[release/10.0.1xx-preview7] Show deprecation warning for OpenAPI analyzers (#49918)

Co-authored-by: Safia Abdalla <safia@microsoft.com>

Author: github-actions[bot]

src/WebSdk/Web/Targets/Sdk.Server.targets

@@ -54,4 +54,10 @@ Copyright (c) .NET Foundation. All rights reserved.
                                     Trim="true" />
   </ItemGroup>
 
+  <Target Name="WarnOnDeprecatedAssets"
+    BeforeTargets="CoreCompile"
+    Condition="'$(IncludeOpenAPIAnalyzers)' == 'true'">
+    <Warning Code="ASPDEPR007" Text="The IncludeOpenAPIAnalyzers property and its associated MVC API analyzers are deprecated and will be removed in a future release." HelpLink="https://aka.ms/aspnet/deprecate/007" />
+  </Target>
+
 </Project>

test/Microsoft.NET.Sdk.Web.Tests/DeprecationTests.cs

@@ -0,0 +1,81 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+#nullable disable
+
+namespace Microsoft.NET.Sdk.Web.Tests;
+
+public class DeprecationTests(ITestOutputHelper log) : SdkTest(log)
+{
+    [Fact]
+    public void It_does_not_show_deprecation_warning_when_IncludeOpenAPIAnalyzers_is_not_set()
+    {
+        var testProject = new TestProject()
+        {
+            Name = "WebAppWithoutOpenAPIAnalyzers",
+            TargetFrameworks = ToolsetInfo.CurrentTargetFramework,
+            ProjectSdk = "Microsoft.NET.Sdk.Web"
+        };
+
+        var testAsset = _testAssetsManager.CreateTestProject(testProject);
+
+        var buildCommand = new BuildCommand(testAsset);
+        buildCommand
+            .Execute()
+            .Should()
+            .Pass()
+            .And
+            .NotHaveStdOutContaining("ASPDEPR007")
+            .And
+            .NotHaveStdOutContaining("IncludeOpenAPIAnalyzers");
+    }
+
+    [Fact]
+    public void It_does_not_show_deprecation_warning_when_IncludeOpenAPIAnalyzers_is_false()
+    {
+        var testProject = new TestProject()
+        {
+            Name = "WebAppWithOpenAPIAnalyzersFalse",
+            TargetFrameworks = ToolsetInfo.CurrentTargetFramework,
+            ProjectSdk = "Microsoft.NET.Sdk.Web"
+        };
+
+        testProject.AdditionalProperties["IncludeOpenAPIAnalyzers"] = "false";
+
+        var testAsset = _testAssetsManager.CreateTestProject(testProject);
+
+        var buildCommand = new BuildCommand(testAsset);
+        buildCommand
+            .Execute()
+            .Should()
+            .Pass()
+            .And
+            .NotHaveStdOutContaining("ASPDEPR007");
+    }
+
+    [Theory]
+    [InlineData(ToolsetInfo.CurrentTargetFramework)]
+    [InlineData("net8.0")]
+    [InlineData("net9.0")]
+    public void It_shows_deprecation_warning_across_target_frameworks(string targetFramework)
+    {
+        var testProject = new TestProject()
+        {
+            Name = $"WebApp_{targetFramework.Replace(".", "_")}",
+            TargetFrameworks = targetFramework,
+            ProjectSdk = "Microsoft.NET.Sdk.Web"
+        };
+
+        testProject.AdditionalProperties["IncludeOpenAPIAnalyzers"] = "true";
+
+        var testAsset = _testAssetsManager.CreateTestProject(testProject, identifier: targetFramework);
+
+        var buildCommand = new BuildCommand(testAsset);
+        buildCommand
+            .Execute()
+            .Should()
+            .Pass()
+            .And
+            .HaveStdOutContaining("ASPDEPR007");
+    }
+}