teamcapybara--capybara/README.rdoc

= Capybara

* http://github.com/jnicklas/capybara

== Description:

Capybara aims to simplify the process of integration testing Rack applications,
such as Rails, Sinatra or Merb. Capybara simulates how a real user would
interact with a web application. It is agnostic about the driver running your
tests and currently comes with Rack::Test and Selenium support built in.
HtmlUnit and env.js are supported through external gems.

A complete reference is available at
{at rubydoc.info}[http://rubydoc.info/github/jnicklas/capybara/master].

== Install:

Install as a gem:

    sudo gem install capybara

On OSX you may have to install libffi, you can install it via MacPorts with:

    sudo port install libffi

== Development:

* Source hosted at {GitHub}[http://github.com/jnicklas/capybara].
* Please direct questions, discussion or problems to the {mailing list}[http://groups.google.com/group/ruby-capybara].
* If you found a reproducible bug, open a {GitHub Issue}[http://github.com/jnicklas/capybara/issues] to submit a bug report.

Pull requests are very welcome (and even better than bug reports)! Make sure
your patches are well tested, Capybara is a testing tool after all. Please
create a topic branch for every separate change you make.

Capybara uses bundler in development. To set up a development environment, simply do:

    git submodule update --init
    gem install bundler --pre
    bundle install

== Using Capybara with Cucumber

Capybara is built to work nicely with Cucumber. Support for Capybara is built into
cucumber-rails. In your Rails app, just run:

    rails generate cucumber:install --capybara

And everything should be set up and ready to go.

If you want to use Capybara with Cucumber outside Rails (for example with Merb
or Sinatra), you'll need to require Capybara and set the Rack app manually:

    require 'capybara/cucumber'
    Capybara.app = MyRackApp

Now you can use it in your steps:

    When /I sign in/ do
      within("#session") do
        fill_in 'Login', :with => 'user@example.com'
        fill_in 'Password', :with => 'password'
      end
      click_link 'Sign in'
    end

Capybara sets up some {tags}[http://wiki.github.com/aslakhellesoy/cucumber/tags]
for you to use in Cucumber. Often you'll want to run only some scenarios with a
driver that supports JavaScript, Capybara makes this easy: simply tag the
scenario (or feature) with <tt>@javascript</tt>:

    @javascript
    Scenario: do something Ajaxy
      When I click the Ajax link
      ...

You can change which driver Capybara uses for JavaScript:

    Capybara.javascript_driver = :culerity

There are also explicit <tt>@selenium</tt>, <tt>@culerity</tt> and
<tt>@rack_test</tt> tags set up for you.

== Using Capybara with RSpec

If you prefer RSpec to using Cucumber, you can use the built in RSpec support
by adding the following line (typically to your <tt>spec_helper.rb</tt> file):

    require 'capybara/rspec'

You can now write your specs like so:

    describe "the signup process", :type => :request do
      before :each do
        User.make(:email => 'user@example.com', :password => 'caplin')
      end

      it "signs me in" do
        within("#session") do
          fill_in 'Login', :with => 'user@example.com'
          fill_in 'Password', :with => 'password'
        end
        click_link 'Sign in'
      end
    end

Capybara is only included in example groups tagged with
<tt>:type => :request</tt> (or <tt>:acceptance</tt> for compatibility with Steak).

If you are testing a Rails app and using the <tt>rspec-rails</tt> gem, these
<tt>:request</tt> example groups may look familiar to you. That's because they
are RSpec versions of Rails integration tests. So, in this case essentially what you are getting are Capybara-enhanced request specs. This means that you can
use the Capybara helpers <i>and</i> you have access to things like named route
helpers in your tests (so you are able to say, for instance, <tt>visit
edit_user_path(user)</tt>, instead of <tt>visit "/users/#{user.id}/edit"</tt>,
if you prefer that sort of thing). A good place to put these specs is
<tt>spec/requests</tt>, as <tt>rspec-rails</tt> will automatically tag them with
<tt>:type => :request</tt>. (In fact, <tt>spec/integration</tt> and
<tt>spec/acceptance</tt> will work just as well.)

