oxford_comma_spec.rb

describe "#oxford_comma" do
  it 'returns a string without any additional formatting when given a 1-element array' do
    expect(oxford_comma(["kiwi"])).to eq("kiwi")
  end
  it "adds 'and' between elements when given a 2-element array" do
    expect(oxford_comma(["kiwi", "durian"])).to eq("kiwi and durian")
  end
  it "adds commas plus a final 'and' when given a 3-element array" do
    expect(oxford_comma(["kiwi", "durian", "starfruit"])).to eq("kiwi, durian, and starfruit")
  end
  it "correctly formats arrays of lengths greater than three" do
    expect(oxford_comma(["kiwi", "durian", "starfruit", "mangos", "dragon fruits"])).to eq("kiwi, durian, starfruit, mangos, and dragon fruits")
    expect(oxford_comma(["kiwi", "durian", "starfruit", "mangos", "dragon fruits", "lychees", "pomelos"])).to eq("kiwi, durian, starfruit, mangos, dragon fruits, lychees, and pomelos")
  end
end