feat: add SwaggerExampleFromExampleProviderAttribute (#123)

src/Altinn.Swashbuckle/src/Altinn.Swashbuckle.Abstractions/Filters/SwaggerExampleFromExampleProviderAttribute.cs

@@ -0,0 +1,14 @@
+using Altinn.Swashbuckle.Examples;
+using System.Diagnostics.CodeAnalysis;
+
+namespace Altinn.Swashbuckle.Filters;
+
+/// <summary>
+/// Attribute for specifying that a type should have example generated using the <see cref="IExampleDataProvider{TSelf}"/> machinery.
+/// </summary>
+[ExcludeFromCodeCoverage]
+[AttributeUsage(AttributeTargets.Class | AttributeTargets.Struct | AttributeTargets.Enum, AllowMultiple = false)]
+public sealed class SwaggerExampleFromExampleProviderAttribute
+    : Attribute
+{
+}

src/Altinn.Swashbuckle/src/Altinn.Swashbuckle.Abstractions/Filters/SwaggerStringAttribute.cs

@@ -5,6 +5,7 @@ namespace Altinn.Swashbuckle.Filters;
 /// <summary>
 /// Attribute for specifying that a type should be represented as a string in the OpenAPI schema.
 /// </summary>
+[ExcludeFromCodeCoverage]
 [AttributeUsage(AttributeTargets.Class | AttributeTargets.Struct | AttributeTargets.Enum, AllowMultiple = false)]
 public sealed class SwaggerStringAttribute
     : Attribute

src/Altinn.Swashbuckle/src/Altinn.Swashbuckle/AltinnSwashbuckleServiceCollectionExtensions.cs

@@ -3,12 +3,14 @@
 using Microsoft.Extensions.DependencyInjection.Extensions;
 using Microsoft.Extensions.Options;
 using Swashbuckle.AspNetCore.SwaggerGen;
+using System.Diagnostics.CodeAnalysis;
 
 namespace Microsoft.Extensions.DependencyInjection;
 
 /// <summary>
 /// Extension methods for adding example-data to the generated OpenAPI spec.
 /// </summary>
+[ExcludeFromCodeCoverage]
 public static class AltinnSwashbuckleServiceCollectionExtensions
 {
     /// <summary>
@@ -32,14 +34,18 @@ public static OptionsBuilder<ExampleDataOptions> AddOpenApiExampleProvider(this
     /// <returns><paramref name="services"/>.</returns>
     public static IServiceCollection AddSwaggerFilterAttributeSupport(this IServiceCollection services)
     {
+        services.AddOpenApiExampleProvider();
+
         services.AddSingleton<SchemaFilterAttributeFilter>();
         services.AddSingleton<SwaggerStringAttributeFilter>();
+        services.AddSingleton<SwaggerExampleFromExampleProviderFilter>();
 
         services.AddOptions<SwaggerGenOptions>()
             .Configure((SwaggerGenOptions options, IServiceProvider s) =>
             {
                 options.SchemaGeneratorOptions.SchemaFilters.Add(s.GetRequiredService<SchemaFilterAttributeFilter>());
                 options.SchemaGeneratorOptions.SchemaFilters.Add(s.GetRequiredService<SwaggerStringAttributeFilter>());
+                options.SchemaGeneratorOptions.SchemaFilters.Add(s.GetRequiredService<SwaggerExampleFromExampleProviderFilter>());
             });
 
         return services;

src/Altinn.Swashbuckle/src/Altinn.Swashbuckle/Filters/SwaggerExampleFromExampleProviderFilter.cs

@@ -0,0 +1,23 @@
+using Altinn.Swashbuckle.Examples;
+using Microsoft.OpenApi.Models;
+using Swashbuckle.AspNetCore.SwaggerGen;
+using System.Diagnostics.CodeAnalysis;
+
+namespace Altinn.Swashbuckle.Filters;
+
+[ExcludeFromCodeCoverage]
+internal class SwaggerExampleFromExampleProviderFilter
+    : AttributeFilter<SwaggerExampleFromExampleProviderAttribute>
+{
+    private readonly OpenApiExampleProvider _provider;
+
+    public SwaggerExampleFromExampleProviderFilter(OpenApiExampleProvider provider)
+    {
+        _provider = provider;
+    }
+
+    protected override void Apply(SwaggerExampleFromExampleProviderAttribute attribute, OpenApiSchema schema, SchemaFilterContext context)
+    {
+        schema.Example ??= _provider.GetExample(context.Type)?.FirstOrDefault();
+    }
+}

src/Altinn.Swashbuckle/src/Altinn.Swashbuckle/Filters/SwaggerStringAttributeFilter.cs

@@ -1,8 +1,10 @@
 using Microsoft.OpenApi.Models;
 using Swashbuckle.AspNetCore.SwaggerGen;
+using System.Diagnostics.CodeAnalysis;
 
 namespace Altinn.Swashbuckle.Filters;
 
+[ExcludeFromCodeCoverage]
 internal class SwaggerStringAttributeFilter
     : AttributeFilter<SwaggerStringAttribute>
 {