angelikatyborska's solution to Pangram on the Ruby track

Instructions

Test suite

Solution

Note:

This solution was written on an old version of Exercism. The tests below might not correspond to the solution code, and the exercise may have changed since this code was written.

Determine if a sentence is a pangram. A pangram (Greek: παν γράμμα, pan gramma, "every letter") is a sentence using every letter of the alphabet at least once. The best known English pangram is:

The quick brown fox jumps over the lazy dog.

The alphabet used consists of ASCII letters a to z, inclusive, and is case insensitive. Input will not contain non-ASCII symbols.

For installation and learning resources, refer to the exercism help 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 pangram_test.rb

To include color from the command line:

ruby -r minitest/pride pangram_test.rb

Source

Wikipedia https://en.wikipedia.org/wiki/Pangram

Submitting Incomplete Solutions

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

pangram_test.rb

require 'minitest/autorun'
require_relative 'pangram'

# Common test data version: 1.3.0 d79e13e
class PangramTest < Minitest::Test
  def test_sentence_empty
    # skip
    phrase = ''
    result = Pangram.pangram?(phrase)
    refute result, "Expected false, got: #{result.inspect}. #{phrase.inspect} is NOT a pangram"
  end

  def test_recognizes_a_perfect_lower_case_pangram
    skip
    phrase = 'abcdefghijklmnopqrstuvwxyz'
    result = Pangram.pangram?(phrase)
    assert result, "Expected true, got: #{result.inspect}. #{phrase.inspect} IS a pangram"
  end

  def test_pangram_with_only_lower_case
    skip
    phrase = 'the quick brown fox jumps over the lazy dog'
    result = Pangram.pangram?(phrase)
    assert result, "Expected true, got: #{result.inspect}. #{phrase.inspect} IS a pangram"
  end

  def test_missing_character_x
    skip
    phrase = 'a quick movement of the enemy will jeopardize five gunboats'
    result = Pangram.pangram?(phrase)
    refute result, "Expected false, got: #{result.inspect}. #{phrase.inspect} is NOT a pangram"
  end

  def test_another_missing_character_eg_h
    skip
    phrase = 'five boxing wizards jump quickly at it'
    result = Pangram.pangram?(phrase)
    refute result, "Expected false, got: #{result.inspect}. #{phrase.inspect} is NOT a pangram"
  end

  def test_pangram_with_underscores
    skip
    phrase = 'the_quick_brown_fox_jumps_over_the_lazy_dog'
    result = Pangram.pangram?(phrase)
    assert result, "Expected true, got: #{result.inspect}. #{phrase.inspect} IS a pangram"
  end

  def test_pangram_with_numbers
    skip
    phrase = 'the 1 quick brown fox jumps over the 2 lazy dogs'
    result = Pangram.pangram?(phrase)
    assert result, "Expected true, got: #{result.inspect}. #{phrase.inspect} IS a pangram"
  end

  def test_missing_letters_replaced_by_numbers
    skip
    phrase = '7h3 qu1ck brown fox jumps ov3r 7h3 lazy dog'
    result = Pangram.pangram?(phrase)
    refute result, "Expected false, got: #{result.inspect}. #{phrase.inspect} is NOT a pangram"
  end

  def test_pangram_with_mixed_case_and_punctuation
    skip
    phrase = '"Five quacking Zephyrs jolt my wax bed."'
    result = Pangram.pangram?(phrase)
    assert result, "Expected true, got: #{result.inspect}. #{phrase.inspect} IS a pangram"
  end

  def test_upper_and_lower_case_versions_of_the_same_character_should_not_be_counted_separately
    skip
    phrase = 'the quick brown fox jumps over with lazy FX'
    result = Pangram.pangram?(phrase)
    refute result, "Expected false, got: #{result.inspect}. #{phrase.inspect} is NOT a pangram"
  end

  # Problems in exercism evolve over time, as we find better ways to ask
  # questions.
  # The version number refers to the version of the problem you solved,
  # not your solution.
  #
  # Define a constant named VERSION inside of the top level BookKeeping
  # module, which may be placed near the end of your file.
  #
  # In your file, it will look like this:
  #
  # module BookKeeping
  #   VERSION = 1 # Where the version number matches the one in the test.
  # end
  #
  # If you are curious, read more about constants on RubyDoc:
  # http://ruby-doc.org/docs/ruby-doc-bundle/UsersGuide/rg/constants.html

  def test_bookkeeping
    skip
    assert_equal 6, BookKeeping::VERSION
  end
end

module BookKeeping
  VERSION = 4
end

class Pangram
  class << self
    ALPHABET = ('a'..'z').to_a

    def pangram?(string)
      (ALPHABET - string.downcase.chars).length.zero?
    end
  end
end

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angelikatyborska's solution

to Pangram in the Ruby Track