Rspec: how to test partial render with locals and params?

Question

I am trying to test this part of controller with Rspec:

def popup_company
  if params[:partial].present?
    render partial: "popup_company/pages", locals: { tab_filter: params[:tab_filter] }
  end
end

Here is my controller spec to test the part mentioned above:

controller.should_receive(:render).with({
:partial => 'popup_company/pages',
:locals => {tab_filter: params[:tab_filter]}
})

However, I am getting this error:

undefined local variable or method `params'

Guys, can you, please, tell me what I should change to overcome this error. I appreciate your help!

Answer 1

Your params is on the spec-side code; it's just trying to be a local variable. Put in whatever you expect params[:tab_filter] to contain.

And, in general, you should not write tests - oops I mean "examples" - that merely repeat what the code says. You don't care your controller calls a partial; you care that the controller responds with HTML containing such-and-so values.

Answer 2

So params[:tab_filter] is in your request, so it's presumably in your get. That is, you have something like:

get :popup_company, tab_filter: 'XXXXX', partial: 'YYYYY'

in your spec. You should create a variable, random value for the tab_filter param and use that to validate the appropriate value is being passed to render. Something like

tab_filter = SecureRandom.hex(10)
get :popup_company, tab_filter: tab_filter, partial: 'YYYYY'
controller.should_receive(:render).with({
  partial: 'popup_company/pages',
  locals: { tab_filter: tab_filter } })

Alternately you could use a render_template('popup_company/pages') spec to confirm that the template is being rendered, and test for the tab filter based on the content of the rendered view.