<tt>rspec-rails</tt> will also automatically include Capybara in <tt>:controller</tt> and <tt>:mailer</tt> example groups.

RSpec's metadata feature can be used to switch to a different driver. Use
<tt>:js => true</tt> to switch to the javascript driver, or provide a
<tt>:driver</tt> option to switch to one specific driver. For example:

    describe 'some stuff which requires js', :js => true do
      it 'will use the default js driver'
      it 'will switch to one specific driver', :driver => :celerity
    end

Finally, Capybara also comes with a built in DSL for creating descriptive acceptance tests:

    feature "Signing up" do
      background do
        User.make(:email => 'user@example.com', :password => 'caplin')
      end

      scenario "Signing in with correct credentials" do
        within("#session") do
          fill_in 'Login', :with => 'user@example.com'
          fill_in 'Password', :with => 'caplin'
        end
        click_link 'Sign in'
      end
    end

This is, in fact, just a shortcut for making a request spec, where
<tt>feature</tt> is an alias for <tt>describe ..., :type => :request</tt>,
<tt>background</tt> is an alias for <tt>before</tt>, and <tt>scenario</tt>
is an alias for <tt>it</tt>/<tt>specify</tt>.

Note that Capybara's built in RSpec support only works with RSpec 2.0 or later.
You'll need to roll your own for earlier versions of RSpec.

== Using Capybara with Test::Unit

To use Capybara with Test::Unit, include the DSL (<tt>include Capybara</tt> up
until version 0.4.x, <tt>include Capybara::DSL</tt> for newer versions) in
whatever test class you are using.  For example, if your classes derive from
<tt>ActionDispatch::IntegrationTest</tt>, use

    class ActionDispatch::IntegrationTest
      include Capybara::DSL
    end

Test::Unit does not support selecting the driver through test metadata, but you
can switch the driver for specific classes using the <tt>setup</tt> and
<tt>teardown</tt> methods.  See the section "Selecting the Driver".

== Using Capybara with Ruby on Rails

If you are using the Rails framework, add this line to automatically configure
Capybara to test against your Rails application:

    require 'capybara/rails'

== Using Capybara with Rack

If you're using Capybara with a non-Rails Rack application, set
<tt>Capybara.app</tt> to your application class:

    Capybara.app = MyRackApp

== Drivers

Capybara uses the same DSL to drive a variety of browser and headless drivers.

=== Selecting the Driver

By default, Capybara uses the <tt>:rack_test</tt> driver, which is fast but does not
support JavaScript.  You can set up a different default driver for your
features. For example if you'd prefer to run everything in Selenium, you could
do:

    Capybara.default_driver = :selenium

However, if you are using RSpec or Cucumber, you may instead want to consider
leaving the faster <tt>:rack_test</tt> as the +default_driver+, and marking only those
tests that require a JavaScript-capable driver using <tt>:js => true</tt> or
<tt>@javascript</tt>, respectively.  By default, JavaScript tests are run using the
<tt>:selenium</tt> driver.  You can change this by setting
<tt>Capybara.javascript_driver</tt>.

You can also change the driver temporarily (typically in the Before/setup and
After/teardown blocks):

    Capybara.current_driver = :culerity  # temporarily select different driver
    ... tests ...
    Capybara.use_default_driver  # switch back to default driver

Note that switching the driver creates a new session, so you may not be able to
switch in the middle of a test.

=== RackTest

RackTest is Capybara's default driver. It is written in pure Ruby and does not
have any support for executing JavaScript. Since the RackTest driver works
directly agains the Rack interface, it does not need any server to be started,
it can work directly work against any Rack app. This means that if your
application is not a Rack application (Rails, Sinatra and most other Ruby
frameworks are Rack applications) then you cannot use this driver. You cannot
use the RackTest driver to test a remote application.
{capybara-mechanize}[https://github.com/jeroenvandijk/capybara-mechanize]
intends to provide a similar driver which works against remote servers, it is a
separate project.

