Add tests and restructure some tests

(#44)

Author: StefH

test/System.Linq.Dynamic.Core.Tests/EntitiesTests.Cast.cs

@@ -0,0 +1,36 @@
+using System.Linq.Dynamic.Core.Tests.Helpers.Models;
+using Xunit;
+
+namespace System.Linq.Dynamic.Core.Tests
+{
+    public partial class EntitiesTests
+    {
+        [Fact]
+        public void Cast_To_nullableint()
+        {
+            // Arrange
+            PopulateTestData(1, 0);
+
+            // Act
+            var expectedResult = _context.Blogs.Select(b => (int?)b.BlogId);
+            var result = _context.Blogs.AsQueryable().Select("int?(BlogId)");
+
+            // Assert
+            Assert.Equal(expectedResult.ToArray(), result.ToDynamicArray<int?>());
+        }
+
+        [Fact]
+        public void Cast_To_newnullableint()
+        {
+            // Arrange
+            PopulateTestData(1, 0);
+
+            // Act
+            var expectedResult = _context.Blogs.Select(x => new { i = (int?)x.BlogId });
+            var result = _context.Blogs.AsQueryable().Select("new (int?(BlogId) as i)");
+           
+            //Assert
+            Assert.Equal(expectedResult.Count(), result.Count());
+        }
+    }
+}