Redux in Ruby

ruby-redux.rb

# Redux in Ruby

class Store
  attr_reader :state

  def initialize(initial_state, *reducers)
    @reducers = reducers
    @state = initial_state || {}
  end

  def dispatch(action)
    @state = @reducers.reduce(state.dup) do |s, reducer|
      reducer.call(s, action)
    end
  end
end

# Reducers

totals_reducer = ->(state, action) do
  case action[:type]
  when 'ADD_ITEM' then state[:total] += 1
  when 'REMOVE_ITEM' then state[:total] -= 1
  end
  state
end

items_reducer = -> (state, action) do
  case action[:type]
  when 'ADD_ITEM' then state[:items] << action[:item]
  when 'REMOVE_ITEM' then state[:items] = state[:items] - [action[:item]]
  end
  state
end

# DEMO

@store = Store.new({ total: 0, items: [] }, items_reducer, totals_reducer)

@store.dispatch type: 'ADD_ITEM', item: 'APPLES'
@store.dispatch type: 'ADD_ITEM', item: 'BANANAS'
@store.dispatch type: 'REMOVE_ITEM', item: 'APPLES'
@store.dispatch type: 'ADD_ITEM', item: 'FEIJOAS'

puts @store.state # => {total: 2, items: ["BANANAS", "FEIJOAS"]}