Acronymize with #map

acronymize.rb

def acronymize(sentence)
  # map => []
  # applies transformations to elements

  # 1. split sentence into words (list use Array)
  words = sentence.split
  # 2. Go through/Take each word
  # and take/grab the first letter (capitalize)
  initials = words.map { |word| word[0].capitalize }
  # 3. Join words into a single sentence
  initials.join
end


# TDD with Rspec
describe "#acronymize" do
  it "should return a string" do
    actual = acronymize("away from keyboard").class.to_s
    expected = "String"
    expect(actual).to eq(expected)
  end

  it "should return an empty string when passed an empty string" do
    actual = acronymize("")
    expected = ""
    expect(actual).to eq(expected) # returns true/false
  end

  it "returns the acronym on downcased sentences" do
    actual = acronymize("working from home")
    expected = "WFH"
    expect(actual).to eq(expected)
  end

  it "returns the acronym on upcased sentences" do
    actual = acronymize("AWAY FROM KEYBOARD")
    expected = "AFK"
    expect(actual).to eq(expected)
  end
end