support for rewriting null conditional access expressions

src/EntityFrameworkCore.Projectables.Abstractions/NullConditionalRewriteSupport.cs

@@ -0,0 +1,30 @@
+namespace EntityFrameworkCore.Projectables
+{
+    /// <summary>
+    /// Configures how null-conditional operators are handeled
+    /// </summary>
+    public enum NullConditionalRewriteSupport
+    {
+        /// <summary>
+        /// Don't rewrite null conditional operators (Default behavior).
+        /// Usage of null conditional operators is thereby not allowed
+        /// </summary>
+        None,
+
+        /// <summary>
+        /// Ignore null-conditional operators in the generated expression tree
+        /// </summary>
+        /// <remarks>
+        /// <c>(A?.B)</c> is rewritten as expression: <c>(A.B)</c>
+        /// </remarks>
+        Ignore,
+
+        /// <summary>
+        /// Translates null-conditional operators into explicit null checks
+        /// </summary>
+        /// <remarks>
+        /// <c>(A?.B)</c> is rewritten as expression: <c>(A != null ? A.B : null)</c>
+        /// </remarks>
+        Rewrite
+    }
+}

src/EntityFrameworkCore.Projectables.Abstractions/ProjectableAttribute.cs

@@ -9,5 +9,6 @@ namespace EntityFrameworkCore.Projectables
     [AttributeUsage(AttributeTargets.Method | AttributeTargets.Property, Inherited = true, AllowMultiple = false)]
     public sealed class ProjectableAttribute : Attribute
     {
+        public NullConditionalRewriteSupport NullConditionalRewriteSupport { get; set; }
     }
 }