Add analyzer support for status code methods and constructors

src/Microsoft.AspNetCore.Mvc.Analyzers/CodeAnalysisExtensions.cs

@@ -123,7 +123,7 @@ namespace Microsoft.CodeAnalysis
             return false;
         }
 
-        private static bool HasAttribute(this ISymbol symbol, ITypeSymbol attribute)
+        public static bool HasAttribute(this ISymbol symbol, ITypeSymbol attribute)
         {
             foreach (var declaredAttribute in symbol.GetAttributes())
             {

src/Microsoft.AspNetCore.Mvc.Analyzers/MvcFacts.cs

@@ -116,6 +116,11 @@ namespace Microsoft.AspNetCore.Mvc.Analyzers
                 return false;
             }
 
+            if (!method.ReturnsVoid)
+            {
+                return false;
+            }
+
             if (method.Parameters.Length != disposableDispose.Parameters.Length)
             {
                 return false;

src/Microsoft.AspNetCore.Mvc.Api.Analyzers/ApiControllerSymbolCache.cs

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using System.Diagnostics;
 using Microsoft.CodeAnalysis;
 
 namespace Microsoft.AspNetCore.Mvc.Api.Analyzers
@@ -24,6 +25,11 @@ namespace Microsoft.AspNetCore.Mvc.Api.Analyzers
             ProducesDefaultResponseTypeAttribute = compilation.GetTypeByMetadataName(ApiSymbolNames.ProducesDefaultResponseTypeAttribute);
             ProducesResponseTypeAttribute = compilation.GetTypeByMetadataName(ApiSymbolNames.ProducesResponseTypeAttribute);
 
+            StatusCodeValueAttribute = compilation.GetTypeByMetadataName(ApiSymbolNames.StatusCodeValueAttribute);
+
+            var statusCodeActionResult = compilation.GetTypeByMetadataName(ApiSymbolNames.IStatusCodeActionResult);
+            StatusCodeActionResultStatusProperty = (IPropertySymbol)statusCodeActionResult.GetMembers("StatusCode")[0];
+
             var disposable = compilation.GetSpecialType(SpecialType.System_IDisposable);
             var members = disposable.GetMembers(nameof(IDisposable.Dispose));
             IDisposableDispose = members.Length == 1 ? (IMethodSymbol)members[0] : null;
@@ -47,6 +53,8 @@ namespace Microsoft.AspNetCore.Mvc.Api.Analyzers
 
         public IMethodSymbol IDisposableDispose { get; }
 
+        public IPropertySymbol StatusCodeActionResultStatusProperty { get; }
+
         public ITypeSymbol ModelStateDictionary { get; }
 
         public INamedTypeSymbol NonActionAttribute { get; }
@@ -56,5 +64,7 @@ namespace Microsoft.AspNetCore.Mvc.Api.Analyzers
         public INamedTypeSymbol ProducesDefaultResponseTypeAttribute { get; }
 
         public INamedTypeSymbol ProducesResponseTypeAttribute { get; }
+
+        public INamedTypeSymbol StatusCodeValueAttribute { get; }
     }
 }

src/Microsoft.AspNetCore.Mvc.Api.Analyzers/ApiSymbolNames.cs

@@ -23,6 +23,8 @@ namespace Microsoft.AspNetCore.Mvc.Api.Analyzers
 
         public const string IActionResult = "Microsoft.AspNetCore.Mvc.IActionResult";
 
+        public const string IStatusCodeActionResult = "Microsoft.AspNetCore.Mvc.Infrastructure.IStatusCodeActionResult";
+
         public const string ModelStateDictionary = "Microsoft.AspNetCore.Mvc.ModelBinding.ModelStateDictionary";
 
         public const string NonActionAttribute = "Microsoft.AspNetCore.Mvc.NonActionAttribute";
@@ -34,5 +36,7 @@ namespace Microsoft.AspNetCore.Mvc.Api.Analyzers
         public const string ProducesResponseTypeAttribute = "Microsoft.AspNetCore.Mvc.ProducesResponseTypeAttribute";
 
         public const string HttpStatusCodes = "Microsoft.AspNetCore.Http.StatusCodes";
+
+        public const string StatusCodeValueAttribute = "Microsoft.AspNetCore.Mvc.Infrastructure.StatusCodeValueAttribute";
     }
 }

src/Microsoft.AspNetCore.Mvc.Api.Analyzers/SymbolApiResponseMetadataProvider.cs

@@ -61,7 +61,8 @@ namespace Microsoft.AspNetCore.Mvc.Api.Analyzers
             }
 
