Updated EnableQuery filter to check if return type is a collection

.editorconfig

@@ -0,0 +1,7 @@
+; Top-most EditorConfig file
+root = true
+
+; 4-column space indention
+[*.cs]
+indent_style = space
+indent_size = 4

Swashbuckle.OData.Tests/Fixtures/GetTests.cs

@@ -62,6 +62,46 @@ public async Task It_has_all_optional_odata_query_parameters()
             }
         }
 
+        [Test]
+        public async Task It_has_collection_odata_query_parameters()
+        {
+            using (WebApp.Start(HttpClientUtils.BaseAddress, appBuilder => Configuration(appBuilder, typeof(CustomersController))))
+            {
+                // Arrange
+                var httpClient = HttpClientUtils.GetHttpClient(HttpClientUtils.BaseAddress);
+
+                // Act
+                var swaggerDocument = await httpClient.GetJsonAsync<SwaggerDocument>("swagger/docs/v1");
+
+                // Assert
+                PathItem pathItem;
+                swaggerDocument.paths.TryGetValue("/odata/Customers", out pathItem);
+                pathItem.get.parameters.Where(parameter => parameter.name.StartsWith("$")).Should().HaveCount(7);
+
+                await ValidationUtils.ValidateSwaggerJson();
+            }
+        }
+
+        [Test]
+        public async Task It_has_single_entity_odata_query_parameters()
+        {
+            using (WebApp.Start(HttpClientUtils.BaseAddress, appBuilder => Configuration(appBuilder, typeof(CustomersController))))
+            {
+                // Arrange
+                var httpClient = HttpClientUtils.GetHttpClient(HttpClientUtils.BaseAddress);
+
+                // Act
+                var swaggerDocument = await httpClient.GetJsonAsync<SwaggerDocument>("swagger/docs/v1");
+
+                // Assert
+                PathItem pathItem;
+                swaggerDocument.paths.TryGetValue("/odata/Customers({Id})", out pathItem);
+                pathItem.get.parameters.Where(parameter => parameter.name.StartsWith("$")).Should().HaveCount(2);
+
+                await ValidationUtils.ValidateSwaggerJson();
+            }
+        }
+
         [Test]
         public async Task It_has_a_parameter_with_a_name_equal_to_the_path_name()
         {

Swashbuckle.OData/Descriptions/ODataSwaggerUtilities.cs

@@ -35,7 +35,7 @@ public static PathItem CreateSwaggerPathForEntitySet(IEdmEntitySet entitySet)
                 .OperationId(entitySet.Name + "_Get")
                 .Description("Returns the EntitySet " + entitySet.Name)
                 .Tags(entitySet.Name)
-                .Parameters(AddQueryOptionParameters(new List<Parameter>()))
+                .Parameters(AddQueryOptionParametersForEntitySet(new List<Parameter>()))
                 .Responses(new Dictionary<string, Response>().Response("200", "EntitySet " + entitySet.Name, entitySet.Type).DefaultErrorResponse()),
                 post = new Operation()
                 .Summary("Post a new entity to EntitySet " + entitySet.Name)
@@ -48,7 +48,7 @@ public static PathItem CreateSwaggerPathForEntitySet(IEdmEntitySet entitySet)
             };
         }
 
-        public static IList<Parameter> AddQueryOptionParameters(IList<Parameter> parameterList)
+        public static IList<Parameter> AddQueryOptionParametersForEntitySet(IList<Parameter> parameterList)
         {
             return parameterList
                 .Parameter("$expand", "query", "Expands related entities inline.", "string", false)
@@ -60,12 +60,19 @@ public static IList<Parameter> AddQueryOptionParameters(IList<Parameter> paramet
                 .Parameter("$count", "query", "Includes a count of the matching results in the response.", "boolean", false);
         }
 
-        /// <summary>
-        /// Create the Swagger path for the Edm entity.
-        /// </summary>
-        /// <param name="entitySet">The entity set.</param>
-        /// <returns></returns>
-        public static PathItem CreateSwaggerPathForEntity(IEdmEntitySet entitySet)
+        public static IList<Parameter> AddQueryOptionParametersForEntity(IList<Parameter> parameterList)
+        {
+            return parameterList
+                .Parameter("$expand", "query", "Expands related entities inline.", "string", false)
+                .Parameter("$select", "query", "Selects which properties to include in the response.", "string", false);
+        }
+
+    /// <summary>
+    /// Create the Swagger path for the Edm entity.
+    /// </summary>
+    /// <param name="entitySet">The entity set.</param>
+    /// <returns></returns>
+    public static PathItem CreateSwaggerPathForEntity(IEdmEntitySet entitySet)
         {
             Contract.Requires(entitySet != null);
             Contract.Ensures(Contract.Result<PathItem>() != null);

Swashbuckle.OData/EnableQueryFilter.cs

@@ -5,6 +5,8 @@
 using System.Web.OData;
 using Swashbuckle.OData.Descriptions;
 using Swashbuckle.Swagger;
+using System.Web.Http;
+using System;
 
 namespace Swashbuckle.OData
 {
@@ -21,7 +23,9 @@ public void Apply(Operation operation, SchemaRegistry schemaRegistry, ApiDescrip
 
             if (HasEnableQueryAttribute(apiDescription) && !HasAnyQueryOptionParameters(operation))
             {
-                operation.parameters = ODataSwaggerUtilities.AddQueryOptionParameters(operation.parameters ?? new List<Parameter>());
+                operation.parameters = ReturnsCollection(apiDescription) 
+                    ? ODataSwaggerUtilities.AddQueryOptionParametersForEntitySet(operation.parameters ?? new List<Parameter>())
+                    : ODataSwaggerUtilities.AddQueryOptionParametersForEntity(operation.parameters ?? new List<Parameter>()); 
             }
         }
 
@@ -36,5 +40,21 @@ private static bool HasEnableQueryAttribute(ApiDescription apiDescription)
             Contract.Assume(httpActionDescriptor != null);
             return httpActionDescriptor.GetCustomAttributes<EnableQueryAttribute>().Any();
         }
+
+        private static bool ReturnsCollection(ApiDescription apiDescription)
+        {
+            var httpActionDescriptor = apiDescription.ActionDescriptor;
+            Contract.Assume(httpActionDescriptor != null);
+
+            Type returnType = httpActionDescriptor.ReturnType;
+
+            var responseTypeAttr = httpActionDescriptor.GetCustomAttributes<ResponseTypeAttribute>().FirstOrDefault();
+            if (responseTypeAttr != null)
+                returnType = responseTypeAttr.ResponseType;
+
+            return returnType.IsCollection();
+        }
+
+
     }
 }