CSHARP-5572: Work in progress

Author: rstam

src/MongoDB.Driver/Linq/Linq3Implementation/KnownSerializerFinders/KnownSerializerFinderVisitMember.cs

@@ -17,13 +17,12 @@
 using System.Collections;
 using System.Collections.Generic;
 using System.Linq.Expressions;
-using System.Reflection;
 using MongoDB.Bson;
 using MongoDB.Bson.Serialization;
 using MongoDB.Bson.Serialization.Options;
 using MongoDB.Bson.Serialization.Serializers;
 using MongoDB.Driver.Linq.Linq3Implementation.Misc;
-using MongoDB.Driver.Support;
+using MongoDB.Driver.Linq.Linq3Implementation.Serializers;
 
 namespace MongoDB.Driver.Linq.Linq3Implementation.KnownSerializerFinders;
 
@@ -50,6 +49,8 @@ protected override Expression VisitMember(MemberExpression node)
                     _ when declaringType == typeof(BsonValue) => GetBsonValuePropertySerializer(),
                     _ when IsCollectionCountOrLengthProperty() => GetCollectionCountOrLengthPropertySerializer(),
                     _ when declaringType == typeof(DateTime) => GetDateTimePropertySerializer(),
+                    _ when declaringType.IsConstructedGenericType && declaringType.GetGenericTypeDefinition() == typeof(Dictionary<,>) => GetDictionaryPropertySerializer(),
+                    _ when declaringType.IsConstructedGenericType && declaringType.GetGenericTypeDefinition() == typeof(IDictionary<,>) => GetIDictionaryPropertySerializer(),
                     _ when declaringType.IsNullable() => GetNullablePropertySerializer(),
                     _ when IsTupleOrValueTuple(declaringType) => GetTupleOrValueTuplePropertySerializer(),
                     _ => GetPropertySerializer()
@@ -136,6 +137,42 @@ IBsonSerializer GetDateTimePropertySerializer()
             };
         }
 
+        IBsonSerializer GetDictionaryPropertySerializer()
+        {
+            if (containingSerializer.Unwrapped() is not IBsonDictionarySerializer dictionarySerializer)
+            {
+                throw new ExpressionNotSupportedException(node, because: "DictionarySerializer does not implement IBsonDictionarySerializer");
+            }
+
+            var keySerializer =  dictionarySerializer.KeySerializer;
+            var valueSerializer = dictionarySerializer.ValueSerializer;
+
+            return memberName switch
+            {
+                "Keys" => DictionaryKeyCollectionSerializer.Create(keySerializer, valueSerializer),
+                "Values" => DictionaryValueCollectionSerializer.Create(keySerializer, valueSerializer),
+                _ => throw new ExpressionNotSupportedException(node, because: $"Unexpected member name: {memberName}")
+            };
+        }
+
+        IBsonSerializer GetIDictionaryPropertySerializer()
+        {
+            if (containingSerializer is not IBsonDictionarySerializer dictionarySerializer)
+            {
+                throw new ExpressionNotSupportedException(node, because: "IDictionarySerializer does not implement IBsonDictionarySerializer");
+            }
+
+            var keySerializer =  dictionarySerializer.KeySerializer;
+            var valueSerializer = dictionarySerializer.ValueSerializer;
+
+            return memberName switch
+            {
+                "Keys" => ICollectionSerializer.Create(keySerializer),
+                "Values" => ICollectionSerializer.Create(valueSerializer),
+                _ => throw new ExpressionNotSupportedException(node, because: $"Unexpected member name: {memberName}")
+            };
+        }
+
         IBsonSerializer GetNullablePropertySerializer()
         {
             return memberName switch

src/MongoDB.Driver/Linq/Linq3Implementation/KnownSerializerFinders/KnownSerializerFinderVisitMethodCall.cs

@@ -794,7 +794,6 @@ void DeduceMethodCallSerializers()
                 case "Atan": DeduceAtanMethodSerializers(); break;
                 case "Atanh": DeduceAtanhMethodSerializers(); break;
                 case "Atan2": DeduceAtan2MethodSerializers(); break;
-                case "CompareTo": DeduceCompareToMethodSerializers(); break;
                 case "Concat": DeduceConcatMethodSerializers(); break;
                 case "Constant": DeduceConstantMethodSerializers(); break;
                 case "Contains": DeduceContainsMethodSerializers(); break;
@@ -889,6 +888,11 @@ void DeduceMethodCallSerializers()
                     DeduceCeilingOrFloorMethodSerializers();
                     break;
 
+                case "Compare":
+                case "CompareTo":
+                    DeduceCompareOrCompareToMethodSerializers();
+                    break;
+
                 case "Count":
                 case "LongCount":
                     DeduceCountMethodSerializers();
@@ -1440,31 +1444,21 @@ void DeduceCeilingOrFloorMethodSerializers()
             }
         }
 
-        void DeduceCompareToMethodSerializers()
+        void DeduceCompareOrCompareToMethodSerializers()
         {
-            if (IsCompareToMethod())
+            if (method.IsStaticCompareMethod() ||
+                method.IsInstanceCompareToMethod() ||
+                method.IsOneOf(StringMethod.StaticCompare, StringMethod.StaticCompareWithIgnoreCase))
             {
-                var objectExpression = node.Object;
-                var valueExpression = arguments[0];
-
-                DeduceSerializers(objectExpression, valueExpression);
+                var valueExpression = method.IsStatic ? arguments[0] : node.Object;
+                var comparandExpression = method.IsStatic ? arguments[1] : arguments[0];
+                DeduceSerializers(valueExpression, comparandExpression);
                 DeduceReturnsInt32Serializer();
             }
             else
             {
                 DeduceUnknownMethodSerializer();
             }
-
-            bool IsCompareToMethod()
-            {
-                return
-                    method.IsPublic &&
-                    method.IsStatic == false &&
-                    method.ReturnType == typeof(int) &&
-                    method.Name == "CompareTo" &&
-                    arguments.Count == 1 &&
-                    arguments[0].Type == node.Object.Type;
-            }
         }
 
         void DeduceConcatMethodSerializers()

src/MongoDB.Driver/Linq/Linq3Implementation/Misc/IBsonSerializerExtensions.cs

@@ -157,4 +157,9 @@ serializer is IBsonDocumentSerializer documentSerializer &&
         valueSerializer = null;
         return false;
     }
+
+    public static IBsonSerializer Unwrapped(this IBsonSerializer serializer)
+    {
+        return serializer is IWrappedValueSerializer wrappedValueSerializer ? wrappedValueSerializer.ValueSerializer.Unwrapped() :  serializer;
+    }
 }