split_keychain.rb

require 'bacon'
Bacon.summary_on_exit

describe 'keychain splitter' do
  def split(keychain)
    return nil, keychain if keychain.first == '0'

    argument, rest = [], []
    digits = true

    keychain.each do |key|
      if digits && key =~ /^\d$/
        argument << key
      else
        digits = false
        rest << key
      end
    end

    unless argument.empty?
      return argument.join.to_i, rest
    else
      return nil, rest
    end
  end

  should 'split keychain with single numeric prefix' do
    keychain = %w[1 f o o]
    split(keychain).should == [1, %w[f]]
  end

  should 'split keychain with multiple numeric prefix' do
    keychain = %w[1 2 3 f o]
    split(keychain).should == [123, %w[f]]
  end

  should 'split keychain without numeric prefix' do
    keychain = %w[f o o 1 2]
    split(keychain).should == [nil, %w[f o o 1 2]]
  end

  should 'split keychain zero prefix' do
    keychain = %w[0 f o o 1 2]
    split(keychain).should == [nil, %w[0 f o o 1 2]]
  end
end