Capybara: How To Assert A Given Number of Elements Exist

Question

I've upgraded my whole stack from a Rails 3.0 based project to 3.1. I have specs passing but my features are now being a bit picky. The issue I'm currently having is this step:

Then /^I should see (\d+) menu item(?:s)? within "([^"]*)"$/ do |count, selector|
  page.find(:css, selector, :count => count.to_i)
end

And in the feature itself, I might put:

Then I should see 5 menu items within "tr#menu_item_row"

The message I get is:

Then I should see 5 menu items within "tr#menu_item_row"                                      # features/step_definitions/admin_menu_steps.rb:1
  Ambiguous match, found 5 elements matching css "tr#menu_item_row" (Capybara::Ambiguous)
  ./features/step_definitions/admin_menu_steps.rb:2:in `/^I should see (\d+) menu item(?:s)? within "([^"]*)"$/'
  features/admin_menu.feature:30:in `Then I should see 5 menu items within "tr#menu_item_row"'

As far as I can tell, the 5 elements match the 5 that were actually found. Did I write this code wrong or has something major changed? Thanks!

Answer 1

If you want to check 5 elements you shouldn't use #find as by default since Capybara 2.0 this method always throws an exception if it finds more or less than one element. This was an intentional and (I believe) a good change.

To assert that 5 elements are present an appropriate method is a rspec matcher:

expect(page).to have_css(selector, count: count.to_i)

I don't recommend to set match to prefer_exact as recommended by @fontno as in most of situations you want Capybara to throw an exception if find finds more than one element.