sub workflow result propagation as output to parent

Author: kfrajtak

src/WorkflowCore/Services/FluentBuilders/StepBuilder.cs

@@ -603,6 +603,16 @@ public IStepBuilder<TData, SubWorkflowStepBody> SubWorkflow(
 
             if (parameters != null)
                 stepBuilder.Input((step) => step.Parameters, parameters);
+            
+            // use the result of the sub workflow as an output
+            // merge it with parent workflow data
+            stepBuilder.Output((body, data) =>
+            {
+                foreach (var prop in typeof(TData).GetProperties())
+                {
+                    prop.SetValue(data, prop.GetValue(body.Result));
+                }
+            });
 
             Step.Outcomes.Add(new ValueOutcome { NextStep = newStep.Id });
             return stepBuilder;

test/WorkflowCore.IntegrationTests/Scenarios/ApprovalScenario.cs

@@ -1,5 +1,6 @@
 using System;
 using FluentAssertions;
+using Newtonsoft.Json.Linq;
 using WorkflowCore.Interface;
 using WorkflowCore.Models;
 using WorkflowCore.Testing;
@@ -58,7 +59,12 @@ public void Build(IWorkflowBuilder<ApprovalInput> builder)
                 .Do(then
                     => then
                         .WaitFor("Approved", e => e.Id)
-                        .Output(i => i.Approved, step => step.EventData) 
+                        .Output((w, input) =>
+                        {
+                            var j = JObject.FromObject(w.EventData);
+                            input.Approved = j["Approved"].Value<bool>();
+                            input.Message= j["Message"].Value<string>();
+                        })
                         .EndWorkflow()
                 )
                 .Join();
@@ -87,15 +93,25 @@ public void Scenario(bool approved)
         WaitForEventSubscription("Approved", workflowId, TimeSpan.FromSeconds(5));
         UnhandledStepErrors.Should().BeEmpty();
 
-        Host.PublishEvent("Approved", workflowId, approved);
+        Host.PublishEvent("Approved", workflowId, new
+        {
+            Approved = approved, 
+            Message = "message " + approved 
+        });
 
         WaitForWorkflowToComplete(workflowId, TimeSpan.FromSeconds(10));
 
         System.Threading.Thread.Sleep(2000);
 
         UnhandledStepErrors.Should().BeEmpty();
         GetStatus(workflowId).Should().Be(WorkflowStatus.Complete);
-        GetData(workflowId).Approved.Should().Be(approved);
+        GetData(workflowId).ShouldBeEquivalentTo(new ApprovalInput
+        {
+            Id = eventKey,
+            Approved = approved,
+            Message = "message " + approved,
+            TimeSpan = TimeSpan.FromMinutes(10)
+        });
     }
 
     [Fact]

test/WorkflowCore.Tests.Sqlite/Scenarios/SqliteApprovalScenario.cs

@@ -0,0 +1,21 @@
+using System;
+using Microsoft.Extensions.DependencyInjection;
+using WorkflowCore.IntegrationTests.Scenarios;
+using Xunit;
+using Xunit.Abstractions;
+
+namespace WorkflowCore.Tests.Sqlite.Scenarios
+{
+    [Collection("Sqlite collection")]
+    public class SqliteApprovalScenario : ApprovalScenario
+    {
+        protected override void ConfigureServices(IServiceCollection services)
+        {
+            services.AddWorkflow(cfg =>
+            {
+                cfg.UseSqlite($"Data Source=wfc-tests-{DateTime.Now.Ticks}.db;", true);
+                cfg.UsePollInterval(TimeSpan.FromSeconds(2));
+            });
+        }
+    }
+}