Fix tests

Check `Paths` and `Operations` are not null.

Author: martincostello

src/Swashbuckle.AspNetCore.ApiTesting/OpenApiDocumentExtensions.cs

@@ -11,17 +11,23 @@ internal static bool TryFindOperationById(
         out string pathTemplate,
         out HttpMethod operationType)
     {
-        foreach (var pathEntry in openApiDocument.Paths ?? [])
+        if (openApiDocument.Paths is { Count: > 0 } paths)
         {
-            var pathItem = pathEntry.Value;
-
-            foreach (var operationEntry in pathItem.Operations)
+            foreach (var pathEntry in paths)
             {
-                if (operationEntry.Value.OperationId == operationId)
+                var pathItem = pathEntry.Value;
+
+                if (pathItem.Operations is { Count: > 0 } operations)
                 {
-                    pathTemplate = pathEntry.Key;
-                    operationType = operationEntry.Key;
-                    return true;
+                    foreach (var operation in operations)
+                    {
+                        if (operation.Value.OperationId == operationId)
+                        {
+                            pathTemplate = pathEntry.Key;
+                            operationType = operation.Key;
+                            return true;
+                        }
+                    }
                 }
             }
         }

test/WebSites/TestFirst.IntegrationTests/ApiTestsSetup.cs

@@ -56,5 +56,4 @@ private static string GetSolutionRelativeContentRoot(
 }
 
 [CollectionDefinition("ApiTests")]
-public class ApiTestsCollection : ICollectionFixture<ApiTestRunner>
-{}
+public class ApiTestsCollection : ICollectionFixture<ApiTestRunner>;