RSpec how to mock method inside another method

Question

In application_controller I've got two methods which results I want to test in a maintenance_mode_controller_specs . How to create mock maintenance_mode_active? which will return false to use it inside check_maintenance? ?

application_controller.rb before_action:check_maintenance?

private

def check_maintenance?
  if maintenance_mode_active? == true
    redirect_to maintenance_mode
  elsif request.fullpath.include?(maintenance_mode_path)
    redirect_to :root
  end
end

def maintenance_mode_active?
  # do sth ...
  mode.active?
end

maintenance_mode_controller_spec.rb

context 'when maintenance mode is active' do
  let(:maintenance_mode?) { instance_double(ApplicationController) }

  before do
    allow(ApplicationController).to receive(:maintenance_mode_active?).and_return(false)
  end

  it 'redirect to root path' do
    expect(described_class).should redirect_to(maintenance_mode_path)
  end
end

Answer 1

maintenance_mode_active is an instance method and you stub it on the class level. You need to use allow_any_instance_of

before do
  allow_any_instance_of(ApplicationController).to receive(:maintenance_mode_active?).and_return(false)
end