How to test strong params with Rspec?

Question

What is the actual strategy to test strong params filtering in Rails controller with Rspec? (Except shoulda matchers) How to write failing test and then make it green?

Answer 1

I personally use shoulda-matcher from thoughtbot.

With something like:

it do
  should permit(:first_name, :last_name, :email, :password).
    for(:update, params: params)
end