CSHARP-5691: Non-deterministic functions should not be evaluated client-side

src/MongoDB.Driver/Linq/Linq3Implementation/ExtensionMethods/ExpressionExtensions.cs

@@ -16,12 +16,29 @@
 using System;
 using System.Linq;
 using System.Linq.Expressions;
+using System.Reflection;
 using MongoDB.Bson.Serialization;
+using MongoDB.Driver.Linq.Linq3Implementation.Misc;
+using MongoDB.Driver.Linq.Linq3Implementation.Reflection;
 
 namespace MongoDB.Driver.Linq.Linq3Implementation.ExtensionMethods
 {
     internal static class ExpressionExtensions
     {
+        private readonly static MethodInfo[] __nonDeterministicMethods =
+        [
+            GuidMethod.NewGuid,
+            RandomMethod.Next
+        ];
+
+        private readonly static PropertyInfo[] __nonDeterministicProperties =
+        [
+            DateTimeProperty.Now,
+            DateTimeProperty.Today,
+            DateTimeProperty.UtcNow,
+            DateTimeOffsetProperty.Now,
+            DateTimeOffsetProperty.UtcNow
+        ];
         public static object Evaluate(this Expression expression)
         {
             if (expression is ConstantExpression constantExpression)
@@ -60,5 +77,20 @@ public static TValue GetConstantValue<TValue>(this Expression expression, Expres
             var message = $"Expression must be a constant: {expression} in {containingExpression}.";
             throw new ExpressionNotSupportedException(message);
         }
+
+        public static bool IsNonDeterministic(this Expression expression)
+        {
+            if (expression is MemberExpression memberExpression &&
+                memberExpression.Member is PropertyInfo propertyInfo)
+            {
+                return propertyInfo.IsOneOf(__nonDeterministicProperties);
+            }
+            else if (expression is MethodCallExpression methodCallExpression)
+            {
+                return methodCallExpression.Method.IsOneOf(__nonDeterministicMethods);
+            }
+
+            return false;
+        }
     }
 }

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

@@ -18,6 +18,7 @@
 using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
+using MongoDB.Driver.Linq.Linq3Implementation.ExtensionMethods;
 using MongoDB.Driver.Linq.Linq3Implementation.Reflection;
 
 namespace MongoDB.Driver.Linq.Linq3Implementation.Misc
@@ -207,6 +208,18 @@ protected override Expression VisitListInit(ListInitExpression node)
                 return node;
             }
 
+            protected override Expression VisitMember(MemberExpression node)
+            {
+                var result = base.VisitMember(node);
+
+                if (result.IsNonDeterministic())
+                {
+                    _cannotBeEvaluated = true;
+                }
+
+                return result;
+            }
+
             protected override Expression VisitMemberInit(MemberInitExpression node)
             {
                 // Bindings must be visited before NewExpression
@@ -231,7 +244,8 @@ protected override Expression VisitMethodCall(MethodCallExpression node)
 
                 var method = node.Method;
                 if (IsCustomLinqExtensionMethod(method) ||
-                    method.Is(QueryableMethod.AsQueryable))
+                    method.Is(QueryableMethod.AsQueryable) ||
+                    result.IsNonDeterministic())
                 {
                     _cannotBeEvaluated = true;
                 }

src/MongoDB.Driver/Linq/Linq3Implementation/Reflection/DateTimeOffsetProperty.cs

@@ -0,0 +1,38 @@
+/* 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.Reflection;
+
+namespace MongoDB.Driver.Linq.Linq3Implementation.Reflection
+{
+    internal static class DateTimeOffsetProperty
+    {
+        // private static fields
+        private static readonly PropertyInfo __now;
+        private static readonly PropertyInfo __utcNow;
+
+        // static constructor
+        static DateTimeOffsetProperty()
+        {
+            __now = ReflectionInfo.Property(() => DateTimeOffset.Now);
+            __utcNow = ReflectionInfo.Property(() => DateTimeOffset.UtcNow);
+        }
+
+        // public properties
+        public static PropertyInfo Now => __now;
+        public static PropertyInfo UtcNow => __utcNow;
+    }
+}

src/MongoDB.Driver/Linq/Linq3Implementation/Reflection/DateTimeProperty.cs

@@ -0,0 +1,41 @@
+/* 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.Reflection;
+
+namespace MongoDB.Driver.Linq.Linq3Implementation.Reflection
+{
+    internal static class DateTimeProperty
+    {
+        // private static fields
+        private static readonly PropertyInfo __now;
+        private static readonly PropertyInfo __today;
+        private static readonly PropertyInfo __utcNow;
+
+        // static constructor
+        static DateTimeProperty()
+        {
+            __now = ReflectionInfo.Property(() => DateTime.Now);
+            __today = ReflectionInfo.Property(() => DateTime.Today);
+            __utcNow = ReflectionInfo.Property(() => DateTime.UtcNow);
+        }
+
+        // public properties
+        public static PropertyInfo Now => __now;
+        public static PropertyInfo Today => __today;
+        public static PropertyInfo UtcNow => __utcNow;
+    }
+}

