private static ObjectComparisonMismatch CompareNodes(GraphNode leftNode, GraphNode rightNode)
{
// check if one of the nodes is null while the other is not
if ((leftNode.ObjectValue == null && rightNode.ObjectValue != null) ||
(leftNode.ObjectValue != null && rightNode.ObjectValue == null))
{
var mismatch = new ObjectComparisonMismatch(
leftNode,
rightNode,
ObjectComparisonMismatchType.ObjectValuesDoNotMatch);
return(mismatch);
}
if (leftNode.ObjectValue != null && rightNode.ObjectValue != null)
{
// compare types
if (leftNode.ObjectType != rightNode.ObjectType)
{
var mismatch = new ObjectComparisonMismatch(
leftNode,
rightNode,
ObjectComparisonMismatchType.ObjectTypesDoNotMatch);
return(mismatch);
}
// compare primitives, strings, datatimes, guids
if (leftNode.ObjectType.IsPrimitive ||
leftNode.ObjectType == typeof(string) ||
leftNode.ObjectType == typeof(DateTime) ||
leftNode.ObjectType == typeof(Guid))
{
if (!leftNode.ObjectValue.Equals(rightNode.ObjectValue))
{
var mismatch = new ObjectComparisonMismatch(
leftNode,
rightNode,
ObjectComparisonMismatchType.ObjectValuesDoNotMatch);
return(mismatch);
}
return(null);
}
}
if (leftNode.ObjectValue != null && rightNode.ObjectValue != null)
{
TypeFilter f = (a, b) => true;
var iComparable = leftNode.ObjectType.FindInterfaces(f, null)
.FirstOrDefault(i => i.IsGenericType &&
i.GetGenericTypeDefinition() == typeof(IComparable <>) &&
i.GetGenericArguments()[0] == rightNode.ObjectType);
if (iComparable != null)
{
var result = (int)iComparable.GetMethods()[0].Invoke(leftNode.ObjectValue, new[] { rightNode.ObjectValue });
if (result != 0)
{
var mismatch = new ObjectComparisonMismatch(
leftNode,
rightNode,
ObjectComparisonMismatchType.ObjectValuesDoNotMatch);
return(mismatch);
}
}
}
// compare the child count
if (leftNode.Children.Count != rightNode.Children.Count)
{
var type = leftNode.Children.Count > rightNode.Children.Count
? ObjectComparisonMismatchType.RightNodeHasFewerChildren
: ObjectComparisonMismatchType.LeftNodeHasFewerChildren;
var mismatch = new ObjectComparisonMismatch(
leftNode,
rightNode,
type);
return(mismatch);
}
// No mismatch //
return(null);
}