Assert_xhtml - test your HTML by example


#1

Rubies:

My quest to get the maximum coverage & diagnostics from the leanest
possible
tests has reached a new level.

This is a Rails functional test on an HTML form:

 user = users(:Moses)
 get :edit_user, :id => user.id

 assert_xhtml do

   form :action => '/users' do
     fieldset do
       legend 'Personal Information'
       label 'First name'
       input :type => 'text',
             :name => 'user[first_name]'
             :value => user.first_name
     end
   end

 end

That’s all. The assertion expects a form with a given action, containing
a
fieldset, a legend, a label, and a populated text input field. The
assertion
forgives any other details, such as intervening structural tags, and
complains
if any required detail is missing, out of order, or ill-formed.

You test HTML by writing an example of what you expect, excluding
details you
don’t care about.

When it fails, the assertion will print out your reference HTML, and
your sample
HTML from your web page.

The assertion faults if…

  • any attribute does not match exactly
  • any text content does not match, stripped
  • any node is not found at all
  • any node is found out of order

The assertion does not fail if

  • nodes contain un-specified attributes
  • the DOM contains any un-specified tags (,
    , etc.)

    Here’s the assertion checking that a list appears in collating order:

     assert_xhtml SAMPLE_LIST do
    
       ul :style => 'font-size: 18' do
         li 'model' do
           li 'Billings criteria'
           li 'Billings report'
           li 'Sales report'
         end
       end
    
     end
    

    The assertion takes a block that renders into a Nokogiri::HTML::Builder.
    Any
    HTML it can build, you can specify by example.

    That freedom causes two issues: The ‘self’ context is different inside
    this
    block, so you must pass variables in as closures. And an element with
    the same
    name as a Builder method, such as .select, need a bang: .select!

    Get the assertion, from assert2-0.3.8.gem, with these incantations:

    gem install assert2 nokogiri

    require ‘assert2/xhtml’ # for Test::Unit::TestCase and derivatives

    Those of you using RSpec will know how to apply this Gist:

    http://gist.github.com/76136

    Good hunting!


#2

On Wed, Mar 11, 2009 at 11:58 PM, Phlip removed_email_address@domain.invalid wrote:

assert_xhtml do

When it fails, the assertion will print out your reference HTML, and your

     li 'Billings report'

block, so you must pass variables in as closures. And an element with the
http://gist.github.com/76136
Any interest in just incorporating this into the lib? So an RSpec user
could say “require ‘assert2/rspec’” or something?


#3

Those of you using RSpec will know how to apply this Gist:

http://gist.github.com/76136

Any interest in just incorporating this into the lib? So an RSpec user
could say “require ‘assert2/rspec’” or something?

Yabsolutely!

And my boss just hit the “crunch mode” button today, after 2 years of
pure
sustainable pace. Guess it’s time to pay out the energy we have stored
up, huh?

(No RSpec onsite. Sorry!)


#4

Amazing stuff :smiley:
Can’t wait to test it out