add union channels

src/Saunter/AsyncApiServiceCollectionExtensions.cs

@@ -23,6 +23,7 @@ public static IServiceCollection AddAsyncApiSchemaGeneration(this IServiceCollec
 
             services.TryAddSingleton<IAsyncApiDocumentCloner, AsyncApiDocumentSerializeCloner>();
             services.TryAddSingleton<IAsyncApiSchemaGenerator, AsyncApiSchemaGenerator>();
+            services.TryAddSingleton<IAsyncApiChannelUnion, AsyncApiChannelUnion>();
 
             services.TryAddTransient<IAsyncApiDocumentProvider, AttributeDocumentProvider>();
 

src/Saunter/AttributeProvider/AttributeDocumentProvider.cs

@@ -16,12 +16,14 @@ internal class AttributeDocumentProvider : IAsyncApiDocumentProvider
     {
         private readonly IServiceProvider _serviceProvider;
         private readonly IAsyncApiSchemaGenerator _schemaGenerator;
+        private readonly IAsyncApiChannelUnion _channelUnion;
         private readonly IAsyncApiDocumentCloner _cloner;
 
-        public AttributeDocumentProvider(IServiceProvider serviceProvider, IAsyncApiSchemaGenerator schemaGenerator, IAsyncApiDocumentCloner cloner)
+        public AttributeDocumentProvider(IServiceProvider serviceProvider, IAsyncApiSchemaGenerator schemaGenerator, IAsyncApiChannelUnion channelUnion, IAsyncApiDocumentCloner cloner)
         {
             _serviceProvider = serviceProvider;
             _schemaGenerator = schemaGenerator;
+            _channelUnion = channelUnion;
             _cloner = cloner;
         }
 
@@ -90,7 +92,13 @@ private void GenerateChannelsFromMethods(AsyncApiDocument document, AsyncApiOpti
                         : null,
                 };
 
-                document.Channels.Add(item.Channel.Name, channelItem);
+                if (!document.Channels.TryAdd(item.Channel.Name, channelItem))
+                {
+                    document.Channels[item.Channel.Name] = _channelUnion.Union(
+                        document.Channels[item.Channel.Name],
+                        channelItem);
+                }
+
                 ApplyChannelFilters(options, item.Method, item.Channel, channelItem);
             }
         }
@@ -131,7 +139,12 @@ private void GenerateChannelsFromClasses(AsyncApiDocument document, AsyncApiOpti
                         : null,
                 };
 
-                document.Channels.Add(item.Channel.Name, channelItem);
+                if (!document.Channels.TryAdd(item.Channel.Name, channelItem))
+                {
+                    document.Channels[item.Channel.Name] = _channelUnion.Union(
+                        document.Channels[item.Channel.Name],
+                        channelItem);
+                }
 
                 ApplyChannelFilters(options, item.Type, item.Channel, channelItem);
             }

src/Saunter/SharedKernel/AsyncApiChannelUnion.cs

@@ -0,0 +1,68 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using LEGO.AsyncAPI.Models;
+using LEGO.AsyncAPI.Models.Interfaces;
+using Saunter.SharedKernel.Interfaces;
+
+namespace Saunter.SharedKernel
+{
+    internal class AsyncApiChannelUnion : IAsyncApiChannelUnion
+    {
+        public AsyncApiChannel Union(AsyncApiChannel source, AsyncApiChannel additionaly)
+        {
+            if (source.Publish is not null && additionaly.Publish is not null)
+            {
+                throw new InvalidOperationException("Publish operation conflict");
+            }
+
+            if (source.Subscribe is not null && additionaly.Subscribe is not null)
+            {
+                throw new InvalidOperationException("Publish operation conflict");
+            }
+
+            if (source.Reference is not null && additionaly.Reference is not null)
+            {
+                throw new InvalidOperationException("Reference operation conflict");
+            }
+
+            var publishOperation = source.Publish ?? additionaly.Publish;
+            var subscribeOperation = source.Subscribe ?? additionaly.Subscribe;
+
+            var servers = source.Servers?.Any() == true
+                ? source.Servers
+                : additionaly.Servers
+                ?? new List<string>();
+
+            var bindings = source.Bindings?.Any() == true
+                ? source.Bindings
+                : additionaly.Bindings
+                ?? new();
+
+            var parameters = source.Parameters?.Any() == true
+                ? source.Parameters
+                : additionaly.Parameters
+                ?? new Dictionary<string, AsyncApiParameter>();
+
+            var extensions = source.Extensions?.Any() == true
+                ? source.Extensions
+                : additionaly.Extensions
+                ?? new Dictionary<string, IAsyncApiExtension>();
+
+            return new()
+            {
+                Publish = publishOperation,
+                Subscribe = subscribeOperation,
+                UnresolvedReference = source.UnresolvedReference,
+
+                Servers = servers,
+                Bindings = bindings,
+                Parameters = parameters,
+                Extensions = extensions,
+
+                Reference = source.Reference ?? additionaly.Reference,
+                Description = source.Description ?? additionaly.Description,
+            };
+        }
+    }
+}

src/Saunter/SharedKernel/Interfaces/IAsyncApiChannelUnion.cs

@@ -0,0 +1,9 @@
+using LEGO.AsyncAPI.Models;
+
+namespace Saunter.SharedKernel.Interfaces
+{
+    public interface IAsyncApiChannelUnion
+    {
+        AsyncApiChannel Union(AsyncApiChannel source, AsyncApiChannel additionaly);
+    }
+}

test/Saunter.Tests/AttributeProvider/DocumentGenerationTests/ArrangeAttributesTests.cs

@@ -29,6 +29,7 @@ public static void Arrange(out AsyncApiOptions options, out AttributeDocumentPro
             documentProvider = new AttributeDocumentProvider(
                 ActivatorServiceProvider.Instance,
                 new AsyncApiSchemaGenerator(),
+                new AsyncApiChannelUnion(),
                 new AsyncApiDocumentSerializeCloner(new FakeLogger<AsyncApiDocumentSerializeCloner>()));
         }
     }