Migrating to v12.0.0

CsvHelper 12 changes the order in which the writer writes the properties of dynamic objects: the order the object gives them, instead of sorted by name. A new setting, DynamicPropertySort, sorts them again. Nothing else changes, except that code that implements IWriterConfiguration needs the new property.

Writing dynamic objects

11 sorted the properties of an ExpandoObject, or of another dynamic object, by name, in the header and in the records. 12 writes them in the order the object gives them, which for an ExpandoObject is the order they were created in. To keep the sorted columns, set DynamicPropertySort to the comparer that 11 sorted with:

dynamic product = new System.Dynamic.ExpandoObject();
product.Name = "Widget";
product.Id = 1;

using var csv = new CsvWriter(writer);
csv.WriteRecords(new List<dynamic> { product });
// Id,Name
// 1,Widget

dynamic product = new System.Dynamic.ExpandoObject();
product.Name = "Widget";
product.Id = 1;

using var csv = new CsvWriter(writer);
csv.Configuration.DynamicPropertySort = Comparer<string>.Default;
csv.WriteRecords(new List<dynamic> { product });
// Id,Name
// 1,Widget

Without the setting, 12 writes Name,Id and Widget,1.

• Use 12.0.1 or later. 12.0.0 still sorted the header when DynamicPropertySort was null, so the header didn't match the values. 12.0.1 fixed it.
• Any order: DynamicPropertySort takes any IComparer<string>. null, the default, keeps the object's order.