Question: I created some public method in controller which does some work.

```
 def current_service
    service_name = params[:controller].gsub('api/v1/', '').gsub(%r{/.+}, '')
 end

```

I would like to test this method using RSpec but I dont't know how can I stub params. How should I do that?

Answer: 
If this is a controller spec, you should be able to do something like this:

```
allow(controller).to receive(:params).and_return({controller: 'a value'})

```

Alternatively, move the `params[:controller]` statement to a separate method and stub that in your spec.
For strong parameters you can stub them as following:

```
params = ActionController::Parameters.new(foo: 'bar')
allow(controller).to receive(:params).and_return(params)

```