balanced_brackets.rb

require 'minitest/autorun'

module BracketTester
  module_function
  def balanced?(str)
    brackets = 0
    str.each_char do |char|
      if char == '('
        brackets += 1
      else
        brackets > 0 ? brackets -= 1 : (return false)
      end
    end
    brackets == 0
  end
end


class TestBracketTester < Minitest::Unit::TestCase
  def test_balanced
    assert_equal true, BracketTester.balanced?('()')
    assert_equal true, BracketTester.balanced?('(())')
    assert_equal true, BracketTester.balanced?('()()')
    assert_equal true, BracketTester.balanced?('(()())')
    assert_equal false, BracketTester.balanced?(')(')
    assert_equal false, BracketTester.balanced?('()())')
    assert_equal false, BracketTester.balanced?('(()()')
    assert_equal false, BracketTester.balanced?('((())))')
    assert_equal false, BracketTester.balanced?('((()(')
  end
end