Least Significant Bit

Cucumber is in the opinion of many a kick ass project, and no wonder given all it provides. I’ve being using it in several projects with great joy. Sometimes you need an expectation step to exactly negate another expectation step, generally is not clear what’s the meaning of negate an expectation step, but in boolean expectations it is easy to not them.

Let’s say you want to check whether some form exist in your page or not, you can do something like:

Then /^I (should|should not) see the people search form$/ do |maybe|
  people_search_form_should_exist maybe == "should"
end

# and the method hides the complexity out of the step, and remain readable:
def people_search_form_should_exist it_should_exist
  _not = "_not" unless it_should_exist

  response.send "should#{_not}".to_sym, have_tag('form#frmSearch')
end

Matt Wynne suggested another approach more old_skool style that gave me the tips to mine, his is shorter and could even be faster, but I haven’t benchmark it though:

   Then /^I (should|should not) see the people search form$/ do |maybe|
     has_matching_tags = current_dom.css('form#frmSearch').length > 0
     assert has_matching_tags == (maybe == "should")
   end

update

wow! Matt make it even shorter:

Then /^I (should|should not) see the people search form$/ do |maybe|
 response.send maybe.sub(' ','_').to_sym, have_tag('form#frmSearch')
end

which I turn into:

Then /^I (should|should not) see the people search form$/ do |maybe|
  response.send should_or_not(maybe), have_tag('form#frmSearch')
end

# with the method
def should_or_not maybe
  maybe.sub(' ', '_').to_sym
end

Update 2

There was also the non DRY but repeating solution, which I like:

Then /^the correspondence should (not )?have inclusions$/ do |negate|
  if negate
    @outcorr.inclusions.should be_empty
  else
    @outcorr.inclusions.should_not be_empty
  end
end

but David Chelimski came up with a good one too:

Then /^I (should|should not) see the people search form$/ do
|should_or_should_not|
 expect_that(response, should_or_should_not, have_tag('form#frmSearch'))
end

def expect_that(target, should_or_should_not, matcher)
 target.send should_or_should_not.underscore.to_sym, matcher
end

well you pick yours