By the end of this, students should be able to:
- Write the shell of an rspec test
- Instantiate an instance of a class in a before block
- Write descriptions/expectations for instance methods
- Write code to make the rspec tests pass
- Fork and clone this repo, change working directory.
- Run
bundle install. - Run
rspec --init. - Follow along with your instructor. Stage and commit your changes as you progress.
- Push changes to your Github repo
git push origin master.
The Luhn Algorithm calculates a checksum, or a simple string/numeric summary of input data. It is useful for checking accidental errors, such as mistyping a digit, but not for keeping data secure; it is not an ecnryption algorithm.
Wikipedia has a nice summary of the algortihm. A copy is available in algorithm.md (accessed: 2015-01-20).
Some things to consider as you work through the exercise:
- Write your tests first.
- Use a class to encapsulate related data and behavior.
- Try making each step of the algorithm it's own method (test first).
- Compose these smaller methods into one or two methods that do the actual validation check.