[OpenAPI] Add OpenAPI adapter (#8886)

Author: tobias-tengler

src/All.slnx

@@ -181,6 +181,15 @@
   <Folder Name="/HotChocolate/Diagnostics/test/">
     <Project Path="HotChocolate/Diagnostics/test/Diagnostics.Tests/HotChocolate.Diagnostics.Tests.csproj" />
   </Folder>
+  <Folder Name="/HotChocolate/Adapters/" />
+  <Folder Name="/HotChocolate/Adapters/src/">
+    <Project Path="HotChocolate/Adapters/src/Adapters.OpenApi/HotChocolate.Adapters.OpenApi.csproj" />
+    <Project Path="HotChocolate/Adapters/src/Adapters.OpenApi.Core/HotChocolate.Adapters.OpenApi.Core.csproj" />
+    <Project Path="HotChocolate/Adapters/src/Adapters.OpenApi.Fusion/HotChocolate.Fusion.Adapters.OpenApi.csproj" />
+  </Folder>
+  <Folder Name="/HotChocolate/Adapters/test/">
+    <Project Path="HotChocolate/Adapters/test/Adapters.OpenApi.Tests/HotChocolate.Adapters.OpenApi.Tests.csproj" />
+  </Folder>
   <Folder Name="/HotChocolate/Fusion-vnext/" />
   <Folder Name="/HotChocolate/Fusion-vnext/benchmarks/">
     <Project Path="HotChocolate/Fusion-vnext/benchmarks/Fusion.Execution.Benchmarks/Fusion.Execution.Benchmarks.csproj" />

src/Directory.Packages.props

@@ -79,6 +79,7 @@
   <ItemGroup Condition="'$(TargetFramework)' == 'net10.0'">
     <PackageVersion Include="Microsoft.AspNetCore.Authentication.JwtBearer" Version="10.0.0-rc.2.25502.107" />
     <PackageVersion Include="Microsoft.AspNetCore.Components.Web" Version="10.0.0-rc.2.25502.107" />
+    <PackageVersion Include="Microsoft.AspNetCore.OpenApi" Version="10.0.0-rc.2.25502.107" />
     <PackageVersion Include="Microsoft.AspNetCore.TestHost" Version="10.0.0-rc.2.25502.107" />
     <PackageVersion Include="Microsoft.AspNetCore.WebUtilities" Version="10.0.0-rc.2.25502.107" />
     <PackageVersion Include="Microsoft.Data.Sqlite.Core" Version="10.0.0-rc.2.25502.107" />
@@ -106,6 +107,7 @@
   <ItemGroup Condition="'$(TargetFramework)' == 'net9.0'">
     <PackageVersion Include="Microsoft.AspNetCore.Authentication.JwtBearer" Version="9.0.0" />
     <PackageVersion Include="Microsoft.AspNetCore.Components.Web" Version="9.0.2" />
+    <PackageVersion Include="Microsoft.AspNetCore.OpenApi" Version="9.0.2" />
     <PackageVersion Include="Microsoft.AspNetCore.TestHost" Version="9.0.2" />
     <PackageVersion Include="Microsoft.AspNetCore.WebUtilities" Version="9.0.2" />
     <PackageVersion Include="Microsoft.Data.Sqlite.Core" Version="9.0.2" />

src/HotChocolate/Adapters/Adapters.slnx

@@ -0,0 +1,12 @@
+<Solution>
+  <Folder Name="/src/" />
+  <Folder Name="/src/Adapters.OpenApi/">
+    <Project Path="src\Adapters.OpenApi.Core\HotChocolate.Adapters.OpenApi.Core.csproj" />
+    <Project Path="src\Adapters.OpenApi.Fusion\HotChocolate.Fusion.Adapters.OpenApi.csproj" />
+    <Project Path="src\Adapters.OpenApi\HotChocolate.Adapters.OpenApi.csproj" />
+  </Folder>
+  <Folder Name="/test/" />
+  <Folder Name="/test/Adapters.OpenApi.Tests/">
+    <Project Path="test\Adapters.OpenApi.Tests\HotChocolate.Adapters.OpenApi.Tests.csproj" />
+  </Folder>
+</Solution>

src/HotChocolate/Adapters/Directory.Build.props

@@ -0,0 +1,8 @@
+<Project>
+  <Import Project="$([MSBuild]::GetPathOfFileAbove('Directory.Build.props', '$(MSBuildThisFileDirectory)..\'))" />
+
+  <PropertyGroup>
+    <TargetFrameworks>net10.0; net9.0</TargetFrameworks>
+    <LangVersion>Preview</LangVersion>
+  </PropertyGroup>
+</Project>

src/HotChocolate/Adapters/src/Adapters.OpenApi.Core/Diagnostics/AggregateOpenApiDiagnosticEventListener.cs

