# frozen_string_literal: true
          
        
      
        

          

            
            

            

            
          
        
      
        

          

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            class StackIsEmpty < StandardError; end
          
        
      
    
  

    

      
        

          

            
            

            

            # frozen_string_literal: true
          
        
      
        

          

            
            

            

            
          
        
      
        

          

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            require_relative '../structures/stack'
          
        
      
        

          

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            require_relative '../custom_exceptions/stack_is_empty'
          
        
      
        

          

            
            

            

            
          
        
      
        

          

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            RSpec.describe Stack do
          
        
      
        

          

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              let(:stack) { Stack.new }
          
        
      
        

          

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              let(:rand_element) { Faker::Number.number(digits: 5) }
          
        
      
        

          

            
            

            

            
          
        
      
        

          

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              shared_examples 'when stack is empty' do |method|
          
        
      
        

          

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                it "raise StackIsEmpty exception on #{method}" do
          
        
      
        

          

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                  expect{stack.public_send(method)}.to raise_exception(StackIsEmpty)
          
        
      
        

          

            
            

            

                end
          
        
      
        

          

            
            

            

              end
          
        
      
        

          

            
            

            

            
          
        
      
        

          

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              describe 'methods' do
          
        
      
        

          

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                describe 'push' do
          
        
      
        

          

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                  it 'should push an element onto the top' do
          
        
      
        

          

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                    stack.push(rand_element)
          
        
      
        

          

            
            

            

            
          
        
      
        

          

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                    expect(stack.peak).to eq(rand_element)
          
        
      
        

          

            
            

            

                  end
          
        
      
        

          

            
            

            

                end
          
        
      
        

          

            
            

            

            
          
        
      
        

          

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                describe 'pop' do
          
        
      
        

          

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                  it 'return the top element (and removing it) when the stack has element' do
          
        
      
        

          

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                    stack.push(rand_element)
          
        
      
        

          

            
            

            

            
          
        
      
        

          

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                    expect(stack.pop).to eq(rand_element)
          
        
      
        

          

            
            

            

                  end
          
        
      
        

          

            
            

            

            
          
        
      
        

          

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                  it_behaves_like 'when stack is empty', :pop
          
        
      
        

          

            
            

            

                end
          
        
      
        

          

            
            

            

            
          
        
      
        

          

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                describe 'peak' do
          
        
      
        

          

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                  it 'return the top element (without removing it) when the stack has element' do
          
        
      
        

          

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                    stack.push(rand_element)
          
        
      
        

          

            
            

            

            
          
        
      
        

          

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                    expect(stack.peak).to eq(rand_element)
          
        
      
        

          

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                    expect(stack.empty?).to be_falsey
          
        
      
        

          

            
            

            

                  end
          
        
      
        

          

            
            

            

            
          
        
      
        

          

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                  it_behaves_like 'when stack is empty', :peak
          
        
      
        

          

            
            

            

                end
          
        
      
        

          

            
            

            

            
          
        
      
        

          

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                describe 'empty?' do
          
        
      
        

          

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                  it 'return false if the stack has element' do
          
        
      
        

          

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                    stack.push(1)
          
        
      
        

          

            
            

            

            
          
        
      
        

          

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                    expect(stack.empty?).to be_falsey
          
        
      
        

          

            
            

            

                  end
          
        
      
        

          

            
            

            

            
          
        
      
        

          

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                  it 'return true if the stack is empty' do
          
        
      
        

          

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                    expect(stack.empty?).to be_truthy
          
        
      
        

          

            
            

            

                  end
          
        
      
        

          

            
            

            

                end
          
        
      
        

          

            
            

            

              end
          
        
      
        

          

            
            

            

            end
          
        
      
    
  

    

      
        

          

            
            

            

            # frozen_string_literal: true
          
        
      
        

          

            
            

            

            
          
        
      
        

          

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            class Stack
          
        
      
        

          

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              attr_reader :elements
          
        
      
        

          

            
            

            

            
          
        
      
        

          

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              def initialize
          
        
      
        

          

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                @elements = []
          
        
      
        

          

            
            

            

              end
          
        
      
        

          

            
            

            

            
          
        
      
        

          

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              def push(element)
          
        
      
        

          

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                elements.push(element)
          
        
      
        

          

            
            

            

              end
          
        
      
        

          

            
            

            

            
          
        
      
        

          

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              def pop
          
        
      
        

          

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                raise StackIsEmpty if empty?
          
        
      
        

          

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                elements.pop
          
        
      
        

          

            
            

            

              end
          
        
      
        

          

            
            

            

            
          
        
      
        

          

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              def peak
          
        
      
        

          

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                raise StackIsEmpty if empty?
          
        
      
        

          

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                elements.last
          
        
      
        

          

            
            

            

              end
          
        
      
        

          

            
            

            

            
          
        
      
        

          

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              def empty?
          
        
      
        

          

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                elements.empty?
          
        
      
        

          

            
            

            

              end
          
        
      
        

          

            
            

            

            end