Helper method in a controller (created via `helper_method`) not being reachable in a RSpec helper te-CodePudding

Lets say I have the following code on ApplicationController :

class ApplicationController < ActionController::Base
   helper_method :is_happy?

   private

   def is_happy?
      true
   end
end

and then, on my ApplicationHelper I have a method, which I would like to test like this:

def show_mood_text
  return 'Happy' if is_happy?

  'Sad'
end

I would like to test both cases, when is_happy? returns true and when it returns false . So, my option was to stub is_happy? method. For that, I did the following:

it 'returns Sad when when is sad' do
      allow(helper).to receive(:is_happy?).and_return(false)

      expect(helper.show_mood_text).to eq "Sad"
end

But when I try to run this test, I got the following error:

Failure/Error: allow(helper).to receive(:is_happy?).and_return(false)
       #<ActionView::Base:0x00000000009e70> does not implement: is_happy?

EDIT:

Demo code: https://github.com/weezhard0/demo-rails-rspec

$ bundle install
$ bin/rspec

what am I missing here?

CodePudding user response：

This is apparently a known "issue", according, for example, to this Relish page:

NOTE: helper methods defined in controllers are not included.

Having that said, there are some gimmicks that can be done in order to make helper methods defined through helper_method reachable inside your helper spec file.

After some exploratory investigation, I could write (and successfully test) the test/spec file (spec/helpers/application_helper_spec.rb) below using Rails 6.1.7, RSpec 3.11.0, rspec-rails 6.0.1 and Ruby 3.0.3, and it delivers what you're looking for:

# frozen_string_literal: true

require 'rails_helper'

RSpec.describe ApplicationHelper do
  describe '#show_mood_text' do
    subject { helper.show_mood_text }
    before { inject_controller_helper_methods(ApplicationController) }

    context 'when is_happy? returns true' do
      before { allow(helper).to receive(:is_happy?).and_return(true) }

      it { is_expected.to eq('Happy') }
    end

    context 'when is_happy? returns false' do
      before { allow(helper).to receive(:is_happy?).and_return(false) }

      it { is_expected.to eq('Sad') }
    end
  end

  def inject_controller_helper_methods(controller_class)
    helper_module = (controller = controller_class.new)._helpers
    helper_methods = helper_module.instance_methods(false).sort
    helper_method = ->(method) { helper_module.instance_method(method) }

    helper_methods.each do |method|
      helper.class.define_method(method, helper_method[method])
    end

    helper.controller = controller
  end
end

CodePudding user response：

Asking for help on RSpec-rails github repository, I was given the following solution:

require 'rails_helper'

RSpec.describe ApplicationHelper do
  describe '#show_mood' do
    around(:example) do |example|
      without_partial_double_verification do
        example.call
      end
    end

    context 'when is happy' do
      before do
        allow(helper).to receive(:happy?).and_return(true)
      end

      it { expect(helper.show_mood).to eq('Happy') }
    end

    context 'when is not happy' do
      before do
        allow(helper).to receive(:happy?).and_return(false)
      end

      it { expect(helper.show_mood).to eq('Sad') }
    end
  end
end

It works.

Ref.: https://github.com/rspec/rspec-rails/issues/2654#issuecomment-1404983567