Boolean method in Ruby (sibling of Array, Float, Integer and String)
I was reading in data from a file and expected one particular column to contain either ‘true’ or ‘false’. I wanted a nice way to convert the string representation into its object counterpart. I thought to the Kernel#Float (and kin) and decided I wanted a Kernel#Boolean method. So I made one. Tada…
module Kernel
def Boolean(string)
return true if string == true || string =~ /^true$/i
return false if string == false || string.nil? || string =~ /^false$/i
raise ArgumentError.new("invalid value for Boolean: \"#{string}\"")
end
end
require File.dirname(__FILE__) + '/../test_helper'
class KernelTest < Test::Unit::TestCase
def test_should_return_true
assert_equal true, Boolean('true')
assert_equal true, Boolean('TrUe')
assert_equal true, Boolean(true)
end
def test_should_return_false
assert_equal false, Boolean(nil)
assert_equal false, Boolean('false')
assert_equal false, Boolean('FaLsE')
assert_equal false, Boolean(false)
end
def test_should_raise_exception
assert_raise(ArgumentError) { Boolean('true ') }
assert_raise(ArgumentError) { Boolean(' true') }
assert_raise(ArgumentError) { Boolean(' true ') }
assert_raise(ArgumentError) { Boolean('false ') }
assert_raise(ArgumentError) { Boolean(' false') }
assert_raise(ArgumentError) { Boolean(' false ') }
assert_raise(ArgumentError) { Boolean('BLAH') }
assert_raise(ArgumentError) { Boolean(1) }
end
end
