Ruby – In Ruby’s Test::Unit::TestCase, how to override the initialize method

rubytestunitunit testing

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 MyTest < Test::Unit::TestCase 
   def setup 
   end

   def test_1 
   end

   def test_1 
   end
end

But setup and teardown run for every invocation of a test_* method. This is exactly what I don't want. Rather, I want a setup method that runs just once for the whole class. But I can't seem to write my own initialize() without breaking TestCase's initialize.

Is that possible? Or am I making this hopelessly complicated?

Best Answer

As mentioned in Hal Fulton's book "The Ruby Way". He overrides the self.suite method of Test::Unit which allows the test cases in a class to run as a suite. 

def self.suite
    mysuite = super
    def mysuite.run(*args)
      MyTest.startup()
      super
      MyTest.shutdown()
    end
    mysuite
end

Here is an example:

class MyTest < Test::Unit::TestCase
    class << self
        def startup
            puts 'runs only once at start'
        end
        def shutdown
            puts 'runs only once at end'
        end
        def suite
            mysuite = super
            def mysuite.run(*args)
              MyTest.startup()
              super
              MyTest.shutdown()
            end
            mysuite
        end
    end

    def setup
        puts 'runs before each test'
    end
    def teardown
        puts 'runs after each test'
    end 
    def test_stuff
        assert(true)
    end
end
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