Fix YAML deserializer to bind inherited properties in custom step types

src/WorkflowCore.DSL/Services/DefinitionLoader.cs

@@ -222,7 +222,7 @@ private void AttachInputs(StepSourceV1 source, Type dataType, Type stepType, Wor
                 var dataParameter = Expression.Parameter(dataType, "data");
                 var contextParameter = Expression.Parameter(typeof(IStepExecutionContext), "context");
                 var environmentVarsParameter = Expression.Parameter(typeof(IDictionary), "environment");
-                var stepProperty = stepType.GetProperty(input.Key);
+                var stepProperty = stepType.GetProperty(input.Key, BindingFlags.Public | BindingFlags.Instance);
 
                 if (stepProperty == null)
                 {

test/WorkflowCore.TestAssets/DataTypes/CounterBoard.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 
 namespace WorkflowCore.TestAssets.DataTypes
 {
@@ -17,5 +18,6 @@ public class CounterBoard
         public bool Flag1 { get; set; }
         public bool Flag2 { get; set; }
         public bool Flag3 { get; set; }
+        public List<string> DataList { get; set; } = new List<string> { "item1", "item2", "item3" };
     }
 }

test/WorkflowCore.TestAssets/Steps/IterateListStep.cs

@@ -0,0 +1,12 @@
+using WorkflowCore.Interface;
+using WorkflowCore.Models;
+using WorkflowCore.Primitives;
+
+namespace WorkflowCore.TestAssets.Steps
+{
+    public class IterateListStep : Foreach
+    {
+        // This class inherits from Foreach and should be able to use
+        // the RunParallel property from the base class in YAML definitions
+    }
+}

test/WorkflowCore.UnitTests/Services/DefinitionStorage/YamlInheritedPropertyIntegrationTest.cs

@@ -0,0 +1,75 @@
+using System;
+using FakeItEasy;
+using WorkflowCore.Interface;
+using WorkflowCore.Services.DefinitionStorage;
+using Xunit;
+
+namespace WorkflowCore.UnitTests.Services.DefinitionStorage
+{
+    /// <summary>
+    /// Integration test to verify the fix for inherited property binding in YAML definitions.
+    /// This test specifically reproduces the issue mentioned in GitHub issue #1375.
+    /// </summary>
+    public class YamlInheritedPropertyIntegrationTest
+    {
+        [Fact(DisplayName = "Should bind inherited properties like RunParallel from base Foreach class")]
+        public void ShouldBindInheritedPropertiesInYamlDefinition()
+        {
+            // Arrange
+            var registry = A.Fake<IWorkflowRegistry>();
+            var loader = new DefinitionLoader(registry, new TypeResolver());
+
+            // This YAML definition uses a custom step (IterateListStep) that inherits from Foreach
+            // and tries to set the RunParallel property which is defined in the base Foreach class
+            var yamlWithInheritedProperty = @"
+Id: TestInheritedPropertyWorkflow
+Version: 1
+Description: Test workflow for inherited property binding
+DataType: WorkflowCore.TestAssets.DataTypes.CounterBoard, WorkflowCore.TestAssets
+Steps:
+  - Id: IterateList
+    StepType: WorkflowCore.TestAssets.Steps.IterateListStep, WorkflowCore.TestAssets
+    Inputs:
+      Collection: ""data.DataList""
+      RunParallel: false
+";
+
+            // Act & Assert
+            // Before the fix, this would throw: "Unknown property for input RunParallel on IterateList"
+            // After the fix, this should succeed
+            var exception = Record.Exception(() => 
+                loader.LoadDefinition(yamlWithInheritedProperty, Deserializers.Yaml));
+
+            // Verify no exception was thrown
+            Assert.Null(exception);
+        }
+
+        [Fact(DisplayName = "Should still throw exception for truly unknown properties")]
+        public void ShouldStillThrowForUnknownProperties()
+        {
+            // Arrange
+            var registry = A.Fake<IWorkflowRegistry>();
+            var loader = new DefinitionLoader(registry, new TypeResolver());
+
+            var yamlWithUnknownProperty = @"
+Id: TestInheritedPropertyWorkflow
+Version: 1
+Description: Test workflow for inherited property binding
+DataType: WorkflowCore.TestAssets.DataTypes.CounterBoard, WorkflowCore.TestAssets
+Steps:
+  - Id: IterateList
+    StepType: WorkflowCore.TestAssets.Steps.IterateListStep, WorkflowCore.TestAssets
+    Inputs:
+      Collection: ""data.DataList""
+      NonExistentProperty: false
+";
+
+            // Act & Assert
+            // This should still throw an exception for truly unknown properties
+            var exception = Assert.Throws<ArgumentException>(() => 
+                loader.LoadDefinition(yamlWithUnknownProperty, Deserializers.Yaml));
+
+            Assert.Contains("Unknown property for input NonExistentProperty", exception.Message);
+        }
+    }
+}