RackTest can be configured with a set of headers like this:

    Capybara.register_driver :rack_test do |app|
      Capybara::RackTest::Driver.new(app, :browser => :chrome)
    end

See the section on adding and configuring drivers.

=== Selenium

At the moment, Capybara supports {Selenium 2.0
(Webdriver)}[http://seleniumhq.org/docs/01_introducing_selenium.html#selenium-2-aka-selenium-webdriver],
*not* Selenium RC. Provided Firefox is installed, everything is set up for you,
and you should be able to start using Selenium right away.

By default Capybara tries to synchronize Ajax requests, so it will wait for
Ajax requests to finish after you've interacted with the page. You can switch
off this behaviour by setting the driver option <tt>:resynchronize</tt> to
<tt>false</tt>. See the section on configuring drivers.

Note: Selenium does not support transactional fixtures; see the section
"Transactional Fixtures" below.

=== HtmlUnit

There are three different drivers, maintained as external gems, that you can
use to drive {HtmlUnit}[http://htmlunit.sourceforge.net/]:

* {Akephalos}[https://github.com/bernerdschaefer/akephalos] might be the best
  HtmlUnit driver right now.

* {Celerity}[https://github.com/sobrinho/capybara-celerity] only runs on JRuby,
  so you'll need to install the celerity gem under JRuby: <tt>jruby -S gem
  install celerity</tt>

* {Culerity}[https://github.com/sobrinho/capybara-culerity]: Install celerity
  as noted above, and make sure that JRuby is in your path. Note that Culerity
  does not seem to be working under Ruby 1.9 at the moment.

Note: HtmlUnit does not support transactional fixtures; see the section
"Transactional Fixtures" below.

=== env.js

The {capybara-envjs driver}[http://github.com/smparkes/capybara-envjs]
uses the envjs gem ({GitHub}[http://github.com/smparkes/env-js],
{rubygems.org}[http://rubygems.org/gems/envjs]) to interpret
JavaScript outside the browser. The driver is installed by installing the capybara-envjs gem:

  gem install capybara-envjs

More info about the driver and env.js are available through the links above. The envjs gem only supports
Ruby 1.8.7 at this time.

Note: Envjs does not support transactional fixtures; see the section
"Transactional Fixtures" below.

=== Capybara-webkit

The {capybara-webkit drive}[https://github.com/thoughtbot/capybara-webkit] is for true headless
testing. It uses WebKitQt to start a rendering engine process. It can execute JavaScript as well. 
It is significantly faster than drivers like Selenium since it does not load an entire browser.

You can install it with:

  gem install capybara-webkit

And you can use it by:

  Capybara.javascript_driver = :webkit


== The DSL

Capybara's DSL (domain-specific language) is inspired by Webrat. While
backwards compatibility is retained in a lot of cases, there are certain
important differences.  Unlike in Webrat, all searches in Capybara are *case
sensitive*. This is because Capybara heavily uses XPath, which doesn't support
case insensitivity.

=== Navigating

You can use the
<tt>{visit}[http://rubydoc.info/github/jnicklas/capybara/master/Capybara/Session#visit-instance_method]</tt>
method to navigate to other pages:

    visit('/projects')
    visit(post_comments_path(post))

The visit method only takes a single parameter, the request method is *always*
GET.

