game_of_life_natalie_2015.rb

require 'rspec'

class GameOfLife
  def self.will_live?(alive_or_dead, neighbors)
    if alive_or_dead == :alive
      return true if neighbors == 2 || neighbors == 3
    else
      return true if neighbors == 3
    end
    false
  end
end

describe GameOfLife do
  it 'let a cell die if it has fewer than 2 neighbors' do
    expect(GameOfLife.will_live?(:alive, 1)).to eq(false)
  end
  it 'remains alive with 2 neighbors' do
    expect(GameOfLife.will_live?(:alive, 2)).to eq(true)
  end
  it 'remains alive with 3 neighbors' do
    expect(GameOfLife.will_live?(:alive, 3)).to eq(true)
  end
  it 'remains alive with 4 neighbors' do
    expect(GameOfLife.will_live?(:alive, 4)).to eq(false)
  end

  it 'let a cell die if it has fewer than 2 neighbors' do
    expect(GameOfLife.will_live?(:dead, 1)).to eq(false)
  end
  it 'remains alive with 2 neighbors' do
    expect(GameOfLife.will_live?(:dead, 2)).to eq(false)
  end

  it 'becomes alive with 3 neighbors' do
    expect(GameOfLife.will_live?(:dead, 3)).to eq(true)
  end
  it 'remains alive with 4 neighbors' do
    expect(GameOfLife.will_live?(:dead, 2)).to eq(false)
  end
end