Use shared_examples to avoid duplicate test examples

controller_sample.rb

class FruitController < ApplicationController
  before_action :find_super_market, only: [:index, :show]
  before_action :setup_discount, only: [:index, :show]
  
  def index
    #...
  end
  
  def show
    #...
  end
  
  private
  
    def find_super_market
      @super_market = SuperMarket.find_by!(slug: params[:super_market_slug])
    end
  
    def setup_discount
      @discount = #....
    end
end

duplicated_test_examples.rb

# fruit_controller_spec.rb
require 'rails_helper'

RSpec.describe FruitController, type: :controller do  
  describe 'GET #index' do
    subject(:index_request) { get :index, params: { super_market_slug: super_market.slug } }
    
    let(:user) { create(:user, special_pass_available: special_pass_available? }
    #... 
    
    context 'when assigns @discount' do
      let(:super_market) { create(:super_market) }
      
      before { index_request }
      
      context 'when current_user owns special pass' do
        let(:special_pass_available?) { true }
        
        it { expect(assigns(:discount)).to eq(0.5) }
      end
      
      context 'when current_user does not own any special pass' do
        let(:special_pass_available?) { false }
        
        it { expect(assigns(:discount)).to eq(0) }
      end
    end
  end
  
  describe 'GET #show' do
    subject(:show_request) { get :show, params: { super_market_slug: super_market.slug, fruit_id: fruit.id } }
    
    let(:user) { create(:user, special_pass_available: special_pass_available? }
    let(:fruit) { create(:fruit) }
    #...
    
    context 'when assigns @discount' do
      let(:super_market) { create(:super_market) }
      
      before { show_request }
      
      context 'when current_user owns special pass' do
        let(:special_pass_available?) { true }
        
        it { expect(assigns(:discount)).to eq(0.5) }
      end
      
      context 'when current_user does not own any special pass' do
        let(:special_pass_available?) { false }
        
        it { expect(assigns(:discount)).to eq(0) }
      end
    end
  end
end