Tests for an implementation of the Karatsuba multiplication algorithm in Ruby

karatsuba.spec.rb

require 'minitest/autorun'
require './karatsuba'

describe Karatsuba do
  before do
    @karatsuba = Karatsuba.new
  end

  describe "#multiply" do
    it "should multiply small numbers of equal size" do
      assert_equal(@karatsuba.multiply(5, 5), 25)
    end

    it "should multiply small numbers of different size" do
      assert_equal(@karatsuba.multiply(3, 12), 36)
    end

    it "should multiply small numbers with zeros inbetween" do
      assert_equal(@karatsuba.multiply(10, 100), 1000)
    end

    it "should multiply large numbers with zeros inbetween" do
      assert_equal(@karatsuba.multiply(100020001, 10030501), 1003250720050501)
    end

    it "should multiply large numbers of equal size" do
      assert_equal(@karatsuba.multiply(345345345, 146348395), 50540736961471275)
    end

    it "should multiply large numbers of different size" do
      assert_equal(@karatsuba.multiply(7655432, 7853), 60118107496)
    end
  end
end

The Karatsuba class being tested can be found here: https://gist.github.com/diegocasmo/27988de71d4ab22f11654ce0fefff4b1