challenge#2.rb

class Image
  attr_accessor :data
  def initialize (data)
     @data = data  
  end

  def image_blur
    changes = []

    @data.each_with_index do |row, row_index|
      row.each_with_index do |value, column_index|
        if value == 1        
          changes << [row_index, column_index-1] if column_index > 0 
          changes << [row_index-1, column_index] if row_index > 0 
          changes << [row_index+1, column_index] if row_index < @data.size-1 
          changes << [row_index, column_index + 1] if column_index < row.size - 1
        end
      end
    end

    changes.each do |(row_index, column_index)|
      @data[row_index][column_index] = 1
    end
  end   

  def output
    @data.each do |sub|
      sub.each do |cell|
        print cell
      end
      puts "\n"
    end
  end

end

image = Image.new([[0,0,0,0,0,0,0],
                   [0,1,1,0,0,0,1],
                   [0,0,0,0,0,0,0]
                   ])
image.image_blur
image.output


test "pixel on left hand side" do
  image = Image.new([[0,0,0,0,0,0,0],
                     [1,0,0,0,0,0,0],
                     [0,0,0,0,0,0,0]
                   ])
  image.image_blur

  assert_equal(
    [[1,0,0,0,0,0,0],
     [1,1,0,0,0,0,0],
     [1,0,0,0,0,0,0]],
     image.data
  )
end