For #15

Added $top
Net-Http-OData · Nov 13, 2020 · dcd6985 · dcd6985
1 parent 8dac37c
commit dcd6985
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Showing 2 changed files with 36 additions and 1 deletion.
diff --git a/Net.Http.OData.Tests/Linq/ODataQueryOptionsExtensionsTests.cs b/Net.Http.OData.Tests/Linq/ODataQueryOptionsExtensionsTests.cs
@@ -308,5 +308,22 @@ public void ApplyTo_Throws_InvalidOperationException_For_Incorrect_QueryType()
 
             Assert.Throws<InvalidOperationException>(() => queryOptions.ApplyTo(_categories.AsQueryable()));
         }
+
+        [Fact]
+        public void ApplyTo_Top()
+        {
+            TestHelper.EnsureEDM();
+
+            var queryOptions = new ODataQueryOptions(
+                "?$top=4",
+                EntityDataModel.Current.EntitySets["Products"],
+                Mock.Of<IODataQueryOptionsValidator>());
+
+            IList<ExpandoObject> results = queryOptions.ApplyTo(_products.AsQueryable()).ToList();
+
+            Assert.Equal(4, results.Count);
+            Assert.Equal(_products[0].ProductId, ((dynamic)results[0]).ProductId);
+            Assert.Equal(_products[3].ProductId, ((dynamic)results[3]).ProductId);
+        }
     }
 }
diff --git a/Net.Http.OData/Linq/ODataQueryOptionsExtensions.cs b/Net.Http.OData/Linq/ODataQueryOptionsExtensions.cs
@@ -121,14 +121,32 @@ private static IEnumerable<ExpandoObject> ApplyToImpl(ODataQueryOptions queryOpt
         {
             IQueryable q = queryable
                 .ApplyOrder(queryOptions)
-                .ApplySkip(queryOptions);
+                .ApplySkip(queryOptions)
+                .ApplyTop(queryOptions);
 
             foreach (object entity in q)
             {
                 yield return BuildExpando(queryOptions, entity);
             }
         }
 
+        private static IQueryable ApplyTop(this IQueryable queryable, ODataQueryOptions queryOptions)
+        {
+            if (queryOptions.Top.HasValue)
+            {
+                MethodCallExpression skipCallExpression = Expression.Call(
+                    typeof(Queryable),
+                    "Take",
+                    new Type[] { queryOptions.EntitySet.EdmType.ClrType },
+                    queryable.Expression,
+                    Expression.Constant(queryOptions.Top.Value));
+
+                return queryable.Provider.CreateQuery(skipCallExpression);
+            }
+
+            return queryable;
+        }
+
         private static ExpandoObject BuildExpando(ODataQueryOptions queryOptions, object entity)
         {
             IEnumerable<PropertyPath> propertyPaths = queryOptions.Select?.PropertyPaths ?? queryOptions.EntitySet.EdmType.Properties.Where(p => !p.IsNavigable).Select(PropertyPath.For);