Changing my thought process with Ruby

bad_hash_store.rb

# Code is way too verbose
class HashStore
	attr_writer :store
    
    def store
    	@store ||= Hash.new
    end
    
    def add_value(scope, value)
    	it store.has_key?(scope) && store[scope].is_a?(Array)
        	store[scope] << value
        else
        	store[scope] = [value]
        end
    end
end

good_hash_store.rb

# Much cleaner. No forking and 30% reduction in LOC
class HashStore
	attr_writer :store
    
    def store
    	@store ||= Hash.new(Array.new)
    end
    
    def add_value(scope, value)
    	store[scope] << value
    end
end

hash_store_spec.rb

# To run the spec download all three files and run either of the 2 commands:
#
# $ rspec -r ./bad_hash_store.rb hash_store_spec.rb
# $ rspec -r ./good_hash_store.rb hash_store_spec.rb

describe HashStore do
  let(:store) { HashStore.new }
  
  before(:each) { store.ad_value :hello, :world }
  
  it 'adds a new key to the store' do
    expect(store.store[:hello]).to include :world
  end
  
  it 'appends a value to an existing key' do
    store.add_value :hello, :foo_bar
    expect(store.store[:hello]).to include :foo_bar
    expect(store.store[:hello]).to include :world
  end
end