Can all my classes be singletons?

Question

I'm implementing a project where I'm testing my UI. So, each part of my UI is a separate class(Seleniums page object pattern). Now, since it's just a single web page I'm testing, according to me, theres just gotta be one instance of my UI components, while they do change state, I don't see the benefits of multiple instance of these components floating around.

So, I'm tempted to make all of them singletons, is that a bad practice?

For example -

|-------------------------------------------------------------|
|                                                                            |
|                                                                            |
|-------------------------------------------------------------|
|                                      |                                     |
|                                      |                                     |
|                                      |                                     |
|                                      |                                     |
|                                      |                                     |
|                                      |                                     |
|                                      |                                     |
|                                      |                                     |
|                                      |                                     |
|                                      |                                     |
|                                      |                                     |
|                                      |                                     |
|-------------------------------------------------------------|

All of these sections will stay on my page throughout the users session, but they may change state, like toggle, resize, change the data within them, etc.

Any thoughts?

Answer 1

One of the ideas implemented by the page object gem (via Ruby) is to encapsulate the instantiation of your page classes using a page factory type of object. In particular, this is the 'on_page' method, the usage is like

on_page(MyPageClass) do |page|
  page.do_actions
end

Where the block provided should have a single argument to which the instance created in the factory is passed to.

Perhaps you can employ a similar idea. It's better to have instances of page classes in my opinion; my reasoning is that your page class actions should be 'memoryless'.