Table of Contents

Knock Out!

KO! is a test framework for Ruby. Inspired by the discontinuation of Shoulda excellent context system, it seemed time Ruby had a lean but elegant test system.

Here is a simple example. First we will define a reusable context:

context "Calculator Instance" do

  setup do
    require 'calculator'
    @calculator = Calculater.new
  end

end

Then when we define a testcase which utilizes the context:

KO.case "Addition" do

  use "Calculator Instance"

  test "addition of two numbers" do |a,b,c|
    @calculator.push a
    @calculator.push b
    @calculator.add
    @calculator.output == c
  end

  ok 2,2,4
end

KO.case "Subtraction" do

  use "Calculator Instance"

  test "subtraction of two numbers" do |a,b,c|
    @calculator.push a
    @calculator.push b
    @calculator.subtract
    @calculator.output == c
  end

  ok 2,2,0
end

Testing for Truth

class TruthCase < KO::TestCase

  desc "test for truth"

  test "pass-thru" do |obj|
    obj
  end

  ok true
  ok Object.new

  no false
  no nil

end

Testing by Equality

The `ko` method supports a special trailing hash notation.

KO.case "test by equality" do

  test "pass-thru" do |obj|
    obj
  end

  ok 1   => 1.0
  ok :a  => :a
  ok 'A' => 'A'

  no 1   => 2.0
  no :a  => :b

end

Passing a Hash

Because of the specialized notation of `ok`, it’s not possible to pass a trailing hash as an argument to the test procedure as one is normally accustomed to in Ruby code. However, a work around to this is very simple.

KO.case "passing a hash to a test" do

  test do |args|
    arg1, arg2, opts = *args
    opts.is_a? Hash
  end

  ok [1, 2, {:a => 1}]

  # in 1.9+
  #ok [1, 2, :a => 1]

  no [1, 2]

end

Customized Validation

While equality (==) is the normal validation procedure for the `ok` hash notation, this can be customized by supplying a validation procedure with the `valid` method.

KO.case "test validation" do

  valid do |cls, expect|
    expect === cls
  end

  test do |obj|
    obj
  end

  ok 1   => Fixnum
  ok :a  => Symbol
  ok 'A' => String

  no 1   => String

end