src/MongoDB.Driver/Linq/Linq3Implementation/Reflection/GuidMethod.cs

@@ -0,0 +1,35 @@
+/* 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.Reflection;
+
+namespace MongoDB.Driver.Linq.Linq3Implementation.Reflection
+{
+    internal static class GuidMethod
+    {
+        // private static fields
+        private static readonly MethodInfo __newGuid;
+
+        // static constructor
+        static GuidMethod()
+        {
+            __newGuid = ReflectionInfo.Method(() => Guid.NewGuid());
+        }
+
+        // public properties
+        public static MethodInfo NewGuid => __newGuid;
+    }
+}

src/MongoDB.Driver/Linq/Linq3Implementation/Reflection/RandomMethod.cs

@@ -0,0 +1,35 @@
+/* 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.Reflection;
+
+namespace MongoDB.Driver.Linq.Linq3Implementation.Reflection
+{
+    internal static class RandomMethod
+    {
+        // private static fields
+        private static readonly MethodInfo __next;
+
+        // static constructor
+        static RandomMethod()
+        {
+            __next = ReflectionInfo.Method((Random random) => random.Next());
+        }
+
+        // public properties
+        public static MethodInfo Next => __next;
+    }
+}

src/MongoDB.Driver/Linq/Linq3Implementation/Reflection/ReflectionInfo.cs

@@ -62,6 +62,11 @@ public static ConstructorInfo Constructor<T1, T2, T3, T4, T5, T6, T7, TObject>(E
             return ExtractConstructorInfoFromLambda(lambda);
         }
 
+        public static MethodInfo Method<TResult>(Expression<Func<TResult>> lambda)
+        {
+            return ExtractMethodInfoFromLambda(lambda);
+        }
+
         public static MethodInfo Method<T1, TResult>(Expression<Func<T1, TResult>> lambda)
         {
             return ExtractMethodInfoFromLambda(lambda);
@@ -102,6 +107,11 @@ public static MethodInfo Method<T1, T2, T3, T4, T5, T6, T7, T8, TResult>(Express
             return ExtractMethodInfoFromLambda(lambda);
         }
 
+        public static PropertyInfo Property<TProperty>(Expression<Func<TProperty>> lambda)
+        {
+            return ExtractPropertyInfoFromLambda(lambda);
+        }
+
         public static PropertyInfo Property<TObject, TProperty>(Expression<Func<TObject, TProperty>> lambda)
         {
             return ExtractPropertyInfoFromLambda(lambda);

src/MongoDB.Driver/Linq/Linq3Implementation/Translators/ExpressionToAggregationExpressionTranslators/MemberExpressionToAggregationExpressionTranslator.cs

@@ -23,6 +23,7 @@
 using MongoDB.Bson.Serialization.Options;
 using MongoDB.Bson.Serialization.Serializers;
 using MongoDB.Driver.Linq.Linq3Implementation.Ast.Expressions;
+using MongoDB.Driver.Linq.Linq3Implementation.ExtensionMethods;
 using MongoDB.Driver.Linq.Linq3Implementation.Misc;
 using MongoDB.Driver.Linq.Linq3Implementation.Reflection;
 using MongoDB.Driver.Linq.Linq3Implementation.Serializers;
@@ -36,6 +37,20 @@ public static TranslatedExpression Translate(TranslationContext context, MemberE
         {
             var containerExpression = expression.Expression;
             var member = expression.Member;
+            var declaringType = expression.Member.DeclaringType;
+            var memberName = expression.Member.Name;
+
+            if (containerExpression == null)
+            {
+                // TODO: add support for static properties here
+
+                if (expression.IsNonDeterministic())
+                {
+                    throw new ExpressionNotSupportedException(expression, because: $"non-deterministic field or property '{declaringType.Name}.{memberName}' should not be evaluated client-side and is not currently supported server-side");
+                }
+
+                throw new ExpressionNotSupportedException(expression);
+            }
 
             if (member is PropertyInfo property && property.DeclaringType.IsNullable())
             {

src/MongoDB.Driver/Linq/Linq3Implementation/Translators/ExpressionToAggregationExpressionTranslators/MethodCallExpressionToAggregationExpressionTranslator.cs

@@ -14,6 +14,7 @@
 */
 
 using System.Linq.Expressions;
+using MongoDB.Driver.Linq.Linq3Implementation.ExtensionMethods;
 using MongoDB.Driver.Linq.Linq3Implementation.Translators.ExpressionToAggregationExpressionTranslators.MethodTranslators;
 
 namespace MongoDB.Driver.Linq.Linq3Implementation.Translators.ExpressionToAggregationExpressionTranslators
@@ -22,7 +23,10 @@ internal static class MethodCallExpressionToAggregationExpressionTranslator
     {
         public static TranslatedExpression Translate(TranslationContext context, MethodCallExpression expression)
         {
-            switch (expression.Method.Name)
+            var method = expression.Method;
+            var declaringType = method.DeclaringType;
+
+            switch (method.Name)
             {
                 case "Abs": return AbsMethodToAggregationExpressionTranslator.Translate(context, expression);
                 case "Add": return AddMethodToAggregationExpressionTranslator.Translate(context, expression);
@@ -209,6 +213,11 @@ public static TranslatedExpression Translate(TranslationContext context, MethodC
                     return TrimMethodToAggregationExpressionTranslator.Translate(context, expression);
             }
 
+            if (expression.IsNonDeterministic())
+            {
+                throw new ExpressionNotSupportedException(expression, because: $"non-deterministic method '{declaringType.Name}.{method.Name}' should not be evaluated client-side and is not currently supported server-side");
+            }
+
             throw new ExpressionNotSupportedException(expression);
         }
     }