How to run existing test code on Ruby 2.2

Question

The following code (which has no Gemfile) works on Ruby 2.1.1, but not Ruby 2.2.0

require "bundler/setup"
gem "minitest", "4.7.5"
require "test/unit"

class TestFoo < Test::Unit::TestCase
  def test_foo
    assert true, "Useless mesage"
    skip "Skip works"
  end
end

On Ruby 2.1.1, I get

Run options: 

# Running tests:

[1/1] TestFoo#test_foo = 0.00 s
  1) Skipped:
TestFoo#test_foo [test_220.rb:8]:
Skip works

Finished tests in 0.004435s, 225.4791 tests/s, 225.4791 assertions/s.
1 tests, 1 assertions, 0 failures, 0 errors, 1 skips

ruby -v: ruby 2.1.1p76 (2014-02-24 revision 45161) [x86_64-darwin10.0]

But on Ruby 2.2.0, I get

192-168-1-5:test_220 agrimm$ ruby test_220.rb 
Loaded suite test_220
Started
E
===============================================================================
Error: test_foo(TestFoo)
: NoMethodError: undefined method `skip' for #<TestFoo:0x007fb75484f158>
test_220.rb:8:in `test_foo'
      5: class TestFoo < Test::Unit::TestCase
      6:   def test_foo
      7:     assert true, "Useless mesage"
  =>  8:     skip "Skip works"
      9:   end
     10: end
===============================================================================


Finished in 0.001504 seconds.

1 tests, 1 assertions, 0 failures, 1 errors, 0 pendings, 0 omissions, 0 notifications
0% passed

664.89 tests/s, 664.89 assertions/s
$ ruby --version
ruby 2.2.0p0 (2014-12-25 revision 49005) [x86_64-darwin13]

I suspect that this is because of changes associated with Ruby 2.2.0:

Update test-unit 3.0.8 (removed from repository but bundled in tarball)

Update minitest 5.4.3 (removed from repository but bundled in tarball)

How do I make the code work on Ruby 2.2, preferably with the least amount of code change?

Answer 1

Before Ruby 2.2, test/unit was just a thin wrapper over minitest. Even though your test cases inherited from Test::Unit::TestCase, you were in fact using minitest assertions. Hence skip worked, which is a feature of minitest.

The standard Ruby 2.2 distributions bundles test-unit 3.0.8 and minitest 5.4.3, but does not include the integration which existed before. Note that they are in fact 2 separate testing frameworks - essentially two separate gems.

I propose 2 options:

1. Use test-unit - rubydoc

Your tests can keep the Test::Unit::TestCase base class, but you will need to adapt the assertions to use the test-unit ones.

For instance, replace skip with omit:

require "test/unit"

class TestFoo < Test::Unit::TestCase
  def test_foo
    assert true, "Useless mesage"
    omit "Omit works"
  end
end

2. Use minitest - rubydoc

You will keep using the assertions you know, but you will need to require "minitest/autorun" and switch the base class to Minitest::Test:

require "minitest/autorun"

class TestFoo < Minitest::Test
  def test_foo
    assert true, "Useless mesage"
    skip "Skip works"
  end
end