.Should().HaveCount(1);
+                profileEntries[0]["command"]["comment"].AsString.Should().Be(subject.Comment);
+            }
+        }
+
+        [SkippableTheory]
+        [ParameterAttributeData]
+        public void Execute_should_return_expected_result_when_Hint_is_set(
+            [Values(false, true)]
+            bool async)
+        {
+            RequireServer.Check().Supports(Feature.AggregateExplain, Feature.AggregateHint);
+            var subject = new AggregateExplainOperation(_collectionNamespace, __pipeline, _messageEncoderSettings)
+            {
+                Hint = "_id_"
+            };
+
+            var result = ExecuteOperation(subject, async);
+
+            result.Should().NotBeNull();
+        }
+
         [SkippableTheory]
         [ParameterAttributeData]
         public void Execute_should_return_expected_result_when_MaxTime_is_set(