In Ruby's Test::Unit::TestCase, how do I override the initialize method?

Question

I\'m struggling with Test::Unit. When I think of unit tests, I think of one simple test per file. But in Ruby\'s framework, I must instead write:

class M         


        

Answer 1

FINALLY, test-unit has this implemented! Woot! If you are using v 2.5.2 or later, you can just use this:

Test::Unit.at_start do
  # initialization stuff here
end

This will run once when you start your tests off. There are also callbacks which run at the beginning of each test case (startup), in addition to the ones that run before every test (setup).

http://test-unit.rubyforge.org/test-unit/en/Test/Unit.html#at_start-class_method

Answer 2

I know this is quite an old post, but I had the issue (and had already written classes using Tes/unit) and ave answered using another method, so if it can help...

If you only need the equivalent of the startup function, you can use the class variables:

class MyTest < Test::Unit::TestCase
  @@cmptr = nil
  def setup
    if @@cmptr.nil?
      @@cmptr = 0
      puts "runs at first test only"
      @@var_shared_between_fcs = "value"
    end
    puts 'runs before each test'
  end
  def test_stuff
    assert(true)
  end
end

Answer 3

I came across this exact problem and created a subclass of Test::Unit::TestCase for doing exactly what you describe.

Here's what I came up with. It provides it's own setup and teardown methods that count the number of methods in the class that begin with 'test'. On the first call to setup it calls global_setup and on the last call to teardown it calls global_teardown

class ImprovedUnitTestCase < Test::Unit::TestCase
  cattr_accessor :expected_test_count

  def self.global_setup; end
  def self.global_teardown; end    

  def teardown
    if((self.class.expected_test_count-=1) == 0)
      self.class.global_teardown
    end
  end
  def setup
    cls = self.class

    if(not cls.expected_test_count)
      cls.expected_test_count = (cls.instance_methods.reject{|method| method[0..3] != 'test'}).length
      cls.global_setup
    end
  end
end

Create your test cases like this:

class TestSomething < ImprovedUnitTestCase
  def self.global_setup
    puts 'global_setup is only run once at the beginning'
  end

  def self.global_teardown
    puts 'global_teardown is only run once at the end'
  end

  def test_1 
  end

  def test_2
  end
end

The fault in this is that you can't provide your own per-test setup and teardown methods unless you use the setup :method_name class method (only available in Rails 2.X?) and if you have a test suite or something that only runs one of the test methods, then the global_teardown won't be called because it assumes that all the test methods will be run eventually.

Answer 4

To solve this problem I used the setup construct, with only one test method followed. This one testmethod is calling all other tests.

For instance

class TC_001 << Test::Unit::TestCase
  def setup
    # do stuff once
  end

  def testSuite
    falseArguments()
    arguments()
  end

  def falseArguments
    # do stuff
  end

  def arguments
    # do stuff
  end
end