bugfix: improve CollectionShouldNotHaveSameCount_CountShouldNotBeOtherCollectionCount detection

Author: Meir017

src/FluentAssertions.Analyzers/Tips/FluentAssertionsAnalyzer.cs

@@ -408,7 +408,7 @@ private static void AnalyzeInvocation(OperationAnalysisContext context, FluentAs
                         {
                             // TODO: add support for Enumerable.LongCount
                             case nameof(Enumerable.Count) when IsEnumerableMethodWithoutArguments(invocationBeforeShould, metadata):
-                                if (assertion.TryGetSingleArgumentAs<IInvocationOperation>(out var assertionInvocation) && assertionInvocation.TargetMethod.Name is nameof(Enumerable.Count))
+                                if (assertion.TryGetFirstArgumentAs<IInvocationOperation>(out var assertionInvocation) && IsEnumerableMethodWithoutArguments(assertionInvocation, metadata))
                                 {
                                     context.ReportDiagnostic(CreateDiagnostic(assertion, DiagnosticMetadata.CollectionShouldNotHaveSameCount_CountShouldNotBeOtherCollectionCount));
                                 }

src/FluentAssertions.Analyzers/Utilities/OperartionExtensions.cs

@@ -199,6 +199,18 @@ public static bool TryGetSingleArgumentAs<TOperation>(this IInvocationOperation
         return false;
     }
 
+    public static bool TryGetFirstArgumentAs<TOperation>(this IInvocationOperation invocation, out TOperation operation)
+    {
+        if (invocation.Arguments.Length is >= 1 && invocation.Arguments[0].Value.UnwrapConversion() is TOperation op)
+        {
+            operation = op;
+            return true;
+        }
+
+        operation = default;
+        return false;
+    }
+
     public static IOperation UnwrapConversion(this IOperation operation)
     {
         return operation switch