From 3dbc90406cd10481b84e78f73a379fa112c847f5 Mon Sep 17 00:00:00 2001
From: Gian Maria Ricci <alkampfer@nablasoft.com>
Date: Fri, 14 Aug 2020 16:55:28 +0200
Subject: [PATCH 1/3] Fix: Better error when no constructor found

---
 .../Serialization/Serializers/BsonClassMapSerializer.cs         | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/MongoDB.Bson/Serialization/Serializers/BsonClassMapSerializer.cs b/src/MongoDB.Bson/Serialization/Serializers/BsonClassMapSerializer.cs
index e2c7d6dfe6b..4e9df5081e4 100644
--- a/src/MongoDB.Bson/Serialization/Serializers/BsonClassMapSerializer.cs
+++ b/src/MongoDB.Bson/Serialization/Serializers/BsonClassMapSerializer.cs
@@ -414,7 +414,7 @@ private BsonCreatorMap ChooseBestCreator(Dictionary<string, object> values)
 
             if (creatorMap == null)
             {
-                throw new BsonSerializationException("No matching creator found.");
+                throw new BsonSerializationException($"No matching creator found for class {_classMap.ClassType.FullName}.");
             }
 
             return creatorMap;

From 53854aaf4669e8c5affca7c7ccc42f3ec20014ee Mon Sep 17 00:00:00 2001
From: Oleksandr Poliakov <oleksandr.poliakov@mongodb.com>
Date: Thu, 14 Mar 2024 11:30:45 -0700
Subject: [PATCH 2/3] Add unit test

---
 .../BsonClassMapSerializerTests.cs            | 32 +++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/tests/MongoDB.Bson.Tests/Serialization/BsonClassMapSerializerTests.cs b/tests/MongoDB.Bson.Tests/Serialization/BsonClassMapSerializerTests.cs
index f04507eabdf..4b6a7c55cee 100644
--- a/tests/MongoDB.Bson.Tests/Serialization/BsonClassMapSerializerTests.cs
+++ b/tests/MongoDB.Bson.Tests/Serialization/BsonClassMapSerializerTests.cs
@@ -39,10 +39,42 @@ public void Deserialize_should_throw_invalidOperationException_when_creator_retu
             exception.Should().BeOfType<BsonSerializationException>();
         }
 
+        [Fact]
+        public void Deserialize_should_throw_when_no_creators_found()
+        {
+            var bsonClassMap = new BsonClassMap<ModelWithCtor>();
+            bsonClassMap.AutoMap();
+            bsonClassMap.Freeze();
+
+            var subject = new BsonClassMapSerializer<ModelWithCtor>(bsonClassMap);
+
+            using var reader = new JsonReader("{ \"_id\": \"just_an_id\" }");
+            var context = BsonDeserializationContext.CreateRoot(reader);
+
+            var exception = Record.Exception(() => subject.Deserialize(context));
+            exception.Should().BeOfType<BsonSerializationException>()
+                .Subject.Message.Should().Be($"No matching creator found for class {typeof(ModelWithCtor).FullName}");
+        }
+
         // nested classes
         private class MyModel
         {
             public string Id { get; set; }
         }
+
+        private class ModelWithCtor
+        {
+            private readonly string _myId;
+            private readonly int _i;
+
+            public ModelWithCtor(string id, int i)
+            {
+                _myId = id;
+                _i = i;
+            }
+
+            public string Id => _myId;
+            public int I => _i;
+        }
     }
 }

From ea77ff21850ce820e2a284c4819f6b004c45a76c Mon Sep 17 00:00:00 2001
From: Oleksandr Poliakov <31327136+sanych-sun@users.noreply.github.com>
Date: Thu, 14 Mar 2024 12:03:45 -0700
Subject: [PATCH 3/3] Update BsonClassMapSerializerTests.cs

---
 .../Serialization/BsonClassMapSerializerTests.cs                | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/MongoDB.Bson.Tests/Serialization/BsonClassMapSerializerTests.cs b/tests/MongoDB.Bson.Tests/Serialization/BsonClassMapSerializerTests.cs
index 4b6a7c55cee..a9b836302a1 100644
--- a/tests/MongoDB.Bson.Tests/Serialization/BsonClassMapSerializerTests.cs
+++ b/tests/MongoDB.Bson.Tests/Serialization/BsonClassMapSerializerTests.cs
@@ -53,7 +53,7 @@ public void Deserialize_should_throw_when_no_creators_found()
 
             var exception = Record.Exception(() => subject.Deserialize(context));
             exception.Should().BeOfType<BsonSerializationException>()
-                .Subject.Message.Should().Be($"No matching creator found for class {typeof(ModelWithCtor).FullName}");
+                .Subject.Message.Should().Be($"No matching creator found for class {typeof(ModelWithCtor).FullName}.");
         }
 
         // nested classes