Add ChatStats examples and DI support for response examples

- Add ChatStats class and ChatStatsExamplesProvider for response examples
- Implement GetChatStatsAsync in ChatHub and IChatHub
- Enhance SignalROpenApiDocumentGenerator to support DI scopes for example providers
- Add tests verifying response examples in OpenAPI JSON and Swagger UI
- Ensure DI-scoped example providers are resolved in tests
- Register ExampleHub in test server for integration tests

Author: icnocop

samples/SignalR.OpenApi.Sample/Hubs/ChatHub.cs

@@ -76,4 +76,16 @@ public async IAsyncEnumerable<int> Countdown(
             await Task.Delay(1000, cancellationToken);
         }
     }
+
+    /// <inheritdoc />
+    [SignalROpenApiResponseExamples(typeof(ChatStatsExamplesProvider))]
+    public Task<ChatStats> GetChatStatsAsync(string roomName)
+    {
+        return Task.FromResult(new ChatStats
+        {
+            ActiveUsers = 15,
+            TotalMessages = 342,
+            RoomName = roomName,
+        });
+    }
 }

samples/SignalR.OpenApi.Sample/Hubs/ChatStats.cs

@@ -0,0 +1,24 @@
+// Copyright (c) SignalR.OpenApi Contributors. Licensed under the MIT License.
+
+namespace SignalR.OpenApi.Sample.Hubs;
+
+/// <summary>
+/// Represents chat room statistics returned by the hub.
+/// </summary>
+public class ChatStats
+{
+    /// <summary>
+    /// Gets or sets the number of currently active users.
+    /// </summary>
+    public int ActiveUsers { get; set; }
+
+    /// <summary>
+    /// Gets or sets the total number of messages sent.
+    /// </summary>
+    public int TotalMessages { get; set; }
+
+    /// <summary>
+    /// Gets or sets the name of the chat room.
+    /// </summary>
+    public string RoomName { get; set; } = string.Empty;
+}

samples/SignalR.OpenApi.Sample/Hubs/ChatStatsExamplesProvider.cs

@@ -0,0 +1,29 @@
+// Copyright (c) SignalR.OpenApi Contributors. Licensed under the MIT License.
+
+using SignalR.OpenApi.Examples;
+
+namespace SignalR.OpenApi.Sample.Hubs;
+
+/// <summary>
+/// Provides response examples for the GetChatStats method.
+/// </summary>
+public class ChatStatsExamplesProvider : ISignalROpenApiExamplesProvider<ChatStats>
+{
+    /// <inheritdoc/>
+    public IEnumerable<SignalROpenApiExample<ChatStats>> GetExamples()
+    {
+        yield return new SignalROpenApiExample<ChatStats>(
+            "Busy",
+            new ChatStats { ActiveUsers = 42, TotalMessages = 1583, RoomName = "General" })
+        {
+            Summary = "A busy chat room",
+        };
+
+        yield return new SignalROpenApiExample<ChatStats>(
+            "Quiet",
+            new ChatStats { ActiveUsers = 3, TotalMessages = 27, RoomName = "Watercooler" })
+        {
+            Summary = "A quiet chat room",
+        };
+    }
+}

samples/SignalR.OpenApi.Sample/Hubs/IChatHub.cs

@@ -79,4 +79,11 @@ public interface IChatHub
     /// <returns>A stream of countdown numbers.</returns>
     /// <example>10.</example>
     IAsyncEnumerable<int> Countdown(int from, CancellationToken cancellationToken);
+
+    /// <summary>
+    /// Gets the current chat room statistics.
+    /// </summary>
+    /// <param name="roomName">The name of the chat room.</param>
+    /// <returns>The chat statistics for the specified room.</returns>
+    Task<ChatStats> GetChatStatsAsync(string roomName);
 }