public static Expression GetFallbackCollectionValue(this IMemberMapperData mapperData)
{
var targetMember = mapperData.TargetMember;
Expression emptyEnumerable;
if (mapperData.TargetMemberHasInitAccessibleValue())
{
var existingValue = mapperData.GetTargetMemberAccess();
if (mapperData.MapToNullCollections())
{
return(existingValue);
}
emptyEnumerable = targetMember.Type.GetEmptyInstanceCreation(targetMember.ElementType);
return(Expression.Coalesce(existingValue, emptyEnumerable));
}
if (mapperData.MapToNullCollections())
{
return(targetMember.Type.ToDefaultExpression());
}
emptyEnumerable = targetMember.Type.GetEmptyInstanceCreation(targetMember.ElementType);
return(emptyEnumerable.GetConversionTo(targetMember.Type));
}