Ruby testing library selection

[ethnt]

This is still a draft!

Options

There are generally two options when it comes to unit testing in Ruby: RSpec and minitest.

### RSpec

RSpec.describe Imdb do
  it "has a version number" do
    expect(Imdb::VERSION).not_to be nil
  end

  it "does something useful" do
    expect(false).to eq(true)
  end
end

• DSL-based, using describe, context, and it blocks to define specificity of tests
• Human-readable (i.e., you can read it like a sentence — expect(Imdb::VERSION).not_to be nil can be read out loud and you would know what you mean)
• Ships with a large amount of matchers, covering most use-cases
• Larger than minitest, and an extra dependency

Minitest

class TestImdb < Minitest::Test
  def test_that_it_has_a_version_number
    refute_nil ::Imdb::VERSION
  end

  def test_it_does_something_useful
    assert false
  end
end

• Tests are plain Ruby, generally without a DSL — the only convention is that a test method's name begins with test_
  • minitest does offer a DSL, but a minimal one (see Specs section of the README)
• Comes with built-in mocks and stubs
• Less complexity — no complex matcher chaining
• Distributed with Ruby

[amckinney]

Minitest sounds appealing given the smaller dependency footprint, less complexity, and the fact that its distributed with Ruby. I'd like to see how far we could get with Minitest and only introduce RSpec if there's a compelling reason to do so (i.e. less is more).

Plus, for wire testing, it looks like webmock actually supports both Minitest and RSpec (if we ever choose to explore that dependency in the future).

[amckinney]

Discussed more with @ethnt - vcr is another test-specific dependency for us to consider in the future.