alexwebgr's solution to Resistor Color on the Ruby track

Instructions

Test suite

Solution

Resistors have color coded bands, where each color maps to a number. The first 2 bands of a resistor have a simple encoding scheme: each color maps to a single number.

These colors are encoded as follows:

Black: 0
Brown: 1
Red: 2
Orange: 3
Yellow: 4
Green: 5
Blue: 6
Violet: 7
Grey: 8
White: 9

Mnemonics map the colors to the numbers, that, when stored as an array, happen to map to their index in the array: Better Be Right Or Your Great Big Values Go Wrong.

More information on the color encoding of resistors can be found in the Electronic color code Wikipedia article

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 resistor_color_test.rb

To include color from the command line:

ruby -r minitest/pride resistor_color_test.rb

Source

Maud de Vries, Erik Schierboom https://github.com/exercism/problem-specifications/issues/1458

Submitting Incomplete Solutions

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

resistor_color_test.rb

require 'minitest/autorun'
require_relative 'resistor_color'

# Common test data version: 1.0.0 edf1778
class ResistorColorTest < Minitest::Test
  def test_black
    # skip
    assert_equal 0, ResistorColor.color_code("black")
  end

  def test_white
    skip
    assert_equal 9, ResistorColor.color_code("white")
  end

  def test_orange
    skip
    assert_equal 3, ResistorColor.color_code("orange")
  end

  def test_colors
    skip
    expected = ["black", "brown", "red", "orange", "yellow", "green", "blue", "violet", "grey", "white"]
    assert_equal expected, ResistorColor::COLORS
  end
end

=begin
Write your code for the 'Resistor Color' exercise in this file. Make the tests in
`resistor_color_test.rb` pass.

To get started with TDD, see the `README.md` file in your
`ruby/resistor-color` directory.
=end

class ResistorColor
  COLORS = %w[black brown red orange yellow green blue violet grey white]
  def self.color_code(color)
    COLORS.index(color)
  end
end

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alexwebgr's solution

to Resistor Color in the Ruby Track

Source

Submitting Incomplete Solutions

resistor_color_test.rb

Community comments

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