diff --git a/ruby/leap/README.md b/ruby/leap/README.md new file mode 100644 index 0000000..0108e2d --- /dev/null +++ b/ruby/leap/README.md @@ -0,0 +1,57 @@ +# Leap + +Given a year, report if it is a leap year. + +The tricky thing here is that a leap year in the Gregorian calendar occurs: + +```text +on every year that is evenly divisible by 4 + except every year that is evenly divisible by 100 + unless the year is also evenly divisible by 400 +``` + +For example, 1997 is not a leap year, but 1996 is. 1900 is not a leap +year, but 2000 is. + +If your language provides a method in the standard library that does +this look-up, pretend it doesn't exist and implement it yourself. + +## Notes + +Though our exercise adopts some very simple rules, there is more to +learn! + +For a delightful, four minute explanation of the whole leap year +phenomenon, go watch [this youtube video][video]. + +[video]: http://www.youtube.com/watch?v=xX96xng7sAE + +* * * * + +For installation and learning resources, refer to the +[exercism help page](http://exercism.io/languages/ruby). + +For running the tests provided, you will need the Minitest gem. Open a +terminal window and run the following command to install minitest: + + gem install minitest + +If you would like color output, you can `require 'minitest/pride'` in +the test file, or note the alternative instruction, below, for running +the test file. + +Run the tests from the exercise directory using the following command: + + ruby leap_test.rb + +To include color from the command line: + + ruby -r minitest/pride leap_test.rb + + +## Source + +JavaRanch Cattle Drive, exercise 3 [http://www.javaranch.com/leap.jsp](http://www.javaranch.com/leap.jsp) + +## Submitting Incomplete Solutions +It's possible to submit an incomplete solution so you can see how others have completed the exercise. diff --git a/ruby/leap/leap.rb b/ruby/leap/leap.rb new file mode 100644 index 0000000..abb71e5 --- /dev/null +++ b/ruby/leap/leap.rb @@ -0,0 +1,5 @@ +class Year + def self.leap?(year) + (year % 4 == 0 and (year % 400 == 0 or year % 100 != 0)) + end +end diff --git a/ruby/leap/leap_test.rb b/ruby/leap/leap_test.rb new file mode 100644 index 0000000..372ce1c --- /dev/null +++ b/ruby/leap/leap_test.rb @@ -0,0 +1,34 @@ +require 'minitest/autorun' +require_relative 'leap' + +# Common test data version: 1.3.0 e348053 +class Date + def leap? + raise RuntimeError, "Implement this yourself instead of using Ruby's implementation." + end + + alias gregorian_leap? leap? + alias julian_leap? leap? +end + +class YearTest < Minitest::Test + def test_year_not_divisible_by_4_common_year + # skip + refute Year.leap?(2015), "Expected 'false', 2015 is not a leap year." + end + + def test_year_divisible_by_4_not_divisible_by_100_leap_year + # skip + assert Year.leap?(1996), "Expected 'true', 1996 is a leap year." + end + + def test_year_divisible_by_100_not_divisible_by_400_common_year + # skip + refute Year.leap?(2100), "Expected 'false', 2100 is not a leap year." + end + + def test_year_divisible_by_400_leap_year + # skip + assert Year.leap?(2000), "Expected 'true', 2000 is a leap year." + end +end