You can get the {current
path}[http://rubydoc.info/github/jnicklas/capybara/master/Capybara/Session#current_path-instance_method]
of the browsing session for test assertions:

    current_path.should == post_comments_path(post)

=== Clicking links and buttons

<em>Full reference: {Capybara::Node::Actions}[http://rubydoc.info/github/jnicklas/capybara/master/Capybara/Node/Actions]</em>

You can interact with the webapp by following links and buttons. Capybara
automatically follows any redirects, and submits forms associated with buttons.

    click_link('id-of-link')
    click_link('Link Text')
    click_button('Save')
    click_on('Link Text')  # clicks on either links or buttons
    click_on('Button Value')

=== Interacting with forms

<em>Full reference: {Capybara::Node::Actions}[http://rubydoc.info/github/jnicklas/capybara/master/Capybara/Node/Actions]</em>

There are a number of tools for interacting with form elements:

    fill_in('First Name', :with => 'John')
    fill_in('Password', :with => 'Seekrit')
    fill_in('Description', :with => 'Really Long Text...')
    choose('A Radio Button')
    check('A Checkbox')
    uncheck('A Checkbox')
    attach_file('Image', '/path/to/image.jpg')
    select('Option', :from => 'Select Box')

=== Querying

<em>Full reference: {Capybara::Node::Matchers}[http://rubydoc.info/github/jnicklas/capybara/master/Capybara/Node/Matchers]</em>

Capybara has a rich set of options for querying the page for the existence of
certain elements, and working with and manipulating those elements.

    page.has_selector?('table tr')
    page.has_selector?(:xpath, '//table/tr')
    page.has_no_selector?(:content)

    page.has_xpath?('//table/tr')
    page.has_css?('table tr.foo')
    page.has_content?('foo')

You can use these with RSpec's magic matchers:

    page.should have_selector('table tr')
    page.should have_selector(:xpath, '//table/tr')
    page.should have_no_selector(:content)

    page.should have_xpath('//table/tr')
    page.should have_css('table tr.foo')
    page.should have_content('foo')
    page.should have_no_content('foo')

Note that <tt>page.should have_no_xpath</tt> is preferred over
<tt>page.should_not have_xpath</tt>. Read the section on asynchronous JavaScript
for an explanation.

If all else fails, you can also use the
<tt>{page.html}[http://rubydoc.info/github/jnicklas/capybara/master/Capybara/Session#html-instance_method]</tt>
method to test against the raw HTML:

    page.html.should match /<span>.../i

=== Finding

<em>Full reference: {Capybara::Node::Finders}[http://rubydoc.info/github/jnicklas/capybara/master/Capybara/Node/Finders]</em>

You can also find specific elements, in order to manipulate them:

    find_field('First Name').value
    find_link('Hello').visible?
    find_button('Send').click

    find(:xpath, "//table/tr").click
    find("#overlay").find("h1").click
    all('a').each { |a| a[:href] }

Note that <tt>find</tt> will wait for an element to appear on the page, as explained in the
Ajax section. If the element does not appear it will raise an error.

These elements all have all the Capybara DSL methods available, so you can restrict them
to specific parts of the page:

    find('#navigation').click_link('Home')
    find('#navigation').should have_button('Sign out')

=== Scoping

Capybara makes it possible to restrict certain actions, such as interacting with
forms or clicking links and buttons, to within a specific area of the page. For
this purpose you can use the generic
<tt>{within}[http://rubydoc.info/github/jnicklas/capybara/master/Capybara/Session#within-instance_method]</tt>
method. Optionally you can specify which kind of selector to use.

    within("li#employee") do
      fill_in 'Name', :with => 'Jimmy'
    end

    within(:xpath, "//li[@id='employee']") do
      fill_in 'Name', :with => 'Jimmy'
    end

Note that <tt>within</tt> will scope the actions to the _first_ (not _any_)
element that matches the selector.

