support:

activity with no parameters
activity inside anonymous method
activity inside local function under a method

Author: shaykeren

rider/Digma.Rider.Plugin/Digma.Rider/Discovery/CodeObjectsDiscoveryMethodProcessor.cs

@@ -1,12 +1,17 @@
+using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using Digma.Rider.Protocol;
 using Digma.Rider.Util;
 using JetBrains.ReSharper.Psi.CSharp.Tree;
 using JetBrains.ReSharper.Psi.Tree;
+using JetBrains.ReSharper.Psi.VB.Tree;
 using JetBrains.Util;
 using static Digma.Rider.Logging.Logger;
 using static JetBrains.Util.Logging.Logger;
+using IBlock = JetBrains.ReSharper.Psi.CSharp.Tree.IBlock;
+using ILambdaExpression = JetBrains.ReSharper.Psi.CSharp.Tree.ILambdaExpression;
+using ILocalVariableDeclaration = JetBrains.ReSharper.Psi.CSharp.Tree.ILocalVariableDeclaration;
 
 namespace Digma.Rider.Discovery
 {
@@ -66,9 +71,13 @@ public override bool InteriorShouldBeProcessed(ITreeNode element)
                 case IBlock block:
                 case ICSharpStatement cSharpStatement:
                 case IMultipleLocalVariableDeclaration multipleLocalVariableDeclaration:
+                case ILocalVariableDeclaration localVariableDeclaration:
+                case IExpressionInitializer expressionInitializer:
+                case ILambdaExpression lambdaExpression:
+                case ILocalFunctionDeclaration localFunctionDeclaration:
                     return true;
             }
-
+            
             return false;
         }
 
@@ -82,7 +91,7 @@ public override void ProcessBeforeInterior(ITreeNode element)
                     Log(Logger, "in '{0}' for method '{1}' in file '{2}'", 
                         element,
                         _functionDeclaration, DiscoveryContext.PsiSourceFile.Name);
-                    var spanDiscovery = new SpanDiscovery(localVariableDeclaration);
+                    var spanDiscovery = new SpanDiscovery(localVariableDeclaration, _methodInfo.Name);
                     if (spanDiscovery.InstLibrary == null || spanDiscovery.SpanName == null)
                     {
                         if (spanDiscovery.HasReferenceResolvingErrors)

rider/Digma.Rider.Plugin/Digma.Rider/Discovery/SpanDiscovery.cs

@@ -1,4 +1,5 @@
 using JetBrains.Annotations;
+using JetBrains.ReSharper.Feature.Services.Html;
 using JetBrains.ReSharper.Psi;
 using JetBrains.ReSharper.Psi.CSharp.Tree;
 using JetBrains.ReSharper.Psi.Resolve;
@@ -10,6 +11,7 @@ namespace Digma.Rider.Discovery
 
     public class SpanDiscovery
     {
+        private readonly string _methodName;
         private const string ActivitySourceClassName = "System.Diagnostics.ActivitySource";
         private const string StartActivityMethodName = "StartActivity";
 
@@ -19,8 +21,9 @@ public class SpanDiscovery
         public bool HasReferenceResolvingErrors { get; private set; } = false;
 
 
-        public SpanDiscovery([NotNull] ILocalVariableDeclaration localVariableDeclaration)
+        public SpanDiscovery([NotNull] ILocalVariableDeclaration localVariableDeclaration , string methodName)
         {
+            _methodName = methodName;
             var expressionInitializer = localVariableDeclaration.Children<IExpressionInitializer>().FirstNotNull();
             var value = expressionInitializer?.Value;
             if (value is IInvocationExpression expression)
@@ -48,15 +51,18 @@ private void DiscoverFromInvocationExpression([NotNull] IInvocationExpression in
             }
         }
 
-        //the arguments to Activity.StartActivity("the argument")
+        /*
+         * the arguments to Activity.StartActivity("the argument")
+         * or Activity.StartActivity()
+        */
         private string DiscoverSpanNameFromInvocationArguments([NotNull] IArgumentList invocationExpressionArgumentList)
         {
             if (invocationExpressionArgumentList.Arguments.Count is 1 or 2)
             {
                 return GetTextFromArgument(invocationExpressionArgumentList.Arguments[0]);
             }
 
-            return null;
+            return invocationExpressionArgumentList.Arguments.Count == 0 ? _methodName : null;
         }
 
         private string DiscoverInstrumentationLibraryFromInvokedExpression(