Add options for HotChocolate (#13)

This is a braking change if you used Enrich delegate.

README.md

@@ -41,6 +41,7 @@ new MassTransitDiagnosticsSubscriber(o =>
 ```
 The same can be used also for `SendLabel`
 ## HotChocolate
+### Usage
 HotChocolate by default is not emitting diagnostic events, but has the infrastructure to instrument each request.
 ```csharp
 public class Startup
@@ -57,6 +58,19 @@ public class Startup
     }
 }
 ```
+### Options
+Elastic APM Transaction can be enriched by registering a delegate on configure parameter. In this way you can add custom data to the transaction.
+```csharp
+services
+    .AddGraphQLServer()
+    .AddObservability(o => 
+        o.Enrich = (transaction, operationDetails) =>
+        {
+            transaction.SetLabel("GraphQLResult", operationDetails.HasFailed);
+            transaction.SetLabel("Department", Environment.GetEnvironmentVariable("DEPARTMENT"));
+        });
+```
+
 ## Community
 
 This project has adopted the code of conduct defined by the [Contributor Covenant](https://contributor-covenant.org/)

src/Elastic.Apm.GraphQL.HotChocolate/HotChocolateDiagnosticListener.cs

@@ -18,25 +18,25 @@ internal class HotChocolateDiagnosticListener : DiagnosticEventListener
 
         private readonly IApmAgent _apmAgent;
         private readonly IConfigurationReader _configuration;
-        private readonly EnrichTransaction? _enrich;
+        private readonly HotChocolateDiagnosticOptions _options;
         private readonly IApmLogger _apmLogger;
 
         internal HotChocolateDiagnosticListener(
             IApmAgent apmAgent,
             IConfigurationReader configuration,
-            EnrichTransaction? enrich)
+            HotChocolateDiagnosticOptions options)
         {
             _apmAgent = apmAgent;
             _configuration = configuration;
-            _enrich = enrich;
+            _options = options;
             _apmLogger = _apmAgent.Logger;
         }
 
         public override IActivityScope ExecuteRequest(IRequestContext context)
         {
             ITransaction? transaction = _apmAgent.Tracer.CurrentTransaction;
             return transaction != null
-                ? new RequestActivityScope(context, transaction, _apmAgent, _enrich)
+                ? new RequestActivityScope(context, transaction, _apmAgent, _options)
                 : EmptyScope;
         }
 

src/Elastic.Apm.GraphQL.HotChocolate/HotChocolateDiagnosticOptions.cs

@@ -0,0 +1,13 @@
+using System;
+using Elastic.Apm.Api;
+
+namespace Elastic.Apm.GraphQL.HotChocolate
+{
+    public class HotChocolateDiagnosticOptions
+    {
+        /// <summary>
+        /// Gives the possibility to enrich transaction data just before <see cref="RequestActivityScope"/> gets disposed.
+        /// </summary>
+        public Action<ITransaction, OperationDetails>? Enrich { get; set; }
+    }
+}

src/Elastic.Apm.GraphQL.HotChocolate/RequestExecutorBuilderExtensions.cs

@@ -1,37 +1,32 @@
 using System;
-using Elastic.Apm.Api;
 using Elastic.Apm.Config;
 using HotChocolate.Execution.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 
 namespace Elastic.Apm.GraphQL.HotChocolate
 {
-    /// <summary>
-    /// Gives the possibility to enrich transaction data just before <see cref="RequestActivityScope"/> gets disposed.
-    /// </summary>
-    /// <param name="transaction"></param>
-    /// <param name="details"></param>
-    public delegate void EnrichTransaction(ITransaction transaction, OperationDetails details);
-
     /// <summary>
     /// Report diagnostic events to Elastic <see cref="IApmAgent"/>
     /// </summary>
     public static class RequestExecutorBuilderExtensions
     {
         public static IRequestExecutorBuilder AddObservability(
             this IRequestExecutorBuilder builder,
-            EnrichTransaction? enrich = default)
+            Action<HotChocolateDiagnosticOptions>? configure = default)
         {
             if (builder == null)
             {
                 throw new ArgumentNullException(nameof(builder));
             }
 
+            var options = new HotChocolateDiagnosticOptions();
+            configure?.Invoke(options);
+
             return builder.AddDiagnosticEventListener(sp =>
             {
                 IApmAgent apmAgent = sp.GetApplicationService<IApmAgent>();
                 IConfigurationReader configuration = sp.GetApplicationService<IConfigurationReader>();
-                return new HotChocolateDiagnosticListener(apmAgent, configuration, enrich);
+                return new HotChocolateDiagnosticListener(apmAgent, configuration, options);
             });
         }
     }

src/Elastic.Apm.GraphQL.HotChocolate/Scopes/RequestActivityScope.cs

@@ -18,17 +18,18 @@ internal class RequestActivityScope : IActivityScope
         private readonly IRequestContext _context;
         private readonly ITransaction _transaction;
         private readonly IApmAgent _apmAgent;
-        private readonly EnrichTransaction? _enrich;
+        private readonly HotChocolateDiagnosticOptions _options;
 
-        internal RequestActivityScope(IRequestContext context,
+        internal RequestActivityScope(
+            IRequestContext context,
             ITransaction transaction,
             IApmAgent apmAgent,
-            EnrichTransaction? enrich)
+            HotChocolateDiagnosticOptions options)
         {
             _context = context;
             _transaction = transaction;
             _apmAgent = apmAgent;
-            _enrich = enrich;
+            _options = options;
         }
 
         public void Dispose()
@@ -51,7 +52,7 @@ public void Dispose()
                     _apmAgent.CaptureException(exception);
                 }
 
-                _enrich?.Invoke(_transaction, operationDetails);
+                _options.Enrich?.Invoke(_transaction, operationDetails);
             }
             catch (Exception ex)
             {

src/Elastic.Apm.Messaging.MassTransit/MassTransitDiagnosticsSubscriber.cs

@@ -9,7 +9,7 @@ namespace Elastic.Apm.Messaging.MassTransit
     /// </summary>
     public class MassTransitDiagnosticsSubscriber : IDiagnosticsSubscriber
     {
-        private MassTransitDiagnosticOptions _options;
+        private readonly MassTransitDiagnosticOptions _options;
 
         public MassTransitDiagnosticsSubscriber(Action<MassTransitDiagnosticOptions>? configure = default)
         {