Scope - concise Ruby unit testing

Scope is a micro Ruby unit testing framework in the spirit of Shoulda and others. It gives you a tight syntax for writing terse, readable unit tests.

• Organize your tests into "contexts", where each context can have its own setup code (see example).
• 150 lines of code, so it's very easy to understand and enhance.
• Tests are run in the order you define them in, instead of alphabetically or randomly, which follows the principle of least surprise.
• setup_once and teardown_once, for writing integration tests (see below for details).
• The ability to call focus() before a test method or context to have only that method/context run. Very useful when writing and troubleshooting tests.
• Built on top of minitest, which is Ruby 1.9's official replacement for test/unit. Minitest is a gem and works in Ruby 1.8 as well.

require "scope"
require "minitest/autorun"

class MarioTest < Scope::TestCase
  context "super mario" do
    setup do
      @game = MarioGame.new
    end

    context "enemy interaction" do
      setup do
        @turtle = @game.add_enemy("turtle", :x => 10, :y => 0)
      end

      should "kill the turtle after jumping" do
        @game.mario.jump(:x => 10, :y => 0)
        assert_equal "dead", @turtle.state
      end

      should "end the game if mario walks into an enemy turtle" do
        @game.mario.move(:x => 10, :y => 0)
        assert_equal "game_over", @game.state
      end
    end

    ...

  end
end

gem install scope

Scope supports "setup_once" and "teardown_once" blocks, which are useful when writing integration tests. If you have some expensive setup code that you want to share across many of your integration tests (e.g. fetching a file, or making real API requests) then use setup_once:

context "tests which require expensive setup" do
  setup_once do
    @@youtube_api = YouYubeApi.connect("my_username", "my_password")
    @@new_video = @@youtube_api.create_video(:name => "Never gonna give you up", :size => 12_282_831)
  end

  should "add video to a channel" do
    @@my_youtube_channel.add(@@new_video.id)
    assert_equal @@my_youtube_channel.lineup.include?(@@new_video.id)
  end

  should "allow setting a video to be private" do
    assert_equal true, @@youtube_api.set_sharing_status(@@new_video.id, :private => true)
  end

  ...
end

You'll notice that variables created in setup_once blocks need to be class variables (e.g. @@youtube_api). This is because new instances of a testcase class are created every time a test is run. If you used simply instance variables, they would be lost when the next test is run.

You can use the focus method to indicate that only a single test/context should be run. When hacking on or troubleshooting tests, this is usually more convenient than running your test with command line parameters (-n). It's also super useful if you're using watchr to run your tests.

should "decrease file count when files are removed" do
  assert_equal 2, @directory.file_count
  @directory.delete("banana.txt")
  assert_equal 1, @directory.file_count
end

focus
should "list files in alphabetical order" do
  assert_equal ["apricot.txt", "banana.txt"], @directory.list
end

In this example, only the test called "list files in alphabetical order" will be run when you run this test file.

Licensed under the MIT license

Phil Crosby (twitter @philcrosby)
Harry Robertson (github harob)