Ruby: dealing with booleans: How to address not using military time for a clock Class - boolean

Question

TDD
gem 'minitest', '~> 5.2'
require 'minitest/autorun'
require 'minitest/pride'
require_relative 'clock'
class ClockTest < Minitest::Test
def test_start_at_6
clock = Clock.new
assert_equal 6, clock.time
end
def test_passage_of_time
clock = Clock.new
clock.wait
assert_equal 7, clock.time
3.times { clock.wait }
assert_equal 10, clock.time
end
def test_clocks_are_not_military_time
clock = Clock.new
8.times { clock.wait }
assert_equal 2, clock.time
end
end
CODE
class Clock
attr_reader :time
def initialize
#time = 6
end
def wait(time = 1)
#time += time
end
def not_military_time
#time += (time - 10)
end
end
Can anyone guide me into figuring out how to address that the clocks are not in military time? It's coming as Expected : 2 , Actual : 14. I feel like there needs to be some of subtraction going in order to address the clock saying 2 instead of 14.
I know what I have in the code does not work, but am I on the right track?

Answer 1

If you look through all of the tests you'll see that apart from test_start_at_6 each test essentially calls wait some number of times and then checks for the right time in clock.time.
If you look at your code, clock.time is generated by attr_reader and so all it will ever do is return the current value of #time. So this leaves you with wait as a place to implement the behaviour needed to make the tests pass.
One other thing to notice is that you're currently overcomplicating the wait method. It's never called with any parameters and so the time parameter isn't needed. So to start simplify that to just:
def wait
#time += 1
end
Next, step away from the code and make a little list showing for each current time what the next time needs to be after wait is called. You can then think about how to change wait so that it matches that required behaviour.
In terms of whether to use an if or a case statement, everything that you could achieve using a case statement can also be done with an if as an alternative. It's best to think about the most common use of a case statement which is for checking the same variable for various possible values. i.e. the case statement
case #time
when 1
puts "One o'clock"
when 2
puts "Two o'clock"
else
puts "Later!"
end
is the same as:
if #time == 1
puts "One o'clock"
elsif #time == 2
puts "Two o'clock"
else
puts "Later!"
end
Often when you're just working out what some logic needs to be you'll write it as an if statement and then once it's working realise that it can more elegantly be expressed as a case statement. In this exercise an if should be fine.