@@ -0,0 +1,13 @@
+namespace HotChocolate.Adapters.OpenApi;
+
+internal sealed class AggregateOpenApiDiagnosticEventListener(IOpenApiDiagnosticEventListener[] listeners)
+    : IOpenApiDiagnosticEventListener
+{
+    public void ValidationErrors(IReadOnlyList<IOpenApiError> errors)
+    {
+        foreach (var listener in listeners)
+        {
+            listener.ValidationErrors(errors);
+        }
+    }
+}

src/HotChocolate/Adapters/src/Adapters.OpenApi.Core/Diagnostics/IOpenApiDiagnosticEventListener.cs

@@ -0,0 +1,9 @@
+namespace HotChocolate.Adapters.OpenApi;
+
+/// <summary>
+/// Register an implementation of this interface in the DI container to
+/// listen to diagnostic events. Multiple implementations can be registered,
+/// and they will all be called in the registration order.
+/// </summary>
+/// <seealso cref="OpenApiDiagnosticEventListener"/>
+public interface IOpenApiDiagnosticEventListener : IOpenApiDiagnosticEvents;

src/HotChocolate/Adapters/src/Adapters.OpenApi.Core/Diagnostics/IOpenApiDiagnosticEvents.cs

@@ -0,0 +1,13 @@
+namespace HotChocolate.Adapters.OpenApi;
+
+/// <summary>
+/// Provides diagnostic events for the OpenAPI integration.
+/// </summary>
+public interface IOpenApiDiagnosticEvents
+{
+    /// <summary>
+    /// Called when errors occur while parsing or validating an OpenAPI document.
+    /// </summary>
+    /// <param name="errors">The errors.</param>
+    void ValidationErrors(IReadOnlyList<IOpenApiError> errors);
+}

src/HotChocolate/Adapters/src/Adapters.OpenApi.Core/Diagnostics/NoOpOpenApiDiagnosticEventListener.cs

@@ -0,0 +1,3 @@
+namespace HotChocolate.Adapters.OpenApi;
+
+internal sealed class NoOpOpenApiDiagnosticEventListener : OpenApiDiagnosticEventListener;

src/HotChocolate/Adapters/src/Adapters.OpenApi.Core/Diagnostics/OpenApiDiagnosticEventListener.cs

@@ -0,0 +1,26 @@
+namespace HotChocolate.Adapters.OpenApi;
+
+/// <summary>
+/// This class can be used as a base class for <see cref="IOpenApiDiagnosticEventListener"/>
+/// implementations, so that they only have to override the methods they
+/// are interested in instead of having to provide implementations for all of them.
+/// </summary>
+public class OpenApiDiagnosticEventListener : IOpenApiDiagnosticEventListener
+{
+    /// <summary>
+    /// A no-op activity scope that can be returned from
+    /// event methods that are not interested in when the scope is disposed.
+    /// </summary>
+    protected static IDisposable EmptyScope { get; } = new EmptyActivityScope();
+
+    public virtual void ValidationErrors(IReadOnlyList<IOpenApiError> errors)
+    {
+    }
+
+    private sealed class EmptyActivityScope : IDisposable
+    {
+        public void Dispose()
+        {
+        }
+    }
+}

src/HotChocolate/Adapters/src/Adapters.OpenApi.Core/Documents/IOpenApiDocument.cs

@@ -0,0 +1,16 @@
+using HotChocolate.Language;
+
+namespace HotChocolate.Adapters.OpenApi;
+
+public interface IOpenApiDocument
+{
+    string Id { get; }
+
+    string Name { get; }
+
+    string? Description { get; }
+
+    Dictionary<string, FragmentDefinitionNode> LocalFragmentLookup { get; }
+
+    HashSet<string> ExternalFragmentReferences { get; }
+}