             return Array.Empty<DeclaredApiResponseMetadata>();
-       }
+        }
+
         private static IMethodSymbol GetMethodFromConventionMethodAttribute(ApiControllerSymbolCache symbolCache, IMethodSymbol method)
         {
             var attribute = method.GetAttributes(symbolCache.ApiConventionMethodAttribute, inherit: true)
@@ -222,6 +223,12 @@ namespace Microsoft.AspNetCore.Mvc.Api.Analyzers
 
             foreach (var returnStatementSyntax in methodSyntax.DescendantNodes(_shouldDescendIntoChildren).OfType<ReturnStatementSyntax>())
             {
+                if (returnStatementSyntax.IsMissing || returnStatementSyntax.Expression.IsMissing)
+                {
+                    // Ignore malformed return statements.
+                    continue;
+                }
+
                 var responseMetadata = InspectReturnStatementSyntax(
                     symbolCache,
                     semanticModel,
@@ -248,11 +255,6 @@ namespace Microsoft.AspNetCore.Mvc.Api.Analyzers
             CancellationToken cancellationToken)
         {
             var returnExpression = returnStatementSyntax.Expression;
-            if (returnExpression.IsMissing)
-            {
-                return null;
-            }
-
             var typeInfo = semanticModel.GetTypeInfo(returnExpression, cancellationToken);
             if (typeInfo.Type.TypeKind == TypeKind.Error)
             {
@@ -267,25 +269,176 @@ namespace Microsoft.AspNetCore.Mvc.Api.Analyzers
 
             if (defaultStatusCodeAttribute != null)
             {
-                var statusCode = GetDefaultStatusCode(defaultStatusCodeAttribute);
+                var defaultStatusCode = GetDefaultStatusCode(defaultStatusCodeAttribute);
-                if (statusCode == null)
+                if (defaultStatusCode == null)
                 {
                     // Unable to read the status code even though the attribute exists.
                     return null;
                 }
 
-                return new ActualApiResponseMetadata(returnStatementSyntax, statusCode.Value);
+                return new ActualApiResponseMetadata(returnStatementSyntax, defaultStatusCode.Value);
             }
-            else if (!symbolCache.IActionResult.IsAssignableFrom(statementReturnType))
+
+            if (!symbolCache.IActionResult.IsAssignableFrom(statementReturnType))
             {
                 // Return expression does not have a DefaultStatusCodeAttribute and it is not
                 // an instance of IActionResult. Must be returning the "model".
                 return new ActualApiResponseMetadata(returnStatementSyntax);
             }
 
+            int statusCode;
+            switch (returnExpression)
+            {
+                case InvocationExpressionSyntax invocation:
+                    // Covers the 'return StatusCode(200)' case.
+                    if (TryGetParameterStatusCode(symbolCache, semanticModel, invocation.Expression, invocation.ArgumentList, cancellationToken, out statusCode))
+                    {
+                        return new ActualApiResponseMetadata(returnStatementSyntax, statusCode);
+                    }
+                    break;
+
+                case ObjectCreationExpressionSyntax creation:
+                    // Covers the 'return new ObjectResult(...) { StatusCode = 200 }' case.
+                    if (TryGetInitializerStatusCode(symbolCache, semanticModel, creation.Initializer, cancellationToken, out statusCode))
+                    {
+                        return new ActualApiResponseMetadata(returnStatementSyntax, statusCode);
+                    }
+
+                    // Covers the 'return new StatusCodeResult(200) case.
+                    if (TryGetParameterStatusCode(symbolCache, semanticModel, creation, creation.ArgumentList, cancellationToken, out statusCode))
+                    {
+                        return new ActualApiResponseMetadata(returnStatementSyntax, statusCode);
+                    }
+                    break;
+            }
+
             return null;
         }
 
