Difference between Unit::Test versus Rspec [closed]

Question

I am interested in Test::Unit and Rspec.

Could someone explain me what is the main difference between the two - in terms of principles on which they operate.

Upper

Answer 1

Test::Unit is more akin to a classic TDD tool like JUnit. Tests are written as classes (because that's how it was done in Java / C++).

Test::Unit is more approachable by those who are used to classic testing tools.

Test::Unit has been completely replaced by Minitest.

require_relative "simple_number"
require "test/unit"
 
class TestSimpleNumber < Test::Unit::TestCase
  def test_add
    assert_equal(4, SimpleNumber.new(2).add(2) )
  end
  def test_multiply
    assert_equal(6, SimpleNumber.new(2).multiply(3) )
  end
end

RSpec is a domain specific language which uses the flexibility of the ruby language to create tests which are "more readable".

Earlier versions of RSpec took this a bit too far and monkeypatched core Ruby classes.

RSpec is more oriented towards the philosophy of Behavior Driven Development where you describe the behavior of the components in your app vs TDD where you slice the app into its smallest components.

require "spec_helper"
require "lib/simple_number"
     
describe SimpleNumber do 
  describe "#add" do
    it "adds a value to the sum" do
      expect(SimpleNumber.new(2).add(2)).to eq(4)
    end 
  end
  describe "#multiply" do
    it "multiplies with the value" do
      expect(SimpleNumber.new(2).multiply(3)).to eq(6)
    end 
  end
end

Which is better?

Thats a matter of opinion.

Minitest has recently had a bit of a resurgence as it is perceived as faster and simpler. However tests can be extremely terse, and what really slows down a suite is integration tests and database IO.

A well written RSpec test suite (or spec suite) is both more readable and easy to navigate. When a spec fails it is pretty easy to tie it to what actually went wrong in the application. Of course there are many suites which are the exact opposite.

Minitest is extremely flexible and can even be used with a spec style syntax. Its very sparse out of the box and does not include a rich assertions library and a mocking library like RSpec. While you can plug anything in you still need to get all the moving parts to work together.

RSpec has a much better test runner and superior documentation.

Helotism

Thank you. That is exactly what I was looking for! When l was looking for literature I found tons of materials describing how to write tests but very little discussing the theoretical underpinnings of these two approaches. You gave me a good starting point from which I can move further. – Upper