There are special methods for restricting the scope to a specific fieldset,
identified by either an id or the text of the fieldet's legend tag, and to a
specific table, identified by either id or text of the table's caption tag.

    within_fieldset('Employee') do
      fill_in 'Name', :with => 'Jimmy'
    end

    within_table('Employee') do
      fill_in 'Name', :with => 'Jimmy'
    end

=== Scripting

In drivers which support it, you can easily execute JavaScript:

    page.execute_script("$('body').empty()")

For simple expressions, you can return the result of the script. Note
that this may break with more complicated expressions:

    result = page.evaluate_script('4 + 4');

=== Debugging

It can be useful to take a snapshot of the page as it currently is and take a
look at it:

    save_and_open_page

== Transactional fixtures

Transactional fixtures only work in the default Rack::Test driver, but not for
other drivers like Selenium.  Cucumber takes care of this automatically, but
with Test::Unit or RSpec, you may have to use the
{database_cleaner}[https://github.com/bmabey/database_cleaner] gem.  See {this
explanation}[https://groups.google.com/d/msg/ruby-capybara/JI6JrirL9gM/R6YiXj4gi_UJ]
(and code for {solution
2}[http://opinionated-programmer.com/2011/02/capybara-and-selenium-with-rspec-and-rails-3/#comment-220]
and {solution 3}[http://pastie.org/1745020]) for details.

== Asynchronous JavaScript (Ajax and friends)

When working with asynchronous JavaScript, you might come across situations
where you are attempting to interact with an element which is not yet present
on the page. Capybara automatically deals with this by waiting for elements
to appear on the page.

When issuing instructions to the DSL such as:

    click_link('foo')
    click_link('bar')
    page.should have_content('baz')

If clicking on the *foo* link causes triggers an asynchronous process, such as
an Ajax request, which, when complete will add the *bar* link to the page,
clicking on the *bar* link would be expeced to fail, since that link doesn't
exist yet. However Capybara is smart enought to retry finding the link for a
brief period of time before giving up and throwing an error. The same is true of
the next line, which looks for the content *baz* on the page; it will retry
looking for that content for a brief time. You can adjust how long this period
is (the default is 2 seconds):

    Capybara.default_wait_time = 5

Be aware that because of this behaviour, the following two statements are *not*
equivalent, and you should *always* use the latter!

    page.should_not have_xpath('a')
    page.should have_no_xpath('a')

The former would incorrectly wait for the content to appear, since the
asynchronous process has not yet removed the element from the page, it would
therefore fail, even though the code might be working correctly. The latter
correctly waits for the element to disappear from the page.

== Using the DSL in unsupported testing frameworks

You can mix the DSL into any context by including +Capybara::DSL+:


    require 'capybara'
    require 'capybara/dsl'

    Capybara.default_driver = :culerity

    module MyModule
      include Capybara::DSL

      def login!
        within("//form[@id='session']") do
          fill_in 'Login', :with => 'user@example.com'
          fill_in 'Password', :with => 'password'
        end
        click_link 'Sign in'
      end
    end

== Calling remote servers

Normally Capybara expects to be testing an in-process Rack application, but you
can also use it to talk to a web server running anywhere on the internets, by
setting app_host:

    Capybara.current_driver = :selenium
    Capybara.app_host = 'http://www.google.com'
    ...
    visit('/')

Note that the default driver (<tt>:rack_test</tt>) does not support running
against a remote server. With drivers that support it, you can also visit any
URL directly:

    visit('http://www.google.com')

By default Capybara will try to boot a rack application automatically. You
might want to switch off Capybara's rack server if you are running against a
remote application:

    Capybara.run_server = false

== Using the sessions manually

For ultimate control, you can instantiate and use a
{Session}[http://rubydoc.info/github/jnicklas/capybara/master/Capybara/Session]
manually.

    require 'capybara'

    session = Capybara::Session.new(:culerity, my_rack_app)
    session.within("//form[@id='session']") do
      session.fill_in 'Login', :with => 'user@example.com'
      session.fill_in 'Password', :with => 'password'
    end
    session.click_link 'Sign in'