+        private static bool TryGetInitializerStatusCode(
+            in ApiControllerSymbolCache symbolCache,
+            SemanticModel semanticModel,
+            InitializerExpressionSyntax initializer,
+            CancellationToken cancellationToken,
+            out int statusCode)
+        {
+            if (initializer == null)
+            {
+                statusCode = default;
+                return false;
+            }
+
+            for (var i = 0; i < initializer.Expressions.Count; i++)
+            {
+                if (!(initializer.Expressions[i] is AssignmentExpressionSyntax assignment))
+                {
+                    continue;
+                }
+
+                if (assignment.Left is IdentifierNameSyntax identifier)
+                {
+                    var symbolInfo = semanticModel.GetSymbolInfo(identifier, cancellationToken);
+
+                    if (symbolInfo.Symbol is IPropertySymbol property && IsInterfaceImplementation(property, symbolCache.StatusCodeActionResultStatusProperty))
+                    {
+                        return TryGetExpressionStatusCode(semanticModel, assignment.Right, cancellationToken, out statusCode);
+                    }
+                }
+            }
+
+            statusCode = default;
+            return false;
+        }
+
+        private static bool IsInterfaceImplementation(IPropertySymbol property, IPropertySymbol statusCodeActionResultStatusProperty)
+        {
+            if (property.Name != statusCodeActionResultStatusProperty.Name)
+            {
+                return false;
+            }
+
+            for (var i = 0; i < property.ExplicitInterfaceImplementations.Length; i++)
+            {
+                if (property.ExplicitInterfaceImplementations[i] == statusCodeActionResultStatusProperty)
+                {
+                    return true;
+                }
+            }
+
+            var implementedProperty = property.ContainingType.FindImplementationForInterfaceMember(statusCodeActionResultStatusProperty);
+            return implementedProperty == property;
+        }
+
+        private static bool TryGetParameterStatusCode(
+            in ApiControllerSymbolCache symbolCache,
+            SemanticModel semanticModel,
+            ExpressionSyntax expression,
+            BaseArgumentListSyntax argumentList,
+            CancellationToken cancellationToken,
+            out int statusCode)
+        {
+            var symbolInfo = semanticModel.GetSymbolInfo(expression, cancellationToken);
+
+            if (!(symbolInfo.Symbol is IMethodSymbol method))
+            {
+                statusCode = default;
+                return false;
+            }
+
+            for (var i = 0; i < method.Parameters.Length; i++)
+            {
+                var parameter = method.Parameters[i];
+                if (!parameter.HasAttribute(symbolCache.StatusCodeValueAttribute))
+                {
+                    continue;
+                }
+
+
+                var argument = argumentList.Arguments[parameter.Ordinal];
+                return TryGetExpressionStatusCode(semanticModel, argument.Expression, cancellationToken, out statusCode);
+            }
+
+            statusCode = default;
+            return false;
+        }
+
+        private static bool TryGetExpressionStatusCode(
+            SemanticModel semanticModel,
+            ExpressionSyntax expression,
+            CancellationToken cancellationToken,
+            out int statusCode)
+        {
+            if (expression is LiteralExpressionSyntax literal && literal.Token.Value is int literalStatusCode)
+            {
+                // Covers the 'return StatusCode(200)' case.
+                statusCode = literalStatusCode;
+                return true;
+            }
+
+            if (expression is IdentifierNameSyntax || expression is MemberAccessExpressionSyntax)
+            {
+                var symbolInfo = semanticModel.GetSymbolInfo(expression, cancellationToken);
+
+                if (symbolInfo.Symbol is IFieldSymbol field && field.HasConstantValue && field.ConstantValue is int constantStatusCode)
+                {
+                    // Covers the 'return StatusCode(StatusCodes.Status200OK)' case.
+                    // It also covers the 'return StatusCode(StatusCode)' case, where 'StatusCode' is a constant field.
+                    statusCode = constantStatusCode;
+                    return true;
+                }
+
+                if (symbolInfo.Symbol is ILocalSymbol local && local.HasConstantValue && local.ConstantValue is int localStatusCode)
+                {
+                    // Covers the 'return StatusCode(statusCode)' case, where 'statusCode' is a local constant.
+                    statusCode = localStatusCode;
+                    return true;
+                }
+            }
+
+            statusCode = default;
+            return false;
+        }
+
         private static bool ShouldDescendIntoChildren(SyntaxNode syntaxNode)
         {
             return !syntaxNode.IsKind(SyntaxKind.LocalFunctionStatement) &&

src/Microsoft.AspNetCore.Mvc.Core/ControllerBase.cs

@@ -10,6 +10,7 @@ using System.Threading.Tasks;
 using Microsoft.AspNetCore.Authentication;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc.Core;
+using Microsoft.AspNetCore.Mvc.Infrastructure;
 using Microsoft.AspNetCore.Mvc.ModelBinding;
 using Microsoft.AspNetCore.Mvc.ModelBinding.Internal;
 using Microsoft.AspNetCore.Mvc.ModelBinding.Validation;
@@ -200,7 +201,7 @@ namespace Microsoft.AspNetCore.Mvc
         /// <param name="statusCode">The status code to set on the response.</param>
         /// <returns>The created <see cref="StatusCodeResult"/> object for the response.</returns>
         [NonAction]
-        public virtual StatusCodeResult StatusCode(int statusCode)
+        public virtual StatusCodeResult StatusCode([StatusCodeValue] int statusCode)
             => new StatusCodeResult(statusCode);
 
