Added nested filter

Saule/Queries/Lambda.cs

@@ -24,9 +24,13 @@ public static Expression SelectPropertyValue(Type type, string property, List<st
             }
 
             var param = Expression.Parameter(type, "i");
-            var propertyExpression = Expression.Property(param, property);
+            Expression propertyExpression = param;
+            foreach (var member in property.Split('.'))
+            {
+                propertyExpression = Expression.PropertyOrField(propertyExpression, member);
+            }
 
-            var expression = queryFilter.GetQueryFilterExpression(type.GetProperty(property));
+            var expression = queryFilter.GetQueryFilterExpression(GetPropertyInfo(type, property));
 
             return typeof(Lambda)
                 .GetMethod(nameof(Convert), BindingFlags.Static | BindingFlags.NonPublic)
@@ -74,17 +78,42 @@ private static Expression<Func<TClass, bool>> Convert<TProperty, TClass>(
 
         private static Type GetPropertyType(Type type, string property)
         {
-            var returnType = type.GetProperty(property)?.PropertyType;
-            if (returnType == null)
+            List<string> properties = property.Split('.').ToList();
+            var returnType = type;
+            foreach (string prop in properties)
             {
-                throw new ArgumentException(
-                    $"Property {property} does not exist.",
-                    nameof(property));
+                returnType = returnType.GetProperty(prop)?.PropertyType;
+                if (returnType == null)
+                {
+                    throw new ArgumentException(
+                        $"Property {property} does not exist.",
+                        nameof(property));
+                }
             }
 
             return returnType;
         }
 
+        private static PropertyInfo GetPropertyInfo(Type type, string property)
+        {
+            List<string> properties = property.Split('.').ToList();
+            var tmpType = type;
+            PropertyInfo propertyInfo = tmpType.GetProperty(property);
+            foreach (string prop in properties)
+            {
+                propertyInfo = tmpType.GetProperty(prop);
+                tmpType = tmpType.GetProperty(prop)?.PropertyType;
+                if (tmpType == null)
+                {
+                    throw new ArgumentException(
+                        $"Property {property} does not exist.",
+                        nameof(property));
+                }
+            }
+
+            return propertyInfo;
+        }
+
         private static MethodInfo CreateExpressionFactory(Type funcType)
         {
             var expressionFactory = typeof(Expression).GetMethods()

Tests/Helpers/Get.cs

@@ -32,6 +32,11 @@ internal static class Get
             "North Street", "Heritage Drive", "Cooper Street", "Route 44",
         };
 
+        private static readonly string[] CompanyNames =
+        {
+            "Awesome Inc.", "Seen Better Days Co", "Stock Inc.", "Bookstore", "Office Supplies",
+        };
+
         public static IEnumerable<Person> People()
         {
             var i = 0;
@@ -95,6 +100,7 @@ public static Company Company(string id = "456")
         {
             return new Company(prefill: true, id: id)
             {
+                Name = CompanyNames[random.Next(CompanyNames.Length)],
                 Location = (LocationType)random.Next(Enum.GetNames(typeof(LocationType)).Length)
             };
         }

Tests/Queries/FilterInterpreterTests.cs

@@ -151,13 +151,25 @@ public void WorksOnStrings()
             Assert.Equal(expected, result);
         }
 
+        [Fact(DisplayName = "Applies nested filtering on strings")]
+        public void WorksOnNestedStrings()
+        {
+            var people = Get.People(100).ToList().AsQueryable();
+            var expected = people.Where(c => c.Job.Name == "Bookstore").ToList();
+            var query = GetQuery(new[] { "Job.Name" }, new[] { "Bookstore" });
+            var result = Query.ApplyFiltering(people, new FilterContext(query), new PersonResource())
+                as IQueryable<Person>;
+
+            Assert.Equal(expected, result);
+        }
+
         [Fact(DisplayName = "Applies filtering on strings with spaces")]
         public void WorksOnStringsWithSpaces()
         {
             var companies = Get.Companies(100).ToList().AsQueryable();
             var expected = companies.Where(c => c.Name == "Awesome Inc.").ToList();
 
-            var query = GetQuery(new[] { "Name" }, new[] { "Aweseom Inc." });
+            var query = GetQuery(new[] { "Name" }, new[] { "Awesome Inc." });
 
             var result = Query.ApplyFiltering(companies, new FilterContext(query), new CompanyResource())
                 as IQueryable<Company>;