TestCase clone issue when a class method is defined

[dmarchaland]

Hi,

I'm hitting the following issue when trying to clone a simple TestCase as defined below

class MyTest < Test::Unit::TestCase

  class << self
    def startup
    end
  end

  def test_trial
  end
  
 end
 
 MyTest.clone

test-unit-3.5.3/lib/test/unit/attribute.rb:203:in \`find_attribute': undefined method \`find_attribute' for nil:NilClass (NoMethodError)
	from test-unit-3.5.3/lib/test/unit/testcase.rb:151:in \`method_added'

This is using Ruby 2.6.8

[kou]

I've fixed this but why do you want to clone?

[dmarchaland]

I wrote a generic TestCase that I want to run on several objects dynamically generated. See pseudo code below for the idea. Basic question is how to reuse a TestCase multiple times?

class MyGenericTestCase < Test::Unit::TestCase

  class << self

    attr_accessor :obj

    def startup
    end

  end

  def test_obj
    assert(self.class.obj)
  end

end


ListOfObjs = [['A'], ['B'], ['C']]

MyTestSuite = Test::Unit::TestSuite.new("My TestSuite")

ListOfObjs.each do |obj|
  klassname = "TestCase_#{obj.first}"
  klass = Object.const_set(klassname, MyGenericTestCase.clone)
  klass.obj = obj
  MyTestSuite << klass.suite
end

[kou]

You should use module for shared tests and inheritance for the parameterization like normal Ruby script:

require "test-unit"

module MyGenericTests
  def test_obj
    assert(self.class.obj)
  end
end

class MyGenericTestCase < Test::Unit::TestCase

  class << self

    attr_accessor :obj

    def startup
    end
  end
end


ListOfObjs = [['A'], ['B'], ['C']]

ListOfObjs.each do |obj|
  klassname = "TestCase_#{obj.first}"
  klass = Object.const_set(klassname, Class.new(MyGenericTestCase))
  klass.obj = obj
  klass.include(MyGenericTests)
end

Or you can use data-driven test feature:

require "test-unit"

class MyGenericTestCase < Test::Unit::TestCase
  class << self
    def startup
    end
  end

  data(:obj, ["A", "B", "C"], keep: true)
  def test_obj1(data)
    obj = data[:obj]
    assert(obj)
  end

  def test_obj2(data)
    obj = data[:obj]
    assert(obj)
  end
end

[dmarchaland]

Module usage makes definitely sense to define the generic tests! Thank you, appreciated your input.