         /// <summary>
@@ -210,10 +211,12 @@ namespace Microsoft.AspNetCore.Mvc
         /// <param name="value">The value to set on the <see cref="ObjectResult"/>.</param>
         /// <returns>The created <see cref="ObjectResult"/> object for the response.</returns>
         [NonAction]
-        public virtual ObjectResult StatusCode(int statusCode, object value)
+        public virtual ObjectResult StatusCode([StatusCodeValue] int statusCode, object value)
         {
-            var result = new ObjectResult(value);
+            var result = new ObjectResult(value)
-            result.StatusCode = statusCode;
+            {
+                StatusCode = statusCode
+            };
 
             return result;
         }

src/Microsoft.AspNetCore.Mvc.Core/Infrastructure/StatusCodeValueAttribute.cs

@@ -0,0 +1,12 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+
+namespace Microsoft.AspNetCore.Mvc.Infrastructure
+{
+    [AttributeUsage(AttributeTargets.Parameter, AllowMultiple = false, Inherited = false)]
+    internal sealed class StatusCodeValueAttribute : Attribute
+    {
+    }
+}

src/Microsoft.AspNetCore.Mvc.Core/StatusCodeResult.cs

@@ -20,7 +20,7 @@ namespace Microsoft.AspNetCore.Mvc
         /// with the given <paramref name="statusCode"/>.
         /// </summary>
         /// <param name="statusCode">The HTTP status code of the response.</param>
-        public StatusCodeResult(int statusCode)
+        public StatusCodeResult([StatusCodeValue] int statusCode)
         {
             StatusCode = statusCode;
         }

test/Mvc.Api.Analyzers.Test/AddResponseTypeAttributeCodeFixProviderIntegrationTest.cs

@@ -33,6 +33,18 @@ namespace Microsoft.AspNetCore.Mvc.Api.Analyzers
         [Fact]
         public Task CodeFixAddsFullyQualifiedProducesResponseType() => RunTest();
 
+        [Fact]
+        public Task CodeFixAddsNumericLiteralForNonExistingStatusCodeConstants() => RunTest();
+
+        [Fact]
+        public Task CodeFixAddsStatusCodesFromMethodParameters() => RunTest();
+
+        [Fact]
+        public Task CodeFixAddsStatusCodesFromConstructorParameters() => RunTest();
+
+        [Fact]
+        public Task CodeFixAddsStatusCodesFromObjectInitializer() => RunTest();
+
         private async Task RunTest([CallerMemberName] string testMethod = "")
         {
             // Arrange

test/Mvc.Api.Analyzers.Test/TestFiles/AddResponseTypeAttributeCodeFixProviderIntegrationTest/CodeFixAddsNumericLiteralForNonExistingStatusCodeConstants.Input.cs

@@ -0,0 +1,17 @@
+namespace Microsoft.AspNetCore.Mvc.Api.Analyzers._INPUT_
+{
+    [ApiController]
+    [Route("[controller]/[action]")]
+    public class CodeFixAddsNumericLiteralForNonExistingStatusCodeConstantsController : ControllerBase
+    {
+        public IActionResult GetItem(int id)
+        {
+            if (id == 0)
+            {
+                return StatusCode(345);
+            }
+
+            return Ok(new object());
+        }
+    }
+}

test/Mvc.Api.Analyzers.Test/TestFiles/AddResponseTypeAttributeCodeFixProviderIntegrationTest/CodeFixAddsNumericLiteralForNonExistingStatusCodeConstants.Output.cs

@@ -0,0 +1,22 @@
+using Microsoft.AspNetCore.Http;
+
+namespace Microsoft.AspNetCore.Mvc.Api.Analyzers._OUTPUT_
+{
+    [ApiController]
+    [Route("[controller]/[action]")]
+    public class CodeFixAddsNumericLiteralForNonExistingStatusCodeConstantsController : ControllerBase
+    {
+        [ProducesResponseType(StatusCodes.Status200OK)]
+        [ProducesResponseType(345)]
+        [ProducesDefaultResponseType]
+        public IActionResult GetItem(int id)
+        {
+            if (id == 0)
+            {
+                return StatusCode(345);
+            }
+
+            return Ok(new object());
+        }
+    }
+}

test/Mvc.Api.Analyzers.Test/TestFiles/AddResponseTypeAttributeCodeFixProviderIntegrationTest/CodeFixAddsStatusCodesFromConstructorParameters.Input.cs

