nihilismus's solution to Scrabble Score on the Ruby track

Instructions

Test suite

Solution

Given a word, compute the scrabble score for that word.

Letter Values

You'll need these:

Letter                           Value
A, E, I, O, U, L, N, R, S, T       1
D, G                               2
B, C, M, P                         3
F, H, V, W, Y                      4
K                                  5
J, X                               8
Q, Z                               10

Examples

"cabbage" should be scored as worth 14 points:

3 points for C
1 point for A, twice
3 points for B, twice
2 points for G
1 point for E

And to total:

3 + 2*1 + 2*3 + 2 + 1
= 3 + 2 + 6 + 3
= 5 + 9
= 14

Extensions

You can play a double or a triple letter.
You can play a double or a triple word.

For installation and learning resources, refer to the Ruby resources page.

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 scrabble_score_test.rb

To include color from the command line:

ruby -r minitest/pride scrabble_score_test.rb

Source

Inspired by the Extreme Startup game https://github.com/rchatley/extreme_startup

Submitting Incomplete Solutions

It's possible to submit an incomplete solution so you can see how others have completed the exercise.

scrabble_score_test.rb

require 'minitest/autorun'
require_relative 'scrabble_score'

class ScrabbleTest < Minitest::Test
  def test_empty_word_scores_zero
    assert_equal 0, Scrabble.new('').score
  end

  def test_whitespace_scores_zero
    skip
    assert_equal 0, Scrabble.new(" \t\n").score
  end

  def test_nil_scores_zero
    skip
    assert_equal 0, Scrabble.new(nil).score
  end

  def test_scores_very_short_word
    skip
    assert_equal 1, Scrabble.new('a').score
  end

  def test_scores_other_very_short_word
    skip
    assert_equal 4, Scrabble.new('f').score
  end

  def test_simple_word_scores_the_number_of_letters
    skip
    assert_equal 6, Scrabble.new('street').score
  end

  def test_complicated_word_scores_more
    skip
    assert_equal 22, Scrabble.new('quirky').score
  end

  def test_scores_are_case_insensitive
    skip
    assert_equal 41, Scrabble.new('OXYPHENBUTAZONE').score
  end

  def test_convenient_scoring
    skip
    assert_equal 13, Scrabble.score('alacrity')
  end
end

# frozen_string_literal: true

class String
  LETTER_VALUE = {
    a: 1, e: 1, i: 1, o: 1, u: 1, l: 1, n: 1, r: 1, s: 1, t: 1,
    d: 2, g: 2,
    b: 3, c: 3, m: 3, p: 3,
    f: 4, h: 4, v: 4, w: 4, y: 4,
    k: 5,
    j: 8, x: 8,
    q: 10, z: 10
  }.freeze

  def scrabble_score
    downcase.chars.map { |character| LETTER_VALUE[character.to_sym] }.compact.sum
  end
end

class NilClass
  def scrabble_score
    0
  end
end

class Scrabble
  def initialize(string)
    @string = string
  end

  def score
    @string.scrabble_score
  end

  def self.score(string)
    string.scrabble_score
  end
end

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nihilismus's solution

to Scrabble Score in the Ruby Track