Fix While activity + add test

src/core/Elsa.Core/Activities/ControlFlow/While/While.cs

@@ -15,13 +15,8 @@ namespace Elsa.Activities.ControlFlow
     )]
     public class While : Activity
     {
-        private readonly IExpressionEvaluator _expressionEvaluator;
-
-        public While(IExpressionEvaluator expressionEvaluator)
-        {
-            _expressionEvaluator = expressionEvaluator;
-        }
-
+        public const string IterateOutcome = "Iterate";
+        
         [ActivityProperty(Hint = "The condition to evaluate.")]
         public bool Condition { get; set; }
 
@@ -30,7 +25,7 @@ namespace Elsa.Activities.ControlFlow
             var loop = Condition;
 
             if (loop)
-                return Combine(Schedule(Id), Done(OutcomeNames.Iterate));
+                return Combine(PostSchedule(Id), Outcome(IterateOutcome));
 
             return Done();
         }

src/core/Elsa.Core/Activities/ControlFlow/While/WhileExtensions.cs

@@ -0,0 +1,14 @@
+using System;
+using Elsa.Builders;
+using Elsa.Services.Models;
+
+// ReSharper disable once CheckNamespace
+namespace Elsa.Activities.ControlFlow
+{
+    public static class WhileExtensions
+    {
+        public static ISetupActivity<While> WithCondition(this ISetupActivity<While> activity, Func<ActivityExecutionContext, bool> value) => activity.Set(x => x.Condition, value);
+        public static ISetupActivity<While> WithCondition(this ISetupActivity<While> activity, Func<bool> value) => activity.Set(x => x.Condition, value);
+        public static ISetupActivity<While> WithCondition(this ISetupActivity<While> activity, bool value) => activity.Set(x => x.Condition, value);
+    }
+}

test/integration/Elsa.Core.IntegrationTests/WhileWorkflowTests.cs

@@ -0,0 +1,27 @@
+using System.Linq;
+using System.Threading.Tasks;
+using Elsa.Core.IntegrationTests.Workflows;
+using Elsa.Testing.Shared.Helpers;
+using Xunit;
+using Xunit.Abstractions;
+
+namespace Elsa.Core.IntegrationTests
+{
+    public class WhileWorkflowTests : WorkflowsUnitTestBase
+    {
+        public WhileWorkflowTests(ITestOutputHelper testOutputHelper) : base(testOutputHelper)
+        {
+        }
+        
+        [Fact(DisplayName = "Runs loop while condition is true.")]
+        public async Task Test01()
+        {
+            const int loopCount = 3;
+            var workflow = new WhileWorkflow(loopCount);
+            var workflowInstance = await WorkflowRunner.RunWorkflowAsync(workflow);
+            var iterationLogs = workflowInstance.ExecutionLog.Where(x => x.ActivityId == "WriteLoopCount").ToList();
+
+            Assert.Equal(loopCount, iterationLogs.Count);
+        }
+    }
+}

test/integration/Elsa.Core.IntegrationTests/Workflows/WhileWorkflow.cs

@@ -0,0 +1,36 @@
+using Elsa.Activities.Console;
+using Elsa.Activities.ControlFlow;
+using Elsa.Builders;
+using Elsa.Services.Models;
+
+namespace Elsa.Core.IntegrationTests.Workflows
+{
+    public class WhileWorkflow : IWorkflow
+    {
+        private const string CounterVariableName = "Counter";
+        private readonly int _loopCount;
+
+        public WhileWorkflow(int loopCount)
+        {
+            _loopCount = loopCount;
+        }
+        
+        public void Build(IWorkflowBuilder workflow)
+        {
+            workflow
+                .Then<While>(
+                    @while => @while.WithCondition(context => GetCounter(context) < _loopCount),
+                    @while =>
+                    {
+                        @while
+                            .When(While.IterateOutcome)
+                            .WriteLine(context => $"Inside while loop. Counter = {context.GetVariable<int>(CounterVariableName)}", id: "WriteLoopCount")
+                            .SetVariable(CounterVariableName, context => GetCounter(context) + 1);
+
+                    })
+                .Then<WriteLine>(writeLine => writeLine.WithText("Done")).WithName("Done");
+        }
+        
+        private int GetCounter(ActivityExecutionContext context) => context.GetVariable<int>(CounterVariableName);
+    }
+}