Question

I am writing a test helper and it has this method:

def todo msg = ''
  assert false, '@TODO: ' + msg
end

Basically I want a quick method to fail a test. Next, I would like to test this method (because it will be encapsulated in a shippable helper). So I would like to write something like this:

test 'todo' do
  result = todo
  expected = '@TODO: '
  assert_equal expected, result
end

but it just fails when assert false gets called. So, how would I test this method?

Answer 1

This helper is supposed to work with Test::Unit, is that right? I believe that assert false throws an exception which is caught by Test::Unit. You could just wrap the call to todo in a begin...rescue block and catch that exception.

The test/unit which comes in the Ruby standard libraries is actually Minitest::Unit — when an assertion fails, it raises a Minitest::Assertion exception. You could rescue that.

For the “real” Test::Unit, it raises a Test::Unit::AssertionFailedError when an assertion fails.