Assignment 1

Due: 11:59pm on Wednesday, September 13th.

Overview

This assignment has several goals:

1. Introduce you to writing your first Ruby program, including getting familiar with iterators, blocks, instance variables, classes, and methods.
2. Get familiar with writing code in the Cloud9 IDE.
3. Gain experience in using github as a source code repository.
4. Use Rubocop to apply standardization rules.

What you need to do to complete this assignment:

1. Create an account on Cloud9. I suggest you make the account name the same as your Github account name.
2. Create an account on Github.
3. Accept the assignment url when it's sent to you.
4. Clone your repository into your Cloud9 environment. (git clone)
5. Create a branch in your local repository. (git branch )
6. Change to that branch to do your work. (git checkout )
7. Do whatever is necessary to ensure that all the tests in game_helper_test.rb pass. (Note that the grader bot will also test your code against some tests that you don't have.) (cd code; ruby game_helper_test.rb)
8. Do whatever is necessary to ensure all Rubocop tests pass. (cd code; rubocop .)
9. Commit your work to the local repository. (git add ., git commit -m )
10. Push your local repository to your Github repository. (git push)
11. Execute a pull request on Github (i.e. via the browser client), which will trigger the grader bot to clone your repository, run all the tests against it, and return the results in your PR. Only the most recent PR will be scored, so you can execute a PR as many times as you want (up to the turn-in deadline after which the grader bot will refuse to grade your repository). What that means is that if you do the PR at 7pm on the due date and then you release you forgot something, you can push another batch of code and do another PR at, say, 11pm, and the grading bot will pay attention to the 11pm PR and ignore the 7pm PR.
12. To make this all work, we need to know how to map from your Github username to your University ID. There is a file in the root directory of the assignment's repository called u-number.txt. Enter your u-number in that file on line 2 (i.e. immediately after the comment line). Be sure the changed version gets committed to your repo.

Rubric

Task	Value
You successfully accept the assignment link and your repository is created on Github under the class account.	10%
Your repository contains at least one non-master branch.	10%
You execute a PR with the correct format to trigger the grader bot.	10%
All the regular tests run to completion.	25%
All the non-regular (i.e. those you don't get ahead of time) run to completion.	5%
Your Ruby code passes all Rubocop tests. This includes both code files in the code directory.	20%
You register your Github username with your U-number with us.	20%

Additional Details for Task 7 - Ruby Tests

Using the supplied code, your job is to add functionality so that the tests in game_helper_test.rb are executed without exceptions and return the correct results to satisfy the assertions. There are generally two kinds of work you'll need to do to get the tests to pass: 1) there are chunks of code missing in the game_helper.rb class. Write the appropriate code for those missing chunks. 2) there are a few tests that you'll need to write...they currently only assert false. Replace that line with code to drive the GameHelper class and verify the results are correct. Hint: the TODO comments will guide you to where you need to work.

To run the tests, just run the game_helper_test.rb script through ruby, e.g.:

  cd code
  ruby game_helper_test.rb

You'll get a bunch of output. Green dots represent tests that passed. A red 'E' is an error, and a red 'F' is a failed test. You need to fix all errors and failed tests until you get a test run with no failures, no errors, and no skips, e.g.:

Run options: --seed 25878

# Running:

.........

Finished in 9.721343s, 0.9258 runs/s, 52924.9919 assertions/s.
9 runs, 514502 assertions, 0 failures, 0 errors, 0 skips

When a test errors-out or fails, the tester will give you a message about the problem along with some context to help you find the issue.

F

Failure:
GameHelperTest#test_case_7 [game_helper_test.rb:86]:
Expected false to be truthy.


bin/rails test game_helper_test.rb:85

.E

Error:
GameHelperTest#test_contains:
NoMethodError: undefined method `each' for nil:NilClass
    game_helper_test.rb:32:in `test_contains'


bin/rails test game_helper_test.rb:27

The first issue is a failed test, i.e. the test expected something to be false but the expression turned out to be true...so something must be wrong in the logic of the code. The test that triggered the problem was named test_case_7 and it failed on line 86 of game_helper_test.rb. That tells you where to start looking.

The second issue is an error, triggered by the test_contains test at line 32 of game_helper_test.rb. The error message comes from Ruby. The code tried to call the each iterator on an object that was nil, i.e. an empty object. If you look at the test, line 32 tried to call each on a variable named selected_terms. selected_terms should have been populated by line 29 as a result of calling @gh.all_words.contains. So, something happened in that line...probably the contains() function didn't operator properly. This makes some sense because the test was designed to verify contains() operates correctly and it's clearly not! If you look at the game_helper.rb file for the definition of contains(), you'll see there's nothing in the body of that function. Write that function, and then the test should pass.

For those of you interested, we're using a Ruby gem (aka library) called minitest to manage our test cases. It's a nice, easy-to-understand gem that lets you write pure ruby to test your code. Once we get to Rails, we'll continue with minitest even though the more standard gem for Rails test is rspec. Rspec has its own domain specific language so there's a bit a learning curve there. If you were going to become a Rails expert, you'd want to learn rspec.

Additional Details for Task 8 - Rubocop

Rubocop is a style checker that is common in the Ruby and Rails communities. To run it, cd into your code directory and run 'rubocop .' from the command line. You may find Rubocop to be awfully persnickety, but following its rules will make you an easier to work with as a team member.

If rubocop is not installed in your c9 environment, run this from the command line:

gem install rubocop

Misc Notes

http://blog.scottlowe.org/2015/01/27/using-fork-branch-git-workflow/ -- an excellent article on how we'll be using Github.

http://rubular.com -- a site for building and testing regular expressions in Ruby.

Remember, if you get confused about something Ruby-related, like the iterators, or you want detail on something like regular expressions in Ruby, the Pickaxe book is your friend. The first version is available online at http://ruby-doc.com/docs/ProgrammingRuby/. There are newer editions available to buy, but for most of our work you don't need them.

http://ruby-doc.org/core-2.4.1/ -- the Ruby API and standard libraries site.

http://ruby-doc.org/ -- the base site for Ruby. Links to tutorials, books, etc.