DragonTest

A simple DSL and test runner DragonRuby Game Toolkit (DRGTK).

New to writing tests? Check out this tutorial introducing the concept in DRGTK!

🚧 DragonTest is a work in progress! It works, but the interfaces may change. 🚧

Given a method in your game called #text_for_setting_val,

def text_for_setting_val(val)
  case val
  when true
    "ON"
  when false
    "OFF"
  else
    val
  end
end

You'd test it like this:

test :text_for_setting_val do |args, assert|
  it "returns proper text for boolean vals" do
    assert.equal!(text_for_setting_val(true), "ON")
    assert.equal!(text_for_setting_val(false), "OFF")
  end

  it "passes the value through when not a boolean" do
    assert.equal!(text_for_setting_val("other"), "other")
  end
end

Get Started

1. Replace mygame/app/tests.rb in your DRGTK with app/tests.rb.
2. Drop in lib/dragon_test.rb
3. Drop in test/tests.rb
4. Place the run_tests script into the mygame folder of your project
5. Write your tests in test/tests.rb
6. Run tests with ./run_tests or just boot up your dragonruby engine and tests will run on file change

Or just use Scale, a project template for DRGTK that includes DragonTest.

Features/Problems

• documentation
• simple DSL
• additonal assertions like assert.exception! and assert.includes!
• easily define custom assertions
• bash script for running on CI with proper exit code and output on failure
• watch your tests run when you start your game with the dragonruby executable and save the tests file

Docs (a.k.a. How It Works)

When running DRGTK tests, the exit status doesn't fail when non-zero. So we want to easily have a way to break the build on CI. Plus we want to properly reset the tests that ran with each run.

Define tests with:

test :method_under_test do |args, assert|
end

You then have access to args that you normally do in #tick for a DRGTK game.

Included assertions

assert is an object you use to make assertions. Three are included by default:

• assert.true! - whether or not what's passed in is truthy, ex: assert.true!(5 + 5 == 10)
• assert.false! - whether or not what's passed in is falsey, ex: assert.false!(5 + 5 != 10)
• assert.equal! - whether or not what's passed into param 1 is equal to param 2, ex: assert.equal!(5, 2 + 3)
• assert.exception! - expect the code in the block to raise an error with optional message, ex: assert.exception!(KeyError, "Key not found: :not_present") { text(args, :not_present) }
• assert.int! - the passed in value is an Integer
• assert.includes! - whether or not the second param is included in the first arrary parameter, ex: assert.includes!([1, 2, 3], 2])
• assert.not_includes! – the second param is not included in the first array param

You can also pass an optional failure message too as the last parameter of many of the assertions: assert.equal(5, 2 + 2, "the math didn't work")

Custom assertions

Define custom assertions within the GTK::Assert class (see the comment and example in the code):

class GTK::Assert
  def rect!(obj)
    true!(obj.x && obj.y && obj.w && obj.h, "doesn't have needed properties to be a rectangle")
  end
end

usage:

test :create_player do |args, assert|
  it "is a rectangle" do
    assert.rect!(create_player(args))
  end
end

Overview of files and methods:

• the ./run_tests script handles running the test suite and outputing any test failures with proper exit code; relies upon the --exit-on-fail flag
• the #run_tests method encapsulates all the test running logic that exists on top of DRGTK
• the #test method is the main entrypoint into the DSL and is where you can define custom assertions
• the #it method is just a nice little way to organize your tests in a block, kinda like RSpec:

test :vel_from_angle do |args, assert|
  it "rounds values four places" do
    assert.equal!(vel_from_angle(90, 10), [10.2323, 12.1231])
  end
end

Run on CI

You'll need to be using DRGTK in a private repo with the Linux engine source checked into the codebase.

In the CI script for your provider, just have it run run_tests.

Then on PR, commit, whatever event, tests will run. If tests fail, the build will break.

Thanks

• 68K (James) for the help/guidance/support!
• Levi for API feedback