== XPath, CSS and selectors

Capybara does not try to guess what kind of selector you are going to give it,
and will always use CSS by default.  If you want to use XPath, you'll need to
do:

    within(:xpath, '//ul/li') { ... }
    find(:xpath, '//ul/li').text
    find(:xpath, '//li[contains(.//a[@href = "#"]/text(), "foo")]').value

Alternatively you can set the default selector to XPath:

    Capybara.default_selector = :xpath
    find('//ul/li').text

Capybara allows you to add custom selectors, which can be very useful if you
find yourself using the same kinds of selectors very often:

    Capybara.add_selector(:id) do
      xpath { |id| XPath.descendant[XPath.attr(:id) == id.to_s] }
    end

    Capybara.add_selector(:row) do
      xpath { |num| ".//tbody/tr[#{num}]" }
    end

The block given to xpath must always return an XPath expression as a String, or
an XPath expression generated through the XPath gem. You can now use these
selectors like this:

    find(:id, 'post_123')
    find(:row, 3)

You can specify an optional match option which will automatically use the
selector if it matches the argument:

    Capybara.add_selector(:id) do
      xpath { |id| XPath.descendant[XPath.attr(:id) == id.to_s] }
      match { |value| value.is_a?(Symbol) }
    end

Now use it like this:

    find(:post_123)

This :id selector is already built into Capybara by default, so you don't
need to add it yourself.

== Beware the XPath // trap

In XPath the expression // means something very specific, and it might not be what
you think. Contrary to common belief, // means "anywhere in the document" not "anywhere
in the current context". As an example:

    page.find(:xpath, '//body').all(:xpath, '//script')

You might expect this to find all script tags in the body, but actually, it finds all
script tags in the entire document, not only those in the body! What you're looking
for is the .// expression which means "any descendant of the current node":

    page.find(:xpath, '//body').all(:xpath, './/script')

The same thing goes for within:

    within(:xpath, '//body') do
      page.find(:xpath, './/script')
      within(:xpath, './/table/tbody') do
        ...
      end
    end

== Configuring and adding drivers

Capybara makes it convenient to switch between different drivers. It also exposes
an API to tweak those drivers with whatever settings you want, or to add your own
drivers. This is how to switch the selenium driver to use chrome:

    Capybara.register_driver :selenium do |app|
      Capybara::Selenium::Driver.new(app, :browser => :chrome)
    end

However, it's also possible to give this a different name, so tests can switch
between using different browsers effortlessly:

    Capybara.register_driver :selenium_chrome do |app|
      Capybara::Selenium::Driver.new(app, :browser => :chrome)
    end

Whatever is returned from the block should conform to the API described by
Capybara::Driver::Base, it does not however have to inherit from this class.
Gems can use this API to add their own drivers to Capybara.

The {Selenium wiki}[http://code.google.com/p/selenium/wiki/RubyBindings] has
additional info about how the underlying driver can be configured.

== Gotchas:

* Access to session and request is not possible from the test, Access to
  response is limited. Some drivers allow access to response headers and HTTP
  status code, but this kind of functionality is not provided by some drivers,
  such as Selenium.

* Access to Rails specific stuff (such as <tt>controller</tt>) is unavailable,
  since we're not using Rails' integration testing.

* Freezing time: It's common practice to mock out the Time so that features
  that depend on the current Date work as expected. This can be problematic,
  since Capybara's Ajax timing uses the system time, resulting in Capybara
  never timing out and just hanging when a failure occurs. It's still possible to
  use plugins which allow you to travel in time, rather than freeze time.
  One such plugin is {Timecop}[http://github.com/jtrupiano/timecop].

* When using Rack::Test, beware if attempting to visit absolute URLs. For
  example, a session might not be shared between visits to <tt>posts_path</tt>
  and <tt>posts_url</tt>. If testing an absolute URL in an Action Mailer email,
  set <tt>default_url_options</tt> to match the Rails default of
  <tt>www.example.com</tt>.

== License:

(The MIT License)

Copyright (c) 2009 Jonas Nicklas

Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
'Software'), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:

The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.