custom exceptions

Author: danielgerlag

ReleaseNotes/1.4.0.md

@@ -98,7 +98,7 @@ Full details of the capabilities of  expression language can be found [here](htt
       "StepType": "MyApp.HelloWorld, MyApp",
       "NextStepId": "Print"
     },
-	{
+    {
       "Id": "Print",
       "StepType": "MyApp.PrintMessage, MyApp",
       "Inputs": { "Message": "\"Hi there!\"" }
@@ -287,7 +287,7 @@ The `.Recur` can be implemented as follows
       "Id": "MyScheduleStep",
       "StepType": "WorkflowCore.Primitives.Recur, WorkflowCore",
       "Inputs": { 
-	    "Interval": "<<expression to evaluate>>",
+        "Interval": "<<expression to evaluate>>",
         "StopCondition": "<<expression to evaluate>>" 
       },
       "Do": [[

src/WorkflowCore/Exceptions/WorkflowDefinitionLoadException.cs

@@ -0,0 +1,14 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace WorkflowCore.Exceptions
+{
+    public class WorkflowDefinitionLoadException : Exception
+    {
+        public WorkflowDefinitionLoadException(string message)
+            : base (message)
+        {            
+        }
+    }
+}

src/WorkflowCore/Services/DefinitionStorage/DefinitionLoader.cs

@@ -11,6 +11,7 @@
 using WorkflowCore.Primitives;
 using WorkflowCore.Models.DefinitionStorage;
 using WorkflowCore.Models.DefinitionStorage.v1;
+using WorkflowCore.Exceptions;
 
 namespace WorkflowCore.Services.DefinitionStorage
 {
@@ -22,7 +23,7 @@ public DefinitionLoader(IWorkflowRegistry registry)
         {
             _registry = registry;
         }
-        
+                        
         public WorkflowDefinition LoadDefinition(string json)
         {
             var source = JsonConvert.DeserializeObject<DefinitionSourceV1>(json);
@@ -107,8 +108,14 @@ private List<WorkflowStep> ConvertSteps(ICollection<StepSourceV1> source, Type d
 
             foreach (var step in result)
             {
+                if (result.Any(x => x.Tag == step.Tag && x.Id != step.Id))
+                    throw new WorkflowDefinitionLoadException($"Duplicate step Id {step.Tag}");
+
                 foreach (var outcome in step.Outcomes)
                 {
+                    if (result.All(x => x.Tag != outcome.Tag))
+                        throw new WorkflowDefinitionLoadException($"Cannot find step id {outcome.Tag}");
+
                     outcome.NextStep = result.Single(x => x.Tag == outcome.Tag).Id;
                 }
             }
@@ -137,8 +144,6 @@ private void AttachInputs(StepSourceV1 source, Type dataType, Type stepType, Wor
             {
                 var dataParameter = Expression.Parameter(dataType, "data");
                 var contextParameter = Expression.Parameter(typeof(IStepExecutionContext), "context");
-                
-                // https://github.com/StefH/System.Linq.Dynamic.Core/wiki/Dynamic-Expressions
                 var sourceExpr = DynamicExpressionParser.ParseLambda(new [] { dataParameter, contextParameter }, typeof(object), input.Value);
                 var targetExpr = Expression.Property(Expression.Parameter(stepType), input.Key);
 
@@ -168,7 +173,7 @@ private void AttachOutputs(StepSourceV1 source, Type dataType, Type stepType, Wo
 
         private Type FindType(string name)
         {
-            return Type.GetType(name);
+            return Type.GetType(name, true, true);
         }
 
     }