Fix conditional expression evaluation in ParameterExtractingEV

Fixes #17942
dotnet · Oct 29, 2019 · 7cdf25b · 7cdf25b
1 parent 45adf14
commit 7cdf25b
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diff --git a/src/EFCore/Query/Internal/ParameterExtractingExpressionVisitor.cs b/src/EFCore/Query/Internal/ParameterExtractingExpressionVisitor.cs
@@ -143,6 +143,30 @@ private bool PreserveConvertNode(Expression expression)
             return false;
         }
 
+        /// <summary>
+        ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+        ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+        ///     any release. You should only use it directly in your code with extreme caution and knowing that
+        ///     doing so can result in application failures when updating to a new Entity Framework Core release.
+        /// </summary>
+        protected override Expression VisitConditional(ConditionalExpression conditionalExpression)
+        {
+            var newTestExpression = TryGetConstantValue(conditionalExpression.Test) ?? Visit(conditionalExpression.Test);
+
+            if (newTestExpression is ConstantExpression constantTestExpression
+                && constantTestExpression.Value is bool constantTestValue)
+            {
+                return constantTestValue
+                    ? Visit(conditionalExpression.IfTrue)
+                    : Visit(conditionalExpression.IfFalse);
+            }
+
+            return conditionalExpression.Update(
+                newTestExpression,
+                Visit(conditionalExpression.IfTrue),
+                Visit(conditionalExpression.IfFalse));
+        }
+
         /// <summary>
         ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
         ///     the same compatibility standards as public APIs. It may be changed or removed without notice in

diff --git a/test/EFCore.Specification.Tests/Query/SimpleQueryTestBase.cs b/test/EFCore.Specification.Tests/Query/SimpleQueryTestBase.cs
@@ -824,6 +824,24 @@ public virtual Task Ternary_should_not_evaluate_both_sides(bool isAsync)
                     }));
         }
 
+        [ConditionalTheory]
+        [MemberData(nameof(IsAsyncData))]
+        public virtual Task Ternary_should_not_evaluate_both_sides_with_parameter(bool isAsync)
+        {
+            DateTime? param = null;
+
+            return AssertQuery(
+                isAsync,
+                ss => ss.Set<Order>().Select(
+                    o => new
+                    {
+                        // ReSharper disable SimplifyConditionalTernaryExpression
+                        Data1 = param != null ? o.OrderDate == param.Value : true,
+                        Data2 = param == null ? true : o.OrderDate == param.Value
+                        // ReSharper restore SimplifyConditionalTernaryExpression
+                    }));
+        }
+
         [ConditionalTheory]
         [MemberData(nameof(IsAsyncData))]
         public virtual Task Null_Coalesce_Short_Circuit(bool isAsync)

diff --git a/test/EFCore.SqlServer.FunctionalTests/Query/SimpleQuerySqlServerTest.Where.cs b/test/EFCore.SqlServer.FunctionalTests/Query/SimpleQuerySqlServerTest.Where.cs
@@ -1450,6 +1450,15 @@ public override async Task Ternary_should_not_evaluate_both_sides(bool isAsync)
 FROM [Customers] AS [c]");
         }
 
+        public override async Task Ternary_should_not_evaluate_both_sides_with_parameter(bool isAsync)
+        {
+            await base.Ternary_should_not_evaluate_both_sides_with_parameter(isAsync);
+
+            AssertSql(
+                @"SELECT CAST(1 AS bit) AS [Data1]
+FROM [Orders] AS [o]");
+        }
+
         public override async Task Where_compare_constructed_multi_value_equal(bool isAsync)
         {
             await base.Where_compare_constructed_multi_value_equal(isAsync);