Fix IReadOnlyDictionary<,> (#495)

Author: StefH

src/System.Linq.Dynamic.Core/Parser/ExpressionParser.cs

@@ -1754,7 +1754,7 @@ Expression ParseMemberAccess(Type type, Expression expression)
         Expression ParseEnumerable(Expression instance, Type elementType, string methodName, int errorPos, Type type)
         {
             bool isQueryable = TypeHelper.FindGenericType(typeof(IQueryable<>), type) != null;
-            bool isDictionary = TypeHelper.FindGenericType(typeof(IDictionary<,>), type) != null;
+            bool isDictionary = TypeHelper.IsDictionary(type);
 
             var oldParent = _parent;
 

src/System.Linq.Dynamic.Core/Parser/TypeHelper.cs

@@ -17,10 +17,13 @@ public static Type FindGenericType(Type generic, Type type)
 
                 if (generic.GetTypeInfo().IsInterface)
                 {
-                    foreach (Type intfType in type.GetInterfaces())
+                    foreach (Type interfaceType in type.GetInterfaces())
                     {
-                        Type found = FindGenericType(generic, intfType);
-                        if (found != null) return found;
+                        Type found = FindGenericType(generic, interfaceType);
+                        if (found != null)
+                        {
+                            return found;
+                        }
                     }
                 }
 
@@ -440,5 +443,16 @@ public static object ParseEnum(string value, Type type)
 
             return null;
         }
+
+        public static bool IsDictionary(Type type)
+        {
+            return
+                FindGenericType(typeof(IDictionary<,>), type) != null ||
+#if NET35 || NET40
+                false;
+#else
+                FindGenericType(typeof(IReadOnlyDictionary<,>), type) != null;
+#endif
+        }
     }
 }

test/System.Linq.Dynamic.Core.Tests/MikArea/Dictionary.cs

@@ -1,5 +1,6 @@
-using System.Collections.Generic;
-using System.Dynamic;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
 using System.Linq.Expressions;
 using FluentAssertions;
 using NFluent;
@@ -13,6 +14,7 @@ public class Customer
         {
             public string City { get; set; }
             public Dictionary<string, Order> Orders { get; set; }
+            public IReadOnlyDictionary<string, Order> ReadOnlyOrders { get; set; }
             public string CompanyName { get; set; }
             public string Phone { get; set; }
         }
@@ -22,13 +24,32 @@ public class Order
         }
 
         [Fact]
-        public void Test_ContainsKey_1()
+        public void ReadOnlyDictionary_ContainsKey_1()
         {
-            var customers = new List<Customer>()
+            var orders = new ReadOnlyDictionary<string, Order>(new Dictionary<string, Order>
             {
-                new Customer() { City = "ZZZ1", CompanyName = "ZZZ", Orders = new Dictionary<string, Order>() },
-                new Customer() { City = "ZZZ2", CompanyName = "ZZZ", Orders = new Dictionary<string, Order>()  },
-                new Customer() { City = "ZZZ3", CompanyName = "ZZZ", Orders = new Dictionary<string, Order>()  }
+                { "TEST", new Order() }
+            });
+            var customers = new List<Customer>
+            {
+                new Customer { City = "abc", CompanyName = "ZZZ", ReadOnlyOrders = orders }
+            };
+
+            var data = customers.AsQueryable()
+                .Where("ReadOnlyOrders.ContainsKey(\"TEST\")")
+                .ToList();
+
+            data.Should().HaveCount(1);
+        }
+
+        [Fact]
+        public void Dictionary_ContainsKey_1()
+        {
+            var customers = new List<Customer>
+            {
+                new Customer { City = "ZZZ1", CompanyName = "ZZZ", Orders = new Dictionary<string, Order>() },
+                new Customer { City = "ZZZ2", CompanyName = "ZZZ", Orders = new Dictionary<string, Order>() },
+                new Customer { City = "ZZZ3", CompanyName = "ZZZ", Orders = new Dictionary<string, Order>() }
             };
             customers.ForEach(x => x.Orders.Add(x.City + "TEST", new Order()));
 
@@ -41,13 +62,13 @@ public void Test_ContainsKey_1()
         }
 
         [Fact]
-        public void Test_ContainsKey_2()
+        public void Dictionary_ContainsKey_2()
         {
-            var customers = new List<Customer>()
+            var customers = new List<Customer>
             {
-                new Customer() { City = "ZZZ1", CompanyName = "ZZZ", Orders = new Dictionary<string, Order>() },
-                new Customer() { City = "ZZZ2", CompanyName = "ZZZ", Orders = new Dictionary<string, Order>()  },
-                new Customer() { City = "ZZZ3", CompanyName = "ZZZ", Orders = new Dictionary<string, Order>()  }
+                new Customer { City = "ZZZ1", CompanyName = "ZZZ", Orders = new Dictionary<string, Order>() },
+                new Customer { City = "ZZZ2", CompanyName = "ZZZ", Orders = new Dictionary<string, Order>() },
+                new Customer { City = "ZZZ3", CompanyName = "ZZZ", Orders = new Dictionary<string, Order>() }
             };
             customers.ForEach(x => x.Orders.Add(x.City + "TEST", new Order()));
 
@@ -61,13 +82,13 @@ public void Test_ContainsKey_2()
         }
 
         [Fact]
-        public void Test_ContainsKey_3()
+        public void Dictionary_ContainsKey_3()
         {
-            var customers = new List<Customer>()
+            var customers = new List<Customer>
             {
-                new Customer() { City = "ZZZ1", CompanyName = "ZZZ", Orders = new Dictionary<string, Order>() },
-                new Customer() { City = "ZZZ2", CompanyName = "ZZZ", Orders = new Dictionary<string, Order>()  },
-                new Customer() { City = "ZZZ3", CompanyName = "ZZZ", Orders = new Dictionary<string, Order>()  }
+                new Customer { City = "ZZZ1", CompanyName = "ZZZ", Orders = new Dictionary<string, Order>() },
+                new Customer { City = "ZZZ2", CompanyName = "ZZZ", Orders = new Dictionary<string, Order>() },
+                new Customer { City = "ZZZ3", CompanyName = "ZZZ", Orders = new Dictionary<string, Order>() }
             };
             customers.ForEach(x => x.Orders.Add(x.City + "TEST1", new Order()));
             customers.ForEach(x => x.Orders.Add(x.City + "TEST2", new Order()));
@@ -91,7 +112,7 @@ public void Test_ContainsKey_3()
 #else
         [Fact(Skip = "Fails in NET452 CI")]
 #endif
-        public void Test_DynamicIndexCall() // https://github.com/zzzprojects/System.Linq.Dynamic.Core/issues/397
+        public void DynamicIndexCall() // https://github.com/zzzprojects/System.Linq.Dynamic.Core/issues/397
         {
             object CreateDicParameter(string name) => new Dictionary<string, object>
             {