@@ -0,0 +1,38 @@
+using Microsoft.AspNetCore.Http;
+
+namespace Microsoft.AspNetCore.Mvc.Api.Analyzers._INPUT_
+{
+    [ApiController]
+    [Route("[controller]/[action]")]
+    public class CodeFixAddsStatusCodesFromConstructorParametersController : ControllerBase
+    {
+        private const int FieldStatusCode = 201;
+
+        public IActionResult GetItem(int id)
+        {
+            if (id == 0)
+            {
+                return new StatusCodeResult(422);
+            }
+
+            if (id == 1)
+            {
+                return new StatusCodeResult(StatusCodes.Status202Accepted);
+            }
+
+            if (id == 2)
+            {
+                const int localStatusCode = 204;
+
+                return new StatusCodeResult(localStatusCode);
+            }
+
+            if (id == 3)
+            {
+                return new StatusCodeResult(FieldStatusCode);
+            }
+
+            return Ok(new object());
+        }
+    }
+}

test/Mvc.Api.Analyzers.Test/TestFiles/AddResponseTypeAttributeCodeFixProviderIntegrationTest/CodeFixAddsStatusCodesFromConstructorParameters.Output.cs

@@ -0,0 +1,44 @@
+using Microsoft.AspNetCore.Http;
+
+namespace Microsoft.AspNetCore.Mvc.Api.Analyzers._OUTPUT_
+{
+    [ApiController]
+    [Route("[controller]/[action]")]
+    public class CodeFixAddsStatusCodesFromConstructorParametersController : ControllerBase
+    {
+        private const int FieldStatusCode = 201;
+
+        [ProducesResponseType(StatusCodes.Status200OK)]
+        [ProducesResponseType(StatusCodes.Status201Created)]
+        [ProducesResponseType(StatusCodes.Status202Accepted)]
+        [ProducesResponseType(StatusCodes.Status204NoContent)]
+        [ProducesResponseType(StatusCodes.Status422UnprocessableEntity)]
+        [ProducesDefaultResponseType]
+        public IActionResult GetItem(int id)
+        {
+            if (id == 0)
+            {
+                return new StatusCodeResult(422);
+            }
+
+            if (id == 1)
+            {
+                return new StatusCodeResult(StatusCodes.Status202Accepted);
+            }
+
+            if (id == 2)
+            {
+                const int localStatusCode = 204;
+
+                return new StatusCodeResult(localStatusCode);
+            }
+
+            if (id == 3)
+            {
+                return new StatusCodeResult(FieldStatusCode);
+            }
+
+            return Ok(new object());
+        }
+    }
+}

test/Mvc.Api.Analyzers.Test/TestFiles/AddResponseTypeAttributeCodeFixProviderIntegrationTest/CodeFixAddsStatusCodesFromMethodParameters.Input.cs

@@ -0,0 +1,38 @@
+using Microsoft.AspNetCore.Http;
+
+namespace Microsoft.AspNetCore.Mvc.Api.Analyzers._INPUT_
+{
+    [ApiController]
+    [Route("[controller]/[action]")]
+    public class CodeFixAddsStatusCodesFromMethodParametersController : ControllerBase
+    {
+        private const int FieldStatusCode = 201;
+
+        public IActionResult GetItem(int id)
+        {
+            if (id == 0)
+            {
+                return StatusCode(422);
+            }
+
+            if (id == 1)
+            {
+                return StatusCode(StatusCodes.Status202Accepted);
+            }
+
+            if (id == 2)
+            {
+                const int localStatusCode = 204;
+
+                return StatusCode(localStatusCode);
+            }
+
+            if (id == 3)
+            {
+                return StatusCode(FieldStatusCode);
+            }
+
+            return Ok(new object());
+        }
+    }
+}

test/Mvc.Api.Analyzers.Test/TestFiles/AddResponseTypeAttributeCodeFixProviderIntegrationTest/CodeFixAddsStatusCodesFromMethodParameters.Output.cs

