In DDD Architecture where do I keep helper classes?

Question

I\'m working in a DDD project where contains these layers: UI, Application, Domain and Infrastructure.

Where should the helpers classes live?

Update:

Answer 1

Classes like [Something]Helper, [Something]Manager and [Something]Util are too generic and often indicate the fact that nobody really thought about a proper name and their responsibility. They tend to grow over time accumulating random pieces of code. So instead of finding the right place for your 'Helper' you should probably rename it and it will become clear whether they belong to Infrastructure or elsewhere.

Note that every .NET object already has a method for diagnostics and logging. So you may not need 'Object Dumper Helper':

ToString is intended to be used for general display and debugging purposes.

Answer 2

It depends on what kind of helper you are talking about.

If it's a Helper that format a value in a friendly display format, then it would fit better in the UI. If you are talking about a SqlServer helper, then it goes to Infra.

Answer 3

Assuming Infra stands for Infrastructure, that's where.