WIP #761 - Integration test reproduces problem

StackOverflowException reproduced exactly as reported.

test/integration/Elsa.Core.IntegrationTests/Autofixture/HostBuilderWithElsaAndJavaScriptExpressionsAttribute.cs

@@ -0,0 +1,18 @@
+using System.Reflection;
+using AutoFixture;
+using AutoFixture.Xunit2;
+using Elsa.Testing.Shared.AutoFixture.Customizations;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace Elsa.Core.IntegrationTests.Autofixture
+{
+    public class HostBuilderWithElsaAndJavaScriptExpressionsAttribute : CustomizeAttribute
+    {
+        public override ICustomization GetCustomization(ParameterInfo parameter)
+        {
+            return new HostBubilderUsingServicesCustomization(services => {
+                services.AddElsa().AddJavaScriptExpressionEvaluator();
+            }, parameter);
+        }
+    }
+}

test/integration/Elsa.Core.IntegrationTests/Scripting/JavaScript/JavaScriptExpressionsIntegrationTests.cs

@@ -0,0 +1,96 @@
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using Elsa.Activities.Console;
+using Elsa.Activities.Primitives;
+using Elsa.Core.IntegrationTests.Autofixture;
+using Elsa.Models;
+using Elsa.Serialization;
+using Elsa.Services;
+using Elsa.Services.Models;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+using Xunit;
+
+namespace Elsa.Core.IntegrationTests.Scripting.JavaScript
+{
+    public class JavaScriptExpressionsIntegrationTests
+    {
+        [Theory(DisplayName = "Running a workflow which uses JSON.stringify upon a JSON.parse'd object should not throw"), AutoMoqData]
+        public async Task RunningAWorkflowThatIncludesJsonStringifyAParsedObjectShouldNotThrow([HostBuilderWithElsaAndJavaScriptExpressions] IHostBuilder hostBuilder)
+        {
+            hostBuilder.ConfigureServices((ctx, services) => services.AddHostedService<HostedWorkflowRunner>());
+            var host = await hostBuilder.StartAsync();
+        }
+
+        class HostedWorkflowRunner : IHostedService
+        {
+            readonly IWorkflowRunner workflowRunner;
+            readonly IContentSerializer serializer;
+            readonly IWorkflowBlueprintMaterializer materializer;
+
+            public async Task StartAsync(CancellationToken cancellationToken)
+            {
+                var workflow = await GetWorkflowBlueprintAsync(GetWorkflowDefinition());
+                var workflowInstance = await workflowRunner.RunWorkflowAsync(workflow);
+
+                Assert.NotNull(workflowInstance);
+                Assert.Null(workflowInstance.Fault);
+            }
+
+            public Task StopAsync(CancellationToken cancellationToken) => Task.CompletedTask;
+
+            async Task<IWorkflowBlueprint> GetWorkflowBlueprintAsync(WorkflowDefinition workflowDefinition)
+            {
+                var json = serializer.Serialize(workflowDefinition);
+                var deserializedWorkflowDefinition = serializer.Deserialize<WorkflowDefinition>(json);
+                return await materializer.CreateWorkflowBlueprintAsync(deserializedWorkflowDefinition);
+            }
+
+            WorkflowDefinition GetWorkflowDefinition()
+            {
+                return  new WorkflowDefinition
+                {
+                    Id = "1",
+                    DefinitionId = "SampleWorkflow",
+                    Version = 1,
+                    IsPublished = true,
+                    IsLatest = true,
+                    PersistenceBehavior = WorkflowPersistenceBehavior.Suspended,
+                    Activities = new[]
+                    {
+                        new ActivityDefinition {
+                            ActivityId = "1",
+                            Type = nameof(SetVariable),
+                            Properties = new List<ActivityDefinitionProperty>
+                            {
+                                ActivityDefinitionProperty.Literal(nameof(SetVariable.VariableName), "MyVariable"),
+                                ActivityDefinitionProperty.JavaScript(nameof(SetVariable.Value), @"JSON.parse(""{\""foo\"":\""bar\""}"")"),
+                            }
+                        },
+                        new ActivityDefinition {
+                            ActivityId = "2",
+                            Type = nameof(SetVariable),
+                            Properties = new List<ActivityDefinitionProperty>
+                            {
+                                ActivityDefinitionProperty.Literal(nameof(SetVariable.VariableName), "MyStringifiedVariable"),
+                                ActivityDefinitionProperty.JavaScript(nameof(SetVariable.Value), @"JSON.stringify(MyVariable)"),
+                            }
+                        }
+                    },
+                    Connections = new[]
+                    {
+                        new ConnectionDefinition("1", "2", OutcomeNames.Done),
+                    }
+                };
+            }
+
+            public HostedWorkflowRunner(IWorkflowRunner workflowRunner, IContentSerializer serializer, IWorkflowBlueprintMaterializer materializer)
+            {
+                this.workflowRunner = workflowRunner ?? throw new System.ArgumentNullException(nameof(workflowRunner));
+                this.serializer = serializer ?? throw new System.ArgumentNullException(nameof(serializer));
+                this.materializer = materializer ?? throw new System.ArgumentNullException(nameof(materializer));
+            }
+        }
+    }
+}