@@ -0,0 +1,44 @@
+using Microsoft.AspNetCore.Http;
+
+namespace Microsoft.AspNetCore.Mvc.Api.Analyzers._OUTPUT_
+{
+    [ApiController]
+    [Route("[controller]/[action]")]
+    public class CodeFixAddsStatusCodesFromMethodParametersController : ControllerBase
+    {
+        private const int FieldStatusCode = 201;
+
+        [ProducesResponseType(StatusCodes.Status200OK)]
+        [ProducesResponseType(StatusCodes.Status201Created)]
+        [ProducesResponseType(StatusCodes.Status202Accepted)]
+        [ProducesResponseType(StatusCodes.Status204NoContent)]
+        [ProducesResponseType(StatusCodes.Status422UnprocessableEntity)]
+        [ProducesDefaultResponseType]
+        public IActionResult GetItem(int id)
+        {
+            if (id == 0)
+            {
+                return StatusCode(422);
+            }
+
+            if (id == 1)
+            {
+                return StatusCode(StatusCodes.Status202Accepted);
+            }
+
+            if (id == 2)
+            {
+                const int localStatusCode = 204;
+
+                return StatusCode(localStatusCode);
+            }
+
+            if (id == 3)
+            {
+                return StatusCode(FieldStatusCode);
+            }
+
+            return Ok(new object());
+        }
+    }
+}

test/Mvc.Api.Analyzers.Test/TestFiles/AddResponseTypeAttributeCodeFixProviderIntegrationTest/CodeFixAddsStatusCodesFromObjectInitializer.Input.cs

@@ -0,0 +1,51 @@
+using Microsoft.AspNetCore.Http;
+
+namespace Microsoft.AspNetCore.Mvc.Api.Analyzers._INPUT_
+{
+    [ApiController]
+    [Route("[controller]/[action]")]
+    public class CodeFixAddsStatusCodesFromObjectInitializerController : ControllerBase
+    {
+        private const int FieldStatusCode = 201;
+
+        public IActionResult GetItem(int id)
+        {
+            if (id == 0)
+            {
+                return new ObjectResult(new object())
+                {
+                    StatusCode = 422
+                };
+            }
+
+            if (id == 1)
+            {
+                return new ObjectResult(new object())
+                {
+                    StatusCode = StatusCodes.Status202Accepted
+                };
+            }
+
+            if (id == 2)
+            {
+                const int localStatusCode = 204;
+
+                return new ObjectResult(new object())
+                {
+                    StatusCode = localStatusCode
+                };
+            }
+
+            if (id == 3)
+            {
+                return new ObjectResult(new object())
+                {
+                    ContentTypes = { "application/json" },
+                    StatusCode = FieldStatusCode
+                };
+            }
+
+            return Ok(new object());
+        }
+    }
+}

test/Mvc.Api.Analyzers.Test/TestFiles/AddResponseTypeAttributeCodeFixProviderIntegrationTest/CodeFixAddsStatusCodesFromObjectInitializer.Output.cs

@@ -0,0 +1,57 @@
+using Microsoft.AspNetCore.Http;
+
+namespace Microsoft.AspNetCore.Mvc.Api.Analyzers._OUTPUT_
+{
+    [ApiController]
+    [Route("[controller]/[action]")]
+    public class CodeFixAddsStatusCodesFromObjectInitializerController : ControllerBase
+    {
+        private const int FieldStatusCode = 201;
+
+        [ProducesResponseType(StatusCodes.Status200OK)]
+        [ProducesResponseType(StatusCodes.Status201Created)]
+        [ProducesResponseType(StatusCodes.Status202Accepted)]
+        [ProducesResponseType(StatusCodes.Status204NoContent)]
+        [ProducesResponseType(StatusCodes.Status422UnprocessableEntity)]
+        [ProducesDefaultResponseType]
+        public IActionResult GetItem(int id)
+        {
+            if (id == 0)
+            {
+                return new ObjectResult(new object())
+                {
+                    StatusCode = 422
+                };
+            }
+
+            if (id == 1)
+            {
+                return new ObjectResult(new object())
+                {
+                    StatusCode = StatusCodes.Status202Accepted
+                };
+            }
+
+            if (id == 2)
+            {
+                const int localStatusCode = 204;
+
+                return new ObjectResult(new object())
+                {
+                    StatusCode = localStatusCode
+                };
+            }
+
+            if (id == 3)
+            {
+                return new ObjectResult(new object())
+                {
+                    ContentTypes = { "application/json" },
+                    StatusCode = FieldStatusCode
+                };
+            }
+
+            return Ok(new object());
+        }
+    }
+}