Allow IFormFile parameters annotated with [FromForm] to be correctly … (#8452)

* Allow IFormFile parameters annotated with [FromForm] to be correctly bound in ApiControllers

Fixes #8311

src/Microsoft.AspNetCore.Mvc.Core/ApplicationModels/InferParameterBindingInfoConvention.cs

@@ -2,7 +2,9 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using System.Collections.Generic;
 using System.Linq;
+using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc.Internal;
 using Microsoft.AspNetCore.Mvc.ModelBinding;
 using Microsoft.AspNetCore.Routing.Template;
@@ -112,7 +114,8 @@ namespace Microsoft.AspNetCore.Mvc.ApplicationModels
                 if (property.BindingInfo != null &&
                     property.BindingInfo.BinderModelName == null &&
                     property.BindingInfo.BindingSource != null &&
-                    !property.BindingInfo.BindingSource.IsGreedy)
+                    !property.BindingInfo.BindingSource.IsGreedy &&
+                    !IsFormFile(property.ParameterType))
                 {
                     var metadata = _modelMetadataProvider.GetMetadataForProperty(
                         controllerModel.ControllerType,
@@ -133,6 +136,7 @@ namespace Microsoft.AspNetCore.Mvc.ApplicationModels
                 if (bindingInfo?.BindingSource != null &&
                     bindingInfo.BinderModelName == null &&
                     !bindingInfo.BindingSource.IsGreedy &&
+                    !IsFormFile(parameter.ParameterType) &&
                     IsComplexTypeParameter(parameter))
                 {
                     parameter.BindingInfo.BinderModelName = string.Empty;
@@ -166,5 +170,11 @@ namespace Microsoft.AspNetCore.Mvc.ApplicationModels
                 .GetMetadataForType(parameter.ParameterInfo.ParameterType);
             return metadata.IsComplexType && !metadata.IsCollectionType;
         }
+
+        private static bool IsFormFile(Type parameterType)
+        {
+            return typeof(IFormFile).IsAssignableFrom(parameterType) ||
+                typeof(IEnumerable<IFormFile>).IsAssignableFrom(parameterType);
+        }
     }
 }

test/Microsoft.AspNetCore.Mvc.Core.Test/ApplicationModels/InferParameterBindingInfoConventionTest.cs

@@ -686,7 +686,7 @@ Environment.NewLine + "int b";
             convention.InferBoundPropertyModelPrefixes(controller);
 
             // Assert
-            var property = Assert.Single(controller.ControllerProperties);
+            var property = Assert.Single(controller.ControllerProperties, p => p.Name == nameof(ControllerWithBoundProperty.TestProperty));
             Assert.Equal(string.Empty, property.BindingInfo.BinderModelName);
         }
 
@@ -720,6 +720,87 @@ Environment.NewLine + "int b";
             Assert.Equal(string.Empty, parameter.BindingInfo.BinderModelName);
         }
 
+        [Fact]
+        public void InferParameterModelPrefixes_DoesNotSetModelPrefix_ForFormFileParametersAnnotatedWithFromForm()
+        {
+            // Arrange
+            var action = GetActionModel(
+                typeof(ParameterBindingController), 
+                nameof(ParameterBindingController.FromFormFormFileParameters),
+                TestModelMetadataProvider.CreateDefaultProvider());
+            var convention = GetConvention();
+
+            // Act
+            convention.InferParameterModelPrefixes(action);
+
+            // Assert
+            Assert.Collection(
+                action.Parameters,
+                parameter =>
+                {
+                    Assert.Equal("p1", parameter.Name);
+                    Assert.Null(parameter.BindingInfo.BinderModelName);
+                },
+                parameter =>
+                {
+                    Assert.Equal("p2", parameter.Name);
+                    Assert.Null(parameter.BindingInfo.BinderModelName);
+                },
+                parameter =>
+                {
+                    Assert.Equal("p3", parameter.Name);
+                    Assert.Null(parameter.BindingInfo.BinderModelName);
+                });
+        }
+
+        [Fact]
+        public void InferParameterModelPrefixes_DoesNotSetModelPrefix_ForFormFileParameters()
+        {
+            // Arrange
+            var action = GetActionModel(
+                typeof(ParameterBindingController), 
+                nameof(ParameterBindingController.FormFileParameters), 
+                TestModelMetadataProvider.CreateDefaultProvider());
+            var convention = GetConvention();
+
+            // Act
+            convention.InferParameterModelPrefixes(action);
+
+            // Assert
+            Assert.Collection(
+                action.Parameters,
+                parameter =>
+                {
+                    Assert.Equal("p1", parameter.Name);
+                    Assert.Null(parameter.BindingInfo.BinderModelName);
+                },
+                parameter =>
+                {
+                    Assert.Equal("p2", parameter.Name);
+                    Assert.Null(parameter.BindingInfo.BinderModelName);
+                },
+                parameter =>
+                {
+                    Assert.Equal("p3", parameter.Name);
+                    Assert.Null(parameter.BindingInfo.BinderModelName);
+                });
+        }
+
+        [Fact]
+        public void InferBoundPropertyModelPrefixes_DoesNotSetModelPrefix_ForFormFileCollectionPropertiesAnnotatedWithFromForm()
+        {
+            // Arrange
+            var controller = GetControllerModel(typeof(ControllerWithBoundProperty));
+            var convention = GetConvention();
+
+            // Act
+            convention.InferBoundPropertyModelPrefixes(controller);
+
+            // Assert
+            var parameter = Assert.Single(controller.ControllerProperties, p => p.Name == nameof(ControllerWithBoundProperty.Files));
+            Assert.Null(parameter.BindingInfo.BinderModelName);
+        }
+
         private static InferParameterBindingInfoConvention GetConvention(
             IModelMetadataProvider modelMetadataProvider = null)
         {
@@ -861,6 +942,10 @@ Environment.NewLine + "int b";
 
             [HttpGet]
             public IActionResult ParameterWithRequestPredicateProvider([CustomRequestPredicateAndPropertyFilterProvider] int value) => null;
+
+            public IActionResult FromFormFormFileParameters([FromForm] IFormFile p1, [FromForm] IFormFile[] p2, [FromForm] IFormFileCollection p3) => null;
+
+            public IActionResult FormFileParameters(IFormFile p1, IFormFile[] p2, IFormFileCollection p3) => null;
         }
 
         [ApiController]
@@ -955,6 +1040,9 @@ Environment.NewLine + "int b";
             [FromQuery]
             public TestModel TestProperty { get; set; }
 
+            [FromForm]
+            public IList<IFormFile> Files { get; set; }
+
             public IActionResult SomeAction([FromQuery] TestModel test) => null;
         }