The OddEven kata

readme.md

The OddEven Kata

- Write a program that prints numbers within specified range lets say 1 to 100. If number is odd print 'Odd'
  instead of the number. If number is even print 'Even' instead of number. Else print number [hint - if number is Prime].

## Steps :

Lets divide into following steps:
- Prints numbers from 1 to 100
- Print "Even" instead of number, if the number is even, means divisible by 2
- Print "Odd" instead of number, if the number is odd, means not divisible by 2 but not divisible by itself too [hint - it should not be Prime]
- Print number, if it does not meet above two conditions, means if number is Prime

app.rb

require './oddeven'

oddeven = OddEven.new
(1..100).each { |number| puts oddeven.print_number(number) }

oddeven.rb

class OddEven
  def print_number(number)
    # Write your code here
  end

  def prime_number?(number)
    # Write your code here
  end
end

oddeven_spec.rb

require './oddeven'

RSpec.describe OddEven do
  subject { described_class.new }

  describe '#print_number' do
    context 'when the number is divisible by 2' do
      it 'returns "EVEN"' do
        [2, 4, 6, 8, 10].each do |number|
          expect(subject.print_number(number)).to eq 'EVEN'
        end
      end
    end

    context 'when the number is not divisible by 2 but not a prime number' do
      it 'returns "ODD"' do
        [1, 15, 21, 25, 27].each do |number|
          expect(subject.print_number(number)).to eq 'ODD'
        end
      end
    end

    context 'when the number is a prime number' do
      it 'returns the same number' do
        [3, 5, 7, 11, 13].each do |number|
          expect(subject.print_number(number)).to eq number
        end
      end
    end
  end

  describe '#prime_number?' do
    context 'when given a prime number' do
      it 'returns true' do
        [2, 3, 5, 7, 11].each do |number|
          expect(subject.prime_number?(number)).to eq true
        end
      end
    end

    context 'when given a non-prime number' do
      it 'returns false' do
        [1, 4, 6, 9, 10, 12, 14].each do |number|
          expect(subject.prime_number?(number)).to eq false
        end
